51:21.13...
1... 335.1:
. .33. r. .
1

H)
a.) L:
2.1 :Xx?1’:a.

I. I. .‘.\K
z; {2391;
Loan. .52:

: 5... ,
1 (2.3::

1 1 2.1.
33.1.9.7): (1.1:!

 

$3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MICHIGAN STATE UNIVERSITY LIBRARIES
ms llHlHH Ill H HllH IHHI
2 3 1293 02079 9221

7 F

This is to certify that the
thesis entitled

Dam Removal Effects on Fisheries Resources,
Habitat, and Summer Diet of Trout in
the Pine River, Manistee County,
Michigan
presented by

Jessica L. Mistak

has been accepted towards fulfillment
of the requirements for

M.S. dem?pinFish. & Wildl.

 

v cit/(JV
Major professor

Date M

0-7639 MSU is an Affirmative Action/Equal Opportunity Institution

PLACE lN RETURN BOX to remo
TO AVOID FINES retu
MAY BE RECALLED with

ve this checkout from your record.
rn on or before date due.
earlier due date if requested.
I
l . . I

 

11/00 CJCIRC/DateDue.p65-p,14

DAM REMOVAL EFFECTS ON FISHERIES RESOURCES, HABITAT,
AND SUMMER DIET OF TROUT IN THE PINE RIVER,
MANISTEE COUNTY, MICHIGAN

By

Jessica L. Mistak

A THESIS
Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE
Department of Fisheries and Wildlife

2000

ABSTRACT
DAM REMOVAL EFFECTS ON FISHERIES RESOURCES, HABITAT,
AND SUMMER DIET OF TROUT IN THE PINE RIVER,
MANISTEE COUNTY, MICHIGAN
By

Jessica L. Mistak

Stronach Dam was built in 1912 as a hydroelectric facility. The Pine River carries a high
bedload of sand, which contributed to the filling of the reservoir and the 1953
decommissioning of the dam. The staged removal of Stronach Dam began in 1996 and is
expected to be complete in 2003. Baseline habitat conditions were assessed in 1995 to
delineate distinct zones: the Downstream Zone, the Impacted Zone, and the Non-
Impacted Zone. Survey data has shown streambed elevation changes in the areas near the
dam. Electrofishing results indicated that trout were most abundant upstream of the dam
and were fast growing compared to state averages, but had a low overall biomass
compared to similar rivers. White suckers were most abundant downstream of the dam
and were slow growing. Annual monitoring of the habitat and fish population will
continue throughout the removal process. A summer trout diet study showed that
stomach fullness was generally high but declined over the summer. Trout fed similarly
throughout the river within a single month. The most abundant prey items found in the
diet were underused in comparison to their availability in the drift. Based on their growth
and diet, trout biomass did not appear to be controlled by a low number of drifting
macroinvertebrates. Further research needs to be conducted to determine the exact cause

of limiting trout numbers.

Copyright by
JESSICA LYNN MISTAK
2000

To all the little brook trout.

iv

ACKNOWLEDGEMENTS

Recognition is given to the Michigan Department of Natural Resources for their
support in the form of funding and assistance in the field. Additional thanks are given to
the US. Forest Service, Consumers Power, and Trout Unlimited for various forms of
support throughout this project. Specific individuals from these agencies who provided
assistance include Tom Rozich, Mark Tonello, Troy Zorn, Bob Stuber, Tom Moris, and
Dave Battige.

I would like to thank my advisor, Dan Hayes, for keeping me entertained while
directing my development as a fisheries scientist. My gratitude is also extending to my
committee members Rich Merritt and Mary Bremigan for their guidance. My lab mates
were a continuous source of ideas and reprieve. I need to especially thank my comrade
in arms, J oAnna Lessard, for motivation and encouragement.

I would never have accomplished my research without the help of my field and
lab technicians: Jeff Leighton, Nolan Banish, Ed McCoy, and Dean Burdett. These

fellow trout lovers deserve recognition for all of their hard work in the field and lab.

TABLE OF CONTENTS

LIST OF TABLES ......................................................................................................... ix
LIST OF FIGURES ....................................................................................................... xi
CHAPTER ONE
Effects of Stronach Dam Removal on Fisheries Resources and Habitat ....................... 1
INTRODUCTION ......................................................................................................... 2
Study Area .......................................................................................................... 8
METHODS .................................................................................................................... 12
Habitat ............................................................................................................... 12
Fish Abundance ................................................................................................. 14
Fish Growth ....................................................................................................... 16
RESULTS ...................................................................................................................... 20
Habitat ............................................................................................................... 20
Fish Abundance ................................................................................................. 30
Age Distribution ................................................................................................. 38
Fish Growth ....................................................................................................... 43
DISCUSSION ................................................................................................................ 52
Habitat ............................................................................................................... 52
Fish Abundance ................................................................................................. 57
Age Distribution ................................................................................................. 62
Fish Growth ....................................................................................................... 63
Management Implications .................................................................................. 65
SUMMARY AND CONCLUSIONS ............................................................................ 68

vi

 

CHAPTER TWO

Trout Diet Variability over a Summer Season on the Pine River .................................. 70
INTRODUCTION ......................................................................................................... 70
STUDY AREA .............................................................................................................. 75
METHODS .................................................................................................................... 76
Diet ..................................................................................................................... 76
Drift .................................................................................................................... 77
Wet Stomach Content Weight ............................................................................. 78
Diet Percent Composition and Mean Number Eaten by Taxa ........................... 79
Diet Similarity .................................................................................................... 80
Drift Density and Taxonomic Composition ....................................................... 80
Electivity ............................................................................................................ 81
RESULTS ...................................................................................................................... 82
Diet and Drift ..................................................................................................... 82
Wet Stomach Content Weight ............................................................................. 82
Diet Percent Composition and Mean Number Eaten by Taxa ........................... 86
Diet Similarity .................................................................................................... 106
Drift Density and Taxonomic Composition ....................................................... 1 l3
Electivity ............................................................................................................ 1 17
DISCUSSION ................................................................................................................ 124
Wet Stomach Content Weight ............................................................................. 124
Diet Percent Composition and Mean Number Eaten by Taxa ........................... 127
Diet Similarity .................................................................................................... l. 29
Drift Density and Taxonomic Composition ....................................................... 130

vii

Electivity ............................................................................................................. 132

Management Implications .................................................................................. 134
SUMMARY AND CONCLUSIONS ............................................................................. 138
APPENDICES ................................................................................................................ l4 1

APPENDIX A. Taxon code list including class, order, family, habitat, and life
stage for prey items collected in the Pine River in 1999 .................................... 142
APPENDIX B. Mean number per stomach and percent for each taxon eaten by
brook trout in each month and zone of the Pine River in 1999 .......................... 146
APPENDD( C. Mean number per Stomach and percent for each taxon eaten by
brown trout in each month and zone of the Pine River in 1999 ......................... 150
APPENDIX D. Mean number per stomach and percent for each taxon eaten by
rainbow trout in each month and zone of the Pine River in 1999 ...................... 156
APPENDIX E. Pine River mean drift density (number per 100m3) and percent of
drift by taxon for each month and zone ............................................................. 162
APPENDIX F. Electivity index values (Ei) reported by month for brook trout,
brown trout, and rainbow trout sampled in 1999 from the Pine River ............... 168

LITERATURE CITED .................................................................................................. 171

viii

LIST OF TABLES
Table 1.1. Size classes and codes used to denote particle composition ........................ 15

Table 1.2. Fish species sampled on the Pine River between 1996 and 1999. An *
indicates questionable identification .................................................................. 31

Table 1.3. Pine River fish population density (number per hectare) for each site sampled
between 1997 and 1999 ..................................................................................... 32

Table 1.4. Pine River fish population density (number per hectare) for each zone
sampled between 1997 and 1999 ....................................................................... 34

Table 1.5. Mean length at capture in mm for Pine River trout and white suckers,
compared to Michigan stream averages (Laarman et a1. 1981). All fish captured
during the growing season. Data from 1996 and 1997 was taken from Klomp
(1998) ................................................................................................................. 44

Table 1.6. Equations and R2 values for body-scale and incremental growth regressions
for trout and white suckers sampled on the Pine River ..................................... 45

Table 1.7. Pine River growth differences (mm) documented in trout and white suckers
sampled on the Pine River ................................................................................. 51

Table 2.1. Mean stomach weight (g) and percent weight (g/g) with standard errors for
trout sampled each month from the Pine River in 1999 .................................... 84

Table 2.2. Mean stomach weight (g) and percent weight (g/g) with standard errors for
trout sampled in each zone from the Pine River in 1999 ................................... 85

Table 2.3. Monthly mean number, standard error, and percent of most common taxa
identified per brook trout sampled on the Pine River in 1999 ........................... 93

Table 2.4. Mean number, standard error, and percent of most common taxa identified per
brook trout sampled in each zone of the Pine River in 1999 ............................. 96

Table 2.5. Monthly mean number, standard error, and percent of most common taxa
identified per brown trout sampled on the Pine River in 1999 .......................... 97

Table 2.6. Mean number, standard error, and percent of most common taxa identified per
brown trout sampled in each zone of the Pine River in 1999 ............................ 99

Table 2.7. Monthly mean number, standard error, and percent of most common taxa
identified per rainbow trout sampled on the Pine River in 1999 ....................... 100

ix

Table 2.8. Mean number, standard error, and percent of most common taxa identified per
rainbow trout sampled in each zone of the Pine River in 1999 ......................... 103

Table 2.9. Monthly mean number, standard errors, and percent contribution of terrestrial
taxa to diets of trout sampled in the Pine River in 1999 .................................... 104

Table 2.10. Mean number, standard errors, and percent contribution of terrestrial taxa to
diets of trout sampled in each zone of the Pine River in 1999 .......................... 105

Table 2.1 1. Monthly mean number, standard errors, and percent contribution of fish to
trout diets sampled on the Pine River in 1999 ................................................... 107

Table 2.12. Mean number, standard error, and percent contribution of fish to trout diets
sampled in each zone of the Pine River in 1999 ................................................ 108

Table 2.13. Morista similarity index values for month to month comparisons of trout
diets sampled on the Pine River in 1999 ............................................................ 110

Table 2.14. Morista similarity index values for zone to zone comparisons of trout diets
sampled on the Pine River in 1999 .................................................................... 112

Table 2.15. Monthly mean number, standard error, and percent of most common taxa
identified in drift (100m3) sampled on the Pine River in 1999 .......................... 114

Table 2.16. Mean number, standard error, and percent of most common taxa identified in
drift (100m3) sampled in each zone of the Pine River in 1999 .......................... 116

Table 2.17. Monthly mean number and percentage of terrestrial taxa identified in drift
(100m3) sampled on the Pine River in 1999 ...................................................... 118

Table 2.18. Mean number and percentage of terrestrial taxa identified in drift (100m3)
sampled in each zone of the Pine River in 1999 ................................................ 119

 

‘2742113:

   

5.47;?“ '_'- -' ‘-

 

LIST OF FIGURES

Figure 1.1. Location of Stronach Dam on the Pine River in relation to the state of

Michigan and Tippy Dam .................................................................................. 9
Figure 1.2. Pine River study region delineated. into zones by distribution of habitat

types .................................................................................................................. 11
Figure 1.3. Cross-sectional survey sites located on the Pine River .............................. 13
Figure 1.4. Fish abundance sampling sites located on the Pine River .......................... 17

Figure 1.5. Pine River cross-sections illustrating examples where changes in streambed
elevation have been detected between 1996 and 1999 ...................................... 21

Figure 1.6. Pine River cross-sections illustrating examples where no changes in
streambed elevation have been detected between 1996 and 1999 ..................... 22

Figure 1.7. Pine River changes in water surface elevation (feet) as deviated from

1996 .................................................................................................................... 23
Figure 1.8. Gradient, or water surface elevation change (meters per kilometer), measured
on the Pine River between 1996 and 1999 ......................................................... 24
Figure 1.9. Pine River overall mean discharge at each site sampled between 1996 and
1999 .................................................................................................................... 26
Figure 1.10. Pine River mean velocity (meters per second) for each site measured
between 1996 and 1999 ..................................................................................... 27
Figure 1.11. Pine River velocity percentage frequency by zone in 1996, 1998, and 1999.
Data from 1997 were unavailable ...................................................................... 28
Figure 1.12. Pine River pebble count means by site for 1996 through 1999 ................ 29

Figure 1.13. Mean brook trout density (number per hectare) for all sites sampled on the
Pine River between 1997 and 1999 ................................................................... 36

Figure 1.14. Mean white sucker density (number per hectare) for all sites sampled on the
Pine River between 1997 and 1999 ................................................................... 37

Figure 1.15. Brook trout age structure within each zone on the Pine River for 1998 and
1999 .................................................................................................................... 39

Figure 1.16. Brown trout age structure within each zone on the Pine River between 1996
and 1999 ............................................................................................................. 40

xi

Figure 1.17. Rainbow trout age structure within each zone on the Pine River between
1996 and 1999 .................................................................................................... 41

Figure 1.18. White sucker age structure within each zone on the Pine River between
1997 and 1999 .................................................................................................... 42

Figure 1.19. Incremental growth regressed on length at previous age by zone for brook
trout sampled on the Pine River between 1998 and 1999 .................................. 47

Figure 1.20. Incremental growth regressed on length at previous age by zone for brown
trout sampled on the Pine River between 1996 and 1999 .................................. 48

Figure 1.21. Incremental growth regressed on length at previous age by zone for rainbow
trout sampled on the Pine River between 1996 and 1999 .................................. 49

Figure 1.22. Incremental growth regressed on length at previous age by zone for white
suckers sampled on the Pine River between 1997 and 1999 ............................ 50

Figure 2.1. Location of Stronach Dam on the Pine River in relation to the state of
Michigan and Tippy Dam .................................................................................. 72

Figure 2.2. Pine River study region delineated into zones by distribution of habitat
Types .................................................................................................................. 74

Figure 2.3. Mean stomach weight (g) and standard errors per Pine River trout length
class (mm) in 1999 ............................................................................................. 87

Figure 2.4. Mean percent stomach content weight (g/ g), + or — 1 standard error, for all
lengths (mm)of brook trout, brown trout, and rainbow trout sampled on the Pine

River in 1999 ...................................................................................................... 88

Figure 2.5. Mean number of organisms per stomach, + or — 1 standard error, for all
lengths (mm) of trout sampled on the Pine River in 1999 ................................. 89

Figure 2.6. Mean number of items consumed on the Pine River during the summer of
1999 by brook trout, brown trout, and rainbow trout ........................................ 91

Figure 2.7. Mean number of items consumed in each zone of the Pine River in 1999 by
brook trout, brown trout, and rainbow trout ...................................................... 92

Figure 2.8. The mean number, + or — 1 standard error, of fish per stomach by varying
length classes of trout sampled on the Pine River in 1999 ................................ 109

Figure 2.9. Mean Ei values sorted from left to right by taxa most frequently consumed by
brook trout on the Pine River in 1999 ................................................................ 121

xii

Figure 2.10. Mean Ei values sorted from left to right by taxa most frequently consumed
by brown trout on the Pine River in 1999 .......................................................... 122

Figure 2.11. Mean Ei values sorted from left to right by taxa most frequently consumed
by rainbow trout on the Pine River in 1999 ....................................................... 123

xiii

Chapter 1

Effects of Stronach Dam Removal on Fisheries Resources and Habitat

INTRODUCTION

The building of dams on North American streams began in the 1800’s (Petts
1980), with the largest effort towards dam construction occurring in the 1930’s (Benke
1990). Dams provide society with drinking water, routes of travel and transport,
irrigation, waste removal, and renewable energy (Allan and F lecker 1993). The
Nationwide Rivers Inventory, completed in 1982 by the National Park Service, estimated
a total 5 ,200,000-km of rivers in the lower 48 states. Of this, less than 200 km of the 42
river systems surveyed were determined to be high quality and free flowing (Benke
1990). Today, all large rivers in the United States have been impounded in at least some
reaches with the exception of the Yellowstone and Salmon rivers (Kohler and Hubeit
1993). The number of dams greater than six feet tall is estimated between 68,000 and
75,000, while millions of dams smaller than six feet in height exist nationwide (Shuman
1995). Of all dams, private entities or municipalities own 90%, while state and federal
government agencies own 7% (Shuman 1995).

The effects of dams have been well documented (Hammad 1972, Ligon et a1.
1995, Shuman 1995, Petts 1980, Cushman 1985, Doppelt 1993, Benke 1990, Bain et al.
1988, and Ward and Stanford 1989). The damming of a river or stream has been called a
cataclysmic event in the life of a riverine ecosystem (Gup 1994). Dams interrupt and
alter most of a river’s ecological processes by changing the flow of water, sediment,
nutrients, energy and biota (Ligon et a1. 1995). Some of the main ecological issues
regarding effects of dams include temperature change, prevention of fish migration, and

altered flow regimes. In many streams, discharge is artificially regulated by dams. Dams

transform long river reaches into impoundments and change downstream reaches,
resulting in streambed degradation (Kohler and Hubert 1993).

Dam removal has become an increasingly visible topic in the past few years
because it not only removes barriers to migrating fish, but also serves as a river
restoration tool. Recent dam removal projects and proposals that have received national
attention include the 1999 removal of Edwards Dam in Maine and the proposed removal
of the four lower Snake River dams in Washington. Across the nation, many smaller
projects are currently being pursued. Wisconsin in particular has actively engaged in the
removal of small dams (Born et a1. 1998) with approximately 30 dams removed in the last
20 to 30 years.

Many of the more than 68,000 large dams in the United States are privately
owned, built 50 to 150 years ago (Haberman 1995). The Federal Energy RegulatOIy
Commission (FERC) is the agency responsible for the licensing of private hydroelectric
projects and issues operational pemiits which are valid for 30 to 50 years (Bowers and
Bowman 1995). In addition, new license applications are subject to an amendment of the
Federal Power Act which requires the FERC to equally consider the “adequate protection,
mitigation, and enhancement of fish and wildlife (including spawning grounds and
habitat)” when licensing hydropower operations (Scurlock et a1. 1993). With hundreds of
dams coming up for relicensing, managers are looking for ways of dealing with aging
dams that are deteriorated, pose safety hazards, or are no longer economical to operate.
For these dams, the cost of rehabilitation is often very high, positioning removal as an
increasingly viable alternative for river restoration (Shuman 1995). Yet with all of this

interest, there is a relatively small amount of scientific information relating to dam

removal, including pre- and post-dam removal studies, to determine the responses of
habitat and fish populations within the river. Hence, more information is needed to
assess the benefits of dam removal projects.

Stronach Dam was built in 1912 on the Pine River, Manistee County, Michigan.
Original construction of the 12-foot concrete dam created a 26-hectare reservoir. The
Pine River is a coldwater stream with valued resident populations of brook trout
(Salvelinusfontinalus), brown trout (Salmo trutta), and rainbow trout (Oncorhynchus
mykiss). As the Pine River flows downstream, it joins with the Manistee River to create
Tippy Reservoir above Tippy Dam.

Logging operations during the late 1800’s created unstable banks along the Pine
River. As a result, the river carries a high sand bedload. Problems with the operation of
the dam’s turbines transpired immediately as a result of this sediment load. Although
attempts were made in the 1930’s and 1940’s to remove the sediment that built up in the
reservoir, these efforts were only marginally successful. Over time the original reservoir,
acting as a sediment trap, filled up with sand and other fine sediment. Subsequently, the
dam was decommissioned by Consumers Power Company as a power-generating plant in
1953.

In the early 1990’s, it was decided that removal of Stronach Dam was an
appropriate action after considering other alternatives that would have involved costly
improvements to maintain the safety of the already deteriorating structure. This removal
was proposed as part of a FERC agreement in the relicensing of the Tippy Dam
hydroelectric project on the Manistee River. The staged removal of Stronach Dam

commenced in fall of 1996 with completion expected in 2003. The removal process

involves the removal of a six-inch stoplog every three months over a course of six years.
Removing the dam in this manner allows the river to gradually restore its channel in the
areas closest to the dam with the least amount of environmental impact, at the lowest
cost, and without impacting the operation of Tippy Dam (Battige et a1. 1997).

With the removal of the darn, it was predicted that downcutting of the streambed
upstream of the dam would expose a gravel/cobble substrate (Resource Management
Group 1994). One of the goals of the dam removal is to restore the 3.8-kilometer
Impacted Zone, where the old reservoir used to be, to near pre-dam conditions. Because
the existing sand substrate in the Impacted Zone provides poor habitat for invertebrate
food organisms (Pennak and VanGerpen 1947, Hynes 1970, Merritt and Cummins 1996),
the existing habitat is considered to be sub-optimal for fish. Additionally, the sand
substrate buries spawning gravel and destroys cover, ultimately reducing survival of early
life stage trout (Alexander and Hansen 1983). Uncovering of a coarser substrate not only
creates more diverse hydraulic and channel conditions favorable for efficient resting and
feeding behavior of fish, it also results in increased habitat for aquatic invertebrates.
Ultimately, it is predicted that the growth rate and abundance of trout in the Impacted
Zone will increase.

To better understand the response of sediment to dam removal, usually one of the
greatest concerns, other studies were consulted. As an example, after the 1969 dam
removal on the Muskegon River in Michigan, it was estimated that nearly 40% of the
sediment from the impoundment flushed downstream immediately (Shuman 1995). The
remaining sand was expected to take 50 to 80 years to fully flush through the Muskegon

River system (Simons and Simons 1991). Likewise, after the removal of the Woolen

Mills Dam in Wisconsin, sediment from the impoundment was scoured out within six
months, leaving behind a gravel and rubble substrate (Kanehl et a1. 1997). Ultimately,
the response of sediment corresponds to dynamic changes within the river system, which
may not reach full equilibrium for many years.

Being a barrier to fish migration, removal of the dam will allow fish populations
that currently reside only below the dam access upstream. Although river connectivity is
generally perceived as favorable, one of the primary concerns of anglers and other
enthusiasts focuses on the potential migration of fish from Tippy Reservoir into the upper
reaches of the Pine River. The reservoir supports coolwater fish species such as yellow
perch (Percaflavescens), northern pike (Esox lucius), walleye (Stizostedion vitreum), and
white suckers (Catostomus commersoni). While some of these species are currently
found upstream of the dam, there is concern that migration may occur in sufficient
numbers to negatively impact the trout fishery above the dam. Overall fish production is
expected to increase as fish, specifically trout, have more access to favorable habitats on a
seasonal basis. Although this is desirable from an ecological perspective, from a fishery
perspective there is some concern that increases in total fish production may occur at the
expense of desirable game species.

The long-term goal of this project is to determine how the dam removal and
potential for fish migration from Tippy Reservoir affect the salmonid populations in the
Pine River. The research presented here continues the evaluation of fish and habitat
response to the removal of Stronach Dam that began in 1995. My continued monitoring
of the Pine River will be added to previously collected baseline data. As a result, changes

in the biotic community will be documented throughout the entire dam removal process.

A planned staged removal provides the opportunity to document subsequent changes in
the fish community and habitat as the dam is removed in a controlled fashion. The results
from this study will provide insight for fisheries managers faced with future dam
removals.

The four major objectives to my study were to: (1) document changes in
streambed elevation, substrate, and gradient along a six-mile stretch of the Pine River; (2)
estimate the abundance of selected species (rainbow trout, brown trout, brook trout, and
white suckers) within the six mile study stretch; (3) determine if growth rates of these
selected species differ between the Downstream Zone, Impacted Zone, and Non-Impacted
Zone, and if growth rates are changing over time; and (4) compare the diet of rainbow
trout, brown trout, and brook trout within and among the Downstream Zone, Impacted

Zone, and Non-Impacted Zone (results for this objective will be presented in Chapter 2).

STUDY AREA

The Pine River, a tributary of the Manistee, is located in the northwest portion of
Michigan’s lower peninsula (Figure 1.1). Rozich (1998) provides a comprehensive
assessment of the Manistee River watershed, including the Pine River. Stronach Dam
lies approximately 5 kilometers upstream of the Manistee and Pine River confluence,
while Tippy Dam lies 1.7 kilometers downstream of this confluence. No dams exist
upstream of Stronach Dam. The river measures 48 miles from the mouth in the East
Branch of the Pine to the backwaters of Tippy Reservoir (Rozich 1998). Substrates in the
watershed are dominated by sandy glacial outwash plains, recessional moraines, and areas
of consolidated clay. The Pine River is deeply entrenched in these soils and is
characterized by steep, sandy banks reaching up to 30 meters above the water surface
(Hansen 1971). Because of the steep banks and logging operations that took place in the
late 1800’s, the Pine River carries a high bedload of sand.

The Pine River has the highest gradient of any stream in northwest lower
Michigan at 15 feet per mile (Rozich 1998), causing the river to have a high flow
velocity. Stronach Dam lies at the foot of a rapid, where the river descends from the
headwaters to its confluence with the Manistee. The Pine River is estimated to drain an
area of about 686 square-kilometers (265 square miles) (Hansen 1971). At the USGS
gauging station number 04125510, located 13 kilometers upstream of Stronach Dam, the
Pine River had an average discharge of 8.18 m3/s (289 cfs) (Blumer et a1. 1998), with the
minimum discharge recorded being 161 cfs, and the flood peak discharge equaling 2240

cfs (Rozich 1998). The Pine River is less stable when compared to other rivers in the

.EmQ Egg paw cawEoLE mo 03% 05 8 5:38 8 $3M 8E 05 so 8mm 538% MO cogooq .: 83E

 

 

SBEEE H
I
30E END
noncobm

          

Mm>~m mZE

Muir/E
mmhmhzg

Ede
235g:

 

 

 

 

 

 

 

 

53%

83:8

 

 

 

 

 

 

Manistee River watershed. During periods of heavy rain or snowmelt, the river may rise
one to four feet above its average level (Rozich 1998).

As noted in Rozich (1998) the Pine River is classified as a “Blue-Ribbon” trout
stream with self-sustaining populations of rainbow trout, brook trout, and brown trout,
eliminating the need for fish stocking. Of note is the presence of Michigan’s largest non-
migratory population of rainbow trout (Rozich 1998). Although the river is home to an
impressive fishery, the biomass of trout is one-third that of other northern Michigan
streams (Alexander and Gowing 1980, Stuber 1996) because of its high sand bedload.

Based on habitat mapping completed in 1995, a 9.2-kilometer stretch of the river
was selected for this study. This study site is located in a relatively remote area of the
Huron-Manistee National Forest and includes a section of the 40 kilometers (25 miles) of
the Pine River designated as a National Wild and Scenic River under the Federal
Michigan Scenic Rivers Act of 1991. The 1995 habitat assessment allowed the river to
be divided into three distinct reaches: the Downstream Zone between Low Bridge and
Stronach Dam (1.1 kilometers); the Impacted Zone above the dam (3.8 kilometers); and

the Non-Impacted Zone (4.3 kilometers) above the Impacted Zone (Figure 1.2).

10

.momb 55¢: Mo 85:95me 3 3:8 0:: woamoczow cowwou Exam $3M 0:5 .N; 235
EwQ noncobm Eoi A803 eczema

_ ____m4 __ _
w s emsmm N a on

 

ocoN 86382-52

      

25M
voyage:

ocoN
Emobmcao u

Z

 

 

953 -_H_ Loom

fiasco ____ OEE ESX

SUNCOH—w
same % - Em

METHODS
Habitat

Habitat conditions were documented prior to dam removal in 1995 (Klomp 1998).
At that time, six miles of stream from Low Bridge (near M-55) to a point approximately
five miles upstream from Stronach Dam were assessed. The assessment provided a
detailed description of physical characteristics and categorization of the stream into
habitat units of runs, riffles, pools, rapids, or complex (a designation where more than one
category applied). Classification of these habitat units was determined following criteria
developed by Hicks and Watson (1985). The effects of the dam on habitat in the Pine
River were apparent in substrate composition and habitat conditions assessed in 1995.
These effects could be seen by the streambed consisting primarily of sand for
approximately 2.4 miles upstream. Downstream of the dam, wide runs with sandy
substrate are the dominant habitat.

Because it has been shown that permanent transects are useful in evaluating
management activities on channel form and trout habitat (Stuber 1985, Kondolf and
Micheli 1995), thirty-one permanent cross-sectional transects were established in 1996.
Twenty-nine transects are located above the dam and two are located below. These
transects, established with the aid of a Michigan Department of Natural Resources survey
crew, allow for the detection of changes in the channel morphology as the dam is
removed (Figure 1.3). In cases where actual elevation was not known, or USGS datum
was not available, assumed elevations were used. These sites were measured annually to
detect changes in streambed elevation attributable to the dam removal, and will continue

to be monitored annually. Photo documentation of each transect, taken in 1999, is

.SZM 0:5 05 so v8.82 3% .833 130303-380 .mg oEwE
Ema camcobm Eon“. Etc 8:920

._ _ .__m _ _ _ _ _
i— _ ___W _ _ _ _ _
Wm H m m f m N F o F

 

     
     

o:0N BOSE ocoN

Emmbwcgoo

 

aEmo mammmou no._
E 9: .6 a: ”t
___I is: "I:
wcmum>> Emuczom n>>m
2228 now m...
Emacsow Emobmcioo "mm.
::m w.>om ”mm

ccoa 695un "am Ema

Ema 326m "om

Maya 2,3 um: Lomcozm

 

archived in the Michigan State University Department of Fisheries and Wildlife Fisheries
Laboratory. Water surface elevation measurement was included in the surveying of each
transect. These data were also used to calculate gradient, or water surface elevation
change in meters per river kilometer.

Flow velocity was measured at 10 of the survey transects using a Marsh-McBimey
Model 201 portable current meter. Data collection began in 1996 and will continue to be
collected throughout the study. Beginning at each bank, flow readings were taken in two-
foot increments to include the entire river. From these data, discharge was calculated
using the equation

Q=w*d*v
where Q equals discharge, w, d, and v are the river width, depth, and mean flow velocity
at each measurement, respectively.

Surface bed material size distributions, or particle composition, was determined
through pebble counts at the survey sites (Wolman 1954, Kondolf and Li 1992). This
method involved randomly selecting 100 streambed particles along a transect and
measuring their intermediate axis before assigning a size class from a modified
Wentworth scale (Table 1.1). These data have been collected on an annual basis since

1996.

Fish Abundance
Fish were collected during the summer of 1996 using a backpack electrofishing
unit, during the spring of 1997 using fyke nets, and during the summers of 1997, 1998,

and 1999 using an electofishing boat. The backpack unit was set to deliver pulsed DC

Table 1.1. Size classes and codes used to denote particle composition.

 

 

Size Code Size Class Particle

1 Organic

2 0.00024-0.004mm Clay

3 004-0062 Silt

4 0.062-2mm Sand

5 2-4mm Very Fine Gravel
6 4-8mm Fine Gravel

7 8-16mm Medium Gravel
8 16-32mm Coarse Gravel
9 32-64mm Very Coarse Gravel
1O 64-128mm Small Cobble
11 128-256mm Large Cobble
12 256—512mm Small Boulder
13 >512mm Medium Boulder

 

 

(10% cycle duty) at 250-450 V. The electrofishing boat consisted of a Smith Root— 1 7
CataRaft delivering pulsed DC (40% cycle duty) at 50-500 V or 4-5 amps.

We sampled fish abundance at 10 sites along the river (Figure 1.4). These sites
ranged individually from 80 to 428 meters in length and a total of 208 meters downstream
from the dam and 2,001 meters above the dam were sampled. A multi-pass removal
method using block nets to enclose sampling sites was used (VanDeventer and Platts
1985). At each site, at least three passes were made within the block nets until a clear
depletion pattern was detected. Fish abundance was sampled in 1997, 1998, and 1999,
and will continue until the dam is removed. MicroFish (Van Deventer and Platts 1985), a
software program using the Burnham maximum-likelihood estimator (Van Deventer and
Platts 1983), was used to estimate abundance. The abundance estimates were then

converted to density estimates (fish/hectare) using river width and site length information.

Fish Growth

Trout and white suckers from the three zones were sampled to determine growth
rates and age distribution. Scales from brook trout, brown trout, and rainbow trout were
collected from the region on the diagonal between the posterior of the dorsal fin and the
anterior of the anal fin, two rows above the lateral line (Minard and Dye 1998). Pectoral
fin rays were collected from white suckers, cutting at least the first three fin rays. The use
of pectoral fin rays has proven to be a more reliable method of aging white suckers than
the scale method (Beamish and Harvey 1969, Scidmore and Glass 1953). While in the

field, total length of the selected species was measured to the nearest millimeter.

Ema comcobm Eoi Eb: cosmic

_ _

Sim 0:5 2: so e882 8% @3383 canvases 5E 42 oSwE

 

_ _ _ _
_ _ _ _
m n m m

ocoN voaoquTcoz

    

whom >23 ”mm
88:83 28.0 mtommou #504
E85560 950 muommou nz>>Ooo._
Emgmqa 99m; emucaom nnS>>m
Emwwasoo 92mg Emuczom uZ>>Oo>>m
E8383 Emcofiw "doom

cam 93m ”mm

econ 6896 "um

Enema: mmucm 33 "dam:

Emmwasoo omvtm 26.. u2>>oomj

_
v

_
_
m

_ _
N w

ocoN “66ng

 

.CON Ewmbwcgoo

 

 

 

Ema
58:95

17

In the laboratory, trout scales were mounted between glass slides for analysis. The
fin rays of white suckers were embedded in epoxy, sectioned using a diamond blade saw,
and mounted between glass slides. An Optimus imaging system was used to age and
measure am1uli of scales and fin rays. After aging, length at capture by age was
determined for the target species and compared to average growth in Michigan streams
(Laarman et al. 1981).

Back-calculated lengths at age were determined from trout lengths and scale radii
sampled between 1996 and 1999 using a linear regression. The same method was also
applied to white sucker lengths and pectoral fin ray cross sections collected between 1997
and 1999. Brook trout length at age was only calculated for 1998 and 1999, as brook
trout scales from 1996 and 1997 have not been analyzed. The Hile formula, a modified
version of the Fraser-Lee method, was used to back-calculate length at age, using the
formula

Bage = ((TL'Rscale)*(Rage/TR))+Rscale
where Bage was the backcalculated length at age, TL was the total length of the fish, Rsmle
was the length of the fish at first scale formation, Rage was the radius (mm) of the scale at
the annuli correspondidng to the age of interest, and TR was the total scale radius (mm)
(Francis 1990).

To determine if length at previous age was a factor affecting fish growth, a general
linear regression was performed. Growth over the previous year was modeled using an
incremental growth model so that growth would not be biased with month of capture

(Manceina 1992, Weisberg 1993).

L = [30 + BIXI + Bzxz +BI2X1X2

 

In this model, L was the incremental change in length, x1 was the beginning length, and
X2 was the indicator zone variable being fit to a generalized linear model. The difference
in back-calculated length between the previous year and the beginning of the current year
was estimated to be the change in length. An analysis of covariance (ANCOVA) was
used to determine differences in annual incremental growth between the three zones with
incremental growth as the response variable, zone as the main effect, and length at
previous age as the covariate. Analyses were performed on untransformed data using the
GLM procedure of SAS (SAS Institute 1988). These analyses tested significance at an

alpha of 0.05.

RESULTS
Habitat

Channel morphology was documented between 1996 and 1999. At the time of
surveying in 1999, the dam had been lowered approximately six feet. Since 1996, the
river has changed dramatically near the dam, by both narrowing and deepening. Both
above and below the dam, the river is shifting to the right or the area where the stoplogs
are being removed and scouring was seen on the right Side as a result of the dam removal
and the rerouting of the river (Figure 1.5). Below the dam, an aggradation of particles can
be seen on the left side where the dam Spillway lies. An overall raising of the streambed
below the dam has resulted from sediment being flushed downstream. Since 1996 there
has been a water level drop of approximately five feet in the area immediately upstream
of the dam. In fact, the 1999 water levels near the dam lie below the 1996 stream bottom.
Although some changes were a result of organic debris being moved along the streambed,
those closest to the dam were likely associated with the dam removal. As predicted, few
changes have occurred in the Non-Impacted Zone, and these changes were attributable to
normal stream events (Figure 1.6).

As the stoplogs have been removed, the longitudinal progression of streambed
changes was seen through differences in water elevation at each transect (Figure 1.7).
Setting the 1996 water levels equal to zero, the progressive changes in the water level due
to dam removal were apparent.

Gradient is reported for the eight upstream stations from 1996 through 1999
(Figure 1.8). These numbers were determined using the change in water surface elevation

from the most upstream to the most downstream transect in a series. The overall gradient

20

 

Impacted Zone
Stronach Pond Transect #5-6

 

 

720 ‘ 1996 and 1999
73.7715 1
Z710 i
O I
'fi 705 it
,>, .
m 700 i
695 I» . *1 , l , . V\ L . _
o 20 4o 50 so 100 120 140
Distance (feet)
Impacted Zone
Stronach Pond Transect #9-10
73° 1996 and 1999
Z
.2
‘5
5
Lu
Distance (feet)
Downstream Zone
715 Below Dam Transect #1 -2
710 L 1996 and 1999

Elevation (feet)

 

 

Distance (feet)

Figure 1.5. Pine River cross-sections illustrating examples where changes in
streambed elevation have been detected between 1996 and 1999.

21

Non-Impacted Zone
Loggers Camp Transect #1
105 .- 1996, 1997, 1998, 1999

Elevation (feet)

 

Distance (feet)

Non-Impacted Zone
Harley Hill Transect #17-18
105 ,. 1996, 1997, 1998, 1999

   
 

Elevation (feet)
(0
0'1

 

90 A
l
85 l 7 7t 7 7) 77 7 77 — 7 7
o 10 20 30 4o 50 so 70 so 90 100
Distance (feet)
Impacted Zone
Schofield Transect #5-6
1996, 1997, 1998, 1999
5
‘ds'
5
Lu

 

Distance (feet)

Figure 1.6. Pine River cross-sections illustrating examples where no changes in
streambed elevation have been detected between 1996 and 1999.

22

‘ — 199675169774 1

 

     

—E—1996-1998 I
+1996-1999

.4!

 

 

 

 

(tee; 0=966L) (teal) uoueAeia 1919M

23

LU€9J18UMOG

peioeduii

peioeduii

peioeduii

peioedtui

peioedtul

p910€du1|

peioeduii

peioeduil

peioeduii

peioedun-uoN

peioeduii-uoN

peioeduii-uoN

peioeduii—uoN

peioeduii-uoN

peioede-uoN

Zone

Figure 1.7. Pine River changes in water surface elevation (feet) as deviated from 1996.

 

 

.903 ES 009 50.303 53m 0:5 2: so voting. .Coonoi SQ £8.25 omega 8:320 8&5; 83>» 5 E3230 .M: oswi

   

 

 

 

mozw
s m t
d
.6 W «Us. M w M m8 nu.” w. _l
d m Si m: E? Ur e n w 1. O O
m e a m m w. m w H e w w
W m w M s ,M m M d m
iiil iii iil ll 1 i i i i ii .i il l i ii i illiili i iii 0
fl m.o
ocoN voaomagéoz F W
ocoN we,
Ewomesoo ocoN 868E. . m
,r m w d
L E
e m
ill ii .1 N m
T82 E285 it w
Emmiceosoi, mm m...
_ so? E9390 +7
S2 EmseoHi W. m
i m.m

 

24

decreases moving downstream, with the highest gradients (>2m/km) found in the Non-
Impacted Zone, and lower gradients (<1m/km) found in the Impacted Zone. Because the
Downstream Zone has only two transects, each in a separate series, gradient could not be
determined. Year to year variability shows no clear patterns, and may be attributed to
seasonal or daily fluctuations in water level.

The average discharge for the years 1997-1999 showed a pattern of increase in a
downstream direction (Figure 1.9). Over time, discharge has ranged from approximately
six to nine cubic meters per second. Mean velocity (cm/s) in the study section tended to
decline in a downstream direction, in contrast to discharge (Figure 1.10). Over time,
mean velocity in the Impacted Zone has become progressively higher with the steeping of
gradient above the dam. Few changes were seen below the dam in the Downstream Zone.

After dividing the annual velocity measurements into percent frequency by zone,
the differences in the study stretch were shown (Figure 1.11). Raw flow data from 1997
were unavailable, although 1997 means were taken from Klomp (1998). In 1996, 1998,
and 1999 the Downstream Zone had the highest frequency of low velocities (0 to 0.5
m/s), while the Impacted Zone had the highest frequency of mid-range velocities (0.5 to 1
m/s). The Non-Impacted Zone had both the largest range of velocities and the highest
frequency of high velocity measurements (0.5 to 1.5 m/s).

Generally, substrate in the Non-Impacted Zone was dominated by medium to very
coarse gravel, and has shown no directional change over time (Figure 1.12). In the
Impacted Zone, the substrate was comprised mostly of very fine gravel to medium gravel.
In 1999, the mean particle size in the Impacted Zone appeared to be increasing through a

coarsening of the bedload. Substrate in the Downstream Zone substrate consisted

25

 

.33 can 33 5953 338% BE :08 S emcenommo :88 :Soxyo $3M uni d; eeswE

 

 

G I.
.1 8 S 0 .m.
m m e w m m a M M... DH. 0 _.
M d J ,A. O S u. n U U 3 O
G 0 O S U H 0 W U 8 u. E 5
m. m m a a m % ..._... p. w AH e w w
w w m m w m s m m M d a
ll 1 i l .11 i ll 1. l... l :1 l . :1- Iii- ooh
ocoN Emobmcsoo ocoN 0908c: ocoN noaomQETcoz
cob
m
S
1 SN m
m
6
N ..
.. Be Me
i II a.
immmrixl \ L .
magi” ... oo o
Romain; .
,ommFIOI . 00.9

 

 

26

 

dog was com: :0050: 00:33:: 02m :03 :05 8:800. :05 £0025 .3623 500:: :35 0:5 .3: 0::m5

 

 

 

 

 

 

 

 

_, N:

e m
_I 8 AW. 8 m Hi. %
e H H d
m m w .m m m 8 M mu m m. m
8 M U. S. niu: m... U. B n a 1
U. :0 .l .J O 1.. U rA U: 0
0. p00 0 H. m. % Alla: mm W H e m
w w w m w m s m m M d
I ll U .. .i iii 1 i i... . ill I -.i i O
0coN Emobwcioo m mcoN coaomag M 0coN 8635752 1 No
a m - so
8211 . w
002+ “ - 0.0 m.
82+ ,.// < M
m Me 0.0

 

27

 

 

 

 

 

 

 

 

 

>
0
C
(D
3
C‘
9
g r_+199‘a
8 +1998
3 j-x—1999l
(U
E
(D
8 — *—_‘—.
:‘i’ 2
Non-Impacted Zone Velocity (m/s)
> 30 .7]
O .
8 25 ~l
3 l
g 20
:3: 15 '+ 1996l
8 +1998;
3 1" .—><— ___19:9_9_l
53’ 5
E
g 0
(D
o. _5 J 2
Impacted Zone Velocity (m/s)

6 45 '1
c 40 -
g
g 35 -
a: 30
g 25 +1995%
8 20 +1998:
3 15 je—1999l
g 10
§ 5 A
52 ° __ _.

-5 2

 

Downstream Zone Velocity (m/s)

Figure 1.11. Pine River velocity percentage frequency by zone in 1996,
1998, and 1999. Data from 1997 were unavailable.

28

 

 

 

 

+1996

Downstream
Zone

 

 

  
    

Impacted Zone

 

 

(D

C

O

N

'C

93

0

(U

Q.

E

a

0

Z
l l l l l l
O) CO I\ (0 L0 V 0’)

epoo ems elomed

29

efipua MO']

wag molaa

puod HOBUOJlS

una sfioa

DIGIJOUOS
weansumoq

DIGUOUGS

SJGlBM
Mepunoa

||!H KelJeH

1U. 9H1 40 dli

dweg $196601

Figure 1.12. Pine River pebble count means by site for 1996 through 1999.

 

primarily of sand and very fine gravel. Substrate size below the dam did not appear to be

shifting.

Fish Abundance

A total of 34 fish species have been encountered on the Pine River since 1996
(Table 1.2). In 1999, redear sunfish (questionable identification) and banded killifish
were added to the list. Of the 34 species sampled, three species were encountered only
upstream from the dam and represent mostly headwater species. Seventeen species were
found only downstream of the dam and represent mostly coolwater species. Some of the
species only found below the dam include walleye, yellow perch, northern pike, and
redhorse suckers (Moxostoma macrolepidotum and M anisurum). Fourteen species were
found both upstream and downstream of the dam.

Density of key species was established over time to compare annual patterns
within different stretches of the river. The population density (number/hectare) for brook
trout, brown trout, rainbow trout, and white suckers was determined for the years 1997
through 1999 at each of the ten sampling sites (Table 1.3). Although there does not
appear to be significant trends over time, patterns have begun to emerge when comparing
the zones (Table 1.4). For example, the overall pattern of density showed that trout
population numbers increased moving in an upstream direction.

Over time, not much change in brook trout abundance was apparent within a zone,
indicating that the relative abundance among zones was stable. In 1999, there was a
sizeable increase in brown trout, both in the Non-Impacted and Downstream Zone.

Rainbow trout density has remained stable, excepting for an increase in the Non-Impacted

3O

 

Table 1.2. Fish species sampled on the Pine River between 1996 and 1999.
An * indicates questionable identification.

 

Taxon

Scientific Name

Esox americanus
Percopsis omiscoma yous
Amblop/ites rupestris
Lepomis gibbosus
Notropis atherinoides
Percina macu/ata
Percina caprodes
lchthyomyzon castaneus
Perca flavescens
Stizostedion vitreum
Esox lucius

Umbra limi

Moxostoma anisiurum
Moxostoma macro/epidotu
Notemigonus cryso/eucas
Etheostoma nigrum
Lepomis microlophus
Luxi/us cornutus
Lampetra appendix

Rhinichthys cataractae
Semoti/us atromaculatus
Lepomis macrochirus
Cottus bairdi

Cottus cognatus
Catostomus commersoni
Salmo trutta
oncorhynchus mykiss
Ame/urus melas
Salve/inus font/na/is
Notropis hudsonius
Micropterus dolomieu
Culaea inconstans
Rhinichthys atratu/us
Fundu/us diaphanus

Downstream from §tronach Dam Upstream from §tronach Dam

Common Name
Grass pickerel
Trout-perch
Rock bass
Pumpkinseed
Emerald shiner
Blackside darter
Logperch
Chestnut lamprey
Yellow perch
Walleye
Northern pike
Central mudminnow
Silver redhorse sucker

Shorthead redhorse sucker

Golden shiner
Johnny darter
*Redear sunfish
Common shiner

American brook lamprey

(ammocetes)
Longnose dace
Creek chub
Bluegill
Mottled sculpin
Slimy sculpin
White sucker
Brown trout
Rainbow trout
Black bullhead
Brook trout
Spottail shiner
Smallmouth bass

31

Common Name

Common shiner

American brook lamprey

(ammocetes)
Longnose dace
Creek chub
Bluegill
Mottled sculpin
Slimy sculpin
White sucker
Brown trout
Rainbow trout
Black bullhead
Brook trout
Spottail shiner
Smallmouth bass
Brook stickleback
Blacknose dace
Banded killifish

 

 

 

 

 

S E R m o o o 0 we see :38 535 33
2 E m om o o o 0 2: no a: 585 33
cm 5 5 ON v o o s New no 28 6955
em m s B NF 2 om N NNN 3 Ex 36m
we 8 R 5 NF 2 NF 9 8m 3 5: 25:06.0,
8 we we mm 3 m t E a? as :38 2925 5958
8 mm mm B we 2 x: R 8m 3 a: new; 3.858
mm mm mm C 2 ow o s ms no 550 9:8 5583
E. 8 E, om mm 5 cm mm x: E a: 9:8 5533
mm a t 9, om E 3. 8 ow em 5.58 22.8
:85. 82 82 $2 :85. $2 32 32
350222: 858;sz was: 3.25523 25

use... E505

“so; xoohm

£95.. 85 Ema E9.“—

3:320

.33 was 39 50363 @0383 02m :23 com $588: $9 $9855 93% :ouflsmom :mm 53m 025 .m; 033.

32

 

 

 

 

98 m: N? x: v o m s we do 558 525m 33
am who. .8 mm; o o o 0 me no a: 585 33
8 F 8 a: E 9 s mm New no 28 6295
8 E R R w m NF 5 NNN 3 Ex 36”.
8 o R 9, 2 a S R SN 3 a: 22.558
om v .2 3‘ mm 3. we 8 wmv am See 5555 52:8
w 2 S N em 8 we 2 mwm 3 a: 2225 52:8
o o o t m: ow 2 0 ms no :38 9:8 2533
mm a: 2 mm mm so 8 s x: E a: 9:8 W583
o o o O we mm ov me 8 hm 5.55m >28
:85. 82 82 $2 :85. 82 82 32
858;sz $585255 $55.5 355523 85
59.25 323 use... 3035?. £95.. 35 E50 :6:

woe-3&0

.6253 S 532.;

33

 

 

mVN
nmN

mm w
EmomesoQ

o
N

V
500502260

0v
or

N w
80050550

0
o

o
Emobmcgoo

w
vm

No
.0300: E.

ON
we

ON
nope—“ES.

vm
0N

mm
nflonaE.

m
Ne

w
c.3038.

ow
NN

F _.
680357.32

m...»
9»

FN
beacon—E202

mm
5N

mm
toaomngéoz

om
vv

nm
6063.2.-52

050.
000.
Near
.9530 822,

mmmv
wmar

ham?
39.... 3353.

mmmv
mamr

name
use... 550.5

mmmv
mag

.39.
«:2... xoohm

.33 0:0 33 :00250: 60—5800 0:8 £000 85 $2800: :0: 898:5 58:0: 5503505 :25 535 0:5 .v: 030%

34

 

 

Zone in 1998 and 1999. Looking at white suckers, numbers in the Non-Impacted Zone
have shown a relatively dramatic increase, along with a subsequent decrease in the
Impacted Zone in 1999.

The spatial distribution of trout and white suckers was established to distinguish
patterns of density within the zones. In general, densities of brook trout, brown trout, and
rainbow trout were highest in the Non-Impacted Zone (Figure 1.13). Brown trout,
however, showed a different spatial distribution in having a substantial number in the
Downstream Zone. Specifically, brook trout were most abundant in the Non-Impacted
Zone, less abundant in the Impacted Zone, and none were captured during our abundance
sampling in the Downstream Zone. A few brook trout were seen in the Downstream
Zone during other sampling efforts, however. Brown trout were nearly equally
distributed between the Non-Impacted and Downstream Zone, and were overall less
abundant in the Impacted Zone. The distribution of rainbow trout was similar to brook
trout. They were found most abundantly in the Non-Impacted Zone, less abundantly in
the Impacted Zone, and rarely in the Downstream Zone. White suckers showed a very
different spatial distribution than trout (Figure 1.14). White suckers were much more
abundant in the Downstream Zone with comparatively few residing above the dam. The
overall abundance of white suckers in the Impacted and Non-Impacted Zone has shifted
over the course of the study, with a higher population number now in the most upstream

sampling sites.

35

 

.009 can 33 :83qu 53m NEE 05 no
318$ 85 :m 8m 8538: Hum 595:: v 355w Bob BEES was .305 E505 .39: x83 282 .m: oSwE

umoq SJSlBM
Mepunog

Mepunog
‘ umoa
3 duieQ $196601
dn
dLUEQ $196601

dn efipua M01
8,988 Apues

UMOC]
efipua M01
1 dn SJeleM

l,

3 puod qoeuons
A03
. dn pleuouos

1

 

 

130;. 33:61 +1 D
, So; 559m +7

 

O
(‘0
GJBweH Jed JeqwnN ueew

 

Soc. xoonm Iol n. om
wcoN "
Emobwcaoo mcoN vmgomag ocoN vouomQETcoz f om

 

36

 

umog
I efipug MO"|

Downstream

   
 
    

dn efipua M01

puod uoeuons

una s,Aoa

Impacted Zone

dn pleuouos

umog SieieM
Mepunog

dn SJGIBM
Mepunog

UMOC]
, dweo $196601

dn
dweg $196601

Non-Impacted Zone

. 3,399 Apues

 

1

"fl- _. _ ._ - __ _. . -1-
O 0
LO O

F F

ampeH Jed JeqLunN ueew

250

200 l

50 7
o

37

Figure 1.14. Mean white sucker density ( number per hectare) for all sites sampled on the Pine River between 1997

and 1999.

 

Age Distribution

Most of the brook trout caught in 1998 and 1999 were age zero and one, while the
remaining were age two and three (Figure 1.15). The age distribution of brook trout
varied among years, but was similar between the Non-Impacted and Impacted Zones.

Most of the brown trout captured between 1996 and 1999 were ages one and two
(Figure 1.16). Upstream of the dam, brown trout were dominated by age zero and one
fish, which comprised over half of the population sampled. Additionally, the majority of
age zero brown trout were found above the dam, while only a small percentage of brown
trout ages three and older were sampled above the dam. Below the dam, the majority of
fish were age two, followed by a relatively high number of ages one, three, and four fish.
Between 1996 and 1999, few age zero rainbow trout were caught, and the majority of the
rainbow trout were age one and two (Figure 1.17). Similar to brown trout, upstream of
the dam rainbow trout were dominated by age one fish, followed by age two. Below the
dam the majority of rainbow trout were age two, followed by a relatively high number of
age one and three fish.

Overall, the age structure of white suckers was dominated by age zero through three,
comprising almost all of those sampled (Figure 1.18). Some differences were apparent in
the age structure among zones, however. The Non-Impacted Zone was dominated by age
zero, while the Impacted Zone was predominately age two and three fish. Similar to the
Non-Impacted Zone, most of the suckers in the Downstream Zone were age zero,

followed closely by ages one, two, and three.

38

80,

80

20

Percent by Age

Percent by Age
A
O

70 ,
60 ~
50 1
4o 1
30 :

 

Non-Impacted Zone

Age

Impacted Zone

 

Age

Figure 1.15. Brook trout age structure within each zone on the Pine River

for 1998

and 1999.

39

Non-Impacted Zone

50
B 40
<
3 30
8 20
e I
0’ 10
r;
0 - - —
0 1 2 3 4 5 6
Age

Impacted Zone

50
40
30
20

1O
0 'I-__
234

Percent by Age

Age

Downstream Zone

Percent by Age
(A)
O

1" IIII

0- -—
01 2 3 4

Age

Figure 1.16. Brown trout age structure within each zone on the Pine River
between 1996 and 1999.

40

 

Non-Impacted Zone

   

 

Age

Impacted Zone

co
0

Age
8 5‘

A
O
1

N
O

 

Percent by
8

.3
o

 

 

O

3 4

50 —
. f l
1 2

Age

Downstream Zone

80 -
< 60
50 -
4o 3
30 w
20 ~
10

ge

Percent by

 

     

 

Age

Figure 1.17. Rainbow trout age structure within each zone on the Pine River
between 1996 and 1999.

41

Non-Impacted Zone

35
0330
U)
<(25
5‘20
515
810
$5

0 I-I_--_ _

012 3 4 5 6 7 8 9101112

Age

Impacted Zone

30
25
15
10
5

1 2 3 5 6 7

0 4 8 9 10 11 12

Percent by Age
N
0

Age

Downstream Zone

35
0230
U)
<25
5‘20
515
210 I
a)
0.5 II
0 -——__ _
012345678911112
Age

Figure 1.18. White sucker age structure within each zone on the Pine River
between 1997 and 1999.

42

 

Fish Growth

The mean length at capture was calculated for trout sampled between 1996 and
1999 (Table 1.5). Compared to the length at capture for Michigan stream averages, it
appears that the Pine River trout are fast growing and white suckers are slow growing.

To back calculate length at age for trout, a linear regression of fish length to total
scale radius was used to determine the length at which scale formation began. Overall,
the regression fit for these equations was quite good (Table 1.6). Although some sizes at
scale formation were calculated to be negative, negative numbers were nonsensical and a
result of non-linear regressions, and in those cases zero was used to back-calculate the
length at annulus formation for previous years.

For brook trout, the pooled regression for 1998 and 1999 had an estimate of
length at scale formation of —l 3 mm. It appeared that this was a result of the lack-of-fit
for the smallest group of fish in the regression, suggesting a non—linear regression for age-
0 fish. Instead of the negative estimate, the size at scale formation was fixed to 0 mm.
The regression of brown trout length to scale radius, pooled from 1996, 1997, 1998, and
1999 also showed negative size at scale (-20 mm), and as with brook trout zero was
instead used. The estimated size at scale formation from the regression of rainbow trout
length to scale radius from 1996, 1997, 1998, and 1999 equaled 10 mm. Previous length
at age was back calculated for white sucker similarly to trout using a regression of white
sucker length to fin ray radius. The size at fin ray formation for white sucker length
regressed on fin ray radius for 1997, 1998, and 1999 was 51 mm.

Incremental growth was regressed on length at previous age for all trout and white

suckers aged between 1996 and 1999 to determine if growth differed among zones and

43

 

 

 

 

 

 

 

omv oov mm... 34 new. mom SN aw magmas, amazes.

m3. m9. Cm as. 5m 8m 8m «8 k: 8 $853 55. 85
w: Be $4 an mmm Sm 8N RN 5 8 $2
. . . owe 4mm Pm vwm 48 N2 8 82
me. one a; 48 N5 vvm x: BF $2 can .89

a +m l +o +m i. +n +~ i a .938 £55
New .0. E 02 mm magi 896:2

2% Sn SN 92 5 £655 55 85

. 3m mew m2 . 88

4mm 4mm m2 82

8..” mmm EN EN 5 32 Em 82

+V +n +N +—. o «39:. 30356”.—

vmm SN gm «.2 E magi $952.2

Rm Ev Ev Nam mom EN 8 $993. 55 8E

mom Ev E. 8.0. EN EN em 82

9a . 84 mwm 8N mNN NS 82

. New a? 3m EN E 32 Em 82

+w +m i. +m +~ i o so: 585

EN mom 9; 8 mmseé 896$

wmm 8N cm: 8 mama? 52m 85

0mm x: 0: mm 32

mmm SN mm: 8 $2

+m +~ i o So: xoem

£3:

QEEM 8on 5&8 £3 32 ES cog 80¢ ENG 503% wEBSw 2t wESw @2598 80>» :mm :< .2on .8 5 caged
wowwagm 8.85m smmanz 8 @8388 .mbxoa BEE can Bob 53m 0:5 Sm 88 E 23me 8 Swan: SEE .m; 2an

44

 

 

 

 

 

 

{Syd rode + xmode- n > whomd mode. + xomwd- n > mmovd vmdov + XVNmrd- u > amxonw 9E>>
vooood wv.mo—. + waood n > mmood Sva + xnmvod u > wood mmmdm + xvomod n > “:9... 2695?.

 

mvao mmwN: x03 to- n > 38.0 $0: + x0570- n > 85.0 moNNF + xmwmfio- u > So; 5505
ommmd Saw: + xmmmmd- n > $56 5.8 + xVONNd- u > So; xooam
mm 0coN 8.00.me260 mm 0coN BEBE. mm 9.3. nmuomaEwcoz

5600.95 5390 EcmEEoE

 

 

8.0.0 3.3.0 - x890 u > .9630 0:55
20.0 mmmod - x83 u > so: 385$.
88.0 008.0 + x380 u > so: c390
020.0 2.8.0 + x286 n > so: v.85

 

mm commmammm 0_mow->vom

 

.0035 0:5 05 no 00383 $00503.
03:3 98 So: 85 $28050“ 538w 59:0806E 98 05084609 85 m020> NM 28 30:03me .0; 033.

45

 

years (Figures 1.19-1 .22). ANCOVA results indicated no significant difference over time
for any of the species analyzed (p > 0.05). However, variability was high and there
appeared to be differences in rainbow trout and brook trout growth. When all years were
analyzed together using the Impacted Zone as the arbitrary standard position, or the basis
for comparison, significant differences were found in growth (Table 1.7). For brook
trout, annual growth was significantly less by l 1.8 mm per year in the Non-Impacted
Zone (p = 0.0079). As no brook trout were caught in the Downstream Zone, growth rates
were not determined in this area. Brown trout showed no significant differences in
growth throughout the river, even though estimated growth was slightly better in the Non—
Impacted Zone by 2.6 mm (p = 0.4380) and in the Downstream Zone by and 9.1 mm (p =
0.0519). Rainbow trout showed slightly slower growth in the Non-Impacted Zone by 2.6
mm (p = 0.3247), and significantly better growth in the Downstream Zone by an average
of 9.5 mm per year (p = 0.0285). Like brown trout, white suckers displayed no
significant difference in growth rate among zones. In the Non-Impacted Zone, white
sucker growth was 5.2 mm higher (p = 0.3785), as well as in the Downstream Zone Where
growth was slightly higher by 0.2 mm (p = 0.9720). Overall, trout seem to be growing
better in the Downstream Zone. Brook and rainbow trout grew slowest in the Non-
Impacted Zone, while brown trout and white suckers exhibited their worst growth in the

Impacted Zone.

46

 

. E] Non-Vlmpactedrzone i
180 . l
l l A Impacted Zone

 

Linear (Non-Impacted i
Zone)

160 T l
1 i ------ Linear (Impacted Zone) l

140‘! * h“

O N
O O

CD
0

Incremental Growth (mm)_.

0)
O
l

 

 

40 r‘ “
‘ ‘
20 t

1 ~
‘ \

017 . if. a . f . .
O 50 100 150 200
Previous Length at Age (mm)

Figure 1.19. Incremental growth regressed on length at previous age by zone
for brook trout sampled on the Pine River between 1998 and 1999.

47

 

 

‘ El Non-Impacted Zone
i

A Impacted Zone
250 .

O Downstream Zone

 

1
Linear (Non-Impacted Zone) 1
El ------ Linear (Impacted Zone) 1

— Linear (Downstream Zone)

 

 

E
E,
.C
E
9
o
a
E
G.)
E
9
8
_ g ..
O
l
0 i
o 100 200 300 400 500 600

Previous Length at age (mm)

Figure 1.20. Incremental growth regressed on length at previous age by zone
for brown trout sampled on the Pine River between 1996 and 1999.

48

r“—‘—‘ ' "“11“ ' 'i
I El Non-Impacted Zone I
A Impacted Zone

0 Downstream Zone

 

200
i Linear (Non-Impacted Zone) =
| |

180 ------ Linear (Impacted Zone) 1
I _. _ - -

160 A El 1 Linear (Downstream Zone) ‘

I I. ,4_ _ ._ . _ A #k 7, . ,
‘u‘.

140

.A
N
O

Incremental Growth (mm)
3
0
ti .
I ..,
a b k
a la 5
>D

 

 

 

O
80 ADD ‘ 0‘ ..
n A
D D D
so at
AA
, n
40 -| A‘ n
I ‘ A
201
i
OI___ _ _ ___,_-- __ _______ _ fl __
o 50 100 150 200 250 300 350

Previous Length at Age (mm)

Figure 1.21. Incremental growth regressed on length at previous age by zone
for rainbow trout sampled on the Pine River between 1996 and 1999.

49

 

l i El Non-Impacted Zone it if
V A Impacted Zone

I O Downstream Zone

I Linear (Non-Impacted Zone)
I ------ Linear (Impacted Zone)

I WNW-"- Linear (Downstream Zone)

 

 

 

E 150
E,
E
9 125
o
“as
E 100
(D
E
9
g 75
50 I
25 j
I
0 i i'V— ' r 7 T’ "Phi" Wfi'“ " ' I— ' '7 7 ’ ¥ '
o 100 200 300 400 500 600

Previous Length at Age (mm)

Figure 1.22. Incremental growth regressed on length at previous age by zone
for white suckers sampled on the Pine River between 1997 and 1999.

50

 

 

 

Es N9 2.85:3 82 Emucsm EE we 28535 62 55.26 922,

ES 08 28255 2336 ES 35 2.8235 82 :5: 38:52

Es 29 23:35 82 seesaw AEE ed 28535 62 so: 56$

8.92% 0:02 2%:me AEE w. F : EmoECQm So; 2005
Emmbmczoo 888E. 868E752

. $2 ea... 82

5953 8:8 Echofifiw Bot @2283 £833. BEE 98 Bob 5 "03:08:08 955 80:20me :35ch 83% 0:5 NA 2an

51

DISCUSSION
Habitat

Sediment transport is undoubtedly one of the major concerns during and following
a dam removal. Although the Pine River does not have toxic sediments, it does carry a
high bedload of sand that could potentially degrade water quality and habitat below the
dam. The staged dam removal was agreed upon in an effort to allow for revegetation of
exposed floodplains. As a result, this protected the downstream area from an increased
amount of erosion, or sediment transport. To monitor changes in the stream channel,
baseline streambed and water elevations were established in 1996 through a series of
transects. At the time of annual surveying in 1999, approximately 6 1/2 feet of the dam
had been removed.

The initial habitat measurements taken in 1995 (Klomp 1998) delineated the river
into distinct habitat zones: the Non-Impacted, Impacted, and Downstream Zones. The
initial findings were used as a basis for comparison to establish the extent of change in
the river correlating to the dam removal. Hammad (1972) stated that a riverbed upstream
of a dam will continue to erode following a dam removal until the natural armoring layer
of coarse sand or gravel was exposed. Because the river is both characterized by a gravel
substrate and is not hydrologically controlled by Stronach dam in the Non-Impacted
Zone, changes in the streambed are not expected in this area as the dam is removed. As
predicted, virtually no changes have been documented in the upstream stretches.
Naturally occurring river dynamics including movement of large rocks or the introduction

of coarse woody debris were attributed to those sites that have exhibited changes.

52

Alternately, changes caused by the dam removal were evident in the Impacted
Zone. The preliminary findings by Klomp (1998) agreed with the results of a sediment
study done by Hansen (1971) on the Pine River, where it was found that Stronach Dam
increased the sediment in the stream channel as far as 2.8 miles, or 4.5 km upstream of
the dam. Thus, changes may be documented up to this point. Currently, in the Stronach
Pond transect series, scouring has degraded the river bottom to the point where several
sites had a 1999 water level elevation below the original 1996 stream bottom. Above and
below the dam, the river has narrowed by shifting to the area where the stoplogs were
being removed. Additionally, the Downstream Zone showed an overall raising of the
stream bottom as a result of sediment being flushed downstream.

Since changes in the streambed parallel water surface elevation changes, the graph
showing water surface changes from 1996 gave a good indication of the sequence of
sediment changes. Compared to baseline data from 1996, the river has changed
dramatically both above and below the dam. Of note were the progressive changes
documented in the Impacted Zone. Here, the process of head-cutting or scouring has
occurred up through an area approximately 2 kilometers above the dam, with most of the
changes documented within the first 1.5 kilometers. Above this, the river is characterized
by a coarser substrate and subsequently more resistant to erosion. Below the dam, the
streambed has risen owing to the aggradation of particles scoured from above the dam.
Because Tippy Dam controls the water up to Stronach Dam, changes below Stronach
Dam will not be detected past Tippy Dam. The hydrological operations at Tippy Dam
can be used as a tool in changing the Downstream Zone streambed. For example, by

drawing down the water levels at Tippy Dam, the mass of sand below Stronach Darn may

53

 

 

be flushed downstream into Tippy Reservoir. Most importantly, the influence of Tippy
Dam reduces the amount of certainty we have in attributing changes detected in the
Downstream Zone to the darn removal.

The overall pattern of river gradient, or water surface elevation change in meters
per river kilometer, decreased moving downstream. The highest gradient was recorded in
the Non-Impacted Zone, while the dam caused the gradient to be reduced in the Impacted
Zone. Because the dam was originally built to provide hydroelectric power to the city of
Manistee, it was constructed over the area of river that contained the highest gradient
water (Battige et al. 1997). As the removal of the dam allows sediment that aggraded in
the upstream areas to erode, water gradient is expected to increase. Changes could not be
documented in the Downstream Zone as each of the transects belonged to a separate
series. Additionally, over the years gradient has not shown any definitive patterns of
change, and those fluctuations seen may be attributed to seasonal or daily water
fluctuations.

As expected, discharge increased as the Pine River flowed downstream. This was
in accordance with the findings of Hansen (1971). Because there are no major tributaries
on the Pine River, this increase was attributed to groundwater inflow. Yet, this increase
displayed no annual pattern and fluctuated between approximately six and nine cubic
meters per second. The variability in point measures of discharge was credited to
seasonal or daily water fluctuations caused by precipitation or groundwater inflow.

Velocity showed a trend of increasing from upstream to downstream. Because the
streambed was being scoured away in the areas above the dam, a resultant increase in

velocity has been occurring in the Impacted Zone since the dam removal began. As

54

mentioned previously, fluctuations in velocity apparent in the Non-Impacted Zone were
most likely a result of precipitation fluctuations. In the Downstream Zone, water
velocities have remained relatively stable since the dam removal began in 1996.

The frequency distribution of velocity within each zone showed the diverse range
of hydraulics within the river. These measurements have utility in showing the range of
velocities that may be used to fulfill the habitat requirements of the various fish species.
Within the Non-Impacted Zone, the velocity not only encompassed the widest range, but
also the highest percentage of high velocities. The most upstream area was most suitable
for trout, although the lesser occurrence of slower water did provide some habitat for
white suckers. As expected, the Impacted Zone had the highest percentage of mid-range
velocities. The increasing water velocity in the Impacted Zone should benefit the trout
population by providing more suitable habitat. A study by Ford (1984) found a
simultaneous increase in brown trout and decrease in white suckers as water velocity
increased in response to habitat restoration. The Downstream Zone contained the lowest
velocities of water sampled on the Pine River, suitable for coolwater reservoir species
such as white suckers, northern pike, yellow perch, and walleye. White suckers
specifically prefer to inhabit slower velocity waters (less than 40 cm/s) such as those
found in the downstream area (Twomey et a1. 1984). Because the area upstream of the
dam does not possess a great deal of slower velocity water, habitat requirements make it
unlikely that those species now found below the dam and in the reservoir will migrate
upstream.

The analysis of pebble count data showed the overall trend of decreasing substrate

size moving downstream, which corresponded to gradient and velocity measurements.

55

The particle composition also related to changes in streambed elevation. In the areas of
greatest streambed change, there was a gradual coarsening of material. However, head-
cutting will transport sand through areas with high erosion. Thus, although coarser gravel
may be uncovered upstream of the dam, it will not be characterized as the dominant
substrate until equilibrium is reached and sand is no longer being eroded from upstream.
Hansen’s (1971) study defended these results by showing a relationship between major
sediment classes and slope of the water surface. As mentioned previously, the Non-
Impacted Zone was dominated by medium to coarse gravel, thus making it more resistant
to change than the fine gravel substrate dominating the Impacted Zone. Although the
river was characterized by the prevalence of sand bedload, as emphasized by Hansen
(1971) who found that sand comprised 70% of the total sediment load, the Downstream
Zone was the only zone in which sand dominated the mean substrate classification.
Because substrate composed of smaller material is more easily transported by higher
velocity water, more changes are expected to occur in the Impacted Zone.

As time passes, further changes in channel morphology and substrate are
expected, especially in areas where the river was inundated by sediment, as in the
Impacted and Downstream Zones. The river will continue to downcut and the channel
will shift as a result of the drawdown. With these changes, the scouring of sediment will
uncover coarser underlying substrate in addition to creating an aggradation of sediment
below the dam. A stable physical equilibrium may take years to reach, and until then, the
extent of change seen in the fish and macroinvertebrate populations will not be fully

expressed (Petts 1980).

56

 

F ish Abundance

Overall trout population density increased moving in an upstream direction,
especially for brook trout and rainbow trout. This corresponded to the increased diversity
in habitat as revealed through diversity in substrate and flow velocities. Alternately, the
number of white suckers increased moving in a downstream direction. Although it is
predicted that the carrying capacity of trout will increase as sand is scoured from the
Impacted Zone, data from 1997, 1998, and 1999 indicated that the number of trout above
the dam was fairly stable, showing little year-to—year variation. On the other hand, white
sucker numbers were increasing in the Non-Impacted Zone while decreasing in the
Impacted Zone. This shift may be attributed to the unsuitability of the substrate in the
areas above the darn. Because white suckers are characterized as benthic foragers
(Magnan 1988), the changing composition of the Impacted Zone may be causing them to
seek more stable substrate refuge in the upstream reaches.

The pattern of abundance for trout found in the Pine River was similar to patterns
seen in other rivers. For instance, in rivers with coexisting populations of brook trout,
brown trout, and rainbow trout, upstream areas were typically characterized by brook
trout, while rainbow and brown trout were found more often downstream (Vincent and
Miller 1969, Gard and Seegrist 1972, Magoulick and Wilzbach 1997). Most of the
reasons for this pattern were thought to stem from differences in competitive abilities
(Rose 1986, Lohr and West 1992), or the adaptation to and selection of different
environmental conditions (Cunjak and Green 1983).

While trout were present throughout the river, their comparatively low biomass

suggested that habitat was limiting. Alexander and Gowing (1980) found that the

57

standing stock (biomass/area) of the Pine River was about one-third that of other northern
Michigan streams. The main underlying reason for low trout numbers appeared to be
controlled by the high sand bedload of the Pine River. Reasons for the low number of
trout in the Pine River might include a limiting production of macroinvertebrates,
embeddedness of spawning gravels by sand, a reduction of diverse habitat, and a relative
lack of coarse woody debris when compared to historical records (Stuber 1996).

Other studies have elaborated on the effects of sand on fish populations (Hansen
1971, Waters 1995, Alexander and Hansen 1983, Alexander and Hansen 1986). As an
example, Ellwood and Waters (1969) found a distinct decrease in the population of brook
trout after flooding inundated pools with sand and caused a decrease in habitat
complexity. Brook trout were least abundant in the Impacted Zone and Downstream
Zone of the Pine River where sand was most abundant and habitat was the least complex.
Additionally, another study by Alexander and Hansen (1986) found that, although trout
growth did not change after an addition of sand to the bedload, it resulted in the presence
of less available food which could only support half of the original trout population.
These results were similar to the Pine River in that it contains trout that are fast growing
trout, but low in density. Most commonly in the literature, the predominance of sand has
been linked to an overall reduction in the number or recruitment of trout. This is
primarily accomplished through low survival rates of early life stages in trout, including
the production of the egg to the health of the fry (Alexander and Hansen 1983, Alexander
and Hansen 1986). Ultimately, this suggested that the combination of limited forage, less
diverse habitat and decreased survival of early life stages reduced the number of trout in a

river.

58

 

 

Improved habitat, whether through the addition of coarse substrate or the removal
of sand, has been shown to be correlated with an increase in trout numbers. As an
example, Alexander and Hansen (1983) were able to show that trout respond positively to
decreased sand bedload through increased numbers in a Michigan stream. It is expected
that the carrying capacity of trout will increase as habitat in the Pine River changes and
sand is flushed downstream. Additionally, coarse substrate provides cover for trout fry by
offering shelter from high water velocities (Heggenes 1988). Thus, the number of trout
should be higher in the most upstream reaches, as well as in the improving Impacted
Zone of the Pine River, where the overall amount of sand is less and coarser substrate can
provide shelter for early life stages of trout.

Other studies have found that dam removal had contributed to both improved
habitat and increased target fish populations. Kanehl et al. (1997) found that in five years
after the Woolen Mills Dam removal in Wisconsin, habitat was improved, smallmouth
bass (target species) abundance was higher, and the abundance of non-desirable carp was
lower. Similarly, the removal of Dead Lake Dam in Florida resulted in improved habitat,
increased overall fish abundance, and the resurgence of anadromous striped bass (Morone
saxatilis) (Hill et al. 1994).

A reduction in population levels has been shown to control competition between
trout species (Larkin 1956, Hayes 1987). However, competitive dominance appeared to
exist in the Pine River as shown by the varying population abundance. For example, few
brook trout were sampled below the dam. Initial hypothesis might point towards limiting
food resources as defined by habitat. However, a few rainbow trout and substantial

numbers of brown trout were sampled in this area. Because rainbow trout and brown

59

trout feed similarly to brook trout (Carlander 1969), these species would not be present if
food was the limiting factor controlling population size. Instead, brook trout and rainbow
trout may be outcompeted by species better suited for certain habitats.

Where optimal habitat has been reduced, as in the Impacted and Downstream
Zones, brown trout have been shown to exclude brook trout from preferred resting
positions (Fausch and White 1981). Moreover, brook trout are more sensitive to angling
and predation than brown trout (Fausch and White 1981). Differences that exist between
brook trout and rainbow trout numbers may be explained by rainbow trout dominance
over brook trout. Yet this dominance was not likely a result of the ability to compete
better for food and space (Fausch 1988). Rather, reduced brook trout fecundity and year
class failures seemed to give rainbow trout a competitive advantage (Clark and Rose
1997). Also, brook trout have been noted for their inability to compete successfully with
non-trout species, especially yellow perch and white suckers (Flick and Webster 1992,
Eschmyer 1938). In the presence of white suckers, brook trout shift their spatial
distribution and feeding habits, especially when food resources are limiting (Schoener
1982). Although the fast growth rates of trout indicate that food resources were non-
limiting, the high numbers of white suckers and other coolwater species in the
Downstream Zone likely contribute to the lack of brook trout in this area. Consequently,
trout in the Pine River seemed to be driven by changes in the physical environment rather
than competition.

Based on the substrate composition, I feel that spawning success was limited by
available substrate in the Impacted and Downstream Zones. Raleigh (1982) found that

brook trout prefer spawning gravel between 30 and 80 mm in size. This size gravel was

60

 

 

.L. fl-fl—fl- .__ ..

typically only found in the Non-Impacted Zone, with the streambed downstream of this
area containing 16 mm to 0.062 mm (sand) sized particles. In comparison, it has been
shown that brown trout and rainbow trout prefer spawning gravel composed of smaller
particle sizes than brook trout. For example, Raleigh and Zuckerman (1996) found that
brown trout prefer particles sized 10 mm to 70 mm, but will use particles between 3 mm
and 100 mm in size. Likewise, Heggenes (1988) found 50 mm to 70 mm to be the
preferred substrate size for brown trout. Rainbow trout less than 500 mm prefer substrate
between 15 mm and 60 mm for spawning gravel (Raleigh and Hickman 1984). Again,
these sizes of substrate were found most commonly in the Non-Impacted Zone, while
some was also found in the Impacted Zone. Together with this, it looked as if brown
trout and rainbow trout were able to utilize both the Non-Impacted and upper stretches of
the Impacted Zone for spawning, while brook trout spawning was likely to be limited to
the Non-Impacted Zone.

White suckers have been shown to prefer a gravel substrate with a current velocity
between 30 and 59 cm/s for spawning (Twomey et al. 1984). Although velocities in the
Pine River that fit into this range occurred most frequently in the Downstream Zone, the
Non-Impacted Zone also had a high amount of velocity measurements that fit within this
range. This may lead to the explanation underlying the higher number of white suckers
inhabiting the Non—Impacted Zone as opposed to the Impacted Zone. White suckers were
generally lacking above the dam and the density of the Non-Impacted Zone was highly
influenced by one of the four Non-Impacted Zone sampling sites. As with any river,

velocity may change by season, allowing periods of suitability. Most importantly,

61

however, velocities that exceed the optimal spawning range for white sucker dominated
the river above the dam.
Age Distribution

Most trout sampled in the Pine River were between ages zero and two. As for
brook trout, the majority sampled was age one, with none older than age three or aged
from below the dam. This indicated that some mechanism was limiting the existence of
older brook trout.

Brown trout were predominately age zero and one above the dam and ages one
through four below. Although these differences may be linked to habitat, I hypothesized
that food resources most likely drive the age distribution of brown trout. Based on
electrofishing data, trout below the dam have access to a larger fish forage base than
exists upstream, which may allow them to select this habitat and, in turn, live longer. The
food base below the dam was comprised of fish including large numbers of trout-perch
(Percopsis omiscomaycus) and slimy sculpin (Cottus cognatus). These trout residing
below the dam also have access to Tippy Reservoir, which may be used as a thermal
refuge in the winter. As for the lack of younger brown trout below the dam, they may be
consumed by species that now exist solely below the dam or below the dam in substantial
numbers. These predatory species which have access to Tippy Reservoir include brown
trout, northern pike, yellow perch, and walleye.

The rainbow trout sampled were mostly ages one and two. Below the dam, age
two fish were more common than age one, while the opposite held true for above the

dam. Because rainbow trout fry do not hatch until spring (Scott and Crossman 1985), few

62

 

young of year rainbow trout were captured owing to their small size and lack of
susceptibility to electrofishing equipment during the summer.

Comparing trout aged in the Pine River to similar streams in Michigan, a study by
F ausch and White (1981) found that in a moderately fished river, the East Branch of the
Au Sable, few brook trout lived to age three and brown trout lived up to age five.
Similarly, Gowing and Alexander (1980) stated that brown trout lived longer than brook
trout, with browns commonly surviving to age seven while brook trout rarely lived to age
four. On the other hand, a study of an unfished population found that brook trout lived to
be ages five or six (Cooper 1967). As stated previously, predation and fishing have been
shown to be more limiting to brook trout when compared to brown trout (Fausch and
White 1981).

White sucker age distribution indicated that most were ages zero through three.
Those older than age three were most often sampled from below the darn. Because
suckers are characterized as benthivores, they do not take advantage of the abundance of
forage fish. Instead, white suckers may also be utilizing Tippy Reservoir, a more
preferred environment based on their habitat requirements, as a winter refuge. This
would allow suckers in the Downstream Zone an increased area of suitable habitat

compared to their upstream counterparts.

Fish Growth
In the Pine River, trout appeared to be growing faster than the Michigan stream
average while white suckers were growing slower than averages recorded for Michigan

(Laarman et al. 1981). Yearly difference in annual length at capture may be attributed to

63

 

 

whether or not the fish was captured earlier or later in the growing season. For example,
fish sampling was conducted approximately one month earlier in 1999, leading to slightly
smaller lengths when compared to other years.

The upstream sections have the least amount of sand, the most suitable substrate
for benthic macroinvertebrates, and the highest amount of overhanging cover. Therefore,
the numbers of drifting and terrestrial macroinvertebrates would be expected to peak in
the Non-Impacted Zone. As a result, my initial hypothesis assumed that trout growth
would be highest in the most upstream or unaltered stretches of the river. Thus far, the
analysis has shown the opposite to be true. Trout do not appear to be affected by the sub-
optimal habitat below the dam, as evidenced by better growth in rainbow trout and brown
trout in the Downstream Zone when compared to the Impacted Zone. Likewise, when
compared to the Impacted Zone, brook trout and rainbow trout exhibited significantly
worse growth in the Non-Impacted Zone. This corresponds to the previously mentioned
findings of Alexander and Hansen (1986), who found that trout growth was not
compromised by an increased sand bedload. Most likely, these differences in growth
were related to the density of trout in each of these zones. Benthic macroinvertebrate
production levels should have been the highest in the Non—Impacted Zone based on
suitable substrate. However, the highest density of trout was documented in the Non-
Impacted Zone. Conversely, the lower numbers of trout inhabiting the Impacted Zone
and Downstream Zone may have offset the low macroinvertebrate production expected to
occur because of the unsuitable substrate documented in these areas.

White suckers showed a similar pattern to trout in that they showed evidence of

higher growth in the Downstream Zone, followed by the Non-Impacted Zone. This

64

indicates that either forage or environment may limit white sucker growth above the dam.
As mentioned before, white suckers are primarily benthic feeders, and the shifting nature
of the Impacted Zone seemed to have driven them further upstream to find better habitat.
As expected, growth was best in the Downstream Zone, which characterized the preferred
habitat for white suckers.

Studies have demonstrated the important role water temperature plays in the
regulation of trout growth (Baldwin 1956, Jenson 1987). In addition to an evaluation
done by Lawler et al. (1992), temperature in the Pine River is monitored continuously by
the Michigan Department of Natural Resources. However, the data have shown that
water temperature does not differ among the zones as Stronach Dam does not retain water

and fluctuations were limited by groundwater input (Kruger 1999).

Management Implications

Although dams and impoundments create benefits for society, advances in our
ecological understanding have demonstrated the negative consequences caused by the
extensive alteration of river systems by dams. In the past, dam removal was usually only
considered when dams either came up for F ERC relicensing, threatened public safety, or
provided a lack of economic revenue. The process of dam removal was often initiated
when it was found that the cost of restoration exceeded the cost of removal. Oftentimes,
however, a darn removal has been shown to be less expensive than a restoration project.
As an example, in Wisconsin, a case study found that the overall cost of repair generally

exceeded the cost of removal by three times (Born et al. 1998). Based on this

65

 

information, economics and legislature will most likely drive future dam removal
initiatives.

Although the above-mentioned reasons still exist and often bring the option of
dam removal to light, a current trend is emerging where dams are being removed as a
river restoration tool. Consequently, the increased interest in dam removal has resulted in
attention being given to environmental as well as socioeconomic dimensions of dam
removal effects (Kanehl et al. 1997, Hill 1994, Shuman 1995, Born et al. 1998). This is
of monumental importance because it has been stated that ecological impacts caused by
dams on entire river systems, which are the hardest for the public to recognize, have the
greatest detrimental impacts (Born et al. 1998).

While little research has been done on the ecological effects of dam removal, even
less has focused on social or economic aspects. One example is the study by Born et al.
(1998) which documented the social, economic, and institutional concerns of dam
removal in Wisconsin, a national leader in the removal of small dams. An example of
social problems in the form of local controversy occurred with the removal of Michigan’s
Salling Darn (Shuman 1995). In this case, concerns involved lowered property values,
lost recreational opportunities, downstream sediment transport, and increased flood
potential. Because dam removal can be controversial, issues such as liability costs,
property values, and stakeholder/community interests need to be addressed.

Controversial problems have largely been avoided in the case of Stronach Dam
removal. Financial liability was undertaken by Consumers Energy in their agreement to
pay for the removal as part of the FERC relicensing of Tippy Dam. Before the dam

removal process began, Consumer Energy had the foresight to have studies conducted on

66

 

the existing habitat including sediment, wetlands, and fish populations of the Pine River.
Additionally, a large portion of the river lies within the Manistee National Forest National
Wild and Scenic River designation and is therefore devoid of riparian property owners,
and the removal is not expected to impact privately owned property which lies further
upstream. Community and stakeholder participants include anglers, fishing guides, canoe
liveries, upstream property owners, Michigan Department of Natural Resources, and the
United States Forest Service. Concerns of these individuals and organizations were
assessed prior to removal and continue as the dam is removed in the form of
presentations, annual reports, and open communication.

A fundamental goal of fisheries science is the synthesis of information regarding
the aquatic environment in order to predict how the stmcture and function of biotic
communities may respond to change. This study is valuable in that it demonstrates a
comparison of zones that will change as the dam is removed, as well as an upstream zone
that is unlikely to change. The monitoring of dam pre and post removal effects is
instrumental to future management actions. Unfortunately, there is a lack of rigorous
stream restoration project evaluations (Kondolf and Micheli 1995). Observations on the

extent of change during and after the Stronach Dam removal will provide valuable
information for management decisions considering other dam removal projects.
Although the dam removal process will be complete in 2003, evidence of further changes

in the river system may occur for several years before equilibrium is reached.

67

SUMMARY AND CONCLUSIONS

Habitat and fisheries resource conditions have been monitored on the Pine River
since 1996, or the same time that Stronach Dam removal began. Since that time,
approximately half of the dam’s stoplog structures have been removed. For the most part,
the response of the river to the removal has been limited to habitat changes within the
proximity of the dam. Changes in fish populations have not been documented, but are
expected to develop as further changes occur within the river.

Changes in sediment have been recognized in both the Impacted and Downstream
Zone. Scouring has taken place up through 2 kilometers upstream of the dam. Similarly,
this scoured sediment has been deposited below the dam, causing an aggradation of the
streambed. Although gradient is expected to increase as the dam is removed, no annual
variation has been detected to date. Corresponding to the scouring seen in the Impacted
Zone streambed, water velocity and substrate sizes have increased in this area above the
dam. These changes are predicted to provide an increasing amount of suitable habitat for
trout.

The population abundance of trout on the Pine River is approximately one-third
that of similar northern Michigan streams. This relatively low biomass is most likely
related to the high bedload of sand within the river. Sand not only provides limited
spawning habitat through embededdness of spawning gravels, but also ultimately results
in high mortality of trout early life stages. Within the river, trout are most abundant in the
upstream stretches while white suckers are most abundant downstream of the dam. It is

expected that fish populations, especially trout, will increase in abundance as the dam is

68

 

removed and habitat becomes more favorable for resting and spawning. Thus far, fish
populations have not amplified in accordance with the improved habitat. Instead, it
appeared as though the shifting nature of the Impacted Zone did not provide a suitable
habitat for fish species. The proposed increase in trout numbers may not occur until the
dam is further removed and river changes are compounded or until the river reaches some
stage of equilibrium.

The age distribution of trout found that the majority were ages one and two, with
few fish older than age four. Brook trout had the shortest life span, with up to three years,
while brown trout were aged up to six years. Trout sampled from below the dam tended
to be older, with few ages zero or one sampled. These fish may live longer as a result of
access to a food resource not available to upstream trout. On the other hand, the absence
of younger fish indicated that either trout were recruited at an older age, or younger trout
succumbed to predation. White sucker age distribution indicated that most were ages
zero through three, with older fish residing below the dam. A possible explanation for
this is that white suckers below the dam may be using Tippy Reservoir as a thermal
refuge, allowing them access to increased suitable habitat which may result in fish
surviving to older ages.

It has been documented that trout in the Pine River are fast growing while white
suckers are slow growing. Contrary to previous findings, a difference in fish growth was
detected when comparing fish from different habitats. All trout species and white suckers
exhibited slower growth in the most upstream areas, with fastest growth documented in
the Downstream Zone. This phenomenon may be further explained through food

availability and fish density comparisons.

69

Chapter 2

Trout Diet Variability over a Summer Season in the Pine River

70

INTRODUCTION

Although many studies have examined trout feeding habits (e. g. Allan 1981, Cada
et al. 1987, Hubert and Rhodes 1989, Angradi and Griffith 1990, Lacasse and Magnan
1992, Bozek et a1. 1994) few have looked at variation within a population occupying
different habitats. Bridcut and Giller (1995) found that most research on salmonid diets
compares populations, seasons, or rivers. Additionally, Rader (1997) determined that
studies of trout diet over large spatial scales, or multiple sites, and a complete growth
season are rare. Rader also reported that most diet analyses are based on small sample
sizes (i.e. 20-25 stomach samples). Quantifying the feeding habits of a large sample of
trout over a full growing season would allow for a greater understanding of possible
ecological processes such as diet selectivity or predatory-prey interactions.

In the Pine River, Manistee County, Michigan, naturally reproducing stocks of
brook trout (Salvelinusfontinalus), brown trout (Salmo trutta), and rainbow trout
(Oncorhynchus mykiss) coexist (Figure 2.1). Stronach Dam, built in 1912, has altered the
habitat of this river. When the dam was built, it created a 26-hectare reservoir extending
approximately 3.8 kilometers upstream. The reservoir, acting as a sediment trap, had
filled in by 1953. As a result of this and operational problems, the dam was
decommissioned in 1953 by Consumers Power Company. The dam created three distinct
habitat zones delineated by Klomp (1998): the Downstream Zone extending for 1.1
kilometers below the dam, consisting entirely of runs; the Impacted Zone 3.8 kilometers

upstream of the dam, consisting mostly of runs, with some riffles and pools; and the Non-

71

 

.EmQ an? can :meBE mo Sam 2: 8 coca—2 E 53% psi 2: co Sea 595ch mo 203804 .mm oeswfi

 

 

$8822 _

I

32 m Ema

concobm

        

Mm>2 mZE

Mm;
mmHmHZ/JZ

can
018582

 

 

 

72

Impacted Zone comprising 4.3 kilometers above the Impacted Zone, consisting of a
complex run, riffle, pool, rapid system (Figure 2.2).

This now defunct dam is being removed in a staged process as part of a Federal
Energy Regulatory Commission (FERC) agreement in the relicensing of the Tippy Dam
hydroelectric project on the Manistee River. The staged removal of Stronach Dam
commenced in fall of 1996 and is expected to be complete in 2003. Concurrent studies
are being conducted to further understand habitat and fish population responses to the
dam removal.

The overall, long term goal of the project is to determine how the dam removal
and potential for fish migration from Tippy Reservoir impact the salmonid population in
the Pine River. Currently, a number of species are found only below the darn. These
species include redhorse suckers (Moxostoma macrolepidotum and M anisurum), walleye
(Stizostedion vitreum), yellow perch (Percaflavescens), and northern pike (Esox lucius).
As the dam is removed, species that now only reside below the dam, or are very abundant
below the dam, have the potential to migrate upstream and compete with trout. The
analysis of trout diets presented here will give an indication of their feeding habits at the
present level of population abundance, prey availability, and fish community
composition. As the dam is removed, a change in trout feeding may indicate competition
or predation resulting from the influx of species from below the dam. Although white
suckers are found throughout the river, they are one of the most abundant fish species
below the dam. From the collection and analysis of trout diets presently coexisting with
varying populations of white suckers, we can draw inferences into how white suckers

impact trout feeding. We can also develop insight into the potential impact an increased

73

.890. Band: 58 8:35me 3 Snow SE 8:85:36 common 33% Six uni .N.N Semi
Sam nowuobm 82m 95: oocfima

 

      

. _ _ _ _
_ _ _ _ _ _
n o m w m N H o #

ocoN
383::

ocoN
Emomeso a

Z

 

 

5...... .5 E

8388 :2 0E2 SEX

noncobm
ease % - Em

74

white sucker population will have on trout if white suckers migrate upstream en masse
once the dam is removed.

The goal of the research reported here is to describe the feeding habits of
coexisting brook trout, brown trout, and rainbow trout in different habitats over a summer
season and compare them to food availability in the drift. This analysis will develop
insight into the diet overlap and selectivity for available food resources. By doing this,
knowledge of feeding patterns for coexisting trout over a summer season (May through
August) will be established. Additionally, this will provide a basis for later comparison
in order to detect possible competition from other upstream migrating fish species.

The major objectives to my study were to: (1) determine the total wet weight of
the stomach contents for rainbow trout, brown trout, and brook trout by month, habitat,
and length class (2) describe the daytime feeding habits of rainbow trout, brown trout, and
brook trout during the summer (3) compare similarity of diet by month, habitat, and trout
species (4) assess the variability of macroinvertebrate drift across summer months and

habitat and (5) determine patterns in electivity of trout across summer months and habitat.

STUDY AREA

(Refer to Chapter 1)

75

METHODS
Diet

A total of 189 trout were collected from May through August 1999 to determine
the taxonomic composition and total wet weight of stomach contents. Fish with a
minimum length of 100 mm were collected with a 17-foot electrofishing boat designed by
Smith-Root. Because studies have shown that summer salmonid feeding occurs mainly
during the day (Swift 1962, Chaston 1969, Tippets and Moyle 1978, Allan 1981,
Campbell and Neuner 1985, Sagar and Glova 1988, Forrester et al. 1994, Young et al.
1997), trout of each species were collected during daylight within each zone. The
stomach samples would then characterize the prey eaten in the previous 12-24 hours
within the spatial scale defined by individual fish movement (Rader 1997). Sampling
was conducted at ten sites along the 9.2—km study stretch. Individual sites ranged from 80
to 428 meters in length and totaled 208 meters downstream from the dam and 2,001
meters upstream from the dam.

Gastric lavage (Foster 1977, Light et al. 1983) was used to sample fish stomach
contents. Using a battery operated pump, a continuous supply of water was flushed via a
tube (4 mm outside diameter) into the stomach of each trout. An initial sub-sample of
approximately five trout from each of the zones was used to determine if the flushing
technique removed all items. Large items lodged in the mouth were removed using
forceps. The stomach contents were flushed into a 250 um sieve before being preserved
in 80% ethanol and placed in a scalable plastic bag. After gastric lavage was performed,

each trout was given a unique site fin clip in order to distinguish these fish on later

76

 

sampling dates. Survival was noted by activity of trout immediately after stomach
flushing and the subsequent recapture of fin clipped trout in the following months.

In the laboratory, items in the diet were counted and identified to the lowest
taxonomic level, usually family, and life stage was recorded when possible. Identification
was based on Amett (1985), Pennak (1989), and Merritt and Cummins (1996). Fragments
of organisms without a head attached were neither counted nor identified, as it was
assumed that the source organism had already been represented in the count of heads or

head capsules.

Drift

Because other studies have shown that trout feed primarily on drift (Hunt 1966,
Elliott 1970, Elliott 1973, Metz 1974, Allan 1981, Angradi and Griffith 1990), drift was
sampled once a month in each zone, concurrent with fish sampling efforts. Studies have
shown that a peak in invertebrate drift occurs after sunset (Waters 1972). Because of this,
every month a series of three nets was placed in each zone to record the drift between
6pm and 12am. The drift nets, measuring 35 x 15 cm with a 350um mesh, were placed in
a transect to encompass as much of the stream width as possible while allowing part of
the net mouth to be above the water surface. The contents of the nets were emptied after
every two-hour period and preserved in 80% ethanol for later analysis. The water depth.
and current velocity (ft/s) were measured at the mouth of each net.

In the laboratory, rose bengal (a biological dye) was added to each sample to
facilitate sorting of organisms. To sub-sample the drift, two of the three nets were

randomly chosen to represent each series. Samples were passed through a series of

77

nested sieves to separate the organisms into 500 um and 1000 um size classes. Because
many of the samples contained a large number of organisms, a Folsom plankton splitter
was used to further sub-sample the material collected. The plankton splitter has a rotating
drum fashioned with a divider to separate a sample into two subdivisions of equal
volume. In order to identify a target of 100 organisms per sample, sorting ranged from an
entire sample to as little as 1/16 of a sample. Because studies have shown that prey
smaller than l-mm are rarely consumed by trout (Hubert and Rhodes 1992, Bozek et al.
1994), only organisms retained in the 1000 um sieve were analyzed from the drift. The
1000 um size drift was counted and identified to the lowest taxonomic level, usually
family, and life stage was recorded when possible. After adjusting for sub-sample size,
drift density was estimated using the following equation provided by Allan and Russek
(1985): Drift density = 100 x ((Number of organisms per net hour)/(m3 filtered per net

hour)).

Wet Stomach Content Weight

Because Glenn and Ward (1968) found that wet weight was highly significantly
correlated with dry weight, and wet weight was a more convenient measure of stomach
contents, total wet stomach content weight was recorded to the nearest 0.01 g in the
laboratory. To reduce the amount of error, attempts were made to blot excess water
before weighing. While preservation in ethanol tends to increase the overall weight
(Parker 1963), consistency of the procedure allowed for useful comparisons to be made.

In order to detect differences between species and habitat, mean stomach content

weight was evaluated by zone, month, and species using the SAS general linear model

78

function (GLM). The procedure performed a generalized analysis of variance appropriate
for unbalanced data (SAS Institute 1988). To see how the amount eaten changed as trout
size increased, mean stomach weight was compared graphically by 50—mm length classes.
Differences in stomach weight, evaluated as a percentage of body weight, were
expressed using mean percent stomach content weight. The results were compared for
varying lengths of each trout species using the SAS GLM function. Mean percent
stomach weight was compared for brook trout, brown trout, and rainbow trout using 50-
1nm length classes. The final analysis reported only those trout that measured between
175 mm and 325 mm in length in order to avoid outlying data points. Because different
prey organisms have different individual weights, the mean number of organisms per

trout stomach was compared across length groups of trout.

Diet Percent Composition and Mean Number Eaten by T axa

After all items in the diet were counted, the mean number of individuals per
stomach in each prey category, along with standard error, was calculated by trout species
for each month and zone. These numbers were then used to determine the individual
importance, or percent composition, of each prey item when looking at all components of
the diet for each species by month and zone. From these data, items accounting for 5% or
greater of the total diet for each month or zone were compared by fish species. Likewise,
the total contribution of terrestrial items to the diet of each species was calculated for
each month and zone. Terrestrial items comprised both terrestrial insects and adult stages

of aquatic insects (e. g. Ephemeroptera adults). To establish which size trout were most

79

 

piscivorous, the mean number of fish in the diet was compared using 50-mm size classes

of trout.

Diet Similarity

Similarity was examined using Morista’s index (Morista 1959) to compare the
relative abundance of items in the diet by adjacent months, all zones, trout species, and to
compare trout diet to the drift.

Morista’s index (Cl) is calculated as:

C), = 2 Z nil 119 where Aj = Z n“ (nii — 1)
(11+ k2) N1 N2 Ni (Ni ' 1)

 

 

and where n” and niz equal the number of individuals of species i in samples 1 and 2
respectively and NJ- represents the total number of individuals in sample j. The index
values range from 0 (no overlap) to 1 (complete overlap). The index gives a ratio of the
probability that an individual selected from sample 1 and one from sample 2 will belong
to the same species versus the probability that two individuals drawn from either sample

1 or 2 will belong to the same species (Krebs 1989).

Drifl Density and Taxonomic Composition

After drift density was calculated, the mean number of each taxon, along with
standard error, was calculated using nets set in each month and zone. These numbers
were then used to determine the percent composition of the drift by month and zone.

Items accounting for 5% or greater of the total drift for each month and zone were

80

compared. Additionally, the percent terrestrial contribution to the drift was calculated for

each month and zone.

Electivity
To compare diet composition with drift composition, electivity was calculated
using Vanderploeg and Scavia’s electivity index (Vanderploeg and Scavia 1979):

Ei* -_- [wi—(l/n)] where WI: fi/pi
[wi + (l/n)] 2i ri/Pi

 

where r, equals the proportion of taxon i in the diet, pi equals the proportion of taxon i in
the environment, and n equals the number of kinds of food items. The index ranges from
+1 to —1. If a taxon constitutes a larger proportion of the diet than in the drift, it is
considered to be preferred, as indicated by a positive number. Likewise, a negative
number designates taxa that were eaten less proportionately in the diet. Taxa that are
eaten in an equal proportion to that which is found in the environment are indicated by a
zero value. Lechowicz (1982) recommends this index owing to its ability to measure the
preference of prey as a function of the abundance of that prey and the abundance of
additional food types. The electivity of individual prey taxa by brook trout, brown trout,
and rainbow trout was calculated from abundance in the drift and compared with the
abundance of prey taxa in diets sampled each month between May and August 1999.
Non-drifting benthic macroinvertebrates were not sampled because trout have been

classified as primarily drift feeders.

81

 

RESULTS
Diet and Drift

A total of 47 brook trout, 79 brown trout, and 63 rainbow trout stomach samples
were analyzed. Initial sub-sampling methods indicated the technique of gastric lavage
was 100% effective. Short-term survival of trout after sampling also appeared to be
100%, as many of the fish sampled were fish that had been previously marked. In noting
behavior immediately after gastric lavage was performed, larger trout (>300 mm) took the
longest to recover, with up to five minutes after stomach flushing, while it did not appear
to affect smaller fish. Of the 189 trout stomachs, seven were empty: one brook trout
sampled in August, two brown trout sampled in June and July each, and one rainbow
trout in May and June.

While the majority of trout sampled were between 150 and 250 mm in length, a
wide range of lengths was encompassed. Brook trout length ranged between 101 mm and
490 mm, with an average of 193 mm. The minimum length of brown trout measured
100 mm, with a maximum length of 605 mm and an overall mean of 313 mm. Rainbow
trout were sampled at a minimum length of 127 mm and a maximum length of 445 mm;
the average length of rainbow trout included in diet analysis was 237 mm. On average,
brook trout were smaller than rainbow trout and rainbow trout were smaller than brown,

trout.

Wet Stomach Content Weight
Mean wet stomach content weight was measured to quantify how the amount

eaten varied with species over time and habitat. Overall, rainbow trout had the highest

82

 

mean stomach weights, followed by brown trout and brook trout. Brook trout tended to
have the highest stomach weight when expressed as a function of body weight, while
brown trout were lower. Looking at the differences among months, an overall pattern of
seasonal decline was observed for both stomach weight and percent weight (Table 2.1).
For example, brook trout and brown trout had the highest stomach weight in May, with a
pattern of decline over the rest of the season. Percent weight showed a summer decline
for all trout species. Dissimilar to the overall stomach weight pattern, rainbow trout had
the highest mean stomach weight in July, followed by May, June, and August.

Within a zone, few patterns were apparent, although the highest mean stomach
weights generally occurred in the Downstream Zone and the highest percent stomach
weight was documented in the Non-Impacted Zone (Table 2.2). Comparisons of stomach
content weight and percent weight of each species were similar across zones and yielded
no clear patterns. Brook trout had the highest stomach weight in the Downstream Zone
and the highest percent weight in the Non-Impacted Zone. Brown trout had the highest
stomach weight and percent weight in the Downstream Zone. For rainbow trout, the
pattern was different with highest mean stomach content weigh and percent weight in the
Non-Impacted Zone.

General linear models indicated that the zone, month, and species effects on
stomach weight varied in significance. The factors of month and species were significant
(p < 0.0025 across all terms), while zone was not significant (p = 0.24). The interaction
terms of zone and month, along with month and species were both significant (p = 0.02

and 0.03). Furthermore, the analysis of mean stomach weight by length class showed the

83

 

 

 

 

 

 

 

mod H 59 mmd H mve 56 H mm; mud H wow 0mmL0><
9 No.0 H 91 mmd H mm: or and H wmd ob? H 80 Son... Boncfim
mm woe H mwN omd H ms; or and H one and H end So; £505
3 wmd H mm: 5.0 H 86 t mmd H 9N 5.0 H vme So; 209m
.0952 mm H mm H Em_0>> 02632 mm H mm H Em_0>>
Em_0>> Ememd Em_0>> Emonwd
“029.4, >3...
and H mmd mad H omd mod H 03» 3.0 H ave 0m000><
m: 00.0 H omd mmd H mmd 3 mod H med 3.0 H med Soc. BonEmm
or 3.0 H 9: wwd H 3N mm omd H NYN w: H Sm Soc. 2265
3 mod H mfim mm: H mm; 0 3.4 H E: and H mod Soc. xoocm.
.0952 mm H mm H Em_0>> 00:52 mm H mm H Em_0>>
Em_0>> “200.0,; Em_0>> Emohmd
0:31 >02

 

.33 E :0>.Hm 0:5 05 80h

5:2: £000 0038.00 :5: :8 08:0 20:55 5:3 A33 E903 0:080: 0:0 @ Ems?» £00880 :002 .mm 2an

84

 

00.0 H 000 00.0 H 00.0 «0.0 H EH :0 H H00 00 H 00.0 00.0 H a0 000.0%
mm 00.0 H 00 00H H 00.0 om 00.0 H 00.0 3.0 H 00.0 E 00.0 H EN 00: H 0.0 so: 28.502
00 00.0 H 00H 00.0 H 00.0 00 2.0 H 00.0 00.0 H 00.0 00 00.0 H 00.0 00H H :0 50: 02,20
2 00.0 H 00.0 00.0 H :1 t 00.0 H EN 000 H 0: : 00 H 00.0 00.0 H 00H so: 5.020
000502 00 H 29“; 00 H 0%; 50:52 00 H 0302, 00 H 3062, 000502 00 H 2925 00 H 5002,
acmohwm “£00.51 Ewogmm

mcoN 000000207202 mcoN nmfimaE. 0:0N 0000:0580

 

 

.33 :m 02% 0:5 05 80m
0:0N 2000 E 003800 :5: How 08:0 0:00:90 firs A33 EmEB 0:080: 0:0 va Ewfik £00890 :00: .N.N 030B

85

expected trend of an increasing amount of food in the stomach as length increased, with
fish between 300 and 350 mm showing a peak in stomach weight (Figure 2.3).

Analysis of stomach weight as a percentage of body weight using general linear
models indicated that length class and month were both significant variables
(p = 0.0001), while species was not significant (p = 0.1682) when comparing brook trout,
brown trout, and rainbow trout.. Because most trout sampled fell within the 175 mm and
325 mm length range, fish outside this range were excluded from analysis. Trout feeding
across length classes was shown to be very similar when stomach weight was expressed
as a function of body weight (Figure 2.4). Using all length classes, brook trout stomach
weight averaged 3.9% of their body weight, while brown trout stomachs equaled 2.6%
and rainbow trout stomach weight comprised 2.7% of their body weight.

Also, the mean number of organisms per trout stomach varied widely among trout
lengths (Figure 2.5). Taking into account the amount of variability, a similar number of

organisms were consumed over all trout lengths.

Diet Percent Composition and Mean Number Eaten by Taxa

At the level of taxonomic classification used, a total of 72 different items were
found in the diet. Overall, taxonomic richness varied little among trout species. For
example, brook trout had a total of 54 different items in their stomach, while brown trout
possessed 60 and rainbow trout diets included 59 different organisms. These items
included varying stages of aquatic and terrestrial insects, as well as organic material, fish,

gastropods, mammals, Hirudinea, and Oligochaeta (Appendix A).

86

£100 H
7200~0 1' I
(100 —

5IM)~ ,\\\\‘r////”

4.00 -~

 

 

 

3.00 -

 

Mean Stomach Weight (g)

2.00 0

1.00 --

 

ocoHHHHH—_H_ .__0_LLL__n_
125 175 225 275 325 375 425 450

Total Length (mm)

 

 

Figure 2.3. Mean stomach weights (g) and standard errors per Pine River
trout length class (mm) in 1999.

87

14 -~

 

 

 

 

 

 

 

E9 -
g) 12 -1 ,-
E
.9
0
g 10 -—
E
Q
8 8 -- . -- .MW
2 ._ —I— Brook Trout
g —e—Brown Trout .
g 6 ‘ lair-Rainbow Trout
5
E
8 4 ~
8
o.
E
a) 2 -
E

l

o -

125 175 225 275 325 375 425 450
Total Length (mm)

Figure 2.4. Mean percent stomach content weight (g/g), + or - 1 standard error,
for all lengths (mm) of brook trout, brown trout, and rainbow trout sampled on
the Pine River in 1999.

88

705

604

 

20—

 

 

Mean Number of Organisms per Stomach

 

1O — ..

 

 

0 -«——-—~-—--—-—-—-.—--»-——---- . . . i »-—— H— -

125 175 225 275 325 375 425 450
Total Length (mm)

Figure 2.5. Mean number of organisms per stomach, + or - 1 standard
error, for all lengths (mm) of trout sampled on the Pine River in 1999.

89

 

The percentage and mean total was calculated for each prey item found in the diet
(Appendix B). The overall trend for all trout showed a decline in the mean number of
prey per stomach as the summer proceeded (Figure 2.6), with trout having the highest
mean number of prey items in their stomachs in May. Temporal differences varied for
each trout species, but showed an overall trend of rainbow trout having notably more
items in their stomach compared to brook trout and brown trout.

The mean number of items in the stomachs of trout showed an overall trend of
increasing as you move in an upstream direction (Figure 2.7). Individually, spatial
differences in the mean number of prey items per stomach were observed for each trout
species. Brown trout and rainbow trout both displayed increasing numbers of items in the
stomach moving upstream. Brook trout, however, had similar numbers across all zones,
with approximately 40 items per stomach. Brown trout also contained considerably fewer
prey items in their stomachs in the Downstream and Impacted Zones when compared to
brook trout and rainbow trout.

In addition to general patterns of temporal distribution, monthly variations in trout
diet were apparent. For example, brook trout diets were characterized by an abundance of
chironomid, ephemerellid, and baetid larvae (Table 2.3). Although ephemerellid larvae
was an important part of the diet, it was only identified in substantial numbers during the
months of May and June. Chironomid larvae contribution to the diet was highest in July
and August, but also formed a substantial portion of the diet in May. Baetid larvae were
most numerous in the diet in July, but made up a relatively large portion of the diet in
May and June. Other taxa that were seasonally important included athericid. larvae in

May, tipulid larvae and brachycentrid larvae in June, and corixid larvae and hydroptilid

90

0:0: 38:50: 0:00 nBob :305
nBob 05005 E 33 mo 008800 05 @550 0035 0:5 05 :0 00:50:00 080: .00 009:5: :002 EN 0::w5

 

 
 

 

 

 

£222
000mg: 22. 0:2, >05.
0

cm
N
n
0.0 W
m.
Sonymmfl om M
EsoLmD W
28ch ow w
0
0
w
cor m
9
p

80

03.

91

.000: 302E000

0:0 n0:00. :305 0:00 x005 E 003 E 0035 0:5 05 50 0:0N E000 E 00:50:00 0:00: 50 009:8: :002 SN 0::w5

 

 
 
 

 

    
   

0:0N
0:0N 000000027002 0:0N 000.000E_ 000M Ewmbmcesoo

1 0

0H
00 m
w
m
i om W
a
i 00 m
w
00 0
S
O
00 m
m
0
0H m

30 Em --
0 . an 00

Est D

xoohm I om

92

 

 

 

00.00 N. F .00 00.00 00.00 0&0: =0 00 .000...
0.0 n: 00.0 00.0 H: 00.0 2050 20:00 2050
00.0 00.0 00.0 00.0 00.0 00.0 020.. 00200202.. 020000202...
00.0 0.0 000 00 00H 000 023 000202022: 0.0000005
0.0.00 00.0 .00 00.0 00.0 00.0 020.. 000.20200>200Lm 020009.05
00.0 3.0 00.0 00.0 00.0 0 0.000. 000.0200 02000.80:
00.0 00.? Re 000 00.0 00.0 =00< 005E002: 02000020220200
00.00 00.0 00.3 00.00 00.0 00.00 0200 000...020E0..0m. 02000020220200
00.0 00.0 00.0 00.0 00.0 00.0 0.000. 0000000 02000020220200
00.0 000 00.0 00.5 009 00.0 020.. 000.0000 02000020220200
0 0.00 00.00 00. E 00.0 t: 0 H .0 020.. 000.30.... 0.00.0.0.
00.0 00.0 00.0 00.0 00.0 00.0 0204 003.002.02.20 02000.0.
00.0 3.0 00.0 N000 00.3 00.3 020.. 0008:0500. 02000.5
E00200 202.“. 200.). E0020n. .05. 200.2 00000 >..E0H. 20020
02002000 02002000
0:2. 05. 2000..

 

.0005 E 00025 0:5

05 :0 0050800 800 00000. :05 00:50:02 0000 :08800 000:: 50 0:00:05 0:0 “000.00 000000 Q0080: :02: 520:02 .00 030.0

93

 

 

 

 

00.0 00.0 00.2 00.00 00.0.. =0 .0 .082
20.00 00.0 00.2 00.02 2.2 00.0 .050 .050 .050
2.2 00.2 2.2 00.0 00.0 00.0 020. 002.0092: 0.0.02.2:
00.0 2.0 00.0 2.0 E0 E0 020. 0002200060.. 0.0.09.2:
20.2 00.0 00.0 00... 2.0 02.0 030. 000...:002005 0.0.0002:
00.00 00.0 00.0 00.0 2.0 00.0 .30... 0002.00 0.0.0.50:
00.0 00.0 00.0 00.0 00.0 00.0 .33. 0000.00.00 00.00.00.200
00.0 00.0 00.0 2.0 00.0 2.0 020. 000.__0.0E0_.00 0.0.00.0...0000
20.. 00.0 00.0 00.0 00.0 00.0 .30.... 002.000 0.0.00.0...0000
00.0 02.0 2.0 00.00 00.0 00.02 020. 002.000 00.00.00.200
00.0 02.0 2.0 00.0 00.0 00.0 020. 000.30: 0.0.0.0
2.2 00.0 0.2 00.00 00.0 00.: 020. 0020.08.30 0.0.0.0
00.0 00.0 00.0 00.0 2.0 00.0 020. 000.0..0...< 0.0.0.0
E0200 Btm. c005. E0201 Btm. 000.2 2.80“. .020
0.00.0.0 0.09.0.0
00:03.. 230 00x0...

 

00.080. 0.0 0.00.0

94

larvae in August. The percentage of taxa contributing to the “other” category generally
increased from May to August.

Like monthly patterns of feeding, brook trout diet varied by zone (Table 2.4).
Chironomid larvae, baetid larvae, and ephemerellid larvae were most prevalent in the
Downstream Zone. Although Chironomid larvae were important in the Impacted Zone,
there were also high numbers of tipulid larvae. In the Non-Impacted. Zone, ephemerellid
larva, baetid larva, and athericid larva were most abundant in brook trout stomachs. The
percentage of taxa in the “other” category was highest in the Downstream Zone, or the
area where habitat was the least complex.

Brachycentrid larvae comprised the overall highest percentage of brown trout diet,
but the percentage decreased from May through August (Table 2.5). Similar to brook
trout, baetid larvae were most abundant in brown trout stomachs in July, but were also
relatively important in May and June. Other items that made up a large part of the diet
include athericid larvae in May, Gastropoda in August, ephemerellid larvae in June, and
corixid larvae in August. The percentage of taxa in the “other” category increased from
May through July.

In the Downstream Zone and Impacted Zone, baetid and brachycentrid larvae
made up the bulk of brown trout diet (Table 2.6). Athericid larvae, followed by
brachycentrid larvae dominated the Non-Impacted Zone. Like the brook trout, the
percentage of organisms in the “other” category was highest in the Downstream Zone.

The analysis for rainbow trout identified brachycentrid, chironomid, and
ephemerellid larvae as constituting the highest monthly percentage of macroinvertebrates

in the diet (Table 2.7). The percentage of brachycentrid and ephemerellid larvae declined

95

 

 

 

.02 00. .0 00. .0 .000 00.2 00.00 050.. ._0 .0 0.8

00. .. 00.. 00.0 00.0 00.0 00.0 00.0. .0. 0 .050 .050 .050
00.0 00.0 00.. 00.0 00.0 0.0 00.0 2.. 2.0 020.. 000.00.000.21 0.0.0000...
00.0 00.0 00.. 00.0. 2.0 00.0 00.0 00.0 2.0 020.. 002.000.0000 0.0.0000...
2.0 00.0 00.0 2.0 .0. 2.0 00.0 00.0 00.0 .30... 0002.00 0.0.0.50:
00.0 ...0 ...0 0.0. 00.0 0.0 00.0 00.0 00.0 .30... 00000020: 0.0.00.0...0000
00.00 00.0 00.0. 00.0 00.0 2.0 2.2 00.0 00.0 020.. 000.00.059.00 00.00.00.030
00.0 0.. . 00.0 00.0 00.0 00.0 00.0 00.0 00.0 .500. 00.05000 0.0.00.0...0000
00.2 00.0 00.0 00.0. 00. . 00.0 00.2 R0 00.0 0.00. 0005000 00.00.050.00
00.0 R0 .00 00.00 0.0 00.0 00.0 00.. 00.. 020.. 000.30: 0.0.0.0
00.. 00.. 00.0 00. .0 2.0 .00 2.00 00.0 00.2 020. 000.595....0 0.0.0.0
00.0. 00.0 ...0 0.0 00.0 00.0 0... 00.. .0. 020. 00.0.0005... 0.0.0.0
0.00.00. .0..m. 0005. 0.00.01 .0..m. 000.2 .c00.0n. .0..m. 0005. 000.0 2.50“. .00.0

Emacgw Emacmfim 0.00...me
0:0N 02000:..-002 0:0N 00.0000... 0:0N E00..0:>>00 00x00

 

.000. 0. 00>... 00.0 0.0 .8

0000 0000 E 00.9000 .00.. 0.005 .00 02.03000. 0000 008800 .008 .00 0000.00. 000 "000.0 0.00.0.0 0.00:5: 0002 .VN 0B0...

96

 

 

 

00.0 00.00 .000 00.00 00.0.. __0 .0 0.0.
00.0. .00 00.0 2.0 00.. .0.0 .050 .050 .050
00.0. 00.. 00.0 00.. 00.0 00.0 0.00. 000.00.000.00... 0.0.0000...
00.0. .0.. 00.0 00.00 00.0 00.0. 020. 000000000000 0.0.0000...
00.0 00.. 0... 00.0 2.0 00.0 .300. 00000.00 0.0.0.50:
00.0 00.0 00.0 00.0 0.0 0.0 .300. 000500900 0.0.00.050000
00.00 00.0 00.0 00.0 00.0 00.0 020.. 002.000.0000 0.0.00.0...0000
00.0 00.0 00.. 00.0 00.0 .00 0.00. 00.00000 00.00.00.200
00.0 00.0 00.0 00.0 00.0 00.0 020. 000.550 0.0.0.0
.00 00.0 ...0 00.0 0.0 00.0 0.00. 002508.20 0.0.0.0
00.0 00.0 00.0 00.00 00.0. 2.00 020. 000.0..05< 0.0.0.0
00.0 00.0 00.0 00.0 0.0 0.0 00.0 0005.00 005.0..0000500
00.0 00.0 00.0 00.0. 00.0 0.0 _.000 000005000 000005000
$00.00 .0..m c002 €00.00. .0..m c002 0005 >__E0u_ .020
0.00.0.0 0.02.0.0
0:2. >05. 00x0»

 

.000. a. 003% 005 0:. 00 00.00.00

.00.. 850.5 .00 005.002 0x0. 008800 .008 (.0 2.00.00 000 0.0.00 0.00020 “.0980: 000:. .2602). .m.N 030B

97

 

 

 

00.0 00.0 00.: 00.00 0E0: :0 00 ES

0.: 00.0 00.0 00.00 00.0 00s 550 .050 .050
00.0 :0 00 ~00 3.0 5.0 023 002005093: 0500002.;
03 00.0 00.0 00.00 kl 0; 020.. 0005082090 9300005
R. E E0 Re :3 00.0 0.0 :02 0002.00 92950:
00.0 00.0 00.0 x: 0: 00.0 :02 00000020: 99020520m
00.0 00.0 00.0 00.0 00.0 03 023 000520523 0.202052%
0.0.0 000 3.0 00.3 #0 00.2 023 0000000 0.200552%
00.0 00.0 00.0 00.0 00.0 00.0 020.. 00003005 90005
5.3 00.0 00.0 00.0 00.0 00.0 023 002500950 9905
00.0 00.0 00.0 00.0 3.0 00.0 023 0020022 9905
00.: ~10 00.0 00.0 3.0 00.0 cm: 002000 mméotcmmeoom
00:0 00.0 E: 00.0 00.0 0: =ma 000000me 00000080
Emohmn. 5cm. cmm_>_ EmEmn. 02m. cam—2 093m >__Emn_ .520

200005 2000me
5:93 22. :98...

 

.6380 0.0 2000

98

 

 

 

 

00.00 0000 R00 00.00 00.0 00.00 00.00 __0 .6 .0000
00.00 00.0 00.0 00. 00 00.0 00.0 00.00 0.0.0 0.0 00.00 00.00 00,00
00.0 00.0 00.0 00.0, 00.0 00.0 31. 00.0 00.0 0200 000200000000: 0000000000
00.00 00.0 00.0 020 00.0 00.0 00.: E 00.0 0200 000000020000 0000000000
00.0 0: 00.0 00.0 00.0 00.0 00.0 00.0 00.0 0200 000000050000 0000000050000
00.0 00.0 00.0 00.00 00.0 00.0 00.00 00.0 00.0 0:00 0000000 00000000500000
00.0 00.0 00.0 0.0 0.0.0 00.0 00.0 00.0 00.0 0200 00005000 0.0005
00.00 00.0 00.00 00.0 00.0 00. F 00.0 00.0 00.0 0200 00000002 0.0005
0 00.0 00.0 0 0 0 00.0 00.0 00.0 000 0000000000 0000000000000
0000 00.0 00.0 00.0 R0 0: 00.0 00.0 00.0 ._000 000000000 000000000
0:00.00 090m 000.2 0:00.00. 020w 0002 0000000. 0000M c002 0005 >__E0u_ 0020
Panama Embcmuw Ewncmww

0coN 00000557002 0coN 000000E_ 0coN 000000000300 0900

.0000 a 003% 00E

05 mo 0:8 £000 E Bob 8505 00m 00:00:02 0x00 088800 0000: 00 E08000 0:0 £8.00 00008000 “0038:: S002 0N 030B

99

 

 

 

00.3 0.30 5N0 00.00 0:000. ..0 B .000...
.0060 000 00.0 00.0 or... m: 0050 00000 0050
mod Rd mod 3.0 we. 0 mm.m 0>00.. 000.092.0000 Pf 000000000...
No.90 3.0 m 0 .om oo. :0 00.5 00.00 0>00.. 00.0.000003005 000000000...
00.0 Ed 00.0 00.0 mfo nmd 0.390. 002x000 0005.000...
mmdm 00.0 00.3 00.00 90.0 00.0.. 020.. 000...000E000m. 000002000003.
00.0 D: 00.0 00.0 m 0 .m 00.0 0>00.. 000.000m 00000990003.
00.0 Fme omN mod v0.0 owe 0)00.. 002.30.... 0.085
N06 mfo 00.0 00.0 00.0 owN 0>00.. 00000000000 0.00.0.5
min 5.0 mud N000 00.0 t». 3 0>00.. 002000000. 0.035
E00001 000m. 000.2 0000000 000.”. 000.2 0005 >..E0u. 0.0.0
200005 200005
002. >05. 00x0...

 

.0000 a 0030 200 20 00 00.0800

Bob 308:0“ 000 000.300? 00000 088800 0008 go E00000. 000 £800 00002000 £00.85: 0008 b50002 SN 030B

100

 

 

 

 

 

00.0 00.00 00.00 00.00 0.000. __0 00 0000
00.00 00.0 0:» 00.3 00.0 0: 00,00 00.00 00,00
00.0 00.0 00.0 00.0 0: 00.0 0200 000200000000»: 0000000000
00.0 00.0 0 F. F 00.00 00.0 00.0 0200 000000030000 00000000.:
00. S 00.0 0: 00.0 00.0 00.0 0_00< 00000000 00000.50:
00.0 00.0 00.0 0000 Re 00.0 0200 000000000000 0000000050000
00.0 00.0 00.0 00.00 00.0 00.00 0200 0000000 0000000050000
00.0 00.0 00.0 00.0 00.0 00.0 0200 000.390 0.0005
00.00 00.0 00.0 00.: 00.0 00.0 0200 000.59.00.00 0.0005
00.0 00.0 00. 0 00.0 00.0 00.0 0:00 00000002 0.0005
0000001 000m. 000.2 0000001 50m. 000.2 0m00w 2.000“. 00000
0.000000 0.000000
00:900. 22, 00x00

 

20.008. 0.0 0.000

101

as the summer progressed, while Chironomid increased. Baetid larvae were the largest
part of the diet in July and athericid larvae were relatively important in May. Similar to
brook trout, the percentage of taxa in the “other” category increased from May to August.

In the Downstream Zone, Chironomid larvae comprised the largest percentage of
rainbow trout diet, followed by baetid and ephemerellid larvae (Table 2.8). Rainbow
trout captured in the Impacted Zone clearly had mostly brachycentrid larvae in their
stomach, whereas rainbow trout in the Non-Impacted Zone had primarily brachycentrid
and ephemerellid larvae. The percentage of taxa making up the “other” category was
highest in the Impacted Zone.

Terrestrial contribution to the diet varied both temporally and spatially. Averaged
across trout species, the highest percentage of terrestrial taxa occurred in July and August,
with 12% and 6% of the trout diets (Table 2.9). Brook trout and brown trout stomachs
had the highest number of terrestrial items in July, while rainbow trout possessed the
highest number in August. Items commonly identified included various Ephemeroptera,
simuliid, formicid, and acridid adults, along with Lepidoptera larvae. Contribution by
zone was highest in the Impacted Zone and Non-Impacted Zone, with 8% and 6% of the
diet (Table 2.10). In the Downstream Zone, terrestrial taxa did not contribute
substantially to the diets of trout. Within the Impacted Zone and Non-Impacted Zone,
brook trout and brown trout contained the highest percentage of terrestrial taxa.

The overall amount of piscivory was low and no cannibalism was documented.
Generally, brown trout were the only species that ate a substantial proportion of fish.
Except for brook trout in August, fish contributed less than 1% to brook trout and

rainbow trout diets during the summer. Across months, fish appeared in the diet most

102

 

 

 

mm. 5 Nodv vvd mwdm omNF m r. Fm 0E0: =0 we .08...
mo. 2. mo... N56 099 00.0 050 mp: mwd mvé 0050 0050 0050
9mm mmd mmé 05¢ mad ooN VNN Fwd QEN 020.. 00.00.030.231 000000000...
NEVN mmh MUN: :. 5 No.0 m P .o 5.3 ooN mmh 020.. 002.000.0000. 0000000000050m.
mo. 5 and mnb and? NYN and w... : NQN va 030.. 000.000m 00000000E000w
56 00.0 mNd omN mvd mm... 0040 de No.0 020.. 000.30: 0006.0
ovd mwd mme mad mwé omd omwm mfim mo. 3 020.. 000.009.00.00 0003.0
vodw FNN NNN 00.0 n we ooN cod D10 vNF 0>00.. 00200050. 0003.0
00000000. 000m 000.2 E00000. 000m. 000.2 0000000 000m. 000.2 0005 2.000“. 00000
0000005 0000005 0000005
000M 00000000002 000M 00.00000. 000N 0000000300 00x0 0.

 

.003 E 003m 05m

0% .00 0000 £000 5 050. 3000.00 000. 000.350. 0000.. 008800 0008 .00 E00000. 000 .8000 000000000 £00.80: G002 .w.m 030...

103

 

 

 

 

 

 

 

 

N00 50 00.0 3.3 VNN 00.0 00000><
00.0 00.0 om... 00.0 . 00.0 mod 0:00... 2600.00“.
00.0 mod mod ND: 000.. No.0 30.... 0265
00.0 mmd 5.0 5.3 00.0 was 0:00... v.00..m.
0000.00 000m. 000.2 0.000000. 000m. 000.2
0000005 0000005
00000.0. 23..
5.0 F: 00.0 No.0 0N0 00.0 000.020
00.0 000 00.0 00.0 mod 00.0 500.0 2600.0”.
and mmd 00.0 0.0.0 000 00.0 500... 0305
00.0 mod wed 00.0 00.0 mud 0000... x005
00020.0. 000.“. 000.2 0.000000. ._otm. 000.2
0000005 0000005
002. >05.
.000. 0. 0005. 00.0 000 0.

00.0800 0000 00 00.0.0 8 0000 0.000000 00 00.05.0000 0000000 000 .0800 00000000 000080 0008 35002 .mN 030.0

104

 

 

 

00.0 00.0 EN No.0 N09 00.N 00.0 00.0 N00 000.020.
00.0 and SN Nod de 0.0.0 ooN 0N0 00.0 300... 2600.0w.
:0 Re NEN 00.0 00.0 N00 00.0 00.0 00.0 500.0 0.505.
N00 00.0 N00 00.: 00.0 {.0 00.N 00.0 00.0 500.0 xoo0m.
000000.”. 000m. 000.2 0000001 .000 000.2 E00001 000m. 000.2
00000000 0000005 00000000

000N 000090.002

000M 0000090.

000M 0000000260

.003 0. 003m 005

05 00 000N 0.000 00. 00.00000 0000 00 00.0.0 8 0000 0.000000 00 00.05.0000 0000000 000 .0800 00000000 000050 0002 .0. .N 0.0.0...

105

strongly in August, when it accounted for nearly 7% of all trout diets, with brown trout
contributing substantially of that total (Table 2.11). Most of the piscivory took place in
the Downstream and Impacted Zones, where fish contributed to 3%and 1% of the diet on
average (Table 2.12).

The overall amount of piscivory was low, with trout 250 mm and greater
consumed the greatest number of fish (Figure 2.8). Piscivory was rare in trout smaller
than 250 mm, with a peak in piscivory occurring when trout reached 250 mm. It is
important to note that the amount of variability for piscivorous feeding probably indicated

that feeding was similar for all trout lengths.

Diet Similarity

The amount of diet overlap varied substantially between species, drift, months,
and zones. Similarity index values ranged from 0.07, indicating almost no overlap, to
0.95, indicating almost complete overlap. The comparison of trout species to other
coexisting trout species found that their diets were highly similar. For example across all
temporal and spatial variables, brown trout and rainbow trout diets were the most similar
(0.84), followed by brook trout and rainbow trout (0.73), then brook trout and brown trout
(0.59). The similarity between diets and drift varied among the trout species. For the
most part, trout diets were not highly similar to the drift. Brook trout showed the highest
similarity (0.70), while brown trout and rainbow trout exhibited low similarity values
(0.30 and 0.43).

Monthly similarity of trout diets was variable, with adjacent months displayed

higher similarity to each other when compared to non-adjacent months (Table 2.13).

106

 

 

 

 

 

 

 

 

00.0 00.0 3.0 00.0 00.0 $0 0m0.0><
00.0 00.0 00.0 $0 000 00.0 50.0 2,000.3”.
N03 N00 00.? 00.0 3.0 3.0 .00... 0.50.0
04 00.0 00.0 :0 00.0 00.0 50... 0.00.0
“000.00 .0..m. 0002 0000.00 .0..m_ 0002
0.00005 0.000%
00:030. 22.
00.0 3.0 8.0 00.0 00.0 00.0 000.020.
N F .0 00.0 00.0 00.0 00.0 00.0 50... 300050
EN 30 00.0 F: 0N0 Rd .00... 030.0
5.0 00.0 00.0 00.0 . 0N0 00.0 30... 0.00.0
000.00 .0..m_ 000_>_ 0000.00 .0..m_ 000.2
0.0005 0.0005
002. >05.
.002 a .030 00E

000 00 003500 3000 0000. 00 02,0 00 0002:0000 0000000 000 .2000 00000000 0000000 00000 E00002 A mm 0300.

107

 

 

 

108

Ed 00.0 000 00.. 2.0 00.0 C0 .00 0.1. 000.03.
00.0 00.0 00.0 00.0 00.0 00.0 ~00 00.0 00.0 so: 38:00
$0 2.0 00.0 50 00.0 5.0 00 00.0 00.. .8: 026.0
8.0 8.0 00.0 00.0 00.0 ~00 5.0 00.0 00.0 so: .090
“Emohmn— ._Otm Cm®_>_ «Cmohwl ._Otw ESQ—2 ”#:00th ._Otm ENE)—
Emncgw 0.09.000 0.000000

000N 00.0000: 000N 000.000300

000N 000.000.7002

.0000 0 003% 00E
000 .00 000w 0000 00 0200000 3000 0000. 00 000 .00 00035000 0000000 000 .0000 00000000 .0000000 0002 .9 .N 0500.

 

1.00

0.80 , -— --

0.60 ~

 

0.50 '

 

0.40 *

 

 

0.30 ,,

 

 

Mean Number of Fish per Stomach

0.20 , L

 

l
l
0.10 g
l

0.00 w - i . 7 . . 0-. y ‘
125 175 225 275 325 375 425 450
Trout Length (mm)

 

Figure 2.8. The mean number, + or -1 standard error, of fish per stomach by
varying length classes of trout sampled on the Pine River in 1999.

109

 

 

 

 

 

 

 

one 9d 2.0 $993.
mmd a F .o 5.0 So; 2695mm
5.0 mmd two Soc. 5505
end nod 56 SE... xooem
“mama/$22. Hmzm:<-mc2. 22:22.
mud vvd 050 $9024
omd mod mad So; 26353.
n _‘ .o nmd Nvd So; 555
m F .o 93 mud 52... xooem
Enos/vim: 22.465. 0:218:

 

.39 2 83m 0:5

2: no @2983 30% Bob mo mnemtmmfioo 5:08 8 5:08 Sm 82$ 52: @2828? 8282 .SN 2an

110

 

 

Similarity also seemed to decline as summer progressed. Zone comparisons indicated
that organisms comprising trout diets were generally similar across the study reaches
(Table 2.14). Again, adjacent zones exhibited higher similarity than the comparison of
non-adj acent zones.

Patterns were evident when comparing each trout species individually. For
example, brook trout diet showed the highest similarity between May and June (0.72),
and the least overlap found between June and August (0.07). Comparing zones, brook
trout diet similarity was highest between the Downstream and Impacted Zones with an
index value of 0.78, and lowest between the Impacted and Non—Impacted Zones with
0.48.

Brown trout diets showed greater seasonal variation than brook trout, with all
monthly overlap values being less than 0.50. Like brook trout, the highest degree of
overlap was between May and June (0.42). The least amount of overlap was found
between July and August with an index value of 0.17. Also similar to brook trout, the
highest similarity among zones was found between the Downstream and Impacted Zones
(0.75). The Downstream and Non-Impacted Zones were found to have the least amount
of overlap (0.47).

Rainbow trout followed a similar monthly pattern of overlap as brook trout and
brown trout with the highest index value were found between May and June (0.95). Also,
parallel to brook trout, the lowest amount of overlap was observed between June and
August (0.19). Overall, diet similarity comparing zones was high, with the Impacted and
Non-Impacted Zone having the highest value of 0.83 and the Downstream and Impacted

Zone having the lowest index value of 0.67.

111

 

112

 

 

 

8.0 $6 Ed 890%
mwd mud nod 52... 385mm
5.0 two mud SPF c265
wvd no.0 and SE... xooum
mcoN umfiomagéoz mcoN nmfimagéoz mCON 883E.
-ocoN EomaE. -mcoN Emmmesoo -mcoN Emmszsoo

 

.33 2 53% 02m
05 so @0383 30% Bob mo 3028928 meow 9 meow 802 $23 5?: 32235 82.82 .3 .m 2an

 

Drifi Density and Taxonomic Composition

Sixty-three different items were identified in the drift (Appendix A). Items which
accounted for five percent or greater of the total drift for each month (Table 2.15) and
zone (Table 2.16) were evaluated (see Appendix C for details on all taxa). Comparing
months, the total number of organisms in the drift was highest in July with a total of 784
i 329 items per 100 m3 of water. The other months had lower numbers and averaged
between 112 i 29 items per 100 m3 in August and 181 i 107 items per 100 m3 in May.
Across zones, the largest number of drifting organisms was observed below the dam in
the Downstream Zone (475 i 228 items per 100 m3), with similar drift density occurring
in the Impacted and Non-Impacted Zones (207 i 97 items per 100 m3 and 244 i items per
100 m3). Although chironomid and baetid larvae dominated overall drift, temporal and
spatial differences existed in drifting macroinvertebrates, as shown by the variability in
the monthly and zonal percent composition.

In May, Chironomid larvae, curculionid adults, and brachycentrid larvae
dominated the drift. This shifted to Chironomid larvae and pupa, as well as baetid larvae
in June. Similar to June, July had a high number of drifting Chironomid and baetid
larvae, but also included a large percentage of Chironomid adults. August showed a
greater percentage of simuliid larvae in addition to patterns observed in prior months.
Other items comprised 5% to 20% of the drift over the season.

Chironomidae in all stages, as well as baetid larvae dominated the drift in all
zones. The Downstream Zone had the highest percentage of chironomid, baetid, and
curculionid adults. Excluding the adult organisms, the Impacted and Non-Impacted

Zones showed similar patterns of drifting organisms when compared to the Downstream

113

 

 

 

8.8 88 8.2: $88 was. :8 .6 EB
38 88 8.2 8.2 8. : 8.8 .85 ago .86
8.0 8.0 8.0 8.0 2: 8.? 823 828898: 99852:
8a 88 £8 8.2 8.2 2.2 823 8288885 99852:
82 8.2 38 98 88 8.: 823 82:88.3 9988588
So 28 mg 8.0 8.0 8.0 .33. 828m 0985588
8.8 8.2 B8 8.2 8... 8.2 88.. 8288 9288588
3%. 8... $8 8.0 8.2 x: 823 82.36% 0920
82 03 8..., Re 03 88 82 82582.5 9922
8.2 8.8 3.8 82 8.N B... 8.5 82582.5 9222
8.? 8.? 8.8 8.8 8.8 8.8 823 82582.5 2.322
8.0 03 03 8.0 88 N8 28.. 822m 99828
m8 2: m: 8.2 8.8 8.8 83. 828.325 99828
Ememn. 5.5. :85. Ememn. .otm. cams. omflw >._Em... .020

2.885 2885

9.2. 8.2 :98...

 

.33 2 83m 02m 05 :0

2292.8 @2503 E8 2 22.552 882 20828 $.02 08 2088. 28 coho 2822me £8.85: 2.82 25202 .CN 2an

114

 

 

115

 

oodm mod: 8de o _. .35 0E9. ..m .6 .90...
vodw cox ovNN 2% 00. Pm 8.00 .050 08:0 .050
88 8. F 88 8.0 8.N EN 88.. 8258898: 88882:
omN ooe wmd No.0 006 cm.» mam... 03.58.002.985 990050.;
nod cod mud 9: 8.3 3.: «$8.. mmc.__m.mEmcam. 2050.0E0fim.
o: co; ome mm.m 8.5 N02 :33. mmvzmmm. mEEoEEmcam.
wit. ooh mmdv vmmm ooNn modom 9:8. mmuzmmm. 905906053
5.? 00¢ No.9 3.0 09% omdm 95.. mmn...:E.w 990.0
N F .m 004 om.m m5; oodn mod: :33. 020889.50 90.0.0
mod 00.? Nvd end 098 NOE mazn. omEEocoEo 905.0
mmém cod BNN 38% ooém Edom mam; 0380:0250 $08.5
mob cod $2 8.0 ooN mozv mam; mmn.E.m. 20300.00
no.0 cod mod mod ood nmd 0.20/v. 03.8.3050 $2000.00
Ememn. .85 53.2 €089”. ._otm. 58.). 0985 >._Emu. .020
05.89% 050:me
6:92. 22. :98...

 

.688. m . .N .282

 

 

 

CON: mm.mvm oon mmbom oodmm vaéh» wEm: =m *0 .33.
mo. FN CONN vnNm mice 00. we ofvm mwwr 00.0w Fmdm $50 .650 550
:d 00.0 mNd mod 00.0 00.0 moN oowm nmdm =:_u< mwnzmmm EmfiohmEmcam
mm. 5 ooNv NQNN NQVN oodm dem mm.©_. CONN van mam]. mmvzwmm EmfiEmEmcaw
00.2 00.0? mwmm mmh 00% mm. : wmé cod VNNN mENJ mmUEEEm 9990
m _. .m oodN FYNN VON oo.m mmd v.01: ooém No.50 =3U< mmU_Eoco._EO $220
mvb OONF mnhv EN? 00.3. ww.mm vow 00.2 mfmm mast mmU_Eoco._EO $990
00.? 09mm Nofiv ondm oo.©m omdw vwdm ooNv Dim: mZNJ mmEEocefo 9990
mod cod omd NNd ood omd om.m oo.©N :dw =3U< mmUEESPSO $535200
Ememn. .95 :82 Ememn. .otm. cmmE Ememn. .otm :85. $85 2E5“. EEO
Emucgm .2836 2.85%
mcoN 86387202 ocoN 363E. mcoN Emmbmcaon. coxmk

 

.33 E 53% 05m 05 mo
BEN :08 E @2998 9.8003 £6 E BEEoE $93 :0888 $08 mo :5on 98 “Hobo @8985 £383: :32 .EN 03mg

116

Zone. Diversity seemed to increase in an upstream direction. For example, the Non-
Impacted Zone was unique in showing a higher number of baetid and simliid larvae in
addition to taxa existing further downstream. The percentage of “other” taxa found in the
drift increased in an upstream pattern.

The terrestrial component of drift increased over the summer and was highest
below the dam. Over time, the contribution of terrestrial taxa to drift increased over May
and June, peaked in July with 23% of the total drift, and declined in August (Tablen2.17).
Individual items responsible for the terrestrial contribution to the July diet include
Chironomid and baetid adults. By zone, the Downstream Zone contributed the highest
percentage of terrestrial items with 24% followed by the Non-Impacted and Impacted
Zone with 12% and 4% of the drift (Table 2.18). Chironomid and baetid adults were

again responsible for the majority of terrestrial taxa identified in the Downstream Zone.

Electivity

Overall, those taxa making up the largest percentage of the diet were generally not
selected for, as indicated by the majority of negative electivity indices. For all trout
species, the Ei, or electivity index included the full range from —1 to 1, with the majority
of values being less than 0. Although electivity indices were calculated to quantify the
preferences for all prey taxa between May and August 1999 (Appendix D), the following
figures report electivity only for those taxa which were found to contribute five percent or
greater to the diet of each trout species.

Brook trout had an overall negative electivity index for ephemerelllid,

chironomid, and baetid larvae, the taxa comprising the highest percentage of their diet

117

 

 

 

 

 

mud kwm vmd mmNN N503 mimt E5
3350qu Btm. cams. mmmEmoEn. .otm :85.
23235 32:55
6:92. 22.
vow mwd mwN omN \uwe Rd £5
mmmwcmoaon. .otm cams. mmficmoumd Etm cams.
Emvcmum Emucfim
0:2. >32

 

.33 E 83% 0:5
ofi :o BEBE @883 fig E 85:82 «53 EEmobB mo owfiaooeom use 838:: :88 55:02 .:.N 2an

118

 

 

of? NQNN nmdm 5m o_..m mm: ondm omdm 3N: £5
Ememn. ._otm cam—2 “swoon. .otm E82 Emoamd Btw cmms.
Emncfiw Emncflw 23:me
mcoN nBoqu_-coz mcoN umfimag mcoN Emmzwssoo

 

/

a
2t .8 EON :23 a 39%... mace : was a 8%qu Se 3.535% 03282 23 265 ammramsi 8.5
.N O~£er

119

(Figure 2.9). Of the additional items observed most abundantly in the diet, only tipulid,
athericid, and hydropsychid larvae were, on average, positively selected for in relation to
the drift. Monthly electivity patterns were variable and included positive selection of
tipulid, athericid, brachycentrid, and hydropsychid larvae, as well as corixid adults, and
unidentified Ephemeroptera adults.

Brown trout also negatively selected for the taxa comprising the highest
percentage of items in the diet, including brachcentrid, baetid, and athericid larvae
(Figure 2.10). Positive selection was seen for Gastropoda, corixid adults, and Cottidae
(sculpin). Drift nets were not efficient in sampling fish species, thus all fish observed in
the diet would show positive selection relative to drift samples. Likewise, Gastropoda
were not effectively sampled in the drift nets, and their electivity was most likely not well
represented. Like brook trout, brown trout electivity showed a highly variable pattern
among months. Peaks in electivity were seen in Cottidae, hydropsychid larvae,
Gastropoda, Corixidae, unidentified Ephemeroptera adults, and athericid larvae.

Rainbow trout were different in that they showed positive selection for the most
frequent item found in their diet, brachycentrid larvae (Figure 2.11). The next most
common items in the diet, chironomid, ephemerellid and baetid larvae were negatively
selected for as seen in the other trout species. Like brook trout, rainbow trout also
positively selected for tipulid, athericid, and hydropsychid larvae. Looking at rainbow
trout electivity for each month, few patterns were shown, however, a higher number of
items were positively selected for, including tipulid, hydropsychid, athericid,

brachycentrid, and ephemerellid larvae, as well as corixid adults.

120

 

 

I May Ei

EJune Ei

ElJuly Ei

EJAugust Ei

 

 

 

 

 

r.

F

 

 

‘ . I .
.l.l.l-I-_l ''''''''

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

nnnnnnnnnnnnnn
...................................
nnnnnnnnnnnnnnnnnnnnnnnnnn

 

 

 

 

l
°Q
o

I
‘0.
O

0.4 a

lllll
NONY‘Q
O 999

-O.8 —

V

(B same/x xepu: Wuoela

121

“MN 3999998

)4an
BJeldOJSUJGLIda

PQUDUGPWH

BN81
eeplmdwpfiH

BNB']
eepgqustJp/(H

ewe-l
eepgnueo/luoeig

BMB'|
eepwuemv

EMB‘I eepundgi

llnPV eepgxuog

BAJB'] eepneeg

ewe-1
eepgwouonuo

ewe-l
eepmaieweudg

Taxon

Figure 2.9. Mean Ei values sorted from left to right by taxa most frequently consumed by brook trout on the

Pine River in 1999.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LTJ .. ________________________
LE LU II] 1;), .............
a) D
>‘ C >5 U)
as 3 3 3
E w w < _
I m [:1 El ........................ 7]
P
22:24 ------------- I
['_-..";'- ...................................
'''''''''''''''''''''''''' '55-‘21]
........ 'j- -.-l
l
Ff .................. '
r
.......................... j
-. , . P; ---------------------- ' 35']
t‘— "t"‘—*'" "‘V‘” I r l l I ““T |
‘— 00. ‘0. “I N. o “l ‘12 ‘9. (’0. ‘T
o o o o 9 C3 9 C?

(B) SGNIBA erDUI filtnnoela

122

BAJB']
eeplunws

llnPV
aieidOJeLuaudg

peunuepwn

BN81
eepgwououuc)

eepmoo

eme1
eepgqustJ pAH

llan 999!X!J°O

BNB'|
aepmarewang

epodonseg)

BNB1
eeptouemv

BAJB'] eepueeg

9M81
eepgnueo/(uoma

Taxon

Figure 2.10. Mean Ei values sorted from left to right by taxa most frequently consumed by brown trout on the

Pine River in 1999.

ElJuIy Ei

 

EJAugust Ei

 

 

 

‘tNON".

OO 00

(:3) senIEA xepUI k1!/\!10'9E|

0.
c?

123

—0.8

 

llnPV 99p!X!JOO

emeq eepundgi

BMB']
eepguofistJp/(H

BAJB']
aepwueuw

BAJE‘] eepneeg

emm
eepmeiaweng

ewe-1
eepgwouonuo

ewe-1
eepmueofiqoeig

Taxon

Figure 2.1 1. Mean Ei values sorted from left to right by taxa most frequently consumed by rainbow trout on the

Pine River in 1999.

DISCUSSION

Because a main concern of ecology is to not only describe patterns of distribution
and abundance, but also to determine which factors are responsible for these patterns, a
diet study was conducted to further understand trout population dynamics and interactions
on the Pine River. Trout have been documented as size selective, visual, opportunistic
generalists, feeding primarily on drift (Hunt 1966, Elliott 1970, Elliott 1973, Allan 1978,
Allan 1981, Newman 1987, Bachman 1984, Angradi and Griffith 1990, Allan 1995,
Rader 1997, Young et al. 1997), with little feeding done on benthos. When quantifying
daytime foraging behavior, Bachman (1984) calculated that brown trout consumed
approximately 87% of their diet from the drift and less than 15% from the substrate.
Because of this, invertebrates that occur in the drift as immature and adult stages
generally provide the most important food resource for trout. Additionally, trout feeding
has been documented as being variable. The main reasons for variation include
availability of prey, which is controlled by factors such as an increase in terrestrial taxa
availability during the day, light intensity, an evening peak in invertebrate drift, river
habitat, age and size of the predator, and social behavior of the trout (Elliott 1967,

Jenkins 1969, Elliott 1973, Allan 1981, Fausch 1984).

Wet Stomach Content Weight
In this study, efficiency of gastric lavage and survival of trout afterwards was
nearly 100%. This correlated to a study by Light et a1. (1983) which found gastric

technique to be effective for 98% of brook trout sampled, with a 100% survival rate.

124

Also, Meehan and Miller (1978) reported a similar method of stomach flushing to be
effective in removing stomach contents from salmonids.

Mean wet weight of stomach contents provided an indication of how trout feeding
changed over the months and zones. Among the trout species, rainbow trout had a higher
mean stomach content weight compared to brook trout and brown trout. For all these
species, the amount of food, as measured by weight and percent weight, declined as the
summer progressed. This decline may be a result of macroinvertebrate life cycles and
emergence schedules. Differences among zones were not significant, but the spatial
pattern of stomach content weight varied among the three species. Trout appeared to
have more food in their stomach in the Downstream and Non-Impacted Zones. It was
also recognized that as trout length increased, the weight of food in the stomach showed a
parallel increase. Stomach weight expressed as a function of body weight showed similar
spatial and temporal patterns to stomach weight. However, brook trout had higher
percent weights and brown trout had lower percent weights when fish length was taken
into consideration.

Analysis of stomach weight as a percentage of body weight using general linear
models established that length class and month were both significant variables, while
species was not significant. These results denoted that trout feeding across length classes
was similar when stomach weight was expressed as a function of body weight. Wet
stomach weight averaged between 2.6 and 3.9% for the present study. This was slightly
higher than values determined by Angradi and Griffith (1990) who found that the relative
wet weight of trout from the Snake River in Idaho averaged between 1.8 and 2.1% of the

total body weight. Also, the mean number of organisms per trout stomach showed a

125

pattern of decline in the number of organisms consumed as trout length increased.
Because previous results indicated that mean stomach weight increased as trout grew, it
was determined that larger trout consumed fewer but bigger organisms. This was
comparable to the literature which has shown that size selection of prey increased with
trout size, although smaller prey continued to be an important part of the diet (Ringler
1979, Allan 1981).

The mean wet weight of trout stomach contents in the Pine River, compared to
other Michigan streams, was much higher. For these comparisons, 1 ml was assumed to
be equal to 1 g (Alexander and Gowing 1976). The average wet stomach content weight
for trout in the Pine River was 2.83 g. On the other hand, Alexander and Gowing (1976)
determined that the mean stomach volume for northern Michigan stream trout was 1.2 ml.

An abundance of empty stomachs could indicate that food was limiting. Looking
at trout from the Pine River, less than 4% of the stomachs were empty, suggesting that
there was an abundant supply of food on which most trout were feeding. In a study of
brown trout and rainbow trout from unproductive southern Appalachian streams, 28% of
the brown trout stomachs and 22% of the rainbow trout stomachs were empty (Cada et al.
1987). Comparatively, it appeared as though Pine River trout were feeding well.

By month, trout stomach weight in the Pine River declined as the summer
progressed. For example, the highest mean stomach weight was noted in May with 5.9 g,
while the lowest average stomach weight of 0.92 g was recorded in August. Stauffer
(1977) found that the mean stomach volume for brown trout sampled in the Au Sable
River between May and September averaged approximately 0.8 ml, while brook trout in

the upper Au Sable River averaged between 0.282 ml and 1.033 ml and brown trout in the

126

upper Manistee River were between 0.1325 ml and 0.720 ml (Strogen 1979). Although
trout in the Pine River had higher average stomach content weights than trout in other
Michigan streams, the patterns were similar in that seasonal changes within these studies
illustrated that the total stomach volume was highest earlier in the summer and declined

through August.

Diet Percent Composition and Mean Number Eaten by Taxa

Trout coexisting in the Pine River can be characterized as opportunistic feeders,
as exemplified by the consumption of 72 different organisms in the diet. Corresponding
to the overall decline of mean wet stomach content weight, the number of items per
stomach declined as summer progressed. A seasonal decline in the number of organisms
eaten has been documented in other studies (Allan 1981, Wilhelm et al. 1999). Brown
trout and rainbow trout were documented as having more food items in their stomachs
moving upstream, while brook trout possessed similar numbers of items across all zones.

Chironomid, ephemerellid, brachycentrid, athericid, and baetid larvae all proved
to be numerically important in the diets of brook trout, brown trout, and rainbow trout.
These families of taxa appear to consistently play an important role in the diets of trout
given their prevalence in this study as well as previous research (Elliott 1973, Metz 1974,
Stauffer 1977, Tippets and Moyle 1978, Strogen 1979, Cada et al. 1987, Angradi and
Griffith 1990). Additionally, most of these studies found that the number and types of
prey eaten by trout varied in different months and habitats. This phenomenon was
observed in this study with an increasing number of taxa contributing to the “other”

category between May and August and in the Downstream Zone and Impacted Zone.

127

 

This indicated that a greater number of food items added to the diet of trout as summer
continued and in the areas of less complex habitat.

Terrestrial organisms, mostly comprised of adult forms of aquatic insects, were an
important part of trout food, contributing an overall 12% of the diet in July and followed
by 6% of the diet in August. Most of the terrestrial taxa were eaten in the Non-Impacted
Zone and Impacted Zones, where the most diverse cover was located. Rainbow trout
contained the highest number of terrestrial items in their stomach during August in the
Non-Impacted Zone, while brook trout and brown trout had the highest number during
July in the areas upstream of the dam. Other results have shown terrestrial organisms to
be more important in the diets of trout later in the summer (Hunt 1975). For example,
Allan (1981) found that trout ate more terrestrial items as aquatic organisms became more
rare in the latter part of summer. Cada et al. (1987) also determined that trout consumed
more terrestrial organisms later in the summer, comprising up to 36% of their total diet.
Reasons for this high number included the low autochthonous productivity of the
Appalachian stream, which forced trout to seek alternative food sources (Cada et al.
1987)

The amount of fish eaten, or piscivory, in the diet was low. For instance, brown
trout were the most piscivorous trout species with approximately 7% of their August diet
being fish. As expected, most incidences of piscivory took place in the Downstream
Zone and Impacted Zone, where forage fishes were comparatively more abundant. Trout
greater than 250 mm had the greatest amount of fish in their stomach. Although no cases
of cannibalism were confirmed during the study, other studies have contradicted these

results by showing cannibalism by trout to be more prevalent (Griffith 1974, Wilhelm et

128

 

al. 1999). The rarity of cannibalism indicated that the abundance of food resources in the
form of drift and forage fishes was plentiful enough for the relatively low abundance of

trout.

Diet Similarity

As mentioned previously, Angradi and Griffith (1990) suggested that index values
greater than 0.6 were viewed as indicating significant overlap. This guideline showed
that trout diets in the present study were all highly similar to each other. Brown trout and
rainbow trout had the most overlap, while brook trout and brown trout had the least
amount of dietary overlap. When comparing the diets of trout to the drift, the amount of
overlap was low for both brown trout and rainbow trout. Brook trout, however,
demonstrated a high level of overlap with drift. Various levels of overlap have been
calculated between drift composition and trout diets in a multitude of research (Elliott
1967, Cada et al. 1987, Hubert and Rhodes 1989, Angradi and Griffith 1990, Forrester et
al. 1994, Young et al. 1997), with some of the studies contending that trout diets
overlapped significantly with drift (Elliott 1970, Elliott 1973, Allan 1978, Allan 1981).
However, comparisons are difficult because selectivity or overlap indices function as a
property of sampling frequency, resolution of taxonomic identification, and the method of
comparison rather than behavior of individual fish (Hunt 1975).

Monthly diet similarity declined as the summer progressed, with adjacent months
showing lower similarity than overlap between diets of different trout species (0.70 to
0.36). In contrast, Elliott (1973) found that brown trout and rainbow trout had very

similar diets from June to August. Wilhelm et a1. (1999) documented the dietary overlap

129

of bull trout between July and September to be greater than 0.60. Time or month seemed
to control the type of organisms available for trout predation. Consequently, similarity
was high for trout diets from all zones, with the Downstream Zone and Impacted Zone

having the highest level of similarity.

Drift Density and Taxonomic Composition

Trout have been characterized as primarily drift feeders. Therefore, it is important
to understand the mechanisms that drive drift. Invertebrates may intentionally or
behaviorally drift to avoid predation (Allan 1978, McIntosh and Peckarsky 1996) or
become accidentally dislodged (Peckarsky 1980, Kohler 1985, Forrester et al. 1994).
Studies have shown that most invertebrates drift after sunset to avoid detection by fish
predators (Elliott 1973, Walton 1980, Cibrowski 1983, Kohler 1985). Above all,
macroinvertebrate drift in trout streams can exhibit high spatial and temporal variability
(N eedham and Usinger 1956, Wiley et al. 1997).

A total of 63 different organisms were identified in the drift. Various stages of
chironomids, as well as baetid and simuliid larvae, were among the most abundant
organisms recognized. Items contributing to the “other” category were responsible for
approximately 5 to 20% of the total drift. Terrestrial items were most abundant in July,
with 23% of the monthly drift. July was noted for its high amount of terrestrial
macroinvertebrates, particularly an abundance of grasshoppers and adult forms of aquatic
insects. The Downstream Zone contained the highest amount of drifting terrestrial taxa
with 24% of the total amount analyzed. The Non-Impacted Zone had the highest amount

of overhanging cover and higher numbers of terrestrial organisms were expected in this

130

 

 

zone. The habitat near the dam was less complex than the upstream areas and fewer
organisms were expected to contribute to the drift in this area. One plausible explanation
for the abundance of terrestrial organisms downstream may be attributed to the lack of
sand banks when compared to the upstream section. The downstream riparian habitat
consisted of banks with vegetative cover in addition to fauna typically found in wetland
regions. Furthermore, many of the terrestrial taxa identified were adult forms of aquatic
macroinvertebrates such as Chironomid and baetid adults.

Initial hypotheses expected that the number of invertebrate food organisms in the
Pine River would be lower as a result of the sand substrate, which has been documented
as the poorest substrate for macroinvertebrates (Pennak and Van Gerpen 1947, Hynes
1970, Merritt and Cummins 1996). Peaks of drift density occurred in July, when
emerging insects and terrestrial organisms were most abundant. Excluding this peak in
July, drift abundance appeared to decline as the summer progressed. These results were
similar to a study of Idaho streams by Griffith (1974) which also found that the number of
drifting organisms declined over the summer. Spatially, peak drift for the river was
documented in the Downstream Zone. The high number of drifting organisms in the
Downstream Zone was partially may be explained by the placement of the drift nets in the
shifting area of water below the dam. Uniform high water levels limited drift net
placement to an area approximately 100 meters below the dam. Consequently, the flow
of water over the stoplog structure in the dam may have caused an increasing number of
macroinvertebrates to be disturbed from the benthos, or have introduced a higher number

of organisms carried from upstream.

131

A correlation between drift and diet in the Pine River existed for stomach weight,
but not number of items. Rainbow trout took advantage of the peak drift in July, as
evidenced by their high stomach weight. Also, brook trout and brown trout had the
highest stomach weights in the Downstream Zone, where drift tended to be higher. As
for the number of organisms, there was no correlation between diet and drift.

The average drift density estimates in the Pine River ranged from 112 to 784
organisms per 100 m3 of water. These estimates were comparable to high drift density
estimates from other rivers. For example, Sagar and Glova (1988) found that drift density
not to be limiting in the Rakaia River, New Zealand with between 200 and 900 organisms
sampled per 100 m3 of water. Likewise, Bowles and Short (1988) found that non-limiting
peak drift densities in a Texas stream ranged between 500 and 600 organisms per 100 m3
of water in May and August. In contrast, several Southern Appalachian streams had drift
densities as low as 0.24 to 27.77 organisms per 100 m3 of water, resulting in food
limitation for salmonids (Cada et al. 1987). Based on the high number of drifting
macroinvertebrates and the fast growth of trout, food did not appear to be limiting in the

Pine River.

Electivity

Although trout are opportunistic feeders, it is known that they are selective for
certain taxa (Bryan and Larkin 1972, Bisson 1978, Forrester et al. 1994). This selectivity
may be seasonal, as demonstrated by the importance of terrestrial taxa in trout diets (Hunt

1975, Aho 1977, Cada et al. 1987, Young et al. 1997).

132

Diet collection was conducted during the day while drift was sampled in the
evening. In the extent of literature on the diets of trout, there has been much emphasis
placed on the timing and rate of trout feeding. The peak in summer salmonid feeding has
been said to occur during the day (Swift 1962, Chaston 1969, Tippets and Moyle 1978,
Allan 1981, Campbell and Neuner 1985, Sagar and Glova 1988, Forrester et al. 1994,
Young et al. 1997), at dusk (Elliott 1970, Jenkins et al. 1970, Ware 1972, Elliott 1973,
Bisson 1978, Bachman 1984, Angradi and. Griffith 1990), and at night (Ringler 1979,
Clapp et al. 1990). Some of these studies have shown that trout feeding is for the most
part continuous, with feeding showing little overall effect for time of day (Jenkins 1969,
Bachman 1984, Dedual and Collier 1995). Overall, studies have determined that
individual trout vary considerably as to when they feed by showing a lack of synchrony
with the peak evening drift (Griffith 1974, Tippets and Moyle 1978, Bisson 1978, Allan
1981). Because of sampling constraints, trout feeding was estimated during the day on
the Pine River. Drift was sampled in the evening to take advantage of peak densities in
order to include the highest number and widest range of organisms. Electivity index
values were not absolute representations of trout preferences for certain taxa because of
the different sampling times and the exclusion of benthic macroinvertebrates that did not
drift. All selection indices are limited in that they cannot explain the underlying
mechanisms of observed selectivity patterns generated by preference, prior experience,
prey detection, or prey availability.

In the Pine River, the majority of electivity values (Ei) were less than 0. This
indicated that organisms comprising the largest percentage of the diet were not highly

selected. Compared to the availability of organisms in the drift, negative values did not

133

 

indicate that these organisms were avoided by trout, but instead underused. Alexander
and Gowing (1976) came to a similar conclusion when determining that trout in northern
Michigan waters were randomly selective and consumed any available organism.

Items that were positively selected for in the Pine River included tipulid, athericid,
hydropsychid, and corixid larvae, as well as Ephemeroptera adults and Gastropoda. A
comparison of trout feeding habits in Idaho also documented a preference for adult
Ephemeroptera (Angradi and Griffith 1990). Rainbow trout displayed a different pattern
in that they positively selected for the most abundant item in their diet, brachycentrid
larvae. Positive selection was seen for all fish found in the diet, as shown by Cottidae
(sculpin). Because drift nets do not effectively sample fish, any fish identified within

trout stomachs would have been assigned a positive electivity.

Management Implications

The Pine River presents special circumstances and opportunities in that it contains
naturally reproducing populations of brook trout, brown trout, and rainbow trout. It has
been documented that these trout are fast growing when compared to other stream
systems in Michigan (Klomp 1998, Chapter 1). The goal of the research reported here
was to describe the feeding habits of these coexisting trout in different habitats over a
summer season and compare them to food availability in the drift. By doing this, I hoped
to develop insight into trout diet overlap and selectivity for available food resources as
well as establishing feeding patterns over a summer season (May through August). These
data will also provide a basis for later comparison in efforts to detect possible

competition from other upstream migrating fish species.

134

Alexander and Gowing (1976) found that quantity, not quality, of food was the
most important factor influencing growth of trout in Michigan. It is also known that the
abundance, or number, of food in the stomach is generally related to the overall growth of
trout (Cooper 1953, Ensign et al. 1990, Nicieza and Metcalfe 1997). I showed that brook
trout had an average total of 54 different organisms in their stomach, while brown trout
contained 80 and rainbow trout had 59 various items. A study by Cada et al. (1987)
which documented trout feeding in a low productivity southern Appalachian stream
described brown trout as having an average of 9 items per stomach, while rainbow trout
averaged 6.5 items per stomach. Comparatively, the majority of trout in the Pine River
was eating a high number of organisms and should not be food limited.

Growth was generally better in the Downstream Zone, with the lowest growth
rates documented in the Non-Impacted Zone. Therefore, feeding did not seem to be
influenced by high populations of white suckers found below the dam. Although the
number of items in trout diets was lowest for the Downstream Zone, trout had the highest
mean stomach weight in this area, as well as the most available drift. Since brown trout
and rainbow trout contained the lowest number of items in their stomach in the
Downstream Zone, some mechanism other than number must be driving growth. As a
result, better growth may be explained by the weight of food, as mean wet stomach
content weights tended to be higher in the Downstream Zone. Also, trout in the
Downstream Zone had a tendency to consume more fish when compared to trout residing
above the dam. The mean wet stomach weight of trout that had fish in their stomach was
substantially higher when compared to trout that ate only macroinvertebrates. It has been

shown in the literature that piscivorous salmonids experience higher growth rates

135

compared to trout feeding on drifting benthic macroinvertebrates (Garman and Nielsen
1982). Consequently, the comparatively high number of organisms found in trout
stomachs was likely responsible for better growth and best growth was achieved through
the selection of fewer, but larger, food items such as fish.

Chapter 1 also explained that the density of trout in the Pine River was
approximately one-third that of other northern Michigan streams (Alexander and Gowing
1980, Stuber 1996). Initial hypotheses pertaining to the mechanism suppressing trout
numbers have involved the high sand bedload of the Pine River. The sand-dominated
substrate was thought to not only reduce the number of benthic macroinvertebrates, but
also result in greater embeddedness of spawning gravels and reduced habitat for trout.

The results of the trout diet, growth, and drift analysis indicated that the numbers
of food organisms in the Pine River were not likely to be limiting. Because food was
abundant, competition between trout species was not evident. Therefore, sand was not
limiting benthic macroinvertebrates in a manner that would cause a reduction in trout
population numbers. Presumably, the low standing stock of trout in the Pine River is
either linked to early life stage survival as mentioned above, predation, or angling.

Although sand may be the driving force controlling the low biomass of trout on
the Pine River, other explanations are plausible. Predation by fish-eating birds has been
shown to be a substantial factor in stocked trout mortality, especially in lakes frequented
by common loons (Gava immer) and great blue herons (Ardea herodias) (Matkowski
1989). A review by Draulans (1988), however, concluded that piscivorous birds did not
considerably decrease the abundance of fish in freshwater habitats. Although not

quantified, trout predation by birds on the Pine River was assumed to be low. Most

136

stretches of the river are too swift for wading birds such as great blue herons. Although a
few diving ducks such as common mergansers (Mergus merganser) and hooded
mergansers (Lophodytes cucullatus) were seen on the river, they did not appear in
sufficient numbers to inflict trout population-level changes. It has also been suggested
that cannibalism or predation by piscivorous fish may negatively affect fish populations
(He and Kitchell 1990, Magnuson 1991). Although predation may be occurring with
other fish species, such as those present below the dam, no cases of cannibalism were
noted while examining trout stomach contents on the Pine River in the summer of 1999.

Seasonal fishing restrictions coupled with restricted outfitter and individual
access, limits angling pressure on the Pine River. For example, only two outfitter
services guide on the Pine River and catch and, release fishing is highly promoted.
Individual angler entry is limited by the topography of the Manistee National Forest,
which often includes steep banks and a protected 1A mile corridor.

Although I hypothesize that reduced survival of early life stages is controlling

trout biomass on the Pine River, future research is needed to determine the exact causes.

137

SUMMARY AND CONCLUSIONS

Removal of Stronach Dam has the ability to allow fish species that reside only
below the dam, or are abundant below the dam, to migrate up and potentially compete
with the resident trout population. The Pine River is noted for its naturally reproducing
population of brook trout, brown trout, and rainbow trout, and it is of utmost importance
to preserve the integrity of these species. To this effect, a trout diet study was conducted
to document feeding in comparison to macroinvertebrate drift availability at present
levels of population abundance and community level competition. Thus, if species from
below the darn ultimately have negative effects on the trout population, these effects will
be recognized through slower growth and a change of feeding habits or food availability.
This study also attempted to characterize how trout feeding differed with a varying
population abundance of white suckers, which are one of the most abundant species
occurring below the dam. I attempted to use this information to develop insight into the
diet overlap and selectivity for food resources over a summer season.

The wet stomach content weight of trout in the present study was much higher
than the average for similar northern Michigan streams. Seasonally, comparable to other
studies, stomach content weight declined as the summer progressed. Trout appeared to
eat more in weight as they grew longer, but had fewer organisms in their stomach.
Overall wet stomach content weight was highest in the Downstream Zone, where trout
had access to a high number of forage fishes.

Macroinvertebrate families that included Chironomidae, Ephemerellidae,
Brachycentridae, Athericidae, and Baetidae larvae dominated trout stomach contents. The

number of organisms identified in each stomach declined between May and August,

138

likely owing to the increasing number of emerging insects. This was confounded by an
increase of taxa contributing to the “other” category and to the Downstream and Impacted
Zone, or areas of less complex habitat. Terrestrial taxa were an important part of trout
diets later in the summer and in the upstream areas. Overall piscivory was low, occurring
mostly in fish greater than 250 mm that resided downstream.

Trout stomach contents were highly similar to each other, with only brook trout
showing a high degree of similarity to the drift. Although month to month similarity was
variable, similarity between zones was high. This indicated that trout tended to eat the
same things because similar prey organisms were available to all trout within each month.

Macroinvertebrate drift was dominated by various life stages of Chironomidae, as
well as Baetidae and Simuliidae larvae. Drift appeared to decline over the summer,
except for a peak in July attributed to the increasing amount of terrestrial organisms.
Because the Pine River is characterized by its high sand bedload, which is the poorest
substrate for macroinvertebrate suitability, it was anticipated that the number of
macroinvertebrate food organisms would be low. However, the drift density estimates
from this study were comparable to non-limiting drift densities recorded in other river
systems. This, combined with the knowledge that trout in the Pine River are fast
growing, indicates that drift was not limiting.

The majority of organisms identified in the stomach contents of trout were not
highly selected. Instead, these items were most likely underused when compared to their
availability in the drift. Positive selection was documented for larger prey items such as

Athericidae and Tipulidae larvae, fish, and adult forms of aquatic insects.

139

Feeding did not appear to be influenced by the number of white suckers. In the
Downstream Zone, where white suckers are most abundant, trout growth was generally
better as a result of higher wet stomach content weight and increased availability of
drifting organisms.

It can be deduced that the low biomass of trout in the Pine River is not caused by
a limiting production of benthic macroinvertebrates. Instead, the abundance of sand most
likely results in low survival of trout early life stages through the burying of spawning
gravel. Other possible causes, although improbable, leading to low numbers of trout
include predation and angling pressure. Further research needs to be conducted to

determine the exact reason for low trout biomass.

140

APPENDICES

141

 

 

 

 

:33. .mEmotm... 32.55233 muoaeoEofim 903:. K
95.. 03333. vo_E:ov_:3 99:99:23 903:. om
:33. 353:8. omn_n_wo> 53:058.»: 9035 9
:33. 3:78th mmEoEto”. $9858.»: 908:. w:
mam: 2:333. omEEo~>Eobma moE:oE:o~>Eo=mn_ 25:3. mm
339.. 6:38:97 . . 88220 5
:33. 2633. 38:52 3030330 an
.395 395 335m 335m. 30 .3qu E
:33 358:8 . . 882:5 t
:33 26:3 98:89.0 2
:33. 2333. mvoain< mombmoomfis. m:
:33. 2533.4 mnoaofl mombmoomfis. .3
:33. 2633. «32580 8960865. m w
:33. 2633 8:88:82... 8533:: N7
:33. 2533. $2523.»: 30395382: 3030330 F r
:33. 3:595... 32.525 «35:01 m__mEEm_2 or
:33. 0:333. :wE 5505:: :mE 5.65:: $332660 3
:33. 033.3. mmeaooEn. mmE:o:maoo:mn. mm>£:o_9mo m
:33. 03333. 32:00 moE:o::mm&oom $330660 N.
:33. 0:333. . mctmofigI mu_::om:< o
:33. $5338. m::m3. m3_::om:< m
. . . 8m. sausage v
xoomBEmQO m

30032590 m

cos—363622590 P

3me o=m3c<\_m_:wm:m._. >__Emn_ EEO $30 6:00
0:3 :98:
.332 5 83m 23m

>‘fl’ ‘Ud. 3’i>)11>’ )“"D‘ “-‘L

142

,..._ .-____7--._.-..—.___...__,. ._ .A- 3

 

 

 

:33. 00030.0 002::m. 0050.00 0500:. 00
0>:0.. 2.0300 002E.m. 0050.00 0500:. mv
:30.0 .0_:.00::0... 000.5005: 0050.00 0500:. En
0>:0.. 00030.0 0000050000020 0:050:00... 0500:. m...
0>:0.. 00030.0 000...:00:E.._ 0:050:05. 0500:. N0
0>:0.. 00030.0 002:0..05. 0:050:00... 0500:. S.
0>:0.. 00030.0 00200050.. 00505:... 0500:. 00
0>:0.. 00030.0 000.:0>000:0>I 0:050:00: 0500:. mm
0>:0.. 00030.0 00005003000 0:050:05. 0500:. mm
:33. .0.:50::0... 000.5025. 0:050:00... 0500:. mm
0030 2.0300 000.5025. 0:050:00... 0500:. on
0>:0.. 2.0300 000.5025. 0:050:00... 0500:. mm
0>:0.. .0_:50::0._. 000.5025. 0050200.. 0500:. 00
0>:0.. 00030.0 002.030 0050200.. 0500:. mm
:33. 000304. 002500 005.00... 0500:. mm
0>:0.. 00030.0 00200.00 00580.0 0500:. 5
0>:0.. 00030.0 0025:0005 00580.0 0500:. cm
0>:0.. 00030.0 000.5005: 00580.0 0500:. mm
0>:0.. 000300 00238255 00500::0:0m. 0500:. mm
0>:0.. 00030.0 0025:0005. 0:050:050:0m. 0500:. um
0>:0.. 0.5300 002__0:0E0:0m. 0:050:0E0:0m. 0500:. mm
0>:0.. 2.0300 002500050... 00500::0:0m 0500:. mm
0>:0.. 00030.0 00200000.. 00500::0:0m. 0500:. VN
:33. .0_:50::0.r 000.00m 0:050:0E0:0m. 0500:. mm
0>:0.. 2.0300 000.00m 00500::0:0m. 0500:. mm
0d0.m 0003000505000... 2.50“. 00:0 000.0 0000

:0x0...

0:.

 

143

 

 

 

0>:0.. 03030.0 002::000 030:000 0500:. F n
.39. o..0:c<._::00 003.20... 0:03:25 0000:. 2
3.30.0 .0.300:0... 002..0000.0 005080... 0500:. 00
3.30.0 0.30030... 00225.0 0:050:00 0500:. mm
0>:0.. 03030.0 0023:2030 005.0 0500:. mm
3.300 .0.300::0... 000.203.”. 005.0 0500:. mm
0>:0.. 03030.0 00220Em. 005.0 0500:. mm
0>:0.. 03030.0 0020.030 005.0 0500:. we
0>:0.. 03030.0 000.000.: 005.0 0500:. no
3.30.0 .0.300:0... 002..3E.m 003.0 0500:. No
0030 03030.0 002.320 003.0 0500:. 5
0>:0.. 030300 002.220 005.0 0500:. cm
0>:0.. 03030.0 002000003000 005.0 0500:. mm
3.300 .0.300:0:. 000.Eo:0:.:0 003.0 0500:. mm
0>:0.. 03030.0 000.Eo:0:.:0 005.0 0500:. mm
3.30.0 .0.300:0._. 00250.9 005.0 0500:. mm
0030 03030.0 002.30.... 005.0 0500:. mm
0>:0.. 03030.0 002.30.... 003.0 0500:. 0m
3.30.0 03030.0 002::30 00300.00 0500:. mm
0>:0.. 03030.0 00200.30 00500.00 0500:. mm
3.300 .0.300:0... 002:0..30:30 00500.00 0500:. 5
3.30.0 03030.0 002:0..30:30 00300.00 0500:. on
0>:0.. 03030.0 000...:00:0>... 00300.00 0500:. 00
0>:0.. .0.300:0.r 000._0::00>::0 00300.00 0500:. 0..
3.30.0 03030.0 000..0E00>::0 0050050 0500:. 0...
0003.0 03030030300300. >..E00 00:0 000.0 0000

:0x0...

03...

 

144

‘ -.'-

 

 

 

0>:0.. 03030.0 000330802 00580.0 0500:. 00
3.30.0 030300 000...:00:0>I 00300.00 0500:. 00
0>:0.. 03030.0 000.:000 005008030 0500:. mm
3.300 03030.0 002.0..0... 00500.00 0500:. mm
0030 03030.0 000.80:0:.:0 005.0 0500:. .00
3.30.0 0.30080... 00208030 005008030 0500:. mm
0>:0.. 03030.0 002.300:0>I 0:050:03... 0500:. cm
3.300 0.30080... 00230 003080... 0500:. ms
3.30.0 0:300:00 0033:0030 005.80... 0500:. 00.
3.30.0 0.30080... 003.3025. 00580.0 0500:. on
0>:0.. 03030.0 0023800 030000 0500:. mu
3.30.0 03030.0 0033:0030 05080.50 0500:. MK
3.30.0 .0.300::0.r 0033:0030 005080... 0500:. mm
00030 03030030330080... 2.800 00:0 000.0 0000

0:.— 00x0...

 

K3 a44>)/ 4 0 Alqul 4 a

145

 

 

 

 

8.: 00.0 :0: 00.0 :0 2.0 00.0 00.0 000.255“.
:0: 00.0 00.0 00.0 00.0 00.0 00.0 0:0 000 50.“.
00.0 00.0 00.0 00.0 00.0 R: 00.0 00.0 0.00... 00005050500
00.0 00.0 0:... 0:0 00.00 00.: 00.00 00.0: 020. 0020050500
:0: 00.0 00.0 8.0 00.0 00.0 00.0 00.0 020. 000.0050
00.0 00.0 00.0 00.0 00.0 00.0 00.0 0:0 .50.. 000.0050
00.0 2.0 00.0 $0 :00 00.0 00.0 00.0 0000205
00.0 00.0 :0 00.0 00.0 00.0 00.0 00.0 00000.... 0.00... 000525050
00.0 00.0 0.0.0 0:0 00.0 00.0 00.0 00.0 90500500 .50... 000525500
5.: 00.0 :0 00.0 00.0 00.0 00.0 00.0 000.000
00.00 00.0 00.0 00.0 00.0 00.0 00.0 00.0 :00... 0000.000
00.0 00.0 00.0 0:0 :0 0:0 00.0 0:0 :00... 00.00000
00.0 00.0 00.0 00.0 :00 0:0 00.0 00.0 .30.. 000___0000_0
00.0 00.0 00.0 00.0 00.: 00.0 00.0 0:0 :00... 0000500550
00.0 00.0 00.0 00.0 00.0 00.0 00.0 00.0 0000 000505250
0:0: 00.: 00.00 00.: 00.0 00.0 00.0 00.0 020. 000.505550
00.0 00.0 :0 00.0 00.0 00.0 00.0 00.0 0203 000500002000
:0: 00.0 00.0 0:..0 00.0: :00 00.0 00... 020. 00005005000
000 0:0 00.00 00.0: .000 00.0 00.0 00.0 0>:0.. 0000000
8.: 00.0 00.0 00.0 00.0 00.0 00.0 00.0 0.00... 0000000
00.0 00.0 00.0 00.0 00.0 00.: 00.00 00.3 020. 000.0005...
00.0 00.0 :0 00.0 00.0 00.0 00.0 0:0 0000505..
00.0 00.0 :0 00.0 :00 8.0 00.0 00.0 0050050.: 0.00.. 000.000...
00.0 0 :0 .000 «:0 00.0 00.0 00.0 00.0 00000....500. 0.00.. 000.0504.
:0: 00.0 ~00 «:0 00.0 00.0 00.0 2.0 05:00.0
3:00:00. 0002 3:00:00. 0005— 3000000 cam—2 3:00:00 0005. mEmZ 0983.
30303.0 230 0:33 .05.

 

.000. 5 03M 0:5

146

 

 

 

 

 

:0.: 000 000 00.0 00.0 00.0 00.0 00.0 000.000>
000 00.0 00.0 000 :00 000 00.0 0:0 00.0 500503
00.0 00.0 :0 000 :00 000 000 000 0000 0.0000000:
00.0 00.0 000 00.0 :00 0:0 000 000 020._ 0.0000000:
:0: 000 00.0 00.: 00.0 00.0 00.0 00.0 0000 000.30.:
00.0 0:0 000 000 0:00 00.: 00.0 0:0 0200 000.30.:
00.0 00.0 000 0:0 000 :00 00.0 00.0 020.. 0005000:
000 00.0 :00 000 000 00.0 0:.: 000 0000 000.._05.m
:0.: 000 00.0 :0: 00.0 00.0 00.0 :0 0200 000..35.w
00.0 00.0 :00 000 000 000 00.0 0:0 030...: 000.._05.m
00.0 00.0 000 000 :00 000 00.0 0:0 020._ 000.330
:0: 000 00.0 00.0 00.0 00.0 000 00.0 020._ 000.00.000.00
00.0 00.0 00.0 00.0 00.0 00.0 :00 000 020._ 00000000
00.0 00.0 00.0 000 00.0 00.0 000 000 000.0000000
:0. : 000 : :0 000 :00 000 000 000 00000095
00.0 00.0 00.0 00.0 :00 0:0 000 00.0 0200 00050__0s_
00.0 00.0 00.0 00.0 :00 000 00.0 00.0 020._ 000...:0055:
00.0 0:0 000 000 :00 000 00.0 00.0 0200 000000.000
00.0 00.0 :0 000 00.0 00.0 00.0 0:0 000002
0:0: 0:: 00.0 00.0 000 000 00.0 00.0 020.. 000.3022:
000 :00 0:0 ::.0 000 000 0:0 00.0 0200 000500000200:
00.0 00.0 :0 000 000 000 000 00.0 020._ 000._...00.0>:
00.0 00.0 :00 000 00.0 00.0 000 0:0 000000.020
00.0 0:0 :0 000 00.0 00.0 0:.: 000 0200 0005000000:
000 00.0 00.0 000 :00 000 000 000 020._ 00050500
00.0 00.0 00.0 0:.0 00.0 000 00.0 00.0 000000000
Emohmn. cam—2 €00th ram—>— Ewohmm cam—2 .300th Ema—2 mEmZ .00me
$0900. 200 0:00 >05.

 

147

 

 

 

mcoN 000000;.7002

chN 000000E_

mcoN Emmbmcaoo

000 :00 000 0:0 0:: 000 000.0.5200
0:0 000 00.0 00.0 000 000 000 00.0
000 : :0 0:.0: 0:.0 00.0 00.0 0000 000000050000
0000 :00: 00.0 0:0 0:0: :00 0200 000000050000
000 0:0 00.0 000 000 00.0 020.. 000.0050
000 000 00.0 000 000 000 000.0 000.0350
000 :00 0:0 000 000 000 0000205
000 000 000 0:0 000 000 00000.0. 0.300 000.00.30.00
00.0 000 000 00.0 00.0 00.0 00.000530 0000 000.00.30.00
000 000 0:0 000 000 000 000.000
0:0 000 0:0 0:0 000 000 0000 0000000
0:0 000 000 0:0 000 0 :0 0000 000000030
00.0 00.0 000 0:.0 00.0 00.0 0000 000000020
00.0 00.0 0:.0 000 000 000 0000 00000500200
00.0 00.0 00.0 00.0 0:: 000 0000 000.52.02.00
00.: 000 00. :0 ::.0 0:00 :00: 020._ 000.50.00.50
0:0 000 000 00.0 000 0:0 0200 0005000000000
00.0 :0: 000: 00.0 00.0 0:0 0200 000050050000
00.0: 00.0 000: 00.0 00.0: 0:0 0200 0000000
00.0 00.0 00.0 00.0 00.0 000 000.0 0000000
00.0: :0 0:0 000 ::.0 :0: 0200 000300000
0:0 000 000 00.0 000 000 00005050
0:0 000 0:0 000 000 000 000000080 0000 000.0000
0:0 000 000 00.0 000 000 0000000500. :300 000.0000
000 :0 000 000 000 000 000000
0:00.000 :00—)— gcmohmm :00—2 #:000000— cmm_>_ 9:02 .5me

 

148

 

 

 

mcoN 00000067002

mcoN 000000E_

mCON Emmbwcgoo

0:0 000 00.0 00.0 00.0 00.0 000.000>
00.0 00.0 :0 00.0 00.0 00.0 00.0 5005.03
0:0 000 0:0 000 00.0 00.0 0000 000000000:
00.0 00.0 00.0 0:.0 00.0 00.0 0200 0.0000000:
:0: 00.0 00.0 00.0 :00 :00 0000 000.30.:
00.0 :00 00.00 00.0 00.0 00.: 0200 000.30.:
00.0 :00 0:0 000 00.0 00.0 020._ 0005000:
00.: 00.0 00.0 00.0 00.0 00.0 0000 0000350
00.0 00.0 :00 00.0 0:: 00.0 020._ 000.0050
0:0 000 00.: 00.0 000 00.0 000.0 0000350
00.0 :0 00.0 00.0 00.0 00.0 020._ 00000.00
0:0 000 00.0 00.0 00.0 00.0 0200 000.00.000.00
00.0 00.0 00.0 00.0 00.0 :00 020._ 000.00000
00.0 00.0 00.0 00.0 000 0:0 0000000000
000 0:0 00.0 00.0 000 0:0 0000000000
00.0 00.0 00.0 0:.0 00.0 00.0 020._ 000.00__0s_
0:0 000 00.0 00.0 00.0 00.0 0200 000020005:
000 :0 0:.0 00.0 00.0 00.0 020._ 000000.000
00.0 00.0 :0 00.0 00.0 00.0 000002
:0: 000 0:0 000 00.0 00.0 0200 0000000200:
0: 00.0 000 0:.0 00.0 0:0 0200 000.000.000.00:
0:0 000 00.0 00.0 00.0 00.0 020._ 0000000000:
000 00.0 00.0 00.0 000 0:0 050000.00:
000 :00 00.0 0:.0 000 0:0 0200 00000000000:
00.0 00.0 :0 00.0 00.0 00.0 0200 00020500
00.0 :0 0:0 000 00.0 00.0 000000000
Emohmn— :02). 0:00.00; 2002 #:000000— :002 0EmZ :98...

 

149

 

 

 

00.:0 00.: 00.0 0:.: :00 0:.0 :00: 0:.: 000000000
00.0 00.0 00.0 00.0 00.0 00.0 00.0 0:0 000.0.5000
0:.0 00.0 00.0 00.0 00.0 00.0 00.0 00.0 000 20.0
00.0 00.0 00.0 00.0 00.0 00.0 :00 00.0 020._ 0000000050200
00.0 00.0 00.: 00.0 00.0 00.0 00.0 0:.0 0000 000000050200
00.0 00.0 00.0 00.: 00.:0 0:0 000 00.0 0200 000000050000
00.0 00.0 0:.0 00.0 00.0 00.0 00.0 0:0 :300 000.50
00.0 00.0 00.0 00.0 :00 :0 00.0 00.0 00000.05
00.0 00.0 0:.0 00.0 00.0 00.0 00.0 00.0 00000000
00:: 00.: 00.0 00.0 00.0 00.0 00.0 0:.0 000.000
:0. :0 :0. : :0: 000 000 0:.: 00.0 00.0 0000 0000000
00.0 00.0 000 0:0 :00 : :0 0 :0 00.0 0000 000000000
00.0 00.0 0:.: 00.0 00.0 00.0 00.0 00.0 0000 000200020
00.0 00.0 00.0 00.0 00.0 00.0 :00 000 0300 00000500220
00.0 00.0 00.0 00.0 00.0 00.0 00.0 00.0 0000 000.50.20.20
:00: 0:0 00.0 00.: :00 :0 00.0 00.0 020._ 000.50.00.20
00.: 00.0 0:0: :0 00.0: 00.0 0:.:0 :00: 0200 0000200020000
00.0 00.0 00.0 00.0 00.0 00.0 :00 000 0200 000.000000
00.0 0:.0 00.00 000: 00.0 :0: 00.0 :00 0200 0000000
00.0 00.0 00.0 00.0 0:.0 0:.0 00.0 00.0 000.0 0000000
00.0 00.0 00.0 0:.0 :00 0:.0 00.00 0:00 020._ 00000050
00.0 00.0 00.0 00.0 :00 :0 00.0 00.0 00002050
0:.0 00.0 :0: 00.0 00.0 00.0 00.0 00.0 8000005000 0000 000.0000
00.0 00.0 00.0 0:.0 00.0 00.0 00.0 00.0 00000500 :300 000.0000
00.0 00.0 0:.0 00.0 00.0 00.0 00.0 00.0 000000
:c0000n_ :00—>— Emohmn— :00—>— EmSma :00—2 Ememn. :00—2 meZ .5me
003030 22. 0:2. >05.

 

$33 a: .831 0:5

 

150

 

 

 

 

 

151

0:.0 00.0 00.: 0:.0 00.0 00.0 00.0 000 0030 000000.:
00.: 000 :0: 00.0 00.0 00.0 00.0 000 0200 000000...
00.0 0:.0 00.0 0:.0 000 00.0 :00 00.0 0200 000.0000:
00.0 00.0 00.0 00.0 :0: 000 0:.0 000 020._ 00000002000
0:.0 00.0 00.0 00.: :00 ::.0 :00 00.0 0000 00000000
00.0 00.0 00.0 :00 00.0 00.0 00.0 00.0 020._ 00000000
0:.0 00.0 0:.0 0:.: 00.0 00.0 000 :00 0000 00000000
00.0 00.0 00.0 00.0 00.0 00.0 :00 00.0 0000000
00.0 00.0 00.0 00.0 00.0 00.0 :00 00.0 020._ 0000000.
0:.0 00.0 0:.0 00.0 0:.0 0:.0 000 0:.0 020._ 000.00.000.90
00.0 00.0 00.0 00.0 :00 ::.0 000 0:.0 0200 0.0000000
0:.0 00.0 00.0 00.0 000 00.0 00.0 00.0 0000 0000000000000
00.0 00.0 00.0 00.0 000 00.0 00.: 00.: 020._ 000.00000
00.0 00.0 00.0 00.0 00.0 00.0 00.0 000 0000000000
0:.0 00.0 00.0 00.0 000 00.0 0:.0 000 000000000
00.0 00.0 000 0:0 00.0 00.0 00.0 00.0 020._ 000.00__0_2
0:.0 00.0 00.0 00.0 00.0 00.0 00.0 00.0 020._ 000020000:
00.0 00.0 000 0:0 000 00.0 00.0 00.0 020._ 000000.000
00.: 000 0:.0 00.0 00.0 00.0 00.0 00.0 000002
00.0 0:.0 000 :00 ::.:: 00.0 00.: 0:.0 0200 000.090.00.00:
0:.0 00.0 0:.0 000 00.0 00.0 00.0 00.0 000.. 0000000000:
00.0 00.0 00.0 00.0 00.0 00.0 000 0:.0 00000000:
00.0 00.0 00.0 00.0 0:.0 0:.0 00.0 00.0 000.000.:
00.0 00.0 00.0 00.0 000 00.0 00.0 :0: 020._ 0000000000:
00.0 00.0 00.0 000 00.0 00.0 00.0 00.0 0000 0.000.000:
0:.0 00.0 00.0 00.0 000 00.0 00.0 00.0 0000 000.0056.
Ememn. cam—2 60801 0:002 ::0200 0022 000800 0022 00002 098:.
50900 >50 0000 >02

 

 

ood ood mod mmd 00.0 00.0 cod cod mmanm>
mud mod cod 00.0 5.0 00.0 no.0 mod 20E :26:ch
00.0 00.0 96 mod cod 00.0 00.0 cod was; 05:00:20.0
00.0 00.0 cod 006 Ed :70 cod cod 020._ 90:00:00.0
cod 00.0 90.0 m 0 .o cod ood cod 00.0 020.0: 05305:...
Ememn. c002 :cmEmn. c022 :cwEmn. cam—2 Emema cam—2 9:02 .5me
0.03910 >_2. 0:2. >02

 

152

 

 

 

000N 008002-002

mcoN 00:000&_

ocoN 00000000300

 

00.0 00.0 00.0 00.0 00.0 00.0 0.000 000.0008
:00: 0:.0 00.0 00. : 00.0 00.0 000000000
00.0 0:.0 :00 0:.0 00.0 00.0 000.0.0000
00.0 00.0 00.0 00.0 00.0 00.0 000 00.0
00.0 00.0 00.0 00.0 00.0 00.0 0200 0000000000000
00. : 0:0 :00 00. : 00.0 00.0 0000 0.0:000000000
:0: 00.0 00.0 00.: 00.0 00.0 0000 0020000000000
00.0 00.0 :00 0:.0 00.0 00.0 0000 000.000
::.0 00.0 00.0 00.0 00.0 00.0 0000205
00.0 00.0 0:.0 00.0 00.0 00.0 00000000
00.0 00.0 00.0 0:.0 00.0 00.0 000.000
00.0 00. : 00. : 000 00.0 00.0 0000 0000000
::.0 000 00.0 0:0 00.0 00.0 0000 000000060
00.0 :00 00.0 00.0 00.0 00.0 0000 000000005
00.0 00.0 0:.0 00.0 00.0 00.0 0000 000000000000
00.0 00.0 00.0 00.0 :0: 000 0000 00200000000
00.: 0:.0 :00 :00 00.0 00.0 020._ 0025000000
00.0: 0:0 0:. :0 00.: 00.:: 0:.0 0:00 0000000020000
00.0 00.0 00.0 00.0 00.0 00.0 0200 000000000
00.0 00.0 :00: 00.0 :000 0:.0 0000 0000000
::.0 000 00.0 00.0 00.0 00.0 0000 0000000
00.00 00.0: :00 00.: 00.0 00.0 020._ 000000.00
: :0 00.0 00.0 00.0 00.0 00.0 0000.00.00
00.0 00.0 00.0 00.0 :0: 00.0 0000000000000 0000 000.0000
:00 00.0 00.0 00.0 00.0 0:.0 0000000000 0000 000.0000
00.0 00.0 000 00.0 00.0 00.0 000000
Emewa :52). #5201 cam—)— Emema 500—2 mEmZ £980.

153

 

 

 

mcoN 00000907002

mcoN 000000;:

0:0N 2.000000on

:0 00.0 00.0 00.0 00.0 00.0 0000 0000000000
00.0 00.0 00.0 00.0 00.0 00.0 0000 000000. 0
00.0 00.0 00.0 00.0 00.0 000 0>000 00930:.
0N0 N00 000 00.0 00.0 00.0 0>:0.. 00200000.
:0 00.0 00.0 00.0 00.0 00.0 0.000 00000002005
00.0 00.0 00.0 00.0 00.0 00.0 0000 000.0055
00.0 00.0 000.0 00.0 000.0 00.0 020._ 000___0E_w
N: 00.0 00.0 00.0 00.0 00.0 0000 000.0200
00.0 00.0 00.0 00.0 00.0 00.0 0.000000.
00.0 00.0 00.0 00.0 00.0 00.0 03.00 000000.00.
0N0 00.0 00.0 00.0 00.0 00.0 0300 0003000000000.
00.0 00.0 00.0 00.0 00.0 00.0 0.000 0.000890
00.0 00.0 00.0 00.0 00.0 00.0 020._ 000.008.800.000
0: 00.0 00.0 00.0 00.0 00.0 020._ 00200000.
00.0 00.0 00.0 00.0 00.0 00.0 0020000000
00.0 00.0 00.0 00.0 00.0 00.0 000000000
2.0 00.0 00.0 00.0 00.0 00.0 0.000 000.0002).
00.0 00.0 00.0 00.0 00.0 00.0 0.000 00000000000
000 00.0 00.0 00.0 $0 3.0 020._ 0000002000
00.0 00.0 00.0 00.0 00.0 00.0 000002
00.0 00.0 00.0 00.0 00.0 00.0 0.000 000.00.000.00:
00.0 00.0 00.0 00.0 00.0 00.0 0300 000030003:
00.0 00.0 000 N00 00.0 00.0 m:..mom.0>I
00.0 00.0 00.0 ~00 00.0 00.0 000.02.:
00.0 3.0 00.0 Rd N00 00.0 05.00 002.000.0000:
000 N00 00.0 00.0 00.0 00.0 0000. 0.000.200:
#50th cam—2 0:00.50; cam—2 00.50.51 ENG—2 mEmZ .00me

154

 

 

00.0 00.0 00.0 00.0 00.0 00.0 000.000>
00.0 00.0 00.0 00.0 00.0 00.0 00.0 0.000000
00.0 00.0 00.0 00.0 00.0 00.0 0000 0000000000
00.0 00.0 00.0 00.0 00.0 00.0 0.000 00000000.:

0:00.00. :82 0:00.00 0005. 0:00.00. 0002 00:02 0980.

mcoN 00000907002

mcoN 030.00g

®CON EmwwaSOD

 

155

 

 

00.0 00.0 00.0 00.0 00.0 00.0 8.0 0N0 020._ 000.295.
00.0 00.0 00.0 00.0 00.0 00.0 00.0 00.0 0000. 000_0_0Em
00.0 00.0 0N0 00.0 00.0 00.0 00.0 00.0 020._ 000_E_m_
00.0 00.0 N00 00.0 3N 00.0 00.0 00.0 0000. 000_E_m
00.0 00.0 N00 000 00.0 00.0 00.0 00.0 020._ 000200.05
0.00 00.0 00.0 00.0 0010 00.0 00.0 00.0 0000205
00.0 00.0 N00 000 00.0 00.0 00.0 00.0 00000000 0200. 0020000050
00.0 20 N00 000 00.0 00.0 00.0 00.0 00000000.: 0000. 000.00.300.00
00.0 00.0 00.0 00.0 00.0 00.0 00.0 00.0 002000
mm. 3 00.0 00.0 00.0 00.0 00.0 000 Rd 0200. 0002.00
00.0 00.0 0N0 00.0 00.0 00.0 00.0 00.0 :09... 000000060
00.0 00.0 0N0 00.0 00.0 00.0 00.0 00.0 0000. 00300005
00.0 00.0 N00 000 00.0 00.0 00.0 00.0 0000. 000000000ch
00.00 00.0 00.: 00.0 00.0 00.0 00.0 0N8 0>000 000.000.000.00
00.0 00.0 00.0 00.0 00.0 00.0 00.0 00.0 00000000
00.0 00.0 ~00 00.0 00.0 00.0 00.0 00.0 020._ 00200000000000
mmN m: 00.00 00.0 «0.00 3.0m 00. :0 00.00 0>:0.. 00050003005
00.0 00.0 00.0 00.0 N00 00.0 00.0 00.0 020._ 00200003
000 00.0 00.0w $0.00 00.0 00.0 00.0 00.0 0300 000.003
00.0 00.0 N00 00.0 00.0 00.0 00.0 00.0 00.00. 002003
00.0 00.0 00.0 00.0 00.0 mud 00.00 0.0. E 0200 002000500
000 00.0 0N0 00.0 00.0 00.0 00.0 00.0 000.0. 000.000.
00.0 00.0 00.0 00.0 00.0 00.0 00.0 00.0 0000.00.00.
00.0 0N0 00.0 00.0 00.0 00.0 00.0 00.0 cme0t0b 000.0. 000.0000.
00.0 00.0 00.0 000 N00 000 00.0 00.0 000000.
E00000 0002 E00000 0002 0:00.00 0005. E00000 0005. 00002 09200.
00000.0. 22. 0:00 >02

 

.002 E 003M 0:5

156

 

 

 

05.0 9.0 55.0 55.0 00.0 00.0 00.0 00.0 0000 00300:.
90.5 5.0 55.5 00.5 50.5 55.5 00.5 05.9 030.. 000.30;
00.0 00.0 59.0 50.0 00.0 00.0 00.0 00.0 0.000. 000.30....
5.5 00.0 05.0 5.0 55.0 9.0 5.0 05.0 030.. 000.0003
00.0 00.0 05.0 9.0 00.0 00.0 00.0 00.0 030.. 00030300005
00.0 00.0 00.0 00.0 00.0 00.0 50.0 00.0 030.. 00000000205
5.5 3.0 05.5 9.9 00.0 00.0 9.0 9.0 00:0 000_._0E_w
05.9 9.0 50.9 00.9 59.0 50.0 55.0 05.0 030.. 0005255
00.0 50.0 00.0 00.0 59.0 50.0 50.0 00.0 .300. 0005255
00.0 00.0 00.0 00.0 59.0 50.0 9.0 9.0 030.. 002.030
5.5 55.0 05.0 5.0 05.0 55.0 50.0 55.0 030.. 0025.08.05
00.0 00.0 00.0 00.0 00.0 00.0 50.0 50.0 030.. 0.0.0000.n.
00.0 00.0 00.0 00.0 59.0 50.0 5.0 55.0 030.. 000.0250
00.0 00.0 55.0 9.0 00.0 00.0 00.0 00.0 030.. 000.:0__0.>.
5.5 3.0 55.0 9.0 00.0 00.0 00.0 00.0 030.. 039000.000
05.0 9.0 55.0 55.0 5.5.0 9.0 00.0 00.0 000000.
50.0 00.0 05.5 00.5 8+ 00.5 3.0 50.5 020._ 00260090.»:
00.0 50.0 00.0 00.0 55.0 9.0 00.0 00.0 030.. 000...:00303.
00.0 00.0 05.0 5.0 00.0 00.0 9.0 9.0 0:..000.0>...
00.0 00.0 00.0 00.0 00.0 00.0 50.0 50.0 000.02....
05.0 9.0 50.0 55.0 5.0 9.0 55... 05.9 030.. 000.....000500...
05.0 9.0 55.0 9.0 59.0 50.0 00.0 00.0 000000.000
5.9 55.0 55.0 55.0 55.0 9.0 55.0 05.0 000.0.E30n.
00.0 00.0 00.0 00.0 00.0 00.0 50.0 50.0 00m. 00.“.
00.0 00.0 05.0 9.0 9.5 50.9 00.0 00.0 0.00.0. 0.00003060005
00.0 00.0 55.9 55.5 55.55 5.3 55.9 9.9 030.. 000.._0.0E0;0m.
E00000 000.2 300.00 000.). 0000.00 000.). E00000 000.). 0802 00x0...
50:030. 20.. 0:2. >05.

157

 

 

00.0 50.0 00.0 00.0 00.0 00.0 00.0 00.0 000.000>
00.0 00.0 59.0 50.0 59.0 50.0 00.0 00.0 00.“. 03000.0:
5.9 55.0 59.0 50.0 00.0 00.0 00.0 00.0 0000 000000000...
00.0 00.0 59.0 50.0 00.0 00.0 05.0 50 030.. 00000000.;
00.0 50.0 h05.0 9.0 00.0 00.0 00.0 00.0 =00< 000000000...
“000.00.. 000.). 0000000 0005. 000.00 000.). E00000 000.2 00.02 00x0...
00:03. >.:.. 002. >0.>.

 

158

 

 

0005 00.000E_-0oz

0005 00000000.

000M 0.0050260

55.05 05.3 S. 3 500 90.55 50.5 020._ 002.000.0000
00.0 00.0 55.0 500 500 50.0 020._ 000.0050
00.0 00.0 00.0 00.0 500 50.0 .50.... 000.0055.
00.0 00.0 00.0 50.0 500 50.0 0200 000.50.
000 00.0 00.. 55.0 500 50.0 .53. 000.50.
00.0 00.0 00.0 00.0 500 50.0 0.000 000.8050
05.0 3.0 55.0 500 00.0 00.0 00820.0
00.0 00.0 00.0 00.0 00.0 00.0 0000.... .30... 000.00.30.00
00.0 50.0 00.0 50.0 55.0 000 500.005. .300. 000.00.30.00
00.0 50.0 00.0 00.0 00.0 00.0 000.000
00.. 50.0 00.0 55.0 50.0 05.0 .30.... 0003.00
000 00.0 00.0 50.0 50.0 3.0 .304. 00000.00
00.0 00.0 000 000 00.0 00.0 .30.... 000500020
05.0 50.0 05.0 00.0 500 50.0 .304. 0020500000
00.5 50.. 50.0 00.0 00.05 50. : 020._ 000.580....0
00.0 50.0 00.0 00.0 00.0 00.0 00002.00
00.0 00.0 00.0 00.0 500 50.0 020._ 000000009000

00.05 50.59 00.5.. 05.05 05.0. 50.0 0.00.. 00050003000
00.0 00.0 00.0 50.0 00.0 00.0 0200 000000000

00. S 05.0 00.0. 55.5 S. S 05... 0200 0000000
00.0 50.0 00.0 00.0 00.0 00.0 .50... 0000000

00.5. 55.5 05... 00.5 55.0 .05.. 0.000 000.0005...
05.0 3.0 00.0 00.0 00.0 00.0 0.03. 000.09..
00.0 00.0 00.0 50.0 500 50.0 0000.00.00.
00.0 05.0 05.0 00.0 55.0 000 0.00.... 000.0000.
05.0 3.0 00.0 00.0 500 50.0 00:00....

5:00.50. cam—2 5:09.00. :52). Ememn. cam—>— mEmZ 0.0me

 

 

159

 

 

 

0005 00000000002

0005 00800.0.

0005 5000000300

9.0 00.0 00.0 00.0 59.0 50.0 0.00.0. 0.0000000...
55.0 55.0 00.0 00.0 00.0 00.0 0000 000.30....
95.5 55.5 55.5 55.9 00.0 55.9 030.. 000.5005
00.0 50.0 00.0 00.0 00.0 00.0 0.000. 00230.5
50.0 50.0 .050 05.0 05.9 55.0 030.. 000.0000...
00.0 00.0 00.0 50.0 59.0 50.0 030.. 000.>Eo..0._.5
00.0 00.0 00.0 00.0 59.0 50.0 030.. 00003002005
9.9 55.0 00.0 50.0 05... 55.0 0000 000...:E.5
55.0 05.0 00.0 05.0 55.0 9.0 030.. 000...:E.5
9.0 00.0 00.0 00.0 59.0 50.0 H000.0. 00050.05
00.0 50.0 000 000 00.0 00.0 0200 0020.50
95.0 5.0 5.0... 05.0 55.0 3.0 030.. 0003200905
00.0 00.0 00.0 50.0 00.0 00.0 030.. 0.0.0805
.050 3.0 00.0 00.0 55.0 9.0 030.. 00200000
05.0 3.0 00.0 00.0 00.0 00.0 030.. 000.0205.
9.0 00.0 55.0 05.0 05.0 9.0 030.. 0.0.000.00..
09.0 00.0 000 000 50.0 00.0 000002
0.0.5 50... 05.0 05.5 05.5 55.5 030.. 000.00>000.0>...
50.0 50.0 9.0 9.0 00.0 00.0 030.. 000._.00o.0>...
9.0 00.0 00.0 00.0 55.0 .050 000000.03.
50.0 50.0 00.0 00.0 00.0 00.0 000.03....
50.0 55.0 00... 9.3 55.0 05.0 030.. 00000000000...
05.0 55.0 00.0 50.0 00.0 00.0 000000000
9.0 50.0 00.0 05.0 55.0 3.0 0000.00.00.
00.0 00.0 00.0 00.0 53.0 50.0 00m. 00....
05.3 55.0 9.0 9.0 00.0 00.0 0.300. 00000000000005
0000.00 000.). 0000.00 000.2 0000.00. 000.). 00.02 00x0 .5

160

-_ _._ ..

 

 

 

 

 

000M 008090.002

000N 00600.0.

MCON Emmhwwcgofl

8.0 8.0 00.0 8.0 8.0 8.0 000.000>
8.0 8.0 00.0 8.0 ~00 00.0 00“. 026500
50.0 50.0 00.0 50.0 05.0 3.0 000n. 0.0000000...
8.0 00.0 8.0 00.0 8.3 00.0 020._ 0.90220.
“000.0“. 000.). 0000.00 000.). 000000.”. 000.). 0E0z 00x0...

 

161

 

 

162

00.0 00.0 03 00. 2 00.2 0.0.0 0.0.0 00. 2 0200 002.000.0000
20.0 00.0 20.0 2.0 ~00 00.0 00.0 00.0 020. 0000.050.
00.0 00.0 00.0 00.0 00.0 00.0 00.0 00.0 30< 0000.050
00.0 00.0 00.0 00.0 00.0 00.2 00.0 00.0 0200 000.000
20.0 000 E0 00.0 00.0 20.0 00.0 00.0 32 00030.0
00.0 00.0 00.0 00.0 00.0 2.2 00.2 5.00 030.0 000.00.30.00
00.0 00.0 3.0 00.0 00.0 00.0 00.0 00.0 000.0 00000.00
00.0 00.0 20.0 00.0 2.0 2.0 00.0 00.0 0300. 0000.230
00.0 00.0 20.0 2.0 00.0 00.0 00.0 00.0 .30< 000300.00
00.0 00.0 0 2.0 00.2 00.0 00.0 00.0 00.0 33.. 002.0820
00.0 00.0 00.0 00.00 00.2 00.5 00:0. 0.0 0030 000.50.00.30
00.00 20.00 3.00 {.000 00.00 00.00 00.00 00.00 0200 000.000.000.00
2.0 00.0 00.2 00.0 E 00.0 00.0 0.0.2 00.0 30< 000.000.00.30
00.0 00.0 ~00 02.0 00.0 00.0 00.0 00.0 000.. 00030000000000
20 2.0 00.0 00.0 00.0 00.0 00.0 00.0 020. 000.0000
00.0 00.0 00.0 00.0 00.0 E0 00.2 2.2 020._ 000030020000
00.0 00.0 00.0 00.0 00.0 00.0 2.0 00.0 0200 000000000
00.: 00.2 00.00 00.000 00.00 20.00 00.0 2.2 0200 0000000
0: 00.2 00.0 00.00 00.0 2.0 00.0 00.0 030.0 0000000
03 00.2 2.0 00.2 00.0 2.0 00.2 00.2 0200 000000.30
2.0 2.0 00.0 00.0 00.0 00.0 :0 00.0 30.0 00030<
000 R0 00.0 00.0 00.0 00.0 2.0 000 00003002
00.0 00.0 00.0 02.0 00.0 00.0 00.0 00.0 020._ 00030004.
2.0 2.0 00.0 00.0 00.0 00.0 00.0 00.0 .30< 000.0000.
00.0 00.0 20.0 2.0 00.0 00.0 00.0 00.0 00000.0
Emema cam—2 Ememn. :00—>— EmoEn— 500—2 Ememn— c022 wEmZ 0.0me
00300.4 22. 00:0 >05.

 

.DuuDQ .3415 #301341— 0433) «Dd 0443)..)L 343K 444))4 .3.le 1))ddd344/ 5.3.2110), o1¢13 o!)!!. 0 0 0

 

 

163

00.: 2.~ 00.0 00.0 ~00 :.0 :00 ~00 0030 002.3000
00.0: ~02 3.0 00.00 00.0 00 00.0 :0: 020._ 000.3000
03 00.: 00.0 00.0 00.0 00.0 0~.0 00.0 .30... 000..3E_0
00.0 00.0 00.0 00.0 00.0 00.0 :00 ~00 020. 000320000000
00.0 00.0 00.0 00.0 00.0 00.0 -.0 00.0 0.00.. 0.000000...
00.0 00.0 2.0 0~.: 0~.0 3.0 :00 00.: 0200 00030000
00.0 00.0 00.0 00~ 00.0 2.0 00.0 000 0.0000095
~00 00.0 00.0 00.0 00.0 00.0 00.0 00.0 020._ 000.3802
00.0 00.0 00.0 00.0 ~00 00.0 00.0 00.0 020._ 00030.35.
:0 ~00 00.0 00.0 00.0 00.0 03 00.~ 020. 00230000....
~00 0~.0 ~00 2.0 00.0 00.0 00.0 00.0 020. 000....00002.
00... 00.0 00.0 00~ 00.0 00.0 :00 00.: 020. 000.00.000.00:
:~.0 0~.0 :00 00.0 0~.0 00.0 00.0 00.0 020._ 000.2023:
0~.0 0~.0 :00 2.0 00.0 00.0 00.0 00.0 .300. 00003000....
00.~ ~0.~ 0~.: ~00 :00 00.0 00.0 00.0 00.000002.
0~.0 00.0 2.0 0~.0 00.0 00.0 00.0 00.0 0.00.. 00000000000:
~00 00.0 ~00 2.0 2.0 -.0 :00 ~00 .30.... 00.0.50:
00.0 00.0 00.0 ~00 00.0 00.0 00.0 00.0 030.0. 0023.3...
00.0 00.0 ~00 2.0 00.0 00.0 00.0 00.0 30.0 000.030
:.0 ~00 00.0 00.0 00.0 00.0 2.0 0~.0 0.00.. 0000050000020
2.0 :~.0 ~00 2.0 00.0 :00 ~00 2.0 000000000
~3 00.: 00.0 00.0 0~.0 00.0 2.0 :~.0 000.0300“.
00.0 00.0 00.0 00.0 ~00 00.0 00.0 00.0 0200 00.00.00.030
2.0 :~.0 0:0 2.: 0~.0 :00 000 R0 :30... 0.030.000.0000
00.0 00.0 00.0 00.0 00.0 00.0 00.0 00.0 .300. 000.000.0000
#050001 cam—2 Ememn. cam—2 Ememn. cam—2 Ememn— cam—2 mEmZ coxmh

00003.0. 23.. 00:0 >05.

 

o\, J4‘>)/ J “‘.\‘.v {.1 ‘. z ‘

l ._H _|-I .

 

 

 

00.0 00.0 voo 00.0 00.0 00.0 00.0 00.0 000.000>
00.0 00.0 00.0 00.0 00.0 no.0 :0 omo 50.0 0305.0:
00.0 n: 00.0 mvn 00.0 00.0 n00.0 00.0 020._ 0.00.ch2;
00.0 0~.0 nmo :N 00.0 00.0 00.0 00.0 00:0 0.000005
00.0 00.0 No.0 00.0 00.0 00.0 00.0 00.0 020.. 0.0000205.
.000 00.0 3.0 00.0 000 V0.0 :0 0~.0 =00< 0.000002;
3.0 0.0.0 no.0 00.0 00.0 0.20 ofim 00.0 0000 00200:.
N00 mtm mno 00.0 00.0 00.0 00.0 No.0 020._ 00200.0
2.0 00.0 00.0 0~.0 woo 00.0 00.0 00.0 =00< 000.30;
3.0 mmo No.0 mfio 00.0 00.0 00.0 00.0 030.. 000.0002.
no.0 00.0 00.0 00.0 00.0 00.0 00.0 00.0 023 0005:0095
00.0 00.0 00.0 00.0 .000 00.0 00.0 00.0 0>.0._ 00000000205
“000.00 000.2 0:00.00 000.2 0:00.00 0005. 0000.00 000.2 00.02 00x00.
0000.00. 22. 00:0 .02

 

K3311: J 43.37414 4 a:

164

 

 

0:0N 0060067002

0:0N 00.0000:

0:0N E00..0c.soo

00.0 00.0 000 000 00.0 00.0 ..00< 000.0000
00.: 0n... 0: 00.0 000 5. 0.00. 00000.0
000 0: 00.: :0 000 :0: .300. 00000.0
000 000 000 000 00.0 :00 .300. 000.00.30.00
000 000 000 000 000 00.. ..00< 00000.00
:00 .00 00.0 00.0 000 0:0 ..00< 0.00.00.00
00.0 00.0 .00 000 S0 000 ..00< 0.0.0800
00.0 000 00.0 00.0 0:0 000 ..00< 000...0000.0
000 00.0: :00: 00.00 0.0 0:00 0000. 000.0.000..00
00.0: 00.00 02.0 0000 0000 #0.: 0.00. 000.0.000..00
0:0 3.00 00.0 00.0 00.: 00.00 ..00< 000.0.000..00
0:0 000 00.0 00.0 000 :0 0.00. 000.000.000.000
000 :0 00.0 00.0 00.0 00.0 0.00.. 000.0000
00.0 000 :00 000 00.: n00 0.00.. 00000003000
00.0 00.0 00.0 00.0 .00 :0 0.00.. 000000000
00. :0 0.: 00.00 0000 000: 00.00 0.00.. 0000000
:0 000 000 000 000 00.00 ..00< 0000000
00.: 00.0 000 0:0 000 000 0.00.. 000.0..00.<
000 :0 00.0 00.0 00 000 ..00< 000.00<
000 :0 00.0 00.0 80 :00 008.0003
00.0 00.0 00.0 00.0 00.0 :0 0.00. 000.0000<
B0 00 0:0 000 00.0 00.0 .000. 000.0..0<
0:0 000 0:0 000 00.0 00.0 00..00<
”7.00th ENG—>— Hcmo0®n_ CN®S_ acwohwn— Cm®_>_ 05.52 0.0me

 

.03 359/ 3 5371.4 0 E

165

L‘

 

 

 

 

 

166

00.0 00.0 00.0 00.0 000 000 000.. 0.0.0000:
000 000 00.0 000 000 00.: 0.00. 000.00000
n00 000 R0 00.: 000 n: 0.0000005
00.0 00.0 000 000 00.0 00.0 0.00. 000000002
00.0 00.0 .00 00.0 00.0 00.0 000. 00000.05.
00.0 00.0 00.0 .00 000 00.0 000. 000...00000....
000 000 00 :0 00.0 00.0 0.00.. 0000.00.00:
000 00.0 000 000 000 000 0.00.. 000.00.000.00:
000 0:0 :0 000 000 000 0.00. 0000.08.05
n00 :0 000 000 00.0 00.0 .500. 00000020....
0:.: :00 00.0 00.0 :1 00.0 000000.02.
00.0 000 000 000 0.0 20 0.00. 000.00.00.00:
000 0:0 000 00 00.0 00.0 ..00< 0.0.0000:
000 00.0 000 000 00.0 00.0 ..00< 000.000:
000 00.0 00.0 00.0 00.0 :0 ..00< 000.006
000 30 00.0 000 00.0 000 0.00.. 0000000000020
00.0 00.0 NNo 00.0 00.0 0~.0 000000000
000 00.: 000 :00 000 00.0 000000.00
00.0 00.0 :00 00.0 00.0 00.0 0.00. 0.0.00.000000
000 000 0:0 000 30 no.0 ..00< 0.0.00.0.00000
00.0 00.0 00.0 00.0 000 00.0 ..00< 0000000000
00.0 000 000 00.: n0: n00 0.00.. 0000000000.”.
000 0:0 0.0 00.0 20 :00 0.00. 000.0000
0.00.00 0002 .000.00 0005. .000.00 0002 9002 00x00.

0:0N 00.000.01.02 0:0N 00.0000: 0coN 0000:0550

 

00.0.00. .0. .05 7.0200.

L.‘

 

 

 

167

00.0 00.0 00.0 00.0 000 00.0 000.000>
00.0 00.0 000 000 000 20 00.0. 00,000.00
E0 00.: 000 00.0 000 00.0 0.00. 0000000000
B0 00.: 000 :0 00.0 0:0 0000. 0.0000000
00.0 00.0 n00 :0 00.0 00.0 0.00. 00.000000
:0 000 0:0 000 0n0 000 ..00< 0.0000000
000 000 0:0 :00 000 0; 0000. 000.30:
00.: 00.0 :00 00.: 000 0: 0.00. 000.00:
000 :0 000 00.0 00 000 ..00< 000.50:
000 :00 000 000 00.0 00.0 0.00.. 000.0000»
00.0 000 00.0 00.0 :00 .00 0.00. 0003000000
00.0 00.0 000 000 00.0 00.0 0.00. 00000002090
000 00.: 000 00.: 000 00.: 0000. 00000000
000: 00.00 00.0 00. : 00.0 00.00 0.00.. 0000.000
00.: 00.0 000 00.: 000 0:0 ..00< 0000.000
00.0 00.0 :00 00.0 00.0 00.0 0.00.. 0003200905
0:00.01 :00—)— Ememn— :00—2 Ememn— :02)— mEmZ 0.0me

0:0N 00.0002: 0:0N 800.60.500

0:0N 00.000.01.02

 

0‘, ’*‘>’/ I II" .I I

I...“

 

 

00. T 00.0..
. 00.0
00.0 .
00.0
00.0 0~.0-
ooe .
00.0 00.0-
00. T 00. T
. 00.0
00. T 00.0-
. 00.?
00. T 00. T
5.0- 0~.0-
oo. T 00. T
00.0 .
00. T 0~.0
00. T .
5.0 0.0-.0
00.0. 5.0-
00. T 00.0-
000 00.0
9.0 3.0-
00. T 00.0
. 00. T
00. T 00. T
00.0 00.0
N00- 00.0
00000.4 200

30; 260500

00.0

00.0

00.T

00.0-
00. T
00.0

00.0
00.T
00.0-
00. T

00.T

N00
00.0
00.0-
00. T
00.0

00.0
0:30

00. T

00._.

00.T

0T0

00. T
00.0-
00. T

5.0-
00. T
00.0-
00.0
00. T
00. T
00. T

00. T
>05.

00. T

00. T
00.0
00.0
00.T

00. T

00. T
00.0-
00. T

00. T
00. T
00.0-

00.0-
00. T
00. T
00. T
00. T
00. T
00.0
00. T

00:00.0~

00.0-

00.0

00. T
00.0
00.0-
00. T
00.0
00.0

00.0-
00.0-
00. T

00. T
00.0

00.0-
00. T
00.0-
00. T

00. F-
00.0
00.0
0~.0
>30

00.T
00.0
00. T
00.0
0N0

00. T
0N0

00. T
00.T
00. T
00. T
0T0-
00.0-
00.0-
00.0

00.0

00.0

0:20

50:... $520

00.0-

00.T
00._.
0~.0

00.0

00.0
00. T
00. T
00. T

30.0-
00.0-
00.0-
N50
00. T
00. T
00. T

00. T
>02

00.T

00.0

00.T
00.0
00.0
00.T

00.T

00. T
00.0-
00. T

00. T
00. T
00.0-

00.0-
00.0-
0~.0-
00. T
00. T
00. T
00.0
0.20-

003030.

00.T
00.0

00.0
0N0-
00.0
N00-
00. T
N50
00. T

00.0-
000.0-
00. T

0T0
0N0

00.0-
00.0-
who.
00.?
00.0
00.0-
00.0-
00.0
50
>30

00.T

00.0

00.T

N00-
00. T
00.0
00.0
00.—-
00.T
00.0-
00. T

00. T
00.0
00.0-

00. T
N50

00.0

00.0
0:00

50:. x090

00.T

00.T
00.T
00.0

00.0

00.—.-
00.0-
00.T
00.0

00.0-
00.—.-
0.00-
00.0

00.T
00.0-
00.T

00.0-
>05.

=00< 000_E_m_

020.0 0006005

00000.05

00000000

800090 =00< 000023050
20000000.: =00< 0028:0050
0000000

::0< 0000000

030,4 0600.260

«30.4 00000060

=00< 000500005

=00< 002.050.0000

00:0 000_Eo:0:_:0

020.0 000_Eo:o:_:o

0300. 0000:8220
00000.20

0>:0.. 0025000000000
0>:0.. 000E000

0>:0.. 000005050000

0>:0.. 000000000

0>:0.. 0000000

=00< 0000000

0>:0.. 000000000~

050.0. 00000.0.

0000_:0E<

020._ 000_::00<
900000000 030,0 000_0:0<
00000205000 0.0000 000_0:0<
0500.4.

2002

.050 00a 20 000 002 a 000000

300 3000000 000 0:00 8505 0:00 0005 000 £008 3 0000000 03 0020> 0808 0050005 .0 52750.3

168

‘1

 

 

00. T 00. T
00. T .

. ooe
00. T .
00.0 00.0
00.0 00.?
00. T 00. T
0~.0- 00.0
00.0- 00. T
00. T 00. T
00. T 00.0-
:0 0.0.0
00. T 00. T

. 00. T

oo.T
00. T
de 00.0
~00- 00.0-
00. T 00.0-

. 00. T
00. T 0~.0
00.0- 00. T
00. T .
00. T 00.0-

000m0< 200

000:. 260500

00.T

00.T
00.T

00._.

000
N50-

00.T

0T0
00.T

00.0-
00.0-

00. T
00.0
00.0
00. T

00. T
0:00

00.T

00.T

0N0-

00.0-
00._.
00.0-
00. T

00. T
00. T
00.0-
00.0

00.T

00.0-
00.0-
co..-
00. T
>02

00.0- 00. T
00. T .

. ooe
mmd .

. 00.0
00.0 00.?
00. T 00. T
00.0- $0-
000- 00.0
oo.T oo.T
00. T 00. T
00. T 00. T
oo.T 00.0

. oo.T

00. T
00.—- .
oo.T
00.0 00.0
00. T 00.0-
000 .
00. T 00.0

. 00. T
00. T 30.0-
00. T 00. T
00. T .
00. T 00. T

00000< 200

00.0-

00.T
00. T
00.0

00.0
00. T
00. T
00.—-
00.0-
00. T

00.0
00.0-
V00-
00. T
00.0-
0~.0
00. T

00.T
0:00

009.0 5590

00.0
N00-

00.T

00.0-

00.0-

00.0-
00. T

00. T
00.0
00.0-

00.0
00.0-
00.0-
00. T

00. T
>02

30.0- 00.0-

00. T .

00. T
00.? Se
. 00.0
:0 00. T
00.0- 00.0
00. T 30.0
00. T 00. T
00. T Duo.
00.0 00.0-
00. T 00. T
. 00. T
00. T
00. T

00.0 00.0
00.0- 00.0-

009 .
00. T N00
. 00. T
00. T 00.0-
000 00.0

00. T .
00. T 00. T
00000.0. >_00

0~.0-
00.0
:0
00.0

00.0
00.T
00.T
00.T
00. T
00.0
00.T
00.0-
00.T
00.0
00.0
00.T

00.T
0:00

000:... x090

00._‘
00.0-

00.T
00.0

00.0-

00.0-

00.0-
00. T

00.T
00.T
00.T
00..-

00.0-

30.0-
00. T
000
00. T
>0_>_

0000000000
0000:0095

0>:0.. 000000802
0>:0.. 000_:0__o_2
020._ 0005:0055
0>:0.. 00000200..
000000_

0>:0.. 000__000._0>I
0>:0.. 000E0>0020>I
0>:0.. 000___:0o:0>_._
000< 002.2093:
0:0000:0>_._
0050000..

0>:0.. 0000500000:
000,0 0:009:00...
=00< 000__0__0:

=00< 000000

0>:0.. 000E0Eoo
0>:0.. 0000080000020
0000000000
000_0_:.:00

00m. :00.

020._ 0.00090E0c0m
0_00< 0000090823
=00< 0000050000
020._ 000___0:0E0:0m_
0>:0.. 000_0_0Em_
=00< 0000050
0E3 000_E_m_

252

0.0000 0 00020000

169

 

00.0 oo.T
. 00.0
00. T 00. T
00.0 00.0-
. :0
0~.0- 00.0-
000- 00.0
00.0- 00.0
00. T 00.0-
Nnd 00.0
00. T Rd
5.0. 00.0
00.0- 00.0-
000- 00. T
00.0 00.0
00. T 00. T
000000~ >_00

000:... 260500.

00.0-
00. T
00. T

00.T
00...-
00...
00.T
00.0

00. T
00. T
00.0-
N00-
00.0
00...

00.0-
0:00

00.T
00...-

00.0
00. T
00. T
00.0

00.0

00.0-
N00
N00-
00.0-
00...
00.0
00.0-

00.0-
>05.

00.0

00.0 .
00. T 00. T
00. T 00.0-
. oo.T
00. T N50-
000- 00.0
00.0- 00.0-
00. T oo.T
3.0 0.0.0
oo.T oo.T
00.0- 00.0
oo.T Rd-
000- 00.0-
000 00.0

00.0

00. T 00. T
00000.0. >_00

00.0-
00. T
00...-
00.0
00. T
00. T
00.0
00. T
00...

00.0
0~.0-
00. T
00. T

00...
00.0
00.0
000-
0:00

002.0 :390

00.0-
00. T

00.T
00.T
00.0

00...

0T0-
0T0-
00.T
00.0-
00.0
00.0
00.0
000-

No.0-
>05.

03. 00. T
00. T 00. T
00. T «0.0-
. 00. T
00. T 00. T
3.0- 00.0
5.0- 00.0
00. T 00. T
00. T 00.0
00. T 00. T
00. T 0.0.0-
000- N00-
00. T N50-
00.0
00. T 00. T
00000.0. >_00

00.0-
00. T
50.0-
00.0
00. T
00. T
00.0
00. T
00.0

00. T
00. T
00. T
00.0-

00.0

00.T
0:00

000; 0.00:0

{.0-
00...-

00. T
00.T
00.0

00. T
0.0.0
000-
00.0-
00...
00. T
00. T

00.0-
>05.

000.000>

:00. 5505::

0>:0.. 000.5080...
0000 0:900:00...
0>:0.. 0:900:00...
0_00< 0000000000
0000 000.500.
0300 000.30....
=00< 002000

0>:0.. 000E000...
0>:0.. 0005800000
0>:0.. 0000005305
0000 000___0e_0
0>:0.. 000___0E_w
0.00.0. 0000.085
00:003.

0>:0.. 000__0.>n_
0>:0.. 00058050000
0>:0.. 0.0000020
0>:0.. 0000:0N>Eo000
0>:0.. 00000000
0802

00.00000 0. 00020000.

170

 

 

LITERATURE CITED

171

I.”

 

LITERATURE CITED

Aho, R. S. 1977. A population study of the cutthroat trout in an unshaded and shaded
ssection of stream. Master’s thesis. Oregon State University, Corvallis.

A.lexander, G. R., and H. Gowing. 1976. Relationships between diet and growth in
rainbow trout (Salmo gairdneri), brook trout (Salvelinusfontinalus), and brown
trout (Salmo trutta). Michigan Department of Natural Resources Fisheries
Division Special Report 1841, Lansing, Michigan.

\lexander, G. R,. and H. Gowing. 1980. Population dynamics of trout in some streams
of the Northern Lower Peninsula. Michigan Department of Natural Resources,
Fisheries Report 1877, Lansing, Michigan

llexander, G. R., and E. A. Hansen. 1983. Sand Sediment in a Michigan trout stream
Part 11. Effects of reducing sand bedload on a trout population. North American
Journal of Fisheries Management 3:365-372.

llexander, G. R., and E. A. Hansen. 1986. Sand bed load in a brook trout stream. North
American Journal of Fisheries Management 629-23.

.llan, J. D. 1978. Trout predation and the size composition of stream drift. Limnology
and Oceanography 23(6):]231-1237.

.llan, J. D. 1981. Determinants of diet of brook trout (Salvelinusfontinalis) in a

mountain stream. Canadian Journal of Fisheries and Aquatic Sciences 38: 1 84-
192.

.llan, J. D. 1995. Stream ecology: structure and function of running waters. Chapman
and Hall, Inc., New York.

llan, J. D., and A. S. Flecker. 1993. Biodiversity conservation in running waters.
BioScience 43(1):32-43.

llan, J. D., and E. Russek. 1985. The quantification of stream drift. Canadian Journal
of Fisheries and Aquatic Sciences 42:210-215.

ngradi, T. R., and J. S. Griffith. 1990. Diel feeding chronology and the diet selection
of rainbow trout (Oncorhynchus mykiss) in the Henry's Fork of the Snake River,
Idaho. Canadian Journal of Fisheries and Aquatic Sciences 47:199-209.

mett, R. H., Jr. 1985. American insects: A handbook of the insects of America north
of Mexico. Van Nostrand Reinhold, New York.

lchman, R. A. 1984. Foraging behavior of free-ranging wild and hatchery brown trout.
Transactions of the American Fisheries Society 113(1):1-32.

172

Bain, M. B., J. T. Finn, and H. E. Booke. 1988. Streamflow regulation and fish
community structure. Ecology 69(2):382-392.

Baldwin, N. S. 1956. Food consumption and growth of brook trout at different
temperatures. Transactions of the American Fisheries Society 86:323—328.

Battige, D. S., B. L. Fields, and D. L. Sowers. 1997. Removal of Stronach Dam.
Proceedings of the International Conference on Hydropower (WaterPower ’97)
221341—1350.

Beamish, R. J ., and H. H. Harvey. 1969. Age determination in the white sucker. Journal
Fisheries Research Board of Canada 26(3):633-638.

Benke, A. C. 1990. A perspective on America's vanishing streams. Journal of the North
American Benthological Society 9(1):77-88.

Blumer, S. P., T. E. Behrendt, J. M. Ellis, R. J. Minnerick, R. L. LeuBoy, and C. R.
Whited. 1998. Water Resources Data — Michigan, Water Year 1997. U. S.
Geological Survey Water Data Report MI-97-1.

Bisson, P. A. 1978. Diel food selection by two sizes of rainbow trout (Salmo gairdneri)
in an experimental stream. Journal of the Fisheries Research Board of Canada
35:971-975.

Born, S. M., K. D. Genskow, T. L. Filbert, N. Hemandez-Mora, M. L. Keefer, and K. A.
White. 1998. Socioeconomic and institutional dimensions of dam removals: The
Wisconsin experience. Environmental Management 22(3):359-3 70.

Bowers, R., and M. Bowman. 1995. Hydroelectric relicensing: how relicensing can
affect dam removals. River Voices 5(4):7—10.

Bowles, D. E., and R. A. Short. 1988. Size composition of invertebrate drift and fish
predation in a Texas stream. The Southwestern Naturalist 33(2): 177-1 84.

Bozek, M. A., L. D DeBrey, and J. A. Lockwood. 1994. Diet overlap among size classes
of Colorado River cutthroat trout (Oncorhynchus clarki pleuriticus) in a high-
elevation mountain stream. Hydrobiologia 273:9-17.

Bridcut. E. E., and P. S. Giller. 1995. Diet variability and foraging strategies in brown
trout (Salmo trutla) : an analysis from subpopulations to individuals. Canadian
Journal of Fisheries and Aquatic Sciences 52:2543-2552.

Bryan, J. E., and P. A. Larkin. 1972. Food specialization by individual trout. Journal of
the Fisheries Research Board of Canada 29: 1615—1624.

Cada, G. F., J. M. Loar, and D. K. Cox. 1987. Food and feeding preferences of rainbow

and brown trout in southern Appalachian stream. The American Midland
Naturalist 1 17(2):374—3 85.

173

Campbell, R. F., and J. H. Neuner. 1985. Seasonal and diurnal shifts in habitat utilized
by resident rainbow trout in western Washington Cascade Mountain streams.
Pages 39-48 in F. W. Olsen, R. G. White, and R. H. Jamre, editors. Symposium
on small hydropower and fisheries. American Fisheries Society, Western
Division and Bioengineering Section, Bethesda, Maryland.

Carlander, K. D. 1969. Handbook of freshwater fishery biology, volume 1. Iowa State
University Press, Ames.

Chaston, I. 1969. Seasonal activity and feeding pattern of brown trout, Salmo trutta, in a
Dartmoor stream in relation to availability of food. Journal Fisheries Research
Board of Canada 26(8):2165-2171.

Cibrowski, J. J. H. 1983. Influence of current velocity, density, and detritus on drift of
two mayfly species (Ephemeroptera). Canadian Journal of Zoology 61 :1 19-125.

Clapp, D. F., R. D. Clark, Jr., and J. S. Diana. 1990. Range, activity, and habitat of
large, free—ranging brown trout in a Michigan stream. Transactions of the
American Fisheries Society 11921022-1034.

Clark, M. E., and K. A. Rose. 1997. Factors affecting competitive dominance of
rainbow trout over brook trout in southern Appalachian streams: Implications of
an individual-based model. Transactions of the American Fisheries Society
126(11):1-20.

Cooper, E. L. 1953. Periodicity of growth and change in condition of brook trout
(Salvelinusfontinalis) in three Michigan trout streams. Copeia 2:107-114.

Cooper E. L. 1967. Growth and longevity of brook trout (Salvelinusfontinalus) in
populations subjected to light exploitation. Transactions of the American
Fisheries Society 96:383-3 86.

Cunjak, R. A., and J. M. Green. 1983. Habitat utilization by brook char (Salvelinus
fontinalus) and rainbow trout (Salmo gairdneri) in Newfoundland streams.
Canadian Journal of Zoology 61 : 1214—1219.

Cushman, R. M. 1985. Review of ecological effects of rapidly varying flows
downstream from hydroelectric facilities. North American Journal of Fisheries
Management 52330-339.

Dedual, M., and K. J. Collier. 1995. Aspects of juvenile rainbow trout (Oncorhynchus
mykiss) diet in relation to food supply during summer in the lower Tongariro
River, New Zealand. New Zealand Journal of Marine and Freshwater Research
29:381-391.

Doppelt. B. 1993. Entering the watershed: a new approach to save America's river
ecosystems. Island Press, Washington D. C.

174

Draulans, D. 1988. Effects of fish-eating birds on freshwater fish stocks: an evaluation.
Biological Conservation 44:251-263.

Elliott, J. M. 1967. The food of trout (Salmo trutta) in a Dartmoor stream. Journal of
Applied Ecology 4:59-71.

Elliott, J. M. 1970. Diel changes in invertebrate drift and the food of trout, Salmo trutta
L. Journal of Fish Biology 2:161-165.

Elliott, J. M. 1973. The food of brown and rainbow trout (Salmo trutta and S. gairdneri)

in relation to the abundance of drifting invertebrates in a mountain stream.
Oecologia12:161-165.

Ellwood, J. W., and T. F. Waters. 1969. Effects of floods on food consumption and
production rates of a stream brook trout population. Transactions of the
American Fisheries Society 22253-262.

Ensign, W. E., R. J. Strange, and S. E. Moore. 1990. Summer food limitation reduces
brook and rainbow trout biomass in a southern Appalachian stream. Transactions
of the American Fisheries Society 119:894-901.

Eschmeyer, P. S. 1938. Management of a group of small Michigan lakes. Transactions
of the American Fisheries Society 67: 120-129.

Fausch, K. D. 1984. Profitable stream positions for salmonids: relating specific growth
rate to net energy gain. Canadian Journal of Zoology 622441-451.

Fausch, K. D. 1988. Tests of competition between native and introduced salmonids in
streams: what have we learned? Canadian Journal of Fisheries and Aquatic
Sciences 45:2238-2246.

Fausch, K. D., and R. J. White. 1981. Competition between brook trout (Salvelinus
fontinalis) and brown trout (Salmo trutta) for positions in a Michigan stream.
Canadian Journal of Fisheries and Aquatic Sciences 38:1220-1227.

Flick, W. A., and D. A. Webster. 1992. Standing crops of brook trout in Adirondack
waters before and after removal of non-trout species. North American Journal of
Fisheries Management 12:783-796.

Ford, R. 1984. Suckers to trout- effect of habitat restoration on fish populations in Rapid
City, South Dakota. Pages 133-136 in F. Richardson and R. H. Hamre, editors.
Proceedings of the Symposium Wild Trout III. Federaton of Fly Fishers and
others.

Forrester, G. E., J. G. Chace, and W. McCarthy. 1994. Diel and density-related changes
in food consumption and prey selection by brook charr in a New Hampshire
stream. Environmental Biology of Fishes 39:301-311.

175

Foster, J. R. 1977. Pulsed gastric lavage: An efficient method of removing the stomach
contents of live fish. The Progressive Fish Culturist39(4):166-169.

Francis, R. I. C. C. 1990. Back-calculation of fish length: a critical review. Journal of
Fish Biology 36:883-902.

Gard, R., and D. W. Seegrist. 1972. Abundance and harvest of trout in Sagehen Creek,
California. Transactions of the American Fisheries Society 101:463-477.

Garman, G. C., and L. A. Nielsen. 1982. Piscivory by stocked brown trout (Salmo
trutta) and its impact on the nongame fish community of Bottom Creek, Virginia.
Canadian Journal of Fisheries and Aquatic Sciences 39:862-869.

Glenn, C. L., and E. J. Ward. 1968. ‘Wet weight’ as a method of measuring stomach
contents of walleyes, Stizostedion vitreum vitreum. Journal of the Fisheries
Research Board of Canada 25:1505-1507.

Gowing, H., and G. R. Alexander. 1980. Population dynamics of trout in some streams
of the northern lower peninsula of Michigan. Michigan Department of Natural
Resources Fisheries Division Special Report 1877, Lansing, Michigan.

Griffith, J. 8., Jr. 1974. Utilization of invertebrate drift by brook trout (Salvelinus
fontinalus) and cutthroat trout (Salmo clarki) in small streams in Idaho.
Transactions of the American Fisheries Society (lO3):440-447.

Gup, T. 1994. Dammed from here to eternity: dams and biological integrity. Trout
35: 14-20.

Haberman, R. 1995. Dam fights of the 1990’s: Removals. River Voices 5(4):1-6.

Hammad, H. Y. 1972. River bed degradation after closure of dams. American Society
of Civil Engineers, Journal of the Hydraulics Division 98:591-607.

Hansen, E. A. 1971. Sediment in a Michigan trout stream, its source, movement, &
some effects on fish habitat. U. S. Forest Service Research Paper NC-59.

Hayes, J. W. 1987. Competition for spawning space between brown (Salmo trutta) and
rainbow trout (S. gairdneri) in a lake inlet tributary, New Zealand. Canadian
Journal of Fisheries and Aquatic Sciences 44:40-47.

He, X., and J. F. Kitchell. 1990. Direct and indirect effects of predation on a fish
community: a whole-lake experiment. Transactions of the American Fisheries
Society 119:825-835.

Heggenes, J. 1988. Substrate preference of brown trout fry (Salmo trutta) in artificial

stream channels. Canadian Journal of Fisheries and Aquatic Sciences 45: 1801-
1806.

176

Hicks, B. J ., and N. R. N. Watson. 1985. Seasonal changes in abundance of brown trout
(Salmo trutta) and rainbow trout (S. gairdnerii) assessed by drift diving in the
Rangitikei River, New Zealand. New Zealand Journal of Marine and Freshwater
Research 19:1-10.

Hill, M. J ., E. A. Long, and S. Hardin. 1994. Effects of dam removal on Dead Lake,
Chipola River, Florida. Proceedings of the Annual Conference SEAFWA: 512-
523.

Hubert, W. A. and H. A. Rhodes. 1989. Food selection by brook trout in a subalpine
stream. Hydrobiologia 178:225-231.

Hubert, W. A., and H. A. Rhodes. 1992. Sizes of prey consumed by age-O brown trout
In Douglas Creek, Wyoming. Journal of Freshwater Ecology 7:277-282.

Hunt, R. L. 1966. Production and angler harvest of wild brook trout in Lawrence Creek,
Wisconsin. Wisconsin Conservation Department Technical Bulletin 35.

Hunt, R. L. 1975. Food relation and behavior of salmonid fishes. 6.1. Use of terrestrial
invertebrates as food by salmonids. Pages 137-151 in A. D. Hasler, editor.
Coupling of land and water systems. Springer-Verlag, New York.

Hynes, H. B. N. 1970. Ecology of running waters. University of Toronto Press, Toronto,
Canada.

Jenkins, T. M. Jr. 1969. Night feeding of brown and rainbow trout in an experimental
stream channel. Journal of the Fisheries Research Board of Canada 26:3275-
3278.

Jenkins, T. M. Jr., C. R. Feldmeth, and G. V. Elliott. 1970. Feeding of rainbow trout
(Salmo gairdneri) in relation to abundance of drifting invertebrates in a mountain
stream. Journal of the Fisheries Research Board of Canada 27:2356-2361.

J enson, A. J. 1987. Hydropower development of salmon rivers: Effect of changes in
water temperature on growth of brown trout (Salmo trutta) presmolts. Pages 207-
218 in J. F. Craig and J. B. Kemper, editors. Regulated streams: Advances in
ecology. Plenum Press, New York.

Kanehl, P., D. J. Lyons, and J. E. Nelson. 1997. Changes in the habitat and fish
community of the Milwaukee River, Wisconsin, following removal of the Woolen
Mills Dam. North American Journal of Fisheries Management 17:387-400.

Klomp, K. 1998. An initial evaluation of the habitat and fisheries resources associated

with a dam removal in a Michigan coldwater stream. Master’s thesis. Michigan
State University, East Lansing, Michigan.

177

Kohler, S. L. 1985. Identification of stream drift mechanisms: an experimental and
observational approach. Ecology 66: 1749-1761.

Kohler, C. C., and W. Hubert, editors. 1993. Inland fisheries management in North
America. American Fisheries Society, Bethesda, Maryland.

Kondolf, G. M., and E. R. Micheli. 1995. Evaluating stream restoration projects.
Environmental Management 1 9(1): 1-1 5.

Kondolf, G. M., and S. Li. 1992. The pebble count technique for quantifying surface bed
material size in instream flow studies. Rivers 3(2):80-87.

Krebs, C. R. 1989. Ecological methodology. Harper Collins, New York.

Krueger, K. 1999. Personal communication. Michigan Department of Natural
Resources. Mio, Michigan.

Laarman, P. W., J. C. Schneider, and H. Gowing. 1981. Methods in age and growth
analyses of fish. Appendix A—4 in J. W. Merna, G. R. Alexander, W. D. Alward,
and R. L. Eshenroder, editors. Manual of Fisheries Survey Methods. Michigan
Department of Natural Resources Fisheries Management Report No. 9, Lansing,
Michigan.

Lacasse, S., and P. Magnan. 1992. Biotic and abiotic determinants of the diet of the
brook trout Salvelinusfontinalus, in lakes of the Laurential Shield. Canadian
Journal of Fisheries and Aquatic Sciences 49:1001-1009.

Larkin, P. A. 1956. Interspecific competition and population control in freshwater fish.
Journal of the Fisheries Research Board of Canada 13:327-342.

Lawler, Matusky, and Skelly Engineers. 1992. Evaluation of Pine River temperature.
Unpublished report for Consumers Power Company, Cadillac, Michigan.

Lechowicz, M. J . 1982. The sampling characteristics of electivity indices. Oecologia
52:22-30.

Light, R. W., P. H. Adler, and D. E. Arnold. 1983. Evaluation of gastric lavage for
stomach analyses. North American Journal of Fisheries Management 3:81—85.

Ligon, F. K., W. E. Dietrich, and W. J. Trush. 1995. Downstream ecological effects of
dams. BioScience 45(3):183-192.

Lohr, S. C. and J. L. West. 1992. Microhabitat selection by brook and rainbow trout in a

southern appalachian stream. Transactions of the American Fisheries Society
121: (6) 729-736.

178

McIntosh, A. R., and Peckarsky. B. L. 1996. Differential behavioural response of

mayflies from streams with and without fish to trout odour. Freshwater Biology
3 5 : 141 -148.

Magnuson, J. J. 1991. Fish and fisheries ecology. Ecological Applications 1:13-26.

Magoulick, D. D., and M. A. Wilzbach. 1997. Microhabitat selection by native brook
trout and introduced rainbow trout in a small Pennsylvania stream. Journal of
Freshwater Ecology 12(4):607-614.

Magnan, P. 1988. Interactions between brook charr, Salvelinusfontinalis, and
nonsalmonid species: ecological shift, morphological shift, and their impact on

zooplankton communities. Canadian Journal of Fisheries and Aquatic Sciences
45:999-1009.

Manceina, M. J. 1992. A simple regression model to assess environmental effects on
fish growth. Journal of Fish Biology 41:557-565.

Matkowski, S. M. D. 1989. Differential susceptibility of three species of stocked trout to
bird predation. North American Journal of Fisheries Management 9: 1 84-187.

Meehan, W. R., and R. A. Miller. 1978. Stomach flushing: effectiveness and influence
on survival and condition of juvenile salmonids. Journal Fisheries Research
Board of Canada 35:1359-1363.

Merritt, R. W., and K. W. Cummins, editors. 1996. An introduction to the aquatic
insects of North America, 3rd edition. Kendall/Hunt Publishing Company,
Dubuque, Iowa.

Metz, J. P. 1974. Die invertebratendrift an der Oberflache eines Voralpenflusses und

ihre selektive Ausnutzung durch die Regenbogenforellen (Salmo gairdnerz').
Oecologia (Berlin) 14:247-267.

Minard, R. E., and J. E. Dye. 1998. Rainbow trout sampling and aging protocol. Alaska
Department of Fish and Game Special Publication 98-2, Juneau.

Morista, M. 1959. Measuring of interspecific association and similarity between
communities. Memoirs of the Faculty Science Kyushu University, Series E
Biology 3:65-80.

Needham, P. R., and R. L. Usinger. 1956. Variability in the microfauna of a single riffle
in Prosser Creek, California, as indicated by the Surber sampler. Hilgardia
24:383-409.

Newman, R. M. 1987. Comparison of encounter model predictions with observed size-
selectivity by stream trout. Journal of the North American Benthological Society
6(1):56-64.

179

Nicieza, A. G., and N. B. Metcalfe. 1997. Growth compensation in juvenile Atlantic
salmon: responses to depressed temperature and food availability. Ecology
78:2385—2400.

Parker, R. R. 1963. Effects of formalin on length and weight of fishes. Journal of the
Fisheries Research Board of Canada. 20: 144-155.

Peckarsky, B. L. 1980. Predator-prey interactions between stoneflies and mayflies:
behavioral observations. Ecology 61 :932-943.

Pennak, R. W. 1989. Freshwater invertebrates of the United States, Protozoa to
Mollusca, 3rd edition. John Wiley & Sons, New York.

Pennak, R. W., and E. D. Van Gerpen. 1947. Bottom fauna production and physical
nature of the substrate in a northern Colorado trout stream. Ecology 28:42-48.

Petts, G. E. 1980. Long-term consequences of upstream impoundment. Environmental
Conservation 7(4):325-332.

Rader, R. B. 1997. A functional classification of the drift: traits that influence
invertebrate availability to salmonids. Canadian Journal of Fisheries and Aquatic
Sciences 54: 121 1-1234.

Raleigh, R. F. 1982. Habitat suitability index models: Brook trout. U. S. Fish and
Wildlife Service FWS/OBS-82/ 10.24, Washington, D. C.

Raleigh, R. F., and T. Hickman. 1984. Habitat suitability information: Rainbow trout.
U. S. Fish and Wildlife Service FWS/OBS-82/10.60, Washington, D. C.

Raleigh, R. F., and Zuckerman L. D. 1986. Habitat suitability index models and
instream flow suitability curves: Brown trout. U. S. Fish and Wildlife Service
82(10.124), Washington, D. C.

O
Resource Management Group, Inc. 1994. Assessment of potential wetland impacts
associated with the removal of Stronach Dam on the Pine River in Manistee
County, Michigan. Unpublished manuscript for Consumers Power Company,
Cadillac, Michigan.

Ringler, N. H. 1979. Selective predation by drift-feeding brown trout. Journal Fisheries
Research Board of Canada 36:392-403.

Rose, G. A. 1986. Growth decline in subyearling brook trout (Salvelinusfontinalus)
after emergence of rainbow trout (Salmo gairdneri). Canadian Journal of

Fisheries and Aquatic Sciences 43: 187-193.

Rozich, T. J. 1998. Manistee River Assessment. Michigan Department of Natural
Resources Fisheries Division Special Report Number 21, Lansing, Michigan.

180

Sagar, P. M., and G. J. Glova. 1988. Diel feeding periodicity, daily ration and prey
selection of a riverine population of juvenile chinook salmon, Oncorhynchus
tshawytscha (Walbaum). Journal of Fish Biology 33:643-653.

SAS Institute. 1988. SAS user’s guide, version 6.03. SAS Institute, Cary, North
Carolina.

Schoener, T. W. 1982. The controversy over interspecific competition. American
Scientist 70:586-595.

Scidmore, W. J ., and A. W. Glass. 1953. Use of pectoral fin rays to determine age of the
white sucker. Progressive Fish Culturist 15:114-115.

Scott, W. B., and E. J. Crossman. 1985. Freshwater fishes of Canada. Fisheries
Research Board of Canada Bulletin 184.

Scurlock, M., D. Gilcrest, and B. Doppelt. 1993. The failure of existing riverine
protection and restoration policies and programs. Pages 135-368 in B. Doppelt,
M. Scurlock, C. Frissell, and J. Karr editors. Entering the watershed: A new
approach to save America’s river ecosystems. Inland Press, Washington, DC.

Shuman, J. R. 1995. Environmental considerations for assessing dam removal
alternatives for river restoration. Regulated Rivers: Research & Management
11:249-261.

Simons, R. K., and D. B. Simons. 1991. Sediment problems associated with dam
removal- Muskegon River, Michigan. Hydraulic Engineering. Proceedings of the
1991 National Conference of the American Society of Civil EngineersNew York:
ASCE.

Stauffer, T. E. 1977. A comparison of the diet and grth of brown trout (Salmo trutta)
from the South Branch and the Main Stream, AuSable River, Michigan. Michigan
Department of Natural Resources Fisheries Division Special Report 1845,
Lansing, Michigan.

Strogen, J. W., Jr. 1979. A comparison of the diet and growth of the trout from the
upper Au Sable and upper Manistee Rivers, Michigan. Michigan Department of
Natural Resources Fisheries Division Special Report 1867, Lansing, Michigan.

Stuber, R. 1996. Pine River monitoring report 1995: fish habitat and population
information. Unpublished report for the U. S. Forest Service Huron-Manistee
National Forests

Stuber, R. J. 1985. Trout habitat, abundance, and fishing opportunities in fenced vs.
unfenced riparian habitat along Sheep Creek, Colorado. U. S. Forest Service
General Technical Report RM-120:3 10-3 14.

181

Swift, D. R. 1962. Activity cycles in the brown trout (Salmo trutta Lin). Hydrobiologia
20:241-247.

Tippets, W. E., and P. B. Moyle. 1978. Epibenthic feeding by rainbow trout (Salmo
gairdneri) in the McCloud River. California Journal of Animal Ecology 47:549—
559

Twomey, K. A., K. L. Williamson, and P. C. Nelson. 1984. Habitat suitability index
models and instream flow suitability curves: White sucker. U. S. Fish and
Wildlife Service FWS/OBS-82/ 10.64, Washington, D. C.

Vanderploeg, ,H. A., and D. Scavia. 1979. Two electivity indices for feeding with
special reference to zooplankton grazing. Journal of the Fisheries Research Board
of Canada 36:363-365.

Van Deventer, J. S., and W. S. Platts. 1983. Sampling and estimating fish populations
from streams. Transactions of the North American Wildlife and Natural
Resources Conference 48:349-354.

Van Deventer, J. S., and W. S. Platts. 1985. A computer software system for entering,
managing, and analyzing fish capture data from streams. USDA Forest Service
Research Note INT—352. Interrnountain Research Station, Ogden, Utah.

Vincent, R. E., and W. H. Miller. 1969. Altitudinal distribution of brown trout and other
fishes in a headwater tributary of the South Platte River, Colorado. Ecology
50:464-466.

Walton, O. E. 1980. Active entry of stream benthic macroinvertebrates into the water
column. Hydrobiologia 74: 1 29-1 39.

Ward, J. V., and J. A. Stanford. 1989. Riverine ecosystems: the influence of man on
catchment dynamics and fish ecology. Pages 56-64 in D. P. Dodge editor.
Proceedings of the International Large River Sumposium. Canadian Special
Publication of Fisheries and Aquatic Sciences 106.

Ware, D. M. 1972. Predation by rainbow trout (Salmo gairdneri) influence of hunger,
prey density and prey size. Journal of the Fisheries Research Board of Canada
29:1193-1201.

Waters, T. F. 1972. The drift of aquatic insects. Annual Review of Entomology 17:253—
272.

Waters, T. F. 1995. Sediment in streams: sources, biological effects and control.
American Fisheries Society, Monograph 7, Bethesda, Maryland.

Weisburg, S. 1993. Using hard-part increment data to estimate age and environmental
effects. Canadian Journal of Fisheries and Aquatic Sciences 50:1229-37.

182

Wiley, M. J ., S. L. Kohler, and P. W. Seelbach. 1997. Reconciling landscape and local
views of aquatic communities: lessons from Michigan trout streams. Freshwater
Biology 37:133-148.

Wilhelm, F. M., B. R. Parker, D. W. Schindler, and D. B. Donald. 1999. Seasonal food
habits of bull trout from a small alpine lake in the Canadian Rocky Mountains.
Transactions of the American Fisheries Society 12821176-1192.

Wolman, M. G. 1954. A method of sampling coarse river-bed material. Transactions of
the American Geophysical Union 35(6):951-956.

Young, M. K., R. B. Rader, and T. A. Belish. 1997. Influence of macroinvertebrate drift

and light on the activity and movement of Colorado River cutthroat trout.
Transactions of the American Fisheries Society 126:428-437.

183

 

 

nun.»-