I‘H‘an v'.‘

 

 

 

   

 

-_ _ -.-.- "’2‘— -.

.3? ‘

_<.« -L‘.-

"2' it All: 3' .‘ 5 D F)"

'-ll1

.3.

1"

I \"‘.L l' ‘i 'l
n 1 I 1
.n IIQI‘: #3:... ad}
. ‘ (1"\§'u'v"l'.';. Jr A
' ' “(fix-‘h-‘uh‘AIQH '

iv“: A
h.

S
9
v

,.-.|
ML -
-4

.‘u
. M

.
M . 1 t ' v
. "V. v ‘ 4 .‘ V l"
. .‘ LI , -. .,.c. , .. "’
_ ‘ . ‘ .. ," '. .‘..' ‘ - ' . ‘
I . 'III . I ‘ . ‘ 2., .. '3.‘ -‘ § ‘ '
III II'III ‘. "‘--"‘q-."' I 'J‘Lr‘ u {a tu
I ',' ‘x ..‘q "I" I .‘..‘."'u q" 1 {4‘ .I
w‘ \‘ ‘\:,. ‘ '.' . '(‘pI

‘ H"
.‘ ""5 ’ 4
MM" .- " 15
... I.“ l' '\\I‘;.
.m-f ' .u' .v I
0‘“ ' t o

‘ I . J, , "
I> . .‘f' '4..‘ .I" I~ ‘- H. 'h. -‘ " “z
4 l

'.‘ .|- . .

In“ . .‘ :‘I‘ v I
.,‘w' ' , '.' '3'
c. . q '

' I'd} . .I.
~, . H
JEW-

 

I.
\II ‘

 
  
 

 
 
 

LIBRARY

Michigan State
Universi

   

   

17 w‘

“hf-91‘: ‘ ‘.'

This is to certify that the

thesis entitled

Mass Transport of Biological Materials Through
A Once-Through Cooling System on Western Lake Erie:
Impact Upon Phytoplankton and Productivity

presented by

James Andrew Wojcik

has been accepted towards fulfillment
of the requirements for

M.S. degree in Fisheries 8:
Wildlife

., ., /' /"
%’C’/Ql//I/;‘/§72V

Major professor

\

 

Date February 22, 1978

 

07639

 

MASS TRANSPORT OF BIOLOGICAL MATERIALS THROUGH A
ONCE-THROUGH COOLING SYSTEM ON WESTERN LAKE ERIE: IMPACT
UPON PHYTOPLANKTON AND PRODUCTIVITY

By

James Andrew Wojcik

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

1978

ABSTRACT
MASS TRANSPORT OF BIOLOGICAL MATERIALS THROUGH A
ONCE-THROUGH COOLING SYSTEM ON WESTERN LAKE ERIE: IMPACT
UPON PHYTOPLANKTON AND PRODUCTIVITY
By

James Andrew WOJcik

This one year study commenced in November, 1972 at the
3200-megawatt fossil fuel Monroe Power Plant near Monroe,
Michigan. Water for cooling was from a river and Lake Erie
and discharged via a discharge canal into Lake Erie. Five
sampling stations were placed along the discharge and two
at the intake for comparison of samples before and during
entrainment. Phytoplankton abundance, volume, and biomass
changes were assessed along with gross primary productivity
(GPP) and community respiration. Three diel (morning,
afternoon, and evening) samplings were made at two month
intervals.

Results of most samplings indicated no significant
change in phytoplankton populations for any algal class or
species that could be attributed to entrainment. Some
increases noted at plume stations in November and January
Of some algae were seen as a mixing effect Of the discharge

with a more productive open lake. Half the summer daylight

James Andrew Wojcik

measurements of GPP Showed reduced photosynthesis in the
discharge canal with a recovery in the plume without a

clear explanation although chlorination was not totally

ruled out.

ACKNOWLEDGMENTS

I wish to thank Dr. R. A. Cole for his patient super-
vision and thoughtful suggestions during this research. I
must give special thanks to my advisor, Dr. T. G. Bahr,
for his assistance in preparation Of the manuscript and
to other members of my guidance committee, Dr. C. D.
McNabb and Dr. W. E. Wade for their help.

Particular appreciation goes to my good friend D.
Kenaga who gave energetic assistance to my field work
and advice. Other graduate students who helped with the
field work were D. Nelson and M. Simons. My gratitude
also goes to my lab assistants, A. Lee Miller and B.
Hamming, who both patiently withstood the rigors of
algal taxonomy and my frequent reminiscences. I Offer
special thanks to my brother, M. Wojcik, who came to my
rescue with his computer expertice.

Support was made possible through the Environmental
Protection Agency under a contract with the Institute of
Water Research. Use Of the Michigan State University
computer facilities was funded by the Department of
Fisheries and Wildlife.

Finally, to my loving mother and father, I thank you
for your interest, encouragement, and concern of my work.

11

TABLE OF CONTENTS

Page
LIST OF TABLES . . . . . . . . . . . . . . . . . . V
LIST OF FIGURES . . . . . . . . . . . . . . . . . . Vii
INTRODUCTION . . . . . . . . . . . . . . . . . l
Entrainment Stress . . . . . . . . . . . . . 2
Mechanical . . . . . . . . . . . . . . 2
Thermal . . . . . . . . . . . . . . 3
Chemical . . . . . . . . 6
Study Approach and Hypotheses 6
METHODS 8
Description of the Study Area . . . . . . . 8
Sampling Design and Field Procedures . . . . . 1“
Sample Processing and Algal Enumeration . . . 17
Primary Productivity Methods . . . . . . . . . 21
Data Analysis . . . . . . . . . . . . 22
RESULTS . . . . . . . . . . . . . . . . . . . . . . 25
Water Temperatures in the Study Area . . . . . 25
Annual Mean Algal Abundance, Volume, and
Biomass . . . . . . . . . . . 25
Seasonal Comparisons Of Algal Abundance
and Volume . . . . . . . . . . . . . . . . . 32
Total Algae . . . . . . . . . . . . . . . 32
Diatoms . . . . . . . . . . . . . . . . . 38
Green Algae . . . . . . . . . . . . . . . “0
Blue- -green Algae . . . . . . . . . . . . “1
Euglenophyceae . . . . . . . . . . . “3
Centric and Pennate Diatoms . . . . . . . “5
Shifts in Algal Class Dominance . . . . . . A8
Species Composition Within the Cooling
System . . . . . “9
Species Annual Mean Abundance, Volume, and
Biomass . . . . . . . . 55
Seasonal Comparison of Species Abundance and
Volume . . . . . . . . . . . . . 59
Coscinodiscus radiatus . . . . . . . . . 59

 

iii

Cyclotella meneghiniana . . . .
Dictyosphaerium pulchellum, Scenedesmus

 

 

guadricauda var. longispina, and
Ulotrix subtillissima . . . . . .
Anacystis incerta and Aphanizomenon

 

 

 

 

 

 

gracile . . . . . . . .
Mean Specimen Volume Changes for Selected
Species . . . . . . . . . . . . .

Seasonal Changes of species Diversity .
Entrainment Impact Upon Primary Productivity
Annual Mean Changes in the GPP and R . .
Annual Mean Changes in the P/R Ratio . .
Seasonal Changes in the GPP and R
Gross Primary Productivity .
Community Respiration . . . . . .

DISCUSSION . . . . . . . . . . . . . . . . .

Community Structural Changes
Algal Growth . .
Shifts in Algal Dominance . . .
Changes in Species Diversity . . .
Changes in the Sizes of Algae . . .

Algal Metabolic Changes . . .
Evidence of GPP Stimulation or
Depression . . . . . .

Change in Community Respiration
Chlorination Impact Upon GPP . . . .
Entrainment Impact Upon Western Lake Erie
SUMMARY . . . . . . . . . . . . . . . . . .
APPENDICES . . . . - - - - -

LIST OF REFERENCES - . .

iv

Page
61

Table

LIST OF TABLES
Page

Summary Of chemical water quality (in units

of mg/liter except for pH) for the Raisin

River and Lake Erie near the cooling system

intake (data from M.S.U., 197A) . . . . . . . . 12

Annual mean daily abundance (specimens/ml)
of all algae averaged for the diel periods
and stations . . . . . . . . . . . . . . . 27

Abundance (specimens/m1), volume (um3/ml x

105), and biomass (ug C/ml) of the major

algal classes and total algae averaged

across the study year's afternoon samplings . . 30

Percent increase (+%) or decrease (—%) Of

each station's afternoon abundance, volume,

and biomass as compared to the intake sta—

tion for the major classes and total algae . . 31

Major algal species (1% or more of the total

volume during any Sampling) enumerated for

the 1972-73 study year and their relative

afternoon percentage of the total volume at

each station . . . . . . . . . . . . . . . . . 51

Mean daily abundance (specimens/ml), volume

(pm3/ml x 103), and biomass (ug C/ml x 10-3)

of selected species averaged across afternoon
samplings for an annual average at each

station . . . . . . . . . . . . . . . . . . . . 56

Mean cell volume (iS.E.) at each station for
1972-73 afternoon samplings of severn selected
algal species . . . . . . . . . . . . . . . . . 72

Mean station gross primary productivity and
community respiration for the cooling system
stations averaged for winter (Nov., Jan., and
March- April) and summer (June, Aug. and

Sept. -Oct. ) seasonal sets of 1972- 73 (all

values in mg 02 /1iter/hour) . . . . . . . 78

V

Table Page

9 Major algal species (exceeding 1% of the total
volume of algae) in November and January
(afternoon samplings) with their relative per—
centage of the total phytoplankton volume at
selected stations . . . . . . . . . . . . 91

APPENDICES

A1 Estimated relative amounts of river and lake
water contributing to the intake flow along
with discharge data and passage times through
the discharge canal . . . . . . . . . . . . . . 113

A2 Schematic representation of sampling plan . . . 114
A3 Sampling and primary productivity dates of

field collections to be included in this

report . . . . . . . . . . . . . . . . . . . . 115
AA Meterological information pertaining to

plankton and productivity dates of interest

in this study (1972-73) . . . . . . . . . . . . 116

A5 List of all phytoplankton species and unknowns
enumerated during the 1972-73 study year . . . 117

vi

Figure

10.

11.

LIST OF FIGURES

The Monroe Power Plant study area

Estimated percent Raisin River and Lake Erie
water entering the Monroe Power Plant intake
during 1972-73

Map of the sampling stations within the study
area . . . . . . . . . . . . . . . . . . . .

Algal abundance and volume (means of five
replicates) and water temperatures for morn-
ing samplings of 1972-73

Algal abundance and volume (means Of five
replicates) and water temperatures for after-
noon samplings Of 1972-73

Algal abundance and volume (means of five
replicates) and water temperatures for
evening samples of 1972-73

Diatom abundance and volume (means of five
replicates) and water temperatures for after-
noon samplings in 1972-73

Green algae abundance and volume (means of
five replicates) and water temperatures for
afternoon samplings of 1972—73 . .

Blue—green algae abundance and volume (means
of five replicates) and water temperatures for
afternoon samplings of 1972-73

Centric diatom abundance and volume (means of
five replicates) and water temperatures for
afternoon samplings of 1972-73

Pennate diatom abundance and volume (means of

five replicates) and water temperatures for
afternoon samplings of 1972-73

vii

Page

10

15

3A

35

36

39

“2

AA

A6

A7

Figure Page

12. Coscinodiscus radiatus abundance and volume
(means Of five replicates) and water tempera-
tures for afternoon samplings of 1972—73 . . . 6O

 

l3. Cyclotella meneghiniana abundance and volume
(means Of five replicates) and water tempera-
tures for afternoon samplings of 1972-73 . . . 63

 

1A. Dictyosphaerium pulchellum abundance and
volume (means of five replicates) and water
temperatures for afternoon samplings of

1972-73 . . . . . . . . . . . . . . . . . . . 65

 

15. Scenedesmus quadricauda var. longispina
abundance and volume (means Of five replicates)
and water temperatures for afternoon samplings

of 1972-73 . . . . . . . . . . . . . . . . . . 66

 

 

16. Ulothrix subtillissima abundance and volume
(means of five replicates) and water tempera-

 

 

tures for afternoon samplings of 1972-72 . . . 67
I7. Anacystis incerta abundance and volume (means

of five replicates) and water temperatures

for afternoon samplings of 1972-73 . . . . . . 69

18. Aphanizomenon gracile abundance and volume
(means of five replicates) and water tempera—
tures for afternoon samplings of 1972-73 . . . 7O

 

19. Shannon's Species diversity and equitability
indices for algal density and volume for
afternoon samplings Of 1972-73 . . . . . . . . 7A

20. Station water temperatures, algal biomass,
and GPP for June, 1973 measurements . . . . . 82

21. Station water temperatures, algal biomass,
and GPP for August, 1972 measurements . . . . 83

22. Station water temperatures, algal biomass,

and GPP for September-October measurements
Of 1973 . . . . . . . . . . . . . . . . . . . 8“

viii

INTRODUCTION

The ecological effects of large scale entrainment of
biota by water diversion in once-through cooling systems
are under intensive study in the Great Lakes. As part
of this effort, a comprehensive investigation of impact
upon major trophic levels at a large electric power plant
on the western shore of Lake Erie was undertaken in late
1972. This thesis concentrates on phytoplankton and
addresses possible changes having taken place in the
algal assemblage and their metabolism as a result of the
power plant's Operation.

Phytoplankton are the principal autotrophs in Lake
Erie. With the highly enriched state of the lake,
especially in the western basin, nuisance growth of
phytoplankton is common. Entrainment of substantial
numbers of this group could conceivably alter their
growth and thus lead to further deterioration of the
lake. Of particular concern is a further shift Of domi-
nant species from diatoms to less desirable forms, such
as blue-green algae, thus altering the food source for

the primary consumers and affecting the entire food

web. Beside influencing the structure of the algal

assemblage, more direct effects of entrainment might

be seen in their metabolism. A change in photosynthetic
and respiration rates would affect the amount Of carbon

fixed in the lake ecosystem.

Entrainment Stress

 

Entrainment in a cooling system will expose phyto-
plankton tO several environmental changes which, depend-
ing on the magnitude of the changes and the types of
algae, may affect their ability to function. These
environmental changes may be categorized as mechanical,
thermal, and chemical stresses (Morgan and Stross, 1969).

Mechanical: This stress arises from the excessive

 

water turbulence within pumps and condenser tubes. This
turbulence produces Sheering forces that could destroy
or fragment fragile algae. Starr (197A) attributed a
25.5% mortality of entrained motile algae largely to
mechanical factors at two nuclear power plants on Lake
Ontario. In contrast, Gurtz and Weiss (197A) studied a
power plant near Charlotte, North Carlina, on Lake Wylie
where they could control the heat output while maintain-
ing constant pumping rates in the cooling system. By
examining pre— and post-condenser algal productivity
under controlled conditions when no heat shock was
allowed, they found Cl“ primary productivity was stimu-
lated after passage through the condensers. Turbulence
of the water was thought to improve the availability of
nutrients to the algae and thus increase their productiv-

ity.

Thermal: A second entrainment factor is the tempera-
ture increase. Its effect varies with the types of algae
present, the magnitude of the increase, and the initial
environmental conditions. Patrick (1969; 197A) provides
a good discussion and literature review on this topic.
Each algal species usually possess a wide range of tem-
perature tolerance and a narrower optimum range for
maximal growth (e.g., Eppley, 1972). A considerable
amount of laboratory work has been done to determine these
ranges (Altman and Dittmer, 1973; Hoogenhout and Amesz,
1965). At best these results are approximate for natural
populations since the ranges obtained by laboratory
experiments are usually from controlled "ideal growth"
environments. There have been field studies such as on
thermal streams (Castenholz, 1967) which have led to the
conclusion that blue-green algae "prefer" temperatures
above 35°C while green algae do best below this. Diatom
species are reported to grow best usually under 30°C
(Patrick, 1969). Of course, such broad generalizations
can be hazardous due to the many exceptional species and
new strains that can adapt to atypical temperatures
(Sorokin, 1960; 1971). Nevertheless, cases have been
reported where increasing temperatures have coincided
with shifts in dominant forms from diatoms to green and
blue-green algae above 30°C (Cairns, 1956; Patrick 33
31., 1969; Rankin et al., 197“).

Theoretically, lethal temperatures need not be
exceeded for some Species to out compete other less
favored forms if the new temperature is maintained long
enough (Goldman and Carpenter, 197A). However, there
are limits above which irreversible damage to cells can
occur. Apparently, the magnitude of an abrupt tempera-
ture change, such as experienced in power plant conden-
sers, is not as important to algal survival as the maxi-
mum temperature reached. Beyond the upper limit, des-
truction of pigments (cartenoids, chlorophyll) and
extrusion of lipids have been observed for diatoms
(Lanza and Cairns, 1972). Furthermore, Lund (196A)
pointed out that an increase in temperature may kill
algae before the theoretical upper limit is reached.
This would be a consequence of nutrient deficiencies
which could be aggravated by an increased metabolic rate
with a rise in temperature, and this might eventually
"starve" the organism to death. Since different species
have varied nutrient requirements, certain forms may be
eliminated while those more tolerant of low nutrients
survive.

Perhaps, a more definitive way to assess thermal
stress on algae would be to measure their metabolism.
From laboratory studies results have firmly established
that the photosynthetic rate is independent Of tempera—
ture at sublethal levels when light intensity is low

(Aruga, 1965; Nielson and Jorgensen, 1968). Under low

light the photochemical portion (light reaction) of
photosynthesis is limited by the light intensity. At
light saturation such as sunny days, however, the
enzymatic portion (dark reaction) controls the rate and
is limited by temperature. On the other hand, respira-
tion of algae is directly dependent on temperature since
it is usually an enzymatic process (Nielsen and Jorgen-
sen, 1968; Phinney and McIntire, 1965).

Numerous studies have considered primary productiv-
ity in evaluating impacts of power plant thermal dis-
charges. The net primary productivity (NPP) measurements
of artificially incubated algae in a thermal discharge in
Chesapeake Bay (Morgan and Stross, 1969) and the York
River, Virginia (Warinner and Brehmer, 1966) showed an
affect related to the ambient temperature. When intake
temperatures exceeded 15 to 16°C, an increase in tempera-
ture (At) of 3 to 8°C depressed the NPP (using Cl”).
Below these ambient temperatures and with a similar At,
the NPP was stimulated. However, at Charlotte, North
Carolina (Gurtz and Weiss, 197“) under similar condi-
tions, only depression of the NPP was Observed at an
ambient temperature as low as 9.5°C and at At of 5.6°C.
No stimulatory response was seen. This discrepancy in
the point at which the NPP depressions occurred was
attributed to different species. These results indicate

the amount of fixed carbon available to the rest of the

rest of the ecosystem would be, perhaps, increased in
winter and decreased in summer due to entrainment.
Chemical; Entrainment Of algae can also impose
chemical stresses. The most important of these is due
to the use of chlorine in power plants to destroy
attached organisms accumulating in the condensers.
Residual chlorine concentrations as low as 1.5 ppm have
resulted in severe and perhaps irreversible damage to
some algal species (Hirayma and Hirano, 1970). Gross
primary productivity and community respiration were
reduced by 50% from controls at a chlorine concentration
of 0.32 ppm and by 100% at 2.7 ppm or less in experi-

ments of Brook and Baker (1972).

Study Approach and Hypotheses

 

Few workers have tried to assess the effects of
entrainment using natural phytoplankton populations and
in sithprimary productivity measurements. Much of the
data available are from river environments using peri-
phyton as indicators of change (e.g., Cairns, 1956;
Patrick et_al., 1969) rather than phytoplankton of lakes.
One, therefore, encounters difficulty in predicting the
impact of phytoplankton entrainment in the case of Lake
Erie. Consequently, this study sought to measure struc—
tural and functional changes in the phytoplankton
attributable to entrainment. Afterward, the results
were placed in the perspective of assessing their impact

upon the receiving waters--western Lake Erie.

Based on the literature just cited, several hypoth-

eses were explored with regard to phytoplankton entrain-

ment which include:

1.

Entrainment with maximum temperatures <30°C will
create an overall stimulation in the growth of
the total algal community as reflected by
increased abundance and algal volume.

At temperatures >30°C some types such as diatoms
will display reduced growth.

Entrainment will result in an increase in species
diversity at temperatures less than 30°C and
decreased diversity above this.

The average Size (Specimen volume) of fragile
algal species will decrease after entrainment.
Entrainment will stimulate the gross primary
productivity at an ambient temperature below
16°C and depress it above this point.
Entrainment will stimulate community respira-
tion.

Primary productivity and respiration will be

depressed during condenser chlorination.

METHODS

Description 9: the Study Area

 

 

The cooling system under study was the Monroe,
Michigan, Power Plant, a 3200-megawatt fossil fuel
facility Operated by the Detroit-Edison Company. The
intake for cooling water is located on the Raisin River
about 1 km from the river mouth (Figure 1). Water is
pumped through the condensers and released into a 2600
m discharge canal that was dredged to 7 m depth in its
first 1500 m length and to 3 m in the remaining portion.
The heated effluent forms a plume in Lake Erie over a
sandy shoal generally less than 2 m deep.

During this investigation from late 1972 through to
October, 1973, one to three of the four generating units
at the power plant were operational but on a sporadic
schedule. Pumping rates for the cooling water ranged
from A2 m3/sec to 63 m3/sec (Appendix A1). Over the
study period the intake pumps consumed nearly all the
Raisin River flow at all times. At low river flows any
pumping deficit was augmented by Lake Erie water which
moves upstream to the intake of the plant. Thus, the
composition of the cooling water varied from nearly 100%

river watertx>90% lake water (Figure 2).

 

 

 

. o
. and?“

DISCHAI

 

Figure 1.

cl

1"

 

The Monroe Power Plant study
area.

 

 

 

 

 

10

 

 

 

 

r PO
\
\
\
\
‘\ pm
\
\
*
I \ (
i \
. \
: \ fl
‘ D
s. o \
o - J
> L
a. m ‘
a \ .3
o \
c .s ‘ «s
n .l \ 9‘
.- \ —
a ‘ "I
K \
\
s»
-* ----- ---- ‘
I
/’
;I
I '=
I
I
I
I
I ph-
cér-" ’-
Q
~~
‘Q
\~ .3
~
“
\‘~
\
\“ '6
\~ N
“ h
s~ 0‘
—
a
I— I I T 1 V I T ' I 1
O O O O O O O O O O O

U3LVH BXVLNI :10 z

Figure 2. Estimated percent Raisin River and Lake
Erie water entering the Monroe Power Plant
intake during 1972—73.

11

Flow rates through the condensers are about 2 m/sec
with a passage time Of about 7 seconds. The mean velo-
city through the upper discharge canal ranged from 3.9
to 5.8 cm/sec. At this rate from 11.5 to 7.5 hours was
needed for the cooling water to pass through the dis-
charge canal. Due to eddies along the canal, the actual
exposure time Of some entrained algae to the heated
effluent within the canal could be longer. Exposure time
is also increased because of recichlation of much of the
heated discharge back through the intake during the win-
ter to keep it free Of ice. No data were available on
the proportion of the discharge recirculated at that '
time of the year.

Ambient temperatures in the intake area ranged from
3.0 to 27.5°C with the river water usually 1 to 2°C
higher than the lake. The At's observed never exceeded
15°C. The temperature in the discharge canal ranged
from 8.0 to 31.5°C with less than a 10% difference through-
out its length. The plume was estimated to cool to ambient
temperature in 1 to 2 days.

The chemical quality of the cooling water depends on
the relative amount Of lake or river water entering the
plant. The Raisin River was the recipient of secondary
treated municipal wastes and industrial effluents within
about 2 km upstream of the intake. Generally speaking,
the quality of Lake Erie water is somewhat less enriched

with algal nutrients than the river as shown in Table l.

l2

 

 

 

ma.m H.m :wa pm>fim

Hm.o m.m moH Oxmq
mslmoaaoumo

m.ma m.s :ma pm>Hm

m.:a m.s omH mxmq
ms:sowmonso

0.3m mm.H ma.o om.o no>fim

m.wm mm.a No.0 ma.o mxmq
msnmanmo

2.3m os.m mo.o Ha.o nm>am

m.mH HH.H no.0 mo.o mxmq
ms::o:zo

o.mm om.m HH.o om.o hm>am

m.sm NH.: oa.o Hm.o Oxmq
msnmmuao

o.mm mm.w :H.o mm.o nm>Hm

m.:m :m.z no.0 mH.o mxmq
msuoalaa
Noo ma moomo mm o mm 2 mm m mm m mm coapmooq
comm mpacaamxa< conmmo ammonpfiz naponamonm manonmmonm one came

Hapoe cacmmnocH mumppfiz mansaow Hmpoe
. Hmpoe
.21.? .56.:
Eoum mpmov oxencfi Empmzm wcfiaooo on» new: mfinm oxmq can Lm>fim camamm on»

Low Amo you pamoxm nmufia\we no moan: adv mafiamsu noun: awedEmno no zpmeesm .H manna

13

 

 

 

m.om m:.o oo.o ma.o nm>fim

m.Hm sm.o No.0 HH.o mxmq
mslaoloa

m.mm mm.H ma.o mm.o pm>am

m.mm mm.o No.0 ma.o oxmq
msuoaumo
Noo mo moomo mm o mm 2 mm m mm m mm coapmooq
moth zpficaamxa< conamo cowompaz msmosomonm mdponmmonm cam mama

Hmuoe oacmwpocH. mumnpfiz mansaom Hmpoa
Hence

 

.A.e.eeoev H eases

1A

Differences in nutrient concentrations in the power
plant's discharge from those listed in Table 1 were small
(M.S.U., 1976) and probably insignificant. Therefore,
adequate nutrients were assumed to exist throughout the
study area at all times for algal growth with the possible
exception of low C02 in near—Shore Lake Erie in the sum-
mer.

Chlorination of the condensers as reported in plant
records commenced daily at 0800 (lOcal time) and was con-
tinued for 30 minutes. During summer, an additional
evening application was added. Concentrations Of chlo-
rine discharged were not measured but computed to range
from 0.83 to 1.63 mg/l as residual chlorine.

Light penetration in the area was nearly always
limited by high amounts Of suspended matter. Secchi disc
transparencies were usually less than 1 meter throughout
the study area. Annual dredging of the river channel
during late summer and early fall creates an additional
sediment load increasing turbidity during this period.
Only slightly greater transparencies were found in lake

water compared to water from the river or discharge canal.

Sampling Design and Field Procedures

 

Seven stations were established to sample phytoplank-
ton composition and measure primary productivity (Figure
3). Due to turbulence and possibly incomplete mixing of
river and lake water in the short intake canal, intake

water was indirectly measured by sampling at lake station

15

 

 

   

LAKE ERIE

I

l‘ .9.

 

 

 

Figure 3. Map of the sampling stations within the
study area.

16

17 and river station 9. Data from these two locations
were proportioned according to the relative contribu-
tion Of river and lake water used for the intake and
being entrained. Values for this calculation are given
in Appendix A1. The proportioned results were combined
to produce a theoretical intake station designated as
station 18.

The heated effluent was sampled in the discharge
canal at stations 12, 8, and 14 which represent the upper,
middle, and lower discharge canal, respectively. The
plume was sampled near the discharge canal mouth (inner
plume) at station 15 and farther out in the lake (outer
plume) at station 16. These last two stations were vari-
able in location due to the shifting plume direction.

The inner plume station was positioned midway in the
plume at a point where the temperature had decreased to
about half the difference between that in the discharge
canal and the lake ambient temperature. The outer plume
station was at a point along the plume midline near its
outer edge where a 1 to 2°C temperature elevation was
still detectable.

The detailed sampling scheme for the various sta-
tions is shown in Appendix A2. In general, sampling was
conducted once every two months (a seasonal set). During
each seasonal set, three separate samplings were made at
all stations representing various times of the day--

morning, afternoon, and evening. The time of day samplings

17

(hereafter referred to as diel periods) were usually made
on separate days within a span Of one week. Thus, both
long term seasonal and Short term diel variations were
considered. A summary Of the sampling dates for phyto-
plankton composition and primary productivity are listed
in Appendix A3.

Five "replicate" water samples were taken at each
station to census the phytoplankton community. Early in
the study these samples were collected at the water sur-
face. For dates after January 18, 1973, samples were
collected from randomly determined depths (l to 5 m)
along a transect acrosss the river or discharge canal.
This was done to obtain a better spatial and vertical
profile of conditions at the lake and river stations and
the upper, middle, and lower discharge canal stations.
Samples from the plume were all taken from the surface
due to the shallow area and to insure that the buoyant
heated effluent was being sampled.

Samples were obtained with either a 4.1 or 8.1 liter
Van Dorn water bottle at the prescribed depth. Aliquots
of A80 ml were drawn off and immediately preserved with

20 ml of 37% formaldehyde solution.

Sample Processing and Algal Enumeration
Processing and enumeration Of phytoplankton generally
followed the membrane filter technique described in

"Standard Methods" (American Public Health Association,

18

1971) which had been tentatively adopted from McNabb
(1960). Filtration of predetermined aliquots of sample
was done using 0.A5 pm "Millipore" filters (Millipore,
Inc., Bedford, Mass.). These were subsequently "cleared"
with microscope immersion Oil and placed under a phase-
contrast microscope for identification and enumeration.

A "count" constituted a natural algal structural unit
(i.e., a unicell, filament, or colony). Conversion of

a taxon's frequency in 30 microscopic fields to their
sample abundance was determined by the following equa-

tion modified from A.P.H.A. (1971):

dx109

 

Specimens/m1 =
(quadrat area in umz) x (ml filtered)
where "d" is the theoretical density corresponding to a
given frequency.

To facilitate sample analysis, species identifica-
tions were limited to afternoon collections except for
November when all diel period samples were examined to
species. For morning and evening samples Of other
seasonal sets, phytoplankton were identified only to
class.

Except for diatoms, algal species were enumerated
directly on the membrane filters. Diatoms were first
identified and enumerated only to order (Centrales or
Pennales) on the filters. Species identifications

required permanent mount slides prepared according to

l9

Weber (1971) using a muffle furnace at 5A0°C to combust
organic material and hyrax as a mounting medium. By
determining the percentage Of each centric or pennate
species on the permanent mounts, these results were
related back to the filter densities of the respective
diatom orders to produce estimates of diatom species
abundance for each sample.

Only one permanent mount Slide for diatom species
identifications was prepared for each station using
combined concentrations Of a station's water samples.
The relative species abundances obtained from a single
permanent mount for a station were applied to the den-
sities of diatom orders Of each Of the station's five
samples. Thus, diatom species densities varied between
station samples only in response to the variability Of
the centrics or pennates. Although this facilitated
diatom processing, this practice automatically intro-
duced a bias into the data by artificially reducing
the variability between the "replicates" of a station
on the species leve1--a factor that becomes apparent
in the statistical analysis.

Species identifications were based upon a number
of literature sources. Principally, these included
Hustedt (1930a, 1930b), Patrick and Reimer (1966),
Prescott (1970), Smith (1920), Taft (19A5), Taft and
Taft (1971), Thienemann (19A2), and Weber (1971). The

identification of coccoid Cyanophyceae are based on the

2O

revisions of Drouet and Daily (1956). Some questionable
forms were referred to Dr. D. C. Jackson and Dr. F.
Begres of Eastern Michigan University, Ypsilanti, Michi—
gan.

The volume (pm3/m1) Of a taxon in a sample was cal-
culated by multiplying its abundance with its estimated
mean specimen volume (MSV). The MSV for a taxon was
usually approximated based on a modified formula for
volume of common geometric shapes applied to sizes of
enumerated specimens and averaged for the stations of a
diel period. A weighted grand mean annual MSV value was
used for a species' volume calculation of a given diel
period if fewer than 10 specimens were observed on the
membrane filters or permanent mount diatom slides during
regular enumerations. Otherwise, a different MSV was
determined for volume calculations for each diel period.
Unless otherwise noted, individual station estimates of
volume were not used. Algal class MSV'S for morning.
and evening periods (except November) were not Obtained
by direct observations of specimens from their samples.
Rather, estimates were based on computed class volume of
the corresponding afternoon data.

Phytoplankton biomass (carbon content) was theoreti-
cally derived using the formula of Strathmann (1967) with
the taxon's MSV used as its "cell volume". Units are
expressed as micrograms of carbon per milliliter of

sample.

Primary Productivitijethods

 

Gross primary productivity (GPP) and community
respiration (R) were determined in gitu using the change
in oxygen light-dark bottle technique (A.P.H.A., 1971).
Chemical fixation and titration followed the azide modi—
fication of the Winkler method (Environmental Protection
Agency, 197A) with phenylarsine oxide as the titrant.
Three light and three dark bottles plus two initials
(300 ml) were filled at each station with water collected
at a depth of 1/2 m (1/A m for August, 1973, and later
measurements) and immediately resuspended at the same
depth.

Morning, afternoon, and evening measurements were
made from 0800 to 1230 hours, 1200 to 1800 hours, and
after sunset, respectively, with 2 to A 1/2 hour incu-
bations. Morning primary productivity measurements were
timed to approximately coincide with chlorine application
at the power plant in order to assess this impact upon
GPP.

Weather information was Obtained from the National
Weather Service at Toledo, Ohio, A0 km to the south Of
the study area. Weather data are summarized for sampling
and primary productivity measurement dates in Appendix
AM. These data were also supplemented by direct observa-
tion of general weather and light conditions in the study

area.

22

Water transparency was measured with a Secchi disc
on most sampling dates. Beginning in August, 1973, a
model LMD—BA submarine photometer (Whitney Underwater
Instruments, San Luis Opispo, Calif.) was employed to
measure light at depths of 0.5 m, 1.0 m and 1 m inter-
vals below that. Water temperature was measured with a
YSI model 51A combination oxygen-thermistor meter (Yellow

Springs Instruments 00., Yellow Springs, Ohio).

Data Analysis

 

For comparative purposes between all diel periods,
species data were also pooled into class and total algae
density, volume, and biomass to give results on three
taxonomic levels. Arithmetic means were computed for
each station from the replicate data. However, due to
expected heterogeneity of the variances as measured by
the F-max test (SOkal and Rohlf, 1969), abundance and
volume data were transformed to log10(x + 1) for most
statistical analyses. A three-way analysis of variance
(AOV) was performed on the transformed density and
volume results for total algae and the major classes.
The sources Of error (main effects) for these AOV's were
season, diel period, and station for the purpose of
determining where statistically significant variance for
the data lay.

Density and volume estimates for selected species

and centric—pennate diatoms were statistically analysed

23

for afternoon results using a two-way AOV with season

and station as main effects. This was a preliminary

step to ascertain whether significant station differences
for species or orders Of diatoms existed. Since results
were available for all diel periods of the November
seasonal set for centrics and pennates, an additional
two-way AOV was made on those transformed density and
volume data using diel period and station as main effects.

Means of transformed Station results of abundance and
volume were compared with one another using the
Bonferroni-t statistic procedure (Miller, 1966). This
little recognized method was especially useful here in
that it permitted non—orthogonal contrasts among station
means. Thus, a set of comparisons could involve the
intake station mean compared to pooled discharge canal
means and to each discharge canal or plume station result
separately. Significant station variance from the AOV
was not a prerequisite of the Bonferroni-t procedure.

This method was used with transformed data only. Untrans—
formed mean comparisons, such as in the case of biomass
data, utilized 95% confidence intervals.

Diversity indices were computed at each station
using Species density, volume, and biomass data. Two
indices were used for comparative purposes: Margalef‘s
index (Margalef, 1968) and the Shannon-Wiener index
(Pielou, 1969). Equitability among species (E = H'/

loglos where H' is the Shannon-Wiener index and "s" is

2A

the number of Species) was calculated for each station's
replicates and averaged.

GPP and R estimates were expressed in units of mg
Oz/liter/hour of incubation. Analyses (using 95% confi-
dence intervals of station means) were made directly on
these values rather than on extrapolated daily production
or on carbon estimates. These practices reduced the loss
of information through rounding errors. For comparison
with literature values, GPP and R means could be converted
to carbon production using a multiplication factor of

0.312 (Westlake, 1969).

RESULTS

Water Temperatures in the Study Area

 

 

The average At at the water's surface of the dis-
charge relative to the intake was about 5°C (6°C at the
bottom). A maximum At Of 13.5°C occurred at the surface
in November when the ambient temperature was 9°C. In
general, the largest At's were observed during the cold
weather months. The maximum temperatures recorded for
the discharge was 31.5°C (31.0°C at the bottom) on
August 9, 1973, when the ambient water tempeature averaged
26°C. Large variations between diel periods of a seasonal
set, particularly common during the winter, are explained
by fluctuations in the number of generators Operating, by
variable pumping rates, and by the proportion of discharge

water recirculated through the intake.

Annual Mean Algal Abundance, Volume, and Biomass

 

 

Eight algal Classes were recognized during the
enumeration process: the Bacillariophyceae (diatoms),
Chlorobacteriae, Chlorophyceae (green algae), Chrysophy-
ceae, Cryptophyceae, Cyanophyceae (blue—green algae),
Dinophyceae, and Euglenophyceae. Annual mean daily

density of the classes at each station calculated for

25

morning, afternoon, and evening samplings are shown in
Table 2. Clearly, the phytoplankton community was
dominated by three classes which constituted over 95%
of all algae observed--diatoms, green algae, and blue-
green algae. Diatoms were most abundant with green and
blue-green algae being of roughly equal densities. The
Euglenophyceae also exceeded 1% Of the total abundance
but was a relatively rate class.

From Table 2 it can also be observed that total
algae, green algae, and,in particular, blue-green algae
were substantially less abundant in the afternoon than
either morning or evening periods. Densities of diatoms
and other classes did not differ greatly between these
diel periods. Further analysis Of this observation
indicated these differences were probably artifacts of
the enumeration technique. However, analysis of the
results was not greatly affected by this problem.

Differences in algal densities between sampling
stations in Table 2 were not very great. No profound
changes can be seen for algal densities at the discharge
stations compared to the intake. Although total abun-
dance was generally higher in the discharge, this was an
abrupt increase immediately apparent at the upper dis-
charge canal station (12) with little or no further
increase at downstream discharge stations (8, 1A, 15,
and 16). A consistent increase in numbers would have

been expected if growth of algae was stimulated.

27

 

 

poms ass» moss sous mzms some moms Hmow q<eoe
mm we so moa om >5 moa mm ommozsaoconzm
m o o m m o o o mmmomcoocfia
smoa mam new mooa Hooa was mmm mmm mwmoznaocmzo
oa OH ma H: mm m m Ha oncozna0uamto
o o m ea c m m o enmesneonssno
mama ssma omsa mama zmzfl Emma mmm mmsa enmesnaoeoHco
o 0 ma m o o o o omagcuomnopoano
saw: mam: zhmm mmm: mmw: mam: Haom mum: cmooacaoHpmHHaomm
zoozmmem<
maoaa mmmaa zooHH mmzaa :mooa mmooa mama oomoa q<eoe
am :ma HHH mHH ONH sea as ama eneesneoceawsm
m o m o o m z o mmmoacaocfio
comm mmwm onm Hzmm mamm woam :Hma mmmm mmmozcaocmzo
EH mm HA AH m ca m HH enmeszeoeo>to
o o o o o o o H enmesceonseno
:mmm mmmm ozmm doom. smsm Hmmm mwmm Hsmm unmoozzqopoHno
o o o o o o o H mwagcuomnopoHco
mam: wmom omom Ham: mmm: mom: New: wmam oncom2Q0aLwHHHomm
oszmo:
~oa ~ma :H m NH Ama am 5H mmmao oHEocoxme
mszam madam prmcomao Owgmcoman mwpmsoman OxMuCH pm>fim mxmq
pmozo LoccH Lozoq manna: pogo:
ncofiumum
mocmocsn<

 

.mcoaumum new mpOfihma amdo on» Low ommmnm>m mwwam Ham mo AHE\m:OsHooamv mocmocznm

haamo cams stcc<

.N manna

28

.wumo wcamnas no

mmswomn

nmumsfiunm nmozaoch

 

 

 

mama swaoa m:moa azom Hamm cams swam Hams 4<eoe
as mm ow NHH mm mm am He enmesceoceamsm
o o o o o o o o camozcoocdo
mmzm mmom Noam eamm Hesm msam moan mmmm enmesneoceso
m mm mm SH 0 ma ea Ha enmeanoeesto
o o m o m o o o mmoozcaommpco
Hmmm mmmm mmmm wzom msam zmma momm smma mwOo>2QOLOHzo
o o o o o . o o o omdpmpomOOLoHco
mmmm mmsm Hamm mmm: cam: mwsm Ham: moom enmesneoahnfideenm
Lwa Ema :H a ma Ema _m NH nnmao oasocoxme
madam mssam Ownwzomaa cmnmsomaa mwumnomfia oxwucH pm>flm oqu
Louzo mecH hmzoq maooflz Load:
nCOHumum
cosmoczn<

 

.A.e.e:oev m manna

29

NO Obvious shifts in the relative dominance of any
class were observed between station annual means. Vari-
ability was consistently less than 10% and no patterns
were seen.

Table 3 lists the mean daily abundance, volume,
and biomass of the study year for the major classes
(exceeding 1% of the total density) and total algae for
the afternoon period at each station. Diatoms were
dominant when expressed volumetrically (86% of the
total). Their biomass (about 69% of the total) was
slightly greater than their density (65% of the total).
The large sized green algae exceeded blue-green in the
overall proportion of the total volume and biomass.

The Euglenophyceae were relatively insignificant.

For most groups listed in Table 3, considerably
higher abundnace, volume, and biomass were observed
in the discharge relative to the intake. The differ-
ences are more easily seen in Table A which shows the
percent deviation for various stations compared to the
intake station. For most algae the largest increases
were at the plume stations. However, results at the
lake station (17) were as large as these at the plume
stations. Thus, the plume increases Observed may be
merely a reflection of mixing of discharge water with
that in the lake receiving water. Therefore, the
results presented in Tables 3 and A do not demonstrate
a clear trend of steadily increasing abundance, volume,

or biomass.

30

.000080000 003 mmumc

meow so 0000 m:0000z0

 

 

 

000.0 000.0 000.0 000.0 s00.0 000.0 000.0 000.0 0005000
00.00 00.00 00.s0 00.00 00.s0 00.00 0s.0 00.00 ess0o>
s00s 0sss 00ss s0ss 000s s000 000s 0000 000000000

00000 00000

000.0 000.0 000.0 s00.0 000.0 000.0 000.0 000.0 0005000
00.0 00.0 00.0 00.0 00.0 00.0 00.0 00.0 ess0o>
00 00 00 000 00 ss 000 00 000000000

00000000200000 00000

000.0 000.0 000.0 000.0 000.0 000.0 000.0 s00.0 0005000
s0.0 s0.0 s0.0 00.0 00.0 00.0 00.0 00.0 ess0o>
s000 000 000 0000 0000 00s 000 000 000000000

000000 20000-00000 000000002000 00000

000.0 000.0 000.0 s00.0 000.0 000.0 000.0 000.0 0002000
00.0 00.0 s0.0 00.0 00.0 00.0 s0.0 00.0 ess0o>
0000 ss00 0000 0000 0000 0000 000 0000 000000200

000000 200000 0000000000000 00000

s00.0 00s.0 00s.0 ss0.0 00s.0 0s0.0 000.0 000.0 0005000
s0.00 00.00 00.00 00.00 00.00 s0.00 00.0 00.s0 mss0o>
s000 0000 0s00 0000 0000 0000 0000 0s00 000000000

002000000 00000000000000000 00000
000 .00 00 0 00 00 0 s0

08:0m oss0m prmnomaa Owamcom0n 0&002000o 0x00CH Lo>0m 0000

000:0 pmccH 00300 00000: Loan:
00000000

 

.mw:00asmm coocucuuw 0.000» 00:00 on» 000000 ommmuo>m omw00 0000» 0:0 0000000
00w00 00005 ecu no A0E\o may 0005000 new .0000 x 0E\0E:V Osz0o> .A0E\0:Oe00090v oocmoczo< .m 00009

31

 

 

 

000+ 0.00+ 0.0+ 0.0+ 0.0+ 0.0 0.00: 0.00+ 0000500
0.mm+ 0.s0+ 0.00+ 0.0+ 0.00+ 0.0 0.00: 0.sm+ oez0o>
0.0+ 0.00+ m.m0+ m.m0+ 0.0+ 0.0 0.0+ s.0: 00:00::00
m000< 00900
0.00: 0.00: 0.00: 0.00+ 0.0 0.0 0.00+ 0.00: 000000m
0.00: 0.00: 0.0s: 0.0 0.0m+ 0.0 0.00+ 0.00: msz0o>
0.0m: s.00: 0.00: m.mm+ 0.0+ 0.0 0.0m+ m.s0: 00:00:000
m0mowmmozm000m 00000
m.sm m.s0+ 0.0: 0.00: 0.00: 0.0 m.00+ m.s0+ 000000m
0.00+ 0.000+ 0.+ 0.00: 0.0: 0.0 0.00: 0.00+ 0000o>
0.mm+ 0.sm+ 0.00+ s.mm+ 0.0m+ 0.0 s.0m: 0.0+ 00:00:000
0m<00< zmmmo:m00mv m<mowmmoz<>o 00000
m.m0+ 0.mm+ s.00: 0.00+ 0.0: 0.0 0.00: 0.0m+ 0005000
0.00+ 0.00+ 0.0m: 0.0+ 0.0: 0.0 0.s0: 0.0m+ 0000o>
0.00+ 0.00+ s.0+ 0.00+ 0.0+ 0.0 0.00: 0.0+ 000000000
0m000< zmmmcv m<mo>zmomoqmo mm<00
0.00+ 0.00+ 0.m0+ 0.0 s.00+ 0.0 0.00: 0.0m+ 0000000
0.00+ 000+ s.00+ 0.0: s.00+ 0.0 0.00: 0.s0+ 0000o>
0.0+ 0.0+ 0.00+ 0.0+ 0.0+ 0.0 0.00+ s.0: 000000000
002090000 m<mowzmon<quo<m 00000
00 00 00 0 00 00 0 s0
00000 00:00 mw0mzom0a 0000:0000 0w0020000 mxmucH 0m>0m 0000
000:0 00::0 00300 00:00: 0000:
0:000000

 

.mmw00 0000» 0:0 0000000 00005 0:0 000 :000000 mxmuc0 0:0 00 00000000 00 000800:
0:0 .mss0o> .mo:mo::nm :oo:00000 0.:000000 :000 no 00:0 00000000 00 Au+v 00000oc0 0:00000

.0 00000

32

Another interesting observation from Table A is
that the densities of blue-green algae from the dis-
charge canal were greater than at the intake, but
volume and biomass were not. This indicates that
although this class was more abundant in the discharge,

the sizes of the organisms were much smaller.

Seasonal Comparisons of Algal Abundance and Volume

 

 

Since much useful information is lost by averaging
the highly seasonal nature of most algae, emphasis will
now be placed on seasonal station differences in abun-
dance and volume. ,For brevity biomass data is not con-
sidered in this analysis since it closely paralleled

the volume results.

Total Algae: Total algae abundance and volume

 

data were obtained for all three diel periods of the

six seasonal sets thus allowing a three-way AOV to

be performed upon transformed results. The purpose

of this or, indeed, any other AOV was to partition

the data variance to one or more sources. In this

case, the sources of variance considered were

season, diel period, and station. Strongly significant
interactions («10.001) among these main effects prevented
simple interpretation of the sources of variance. How-
ever, most of the variance was, as expected, attributed

to the seasonal factor with the diel period and station

33

main effects sharing equally a much smaller portion of
the variability of the data.

Total algal results are shown in Figures A, 5, and
6 for morning, afternoon, and evening periods, respec-
tively. The majority of the station mean differences
that were statistically significant («50.05) with the
Bonferroni-t procedure occurred in the November, Janu-
ary, and March-April seasonal sets. Differences of a
smaller magnitude, yet still significant, were found in
June (evening) and September-October (evening).

Several examples existed of a trend of increasing
density and/or volume at successive stations down the
discharge's flow. Such trends might represent stimu-
lated growth of algae as exposure time to the elevated
temperatures increased. Specifically, November 9 and
10, 1972, had significant («10.05) increases in only
algal volume for all three diel periods by up to 88% at
the lower discharge canal and plume stations when com-
pared to the intake. Although density results for
November had no (0)0.05) such significant increases,
algal abundance appeared to be larger in the discharge
canal than the intake. January also had trends of both
increasing abundance and volume at the lower discharge
canal and {Hume stations for afternoon and, perhaps,
the evening periods. The January evening changes were

more questionable due to a lack of intake station results.

AauunANCE
Loci0 (I/HL+I)
Y

VOLUME

Figure A.

TEMPERATURE-C

0.7<
+
.J
I
B"\
E

-3 &
O
(J
O
—l

S:

rr'le
8

3H

 

13-09‘73

w
0
I

N
O
l

'°‘ml|lll

01-24-73

:Illlln

0h-05'73

06-12-73

08-09-73

09-29-73

 

t
A

N
l

lllllll

||||||

||l||||l

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1718 IS

 

 

 

STATIONS

 

 

Algal abundance and volume (means of five
replicates) and water temperatures for
morning samplings of 1972—73.

35

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Z ::-:o—72 Ol-Zh-73 ou-os-73 06-l2-73 08-09-73 09-29-73
:30.
3
.—
:20-
I“
Q.
“II “II
.—
l“ InIIIII: I” I
a. I
I
“J
u:
2\
E: 3‘ :5 .<.
0 2 g 3
28 o o
_, z z
2..
3.
2 F
+
0
0,$
I E
23 6- < <
O
> g‘ 5 E
_l O O
z 2
5-
{7.1.8.511'5 V é "'2 I‘LIII6 I l l I I I I I' I I jT
STATIONS
Figure 5. Algal abundance and volume (means of five

replicates) and water temperatures for

afternoon samplings of 1972-73.

 

36

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

? 11-09-72 01-18-73 03—30-73 06-11-73 08-08°73 09-29-73
2.30‘
D
i:
:2” <
.—
zm- g
In
~ lllnlls I.|ll I
1,-
u:
:2
2:3-
=0
3:” 5
—a ‘3
O
2- Z
8-
:74
4.
_l
I
\
M
g E
3V6- "5
00 <
>(J— D
3 S
51
llllll TllllllIlIlIl
l7l8 8 IS 9 l2lh16
STATIONS
Figure 6. Algal abundance and volume (means of five

replicates) and water temperatures for

evening samples of 1972-73.

 

37

Although the increases in November and January
WOUld.suprrtthe hypothesis of stimulated growth of
the algae due to a rise in temperature, these changes
tended to be restricted to the lower discharge canal
and plume stations (1“, 15, and 16). The lake station
(17) algal abundance and volume were very similar to
the results at the lower discharge canal and plume.
Therefore, the observed increases were possibly due to
the discharge water mixing with a more productive algal
assemblage in the open lake.

The other sampling dates had less obvious trends
or no trends at all. Morning total algal results for
the last four seasonal sets (Figure A) showed remark--
ably little variation between the stations. Only June
13th's algal density at the lower discharge canal sta-
tion was significantly below‘that of the plume stations.
Afternoon samplings (Figure 5), likewise, showed little
variation in algal density between stations for the last
four seasonal sets although volumes were much more
erratic but without any consistent trends. Correspond-
ing evening sampling results were more interesting. A
significant («10.05) peak in the density and volume was
observed for algae at the middle discharge canal station
(8) on March 30th. No analagous pattern was seen for
the other diel periods of the March-April seasonal set.
For the evening of June 11th, the algal abundance at the

lower discharge canal and two plume stations was up to

38

55% above that at the intake which was significant
(«10.05). The algal volume at the lower discharge canal
station at this time was “3% above the intake volume.
Beyond the June seasonal set no other significant trends
were evident for the evening period although on August
8th an insignificant increase in density along the dis-

charge occurred.

Diatoms: Diatoms constituted over 75% of the total
algal volume at all times of the study year. Their pro-
portion of the total abundance was also very high (65% to
90%) for the first three seasonal sets but dropped to as
little as 20% of the algal density in August. Thus, over-
all phytoplankton dynamics in the study area were often
largely a reflection of the diatom fluctions.

As with total algae, a three-way AOV was performed
on the transformed diatom abundance and volume data.
However, using the F-max test of variance homogeneity,
the transformed data had significant («10.05) hetero-
geneity. Nevertheless, sufficient rigor was assumed for
the AOV to minimize the consequences of this upon the
parametric analysis. Results of the AOV were inconclu-
sive due to strong interactions among the main effects.

Figure 7 presents the afternoon data of density and
volume for diatoms. Major deviations for the morning and

evening diel periods from the afternoon results shown

Figure 7.

\u

.—

TEMPERATURE‘C
N
o
l

Aauuoauca
LOG‘0(I/HL+I)

VOLUME
Loc‘o(um¥nL+I)

39

 

O
I

O
l

II-lO-72

Ol-Zh-73

0h-05‘73

06-12-73

03-09-73

09'29'73

 

J‘
I

W
l

N

.4

 

 

 

 

 

 

NO DATA

NO DATA

 

 

 

 

 

m
A

N
I

0‘
l

 

 

 

 

 

llllI

 

 

 

 

 

 

NO DATA

 

 

 

 

 

 

 

NO DATA

 

 

 

 

 

 

 

 

 

9 2 k

l I 16

STATIONS

 

 

Diatom abundance and volume (means of five
replicates) and water temperatures for after-
noon samplings in 1972-73.

 

MO

will be mentioned. For at least the first four seasonal
sets (i.e., November, January, March-April, and June),

the diatom results closely resembled those described for
total algae due to the overwhelming dominance of the class
at these times of the year. Not surprisingly, most of

the significant («10.05) station differences occurred in
the first three seasonal sets as they were for total
algae. Trends of increasing abundance and, in particular,
volume were most pronounced in November and January at

the plume stations (15 and 16). The peak abundance and
volume at the middle discharge canal station (8) observed
on March 30th (evening) for total algae was also seen for
diatoms.

The other seasonal sets had few significant differ-
ences among station data for diatoms. In Figure 7 the
visible trends on June 12th of increasing abundance along
the discharge flow and a decrease on August 9th in den-
sity and volume at the lower discharge canal station (1D)

could not be defended statistically.

Green Algae: The problem of excessive heterogeneity

 

of variance for transformed abundance and volume was
greater for green algae than for diatoms. Nevertheless,
the same three-way AOV was used for this transformed data.
As before, results of the AOV for green algae showed strongly

significant («10.001) interactions among the sources of

U1

variance. This complex nature of the variance meant, as
with earlier algal analyses, that station mean compari-
sons had to be made for each sample date separately.

Figure 8 portrays the afternoon green algal results.
The data from the afternoon samplings along with that of
the morning and evening periods were highly variable
between stations making distinguishing unusual station
dfiferences difficult. Virtually all significant («1
0.05) station differences, regardless of diel period,
were found in November. The pattern for that seasonal
set was one of higher density and volume at the lower
discharge canal and plume stations (in, 15, and 16) for
green algae. However, no («>0.05) significant differ-
ence existed between the plume results and those for the
lake station (17). Therefore, mixing of the discharge
which had more production of green algae could explain
these plume increases in density and volume.

Changes seen at the discharge stations in Figure 8
after November were mostly insignificant with only a few
minor exceptions. However, insignificant evidence of
declines in abundance and volume were observed in the
discharge in January and, perhaps, April. Possible

increasesijldensity were indicated in June and August.

Blue-green Algae: The logarithmic transformation

 

for blue—green algal abundance and volume results pro-

duced insignificant (c>0.05) heterogeneity of the

1:2

 

II-IO‘72 OI-2h~73 0h-05-73 06-I2-73 08-09'73 09'29‘73

...l.............nn. mm mIIII mm

lunl mulnlllln
lull“

STATIONS

TEMPERATURE-C
N
c
1

 

 

 

..
+ 3‘
w a
U:
z '\
<§
av
z
a S
n a 2‘
<0
_l

..
I

NO DATA
NO DATA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VOLUME
Logo(um3/HL+I)
VI 0‘ \A
l l l

NO DATA
NO DATA

 

 

 

 

 

 

 

 

 

 

 

Figure 8. Green algae abundance and volume (means of

five replicates) and water temperatures for
afternoon samplings of 1972—73.

w ‘-
l l
_
_
H—
03-—
-—
_
—
—
—
—
—
_
_

lll II II II I I I II I u I
I2

 

 

 

 

 

“3

variances. However, the three-way AOV of this data was,
again, complicated by significant interactions of the
sources of variance.

Figure 9 illustrates the afternoon results of blue—
green algae. Morning and evening station means differed
little in the patterns shown for afternoon. Virtually
all significant station differences were from the Novem-
ber samplings. At this time, blue-green algae from the
lower discharge canal and plume stations (1“, 15, and 16)
were more abundant and had greater volume than at the
intake (18) or upper discharge canal (12) locations.

The lake receiving waters, as indicated by the lake
station (17), also had large density and volume which
suggests that the November increases in the discharge.
noted above were possible due to mixing with productive
Lake Erie.

Large fluctuations of discharge station results on
January 2Uth (afternoon) and March 30th (evening) were
also found significant («10.05) but gave no consistent
trends. On other sampling dates the results were much
too variable to identify any trends and none of the
station differences were statistically significant.

Euglenophyceae: The euglenoids represented the only

 

other class to become an important component of the
phytoplankton. This class was evident principally in

the March-April seasonal set. The three-way AOV showed

Uh

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

u II-IO-72 on-zh-73 0h-os-73 06-12-73 08-09-73 09-29-73
.530-
¢
3
2 20-
K
* ‘ I I]
U
r 1' Innjlllldlll , ,1- 7 ,1
I...
t: 3‘
q.
Ill-J
u!
2\
25:
z 2-
2.? .. i
(:3 h h
4 3 S
'_ 2 2
6-:
E"
u
g as
> ”23. ¢ ‘
u- r-
3 2. 3 3
l a a
II
1718 8 I5 9 uzlhls ' it '

 

 

 

 

 

STATIONS

Figure 9. Blue-green algae abundance and volume (means
of five replicates) and water temperatures
for afternoon samplings of 1972-73.

 

“5

significant interaction among the main effects.
Bonferroni-t mean comparisons indicated only a few
significant («10.05) station mean differences in the
June and September—October sets when the class was
relatively rare. Due to the low densities at these
times, the significant differences probably repre-
sented a patchy distribution of individuals.

Centric and Pennate Diatoms: Up to this point,

 

results presented have dealt only with the algal classes.
However, the two orders of diatoms, Centrales and Pen-
nales, are often recognized as ecologically as well as
morphologically distinct groups. Since data were avail-
able for most of the seasonal sets for the afternoon
period only, a two-way AOV was performed on transformed
abundances and volumes using season and station as the
sources of variance. Results were also obtained for

all three November diel periods for centrics and pen-
nates which required a separate AOV with diel period

and station sources of variance. Heterogeneity of
variances and main effect interactions remained major
problems for these analyses.

Results for the afternoon period samplings for
centrics and pennates are shown in Figures 10 and 11,
respectively. The centric diatoms were the largest
portion of the class and, not surprisingly, their his—
togram was very similar to that for the entire class

(Figure 7). November and January had most of the

146

 

II-IO-72 OI-Zh-73 0h-05'73 06-12-73 08-09'73 09-29-73

TEMPERATURE-C
N
o
l

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

lo-flllllllmnndll | H

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A
w‘o A-
9.:
z:
<\
9.
av
50
n—
<0 3- < <
O h h
.4 < <
a :3
I'll] o a
z z
A
I 8-
.1
I
“in? 7"
I E
3 a.
JV
3 °6" :5 :5
o < <
O S a a
_, ..
O O
I z z
IIIIIII llIfiIll lllllVII'lllI I I I II I [lit
I7 18 8 IS 9 12 Ihl6

STATIONS

Figure 10. Centric diatom abundance and volume (means
of five replicates) and water temperatures
for afternoon samplings of 1972-73.

“7

 

11-10-72 01-210-73 Oh-OS‘73 06-12-73 08-09'73 09'29'73

 

30'

20'

Illll ...m..m ll

TEMPERATURE-C

 

 

 

 

 

U
I

ABUNDANCE
LOGlo (I/NL)
n
1

NO DATA
NO DATA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

lllllllllll

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A
_J
a:
m \ 7'
n
I:
3
J56— < <
o O I— I-
> '— < <
u D O
O -1
45 O O
z z
Illllll I I IIIIIIIIIII l I ll llrtll I II

I l
1718 8 15 9 1211116]
STATIONS

Figure 11. Pennate diatom abundance and volume (means
of five replicates) and water temperatures
for afternoon samplings of 1972-73.

48

significant («10.05) discharge changes with a gradual
increase in centric abundance and volume at the lower
discharge canal and plume stations (1“, 15 and 16).
However, Lake Erie also had similarly high abundance
and volume. Significant drOps in density and, in par-
ticular, volume occurred in April at the upper discharge
canal compared to the intake station (18). As shown in
Figure 10, this April result may be due to overestima—
ting the intake's centric population rather a discharge
reduction due to entrainment. The other sampling dates
lacked any significant changes in the discharge or
trends. -

Pennates (Figure 11) had only scattered station
differences in density and volume which were signifi-
cant. Most of these occurred at the outer plume sta-
tion (16). So, little evidence of change was seen in
the discharge that might be related to pennate entrain-

ment.

Shifts in_Algal Class Dominance

 

It is possible that changes in the relative impor-
tance of algal classes can be affected by the stesses
of entrainment. To assess this, the relative percentage
of the total abundance and volume for each station were
computed using untransformed station means. No statis—

tical analysis of these values was attempted.

49

For the first three seasonal sets, changes in the
relative importance of any algal class along the dis-
charge canal or plume was usually less than 10%. During
this time, the only exception to this statement was in
the March-April set from the evening period when the
outer plume station (16) diatom percentage of the total
abundance rose by almost 15% compared to the intake
largely at the expense of green algae and euglenoids.
However, no trends of increasing diatom importance along
the discharge flow support this outer plume change as
being due to entrainment. .

Of the last three seasonal sets, only June showed
any unusual shifts in class dominance. Diatoms decreased
in percent of total abundance by over 10% (6 to 11% by
volume) from the upper discharge canal station (12) to
the outer plume station (16). At the same time, green
algae and, to a lessor degree, blue-green algae assumed

proportionally greater dominance.

Species Composition Within the Cooling System

 

One would anticipate only severe environmental change
to seriously alter the relative density or volume of
entire algal classes because each is composed of many
species each of which has slightly differing environ-
mental requirements for survival and growth. Results
pooled or averaged at the class level might conceal subtle

but perhaps ecologically important changes in the

50

phytoplankton. Therefore, changes at the species level
were examined.

Of nearly 350 distinctive forms of algae recognized
during the study, 255 represented identifiable species.
Appendix A5 lists all algal forms observed during this
study. An abridged list was prepared (Table 5) which
roughly indicates the percent of total volume of species
which exceeded 1% of this for afternoon samplings of
each seasonal set.

Of the species listed in Table 5, clearly diatoms
were the most prominent and the most diverse. Of the
70 species and unknowns given, 59 were diatoms. Of
course, many of the forms given were relatively rare.
Navicula, for example, was a genus with a large number
of species, but none of those forms ever had a volume
much above 1% of the total. Especially major species
(above 10% of the total volume) frequently were

Coscinodiscus radiatus and Cyclotella meneghiniana and

 

 

less frequently Fragilaria spp., Stephanodiscus astrae,

 

 

and Stephanodiscus niagarae.

 

A detailed analysis of the changes in species'
abundance and volume like that done for the major classes
was practical for only a few species which had suffi-
ciently large numbers to make statistical analysis
useful. Therefore, seven species were chosen for
detailed study. Representative species from each of

three three major classes were selected taking adequate

51

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

..-o-- ..---- ------ -----m -----w ------ ------ ----nm mmmmmmmmm .m
..oon- .moona e1o111 -mo11- encnnw emcawm monuam amouu: mmmmmmmmw .m
.alonn .alonm nluonm unions Inuonm nluoow nuuoow luullu mmmmmmmm .a
ntuoln match: 111091 tulip: union: 1110:: 1100:: 111011 mamansm anamonz
sauna: nmulln 1:101: 11109: auuoom Iluuuw Inlolm It'll: mmmmmmmmm .m
c.1111 umuilu IIIIII unions until: 111111 11:11: 11:11: Enomcassom mswfimopwu
..---- ..---- ----n- ------ ------ ------ ------ ------ ammmnmma .m
..aoua ..no:: nanoas annual unionw unuonm usuonm uuuunu mmmmmwmmm .m
aennnn walnut 1111:: 1:119: 1111:: 111111 11:11: 11:11: Enumpmsm:w mEococmeoc
canon: unoomu amount umoonn Imosmm about: msouau umoouu .odm .M
.muonu amino: Inuit: Inlonm nunonl union: union: union: mamcm:Ouooo magmafiwmpm
:a1111 until: 1111:: 1111:: Innoll 11:11: 111111 1111:: mflammcoaoo mamconHQ
..---- ..---- ----g- ------ ------ ------ c----- ------ mmmwmm» .m
uallal c.1111 until: 1111:: union: unison nulls: Inuit: .om .m
~.uuuu ..cunn nucnnu nucnuu uueunn uuouun use--- uncuuu asumwcoflm meoumfia
..---- ..--n- ------ ------ ------ ------ ------ ------ .aam mmmmmanm
auuoll until: 11101: 111111 ulunnw Iluulw Ilnllm Inulo: moaom wpzoamoumezo
..---- ..---- ------ ------ ------ ...... -m---- ------ mmmwmmmmmm .m
.moonw .aooow monomm nooom< mmoon< umcom< mmaom< 9000mm mcwficfizwwcoe .o
..---- ..---- ------ ------ -----m ------ ------ ------ mammwammmmm .m
.u1111 .mloil 11:19: 11119: Illoal 111191 111091 11111: mumLoEon maamuoaomo
.aaom< .aoom< mmoon< Imaou< manna: mmaomw mmonlm mmoom< mzomfiomp msomaoocfiomoo
teuInu aallln 11:11: 11112: 111191 nnnnnn nunlnn IIIIII mflsocmomam mHmCOOQOO
eulonm unlonm Inuoum 1110:: 11:09: unuoom ulnonm ululnn mmospou adamcofipmom<
cmoozzooapmaafiomm mmmao
ma ma 3H m NH ma m AH oemz mmaomam
mezam ossam owsmzomao owhwzomfio mwpmnomao oxmuCH po>Hm oqu
house Loch Lozoq OH: homo:
mcoauwom

 

_.co«umum zoom on oasao> Hmuou on» go owmucoohco coo:umumw m>aumamp news» can 9mm» mosum
mplmwma on» non Goodnesscm AmCfiHaEmm acm madman oESHo> Hmuou on» no once so “Hy mmaocom Human pend: .m canoe

52

 

.mooow
munom<
xenom<
:ullll
melons
:allll
muslin
tullll
c.1111
c.1111
.n1111
until:
mallnl
amllll
aallll
saint:
.3111:
c.1111
nmllll
c.1111
satin!
:mnlln
twill:
amllnl
atllnl
:ullll

"'O"

napolm
melnm<
macon<
nailll
anions
wanna:
walnut
aallil
munlll
tannin
talus:
uuloll
mallll
aullll
muloll
:cltll
onion:
:cllln
a-IIII
anllll
taunt:
canon:
.atlll
nation
amnion
aellll

IIIODI
IIIODI
IIIODI
IIIIDI
IIIODI
IIIIDI
IIIIDI
IIIIDI
IIIIQI
IIUOIM

I'QIII

can---

annalm
umouu<
«would
nunulm
III-Illa-
IIIODI
I'IID'
IIIOII
III-In-
III-In-
IIIIDQ
Ill-In-
IIIODI
I'IIQI
unconc
IIQIIG

.II-OI-I'

IIIOII
IIUOII
MMIOII
amounm
III-IDI-
Illnla
IIIODI
nluonw
IIIOII
all-I'D-
Inloom
ulnonw
Iloom<
one---
a1ouu-

IIIIDQ

HHH
---Hmu
ulnnuw
HHmH
----n-
nuouna

'mI'I'

mug---

IIIIQI
IIUOII
IWUIII
IIUODQ
'I'ID'
IIUIII
IIIIQI
IOIIIQ
IIIIDI
IIIODI
Illlflm
IIIOII
annual
Illlnw
IIIIDI
IIIODI

-uuun<

-0'|"

l'c'l'

mmcom<
umoon<

IIIOII
IOIIII
IIIIDI

mun---

 

newsman mHHopapzm

.Qm .W

mmpmwmfi: .w

manpumm msomaoocmcmoom
wum>hzo macwnmmoofiocm
mamcmfipm macmaouanm
macaw maLmH3::«m
.Qam .l

M§ .Qm

H§ .om

«Ewan

moaam

mHHHome
mHELogHafim
mmmmmmwmm
mfipmHSOHom wagons»
mascpfi>

muocsafipu .

 

 

 

 

 

0.4 o
ZUZRZZHZWHZHZRHZWZ

 

wawcmmoonocch masca>mz
«cause .m

Ezpumaw .

mpaoammzo .
mamzamooumxpo
mfiamcmo masofi>mz
mamapm> .M

.Qm .m

moaamua .2

 

ztzmfl

 

 

ma

mesam
gonzo

ma
oszam

noCCH

:H

ompmcoman

90304

m

owpmcomfia

UH:

NH

owamzomfim

soda:

meoauwum

ma
oxmucH

po>mm

NH
mxmq

mEmz mmaooqm

 

.A.o.pcoov m magma

53

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

galoll xenon: Illoul 1110:: Intel: 11:11: 11:01: 111111 acuoo>ao> masoanmcompe
mallll *uunll lllll I IIIIII IIIIIIIIIIII Innoll IIIIII maafiowpw macawsm
owmoznoocmawzm mmmao
.wunuu ..1111 uuuuuuuuuuuuuuuuuu unuuuu uuuuuu nucunu .qam afipoumfifiaomo
amount aaolnl llllllllllll nouns: 1m sputum «maaowpw cocoEouficmzm¢
mmmozzoocmzo mmmao
.3011: :.o111 lions: IIUIII Ilonln Ilolln Inuit: Inoulu msfimmfiaafioosm xfipnuoH:
*‘I'Il .‘ll'I .I'Ilu'ln '''''' III-0" IIIII I. ''''' I. llllll ESLOE “CHLOUCML
gaunt: groin: «no.1: 1101:: Ilolll unclul Inclll gloat: masucmwmam maumowzoz
wallll anllll IIIIII IIIIII 1111:: Iuollu Esaamzoasa EzfinmmcmmomuOHo
cullnl zIII: 1111:: IIIIII 1111:: 16:11: 10:11: ImIIII EsmoHsELom esfipmsmoo
3.10:1 mallll 1:111: 11:11: 11:11: lllllllllllllllll 1 ma .om meOEooSEmfico
smulul c.1111 16111: lollul Ionian amalun Imulll Icolum mamcowno mfipmmaoscfim
omooznqonoaco mmwao
:a1111 urinal 1111:: IIIIII IIIIII IIIIIIIIIIIIIIIIII :* ouwccca czocxca
mellll c.1111 unlit: 111:1: giant: «loll! muolnl Input: acoEmHHm owpucmo czocxca
canon: saloon IIIIII IIIIII Invent loolnu IIIIII Invent mumpumccma magmaaonww
mall...» amllll 111121 1111 lllllll I II wwfihmcozmur .M
genial canon: Incoom Icolmm luoomm Ileana ulvlmw alounm mad: .m
c.1111 satin: IIIIII 1111:: I lllll 1111:: m moaocoamm .Lm> monsoon .m
c.1111 .n1111 IIIIII anion: Illonm Tallow quonm 111111 aum>o mHHoLfipsm
ma ma :H w NH ma m NH memz mmaomam
madam macaw mwomnomfia owpmnomaa ompwnomfio mxmucH Lc>Hm oxmq
house LoCCH Lmsoq UH: pogo:
macaumpm

 

.A.c.pcoov m magma

5“

.mpmo oc mmomoaoca A* v xoaampmm c< .moav menao> m mmpmoaoCa AI v ammo <
.mE:ao> ampOp on» mo moavl pan “an mm: mmaomom map mmmeHUCa wwmo pmzoa
muMoaoCa mamppma mmmo ponds

.OESHO> Hauop was no ROHM mm3 mmHoQO mnu
mama mm pmnsmpamm

mama .m umswsa

mama .ma mesa

mama .m aasg<

mama .zm mawscmw

mama .oa amnsm>oz

I wmpmc mcaaQEMm unmammmao on» mpmoamc

m
m

U
o
n
m
H

.m

1'11

”Q
o
Hm
<
mamupma ”maoosmm wanmea

.a.o.pcoov m magma

55

abundance or volume and morphology (i.e., unicell,
colony, or filament) of the species into consideration.

Thus, two unicellular diatoms were chosen: Coscinodis-

 

cus radiatus and Cyclotella meneghiniana. Three green

 

 

algal species were selected: the colonial Dictyosphaerium

 

pulchellum, the coenobial Scenedesmus quadricauda var.

 

 

longispina, and the filamentous Ulothrix subtillissima.

 

 

Two blue-green algal species were included: the colo-

nial Anacystis incerta and the filamentous Aphanizomenon

 

 

gracile. Collectively, these species constituted about

3uz of the average total station abundance.

Species Annual Mean Abundance, Volume, and Biomass

 

 

 

Table 6 presents the annual afternoon station means
of untransformed abundance, volume, and biomass for the
selected algal species. No statistical analysis was
attempted for these results, so the significance of

changes discussed below must be considered tentative.

As mentioned, 9. radiatus was a very important

 

species in the study area. It accounted for 15% of the
diatom abundance and 33% of the class volume. Results
for it in Table 6 indicated an increase of abundance,
volume, and biomass occurred at the lower discharge
canal station (14), and even larger values were evident
at the plume stations (15 and 16). The outer plume
station's abundance, volume, and biomass were all 75%
above those at the intake station. However, data of

the lake station (17) suggests at least some of the

56

 

 

 

 

 

 

 

w.mm m.mm z.ma a.am m.aa a.=m m.a o.mm mmmsoam
:.mmm m.mwm m.maa m.mma :.mma m.maa m.:m o.mmm mezao>
amm omm wma mam oma ama mm cam cosmocso<
meammaaaapnzm xascan:
m.o z.a :.m a.o m.a a.a m.a o.m mmmEOam
m.= m.a m.ma m.m a.a :.o o.a m.m ossao>
mm :m mm mm m: a: m: a: mocmnzzo<
moaamaQOa .Lw>
wczwoapcmzw mssmooocoom
m.m w.: m.m 2.: o.m m.m a.o o.m mmMEOam
o.wa m.mm m.=a a.mm a.am m.ma 3.: a.ma ossao>
mm. aa mm mm om m: aa __m 8:352
Ezmaonoasm Ezapomzomommwac
a.mma m.m:a m.moa :.©oa a.:w m.mm m.mma N.wa mmmsoam
m.aaoa a.oaaa o.mwma o.mmma o.ooma o.o::a m.wmzm m.mmaa mssao>
mom amoa :oma ooma caaa aoma amam mom cosmoczn<
«swacasmmcme waaooOHwNo
o.amm m.mmm a.0mm a.mma m.mam w.aom m.m: m.mam mmMEOam
a.mwma m.mmwm a.:zmm o.amm: a.mmm: m.aam: o.amaa m.:zmm mezao>
ama zmw 0mm :zm :mm mam mam mom mocmczsn<
msumacma mzomaoCCaomoo
ama ama 2a m ma mm 0 am cEmz mmaooam
canam wasam owamzomao mwpmcomao owaonomao mxmch Lo>am oqu
Loose poccH Losoq ca: Logo:
mCOaQMum

 

.coa»Mpm comm um owmao>m amzccm cm pom meaaQEmm coocamumm mmoaom commam>m moaoodm
pouooaom uo Amloa x aE\o wnv mmmano pew .amoa x aE\mE:v mssao> .Aas\m:oanonv cosmocznw maamo :mo: .0 magma

57

.oomeaomm mm: moan wcammaza

 

 

 

 

 

m.am :.mm a.ma m.aa m.am a.ma m.z m.mm mmmanm
w.m:w m.mmm m.mm m.om a.=ma o.mmm m.:m a.mwa oszao>
ama zma mm om ow oa ma moa mocmccsn<
oaaompw cocoeouacmcm<
m.m a.m m.m m.: o.o 0.: m.a m.: mmmEOam
a.:m m.am a.aa o.mm m.o: ~.:m a.m m.mm ossao>
maa woa ow mom ama mm mm :m cosmo23n<
muLmOCa maummdmc<
ima ama :a m ma ma m aa meaz mmaomam
mszam oezam mwamcomao wwawcomaa wwpmcomao mxwuca Lm>am mxwa
gonzo noCCH Lozoq ca: Loom:
mcoauwum

 

.a.o.u:oov m magma

58

increase was due to mixing of discharge and more
productive receiving water.

9. meneghiniana constituted 38% of the diatom

 

density and 11% of the class volume across all sta-
tions. The station means in Table 6 were quite
variable although there was some indication of
decreasing abundance and volume but not biomass.

The three green algal species, 2. pulchellum,

 

S. quadricauda var. longispina, and Ulothrix sub-

 

 

 

tillissima were, respectively, 3.A%, 3.5%, and 13.9%

 

of the class density averaged for the year. They all
tended to be prominent only during the summer. In
Table 6 no unusual differences between the discharge

and the intake were evident. However, g. subtillis-

 

Elflé did have substantially larger plume density,
volume, and biomass.

The two blue-green algal species, A. incerta and
A. gracile, were common summer forms. The former
species was 12% and 10% of its class' abundance and
volume, respectively. The second species was 11% and
52% of the abundance and volume, respectively, of the
class. Only A. gracile had substantially larger
density, volume, and biomass in the discharge plume
stations (15 and 16) over those at the intake. How-
ever, its abundance was so low that this increase is

questionable.

59

Seasonal Comparison g£_Species Abundance and Volume

 

 

Due to the seasonality of many of the selected
species, only an analysis of the station means on that
basis will properly describe the results. For each of
the selected species, a two-way AOV was made on
logarithmically transformed abundances and volumes
from the afternoon samplings using season and station
as the sources of variance.

Coscinodiscus radiatus: Substantial heterogeneity

 

remained for transformed data of g. radiatus based on
the F-max test. Despite this, the AOV indicated
highly significant («10.001) interactions existed
between the main effects. Therefore, station results
were not pooled across the seasonal sets for evalua-
tion of their mean differences.

Figure 12 illustrates the station means of abun-

dance and volume for g. radiatus. Obviously, large

 

fluctuations to zero abundance and volume occurred at
some stations during the first three seasonal sets.
Although the Bonferroni-t mean comparisons indicated
these erratic variations were significant («10.05),
they were most likely artifacts of the enumeration
procedure for diatoms which could easily give zeros
especially when densities were low. Nevertheless,
trends were evident for abundance and volume of the
species in November and January when these values

steadily increased in magnitude along the discharge

Figure

60

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

9 lI-10-72 oI-2I-73 oh-oS-73 06-12—73 08-09-73 09-29-73
W30
1
3
g—
; 20-
U
ul
5 ll llllll'llllll I 7
3-1
m i:
(at
2\
<\ 2‘
av
z 0
g _
° 8
‘4 5 a
" I 5 g
' o o
z 2
7-
6..
,. 5 ‘
_I
I
\II-
“ME < <
=3 I— I-
3 23' a a
:32. g 3
—l
I-
111 l'lllI I III] TI [1
I7 18 15 9 12 IuIe
STATIONS
l2. Coscinodiscus radiatus abundance and volume

 

(means of five replicates) and water
temperatures for afternoon samplings of

1972—73-

 

61

flow. However, again the lake station (17) had
similar density and volume to those of the plume
stations (15 and 16) indicating the discharge
increases were probably due to mixing with the more
productive open lake.

Results of April 5th showed a slight decrease
in density and volume beyond the middle discharge
canal station (8). However, the magnitude of these
changes were small despite their significance («1
0.01) and were subject to substantial error due to
the low densities of Q. radiatus.

June 12th's data had a small but significant
(«10.01) increase at both plume stations in abundance
and volume of the species. Again, the lake station
also had higher values of density and volume than the
intake or most discahrge stations; so, the plume
increases of June for Q. radiatus may be due to mix-
ing with the more productive Lake Erie. No statis-
tically or visually obvious trends were seen on other
sampling dates.

Cyclotella meneghiniana: The log transformation

 

for density and volume data for g. menghiniana was not

 

very successful in reducing heterogeneity of variances.
Therefore, the parametric statistical analyses with
this transformed data must be viewed with some

skepticism.

62

The AOV for this species was plagued by strong
(«10.01) interactions of the main effects. Station
mean comparisons were, therefore, limited to unpooled
results.

Results for this species, as shown in Figure 13,
produced an opposite trend than seen previously in
November. Significantly decreasing density and
volume values were observed at the lower discharge
canal and plume stations (1“, 15, and 16). Neverthe—
less, the reason for the decreases seemed to be the
same. The lake station (17) also had low density and
volume which indicates the open lake was less produc-

tive of Q. meneghiniana than the discharge. Thus, as

 

the plume dispersed into the open lake, the abundance
and volume for this species understandably declined.

The more typical trend appeared in Janaury with
significantly («10.01) higher density at the plume
although volume increases were not significant to the
a = 0.05 level. Mixing of discharge and receiving
water did not seem as likely an explanation here since
the lake station results were not similar to the final
plume levels.

Other sampling dates had some significant fluctua-

tions of g. meneghiniana's abundance and, to a lessor

 

degree, volume in the discharge, but these were erratic

variations without obvious trends.

63

 

11-10-72 01-211-73 0‘0-05-73 06-12-73 08-09-73 09-29-73

mum........mlllnlllll ”1"“

U
0
I

TEMPERATURE-C
— N
o o
l I

 

 

 

 

 

 

 

ABUNDANCE
LOG'O(I/HL+I)
w J-
I l

N
1

NO DATA

NO DATA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Illnl

 

VOLUME
Lac:lo (pm3/ I-1L+I)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

J? U!

I l

.—
mu_

~—
.1“
q“

NO DATA

NO DATA

I7 18 8 15
STATIONS

Figure 13. Cyclotella meneghiniana abundance and volume
(means of five replicates) and water
temperatures for afternoon samplings of

1972-73. '

 

6U

Dictyosphaerium pulchellum, Scenedesmus quadri-

 

 

cauda var. longispina, and Ulothrix subtillissima: Of

 

 

the three green algae species examined, heterogeneity
of transformed density and volume variances for D.

pulchellum and g. subtillissima remained significant

 

 

(«10.01). The AOV results showed almost no interac-
tions between season and station main effects for all

three species. Both Q. pulchellum and g. subtillissima

 

 

had significant («10.05) variability attributed to each
of the main effects with, of course, season assuming

the greater share. However, §. quadricauda var.

 

longispina had significant variance of both abundance

 

and volume attributed to only the season component.
So, presumably no significant station differences
existed over any of the seasonal sets for this one
species. Therefore, no station mean comparisons were

deemed necessary for S. quadricauda var. longispina.

 

 

Figures 1A, 15, and 16 illustrate abundance and

volume results for Q. pulchellum, s. quadricauda var.

 

 

longispina, and g. subtillissima, respecitvely. These

 

 

all were common only during the warmer months. Their
results indicated high variability and so almost no
significant abundance or volume station differences
could be demonstrated for any species. No significant
trends in the data appeared, and simple inspection of
the Figures 1U, 15, and 16 supported this. A possible

exception was g. subtillissima which had a small

 

65

 

 

 

 

 

 

 

 

u II-Io-72 0I-2h-73 oh-os-73 06-12-73 08-09-73 09-29-73
.3 30.1
K
:1
2 mm
C
MI
E.
5 '0‘ I'll llll lllllllllll [II I
5 ll Illlllllnlll ,,_ li,,,,l 777 -1
3.
I
lull—l
332- I
(Q
2“
S 2
a”
(O
«J

—
1

NO DATA
NO DATA

 

 

 

 

 

 

 

 

 

I ' Illlllll I l 3 l

 

\H
I

VOLUHE
L06‘0(un3/HL+1)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2.
'1 I”
I 1.1!! | | I!

'U'ITIIUUfifiT

I7 18 815 9 12 II'I's

 

 

 

 

 

 

STATIONS

Figure l“. Dictyosphaerium pulchellum abundance and
volume (means of five replicates) and
water temperatures for afternoon samplings
of 1972-73.

 

3O

20

TENPEAATUAE-C

U

N

ABUNDANCE
LOG'0(I/NL+I)

VOLUME
LOG'o(uu3/HL+I)

Figure 15.

66

 

11-10-72 OI-ZD-73 Oh-05'73 06-12-73 08-09-73fl09-29‘73

Inllll 1...“...IIIHII I” II I“

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NO DATA
NO DATA

 

 

 

 

 

 

 

 

 

 

 

II III I

 

NO DATA
NO DATA

 

 

 

:11 II "I

f‘jIVIIVUII'III II'IrII' III

17 18 8 IS 9 12 1&16

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

d

STATIONS

Scenedesmus quadricauda var. longispina
abundance and volume (means of five
replicates) and water temperatures for
afternoon samplings of 1972-73.

 

67

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

u 11-10-72 01-210-73 OII-OS-73 06-12-73 08-09-73 09-29'73
$30.
¢
3
:20-
K
II]
E H). IIII llll lllllllllll llllllll
” ||_ "Ilillllnllll_ 7,77, ,. ,__
3-
'3."
Ill-l
U!
32:24
av
z 0
D a—
mu
(0
J
h < <
I— I-
( (
O D
II I II I II =°= 3
:61
4.
J
g i 5‘
3M
5&-
2
g 31
.J
2- < <
I- I-
< <
O G
h I II I II 3 5"
I7TI'8'51115' 531237.13 tfin'” ' ' ‘
STATIONS
Figure 16. Ulothrix subtillissima abundance and volume

 

(means of five replicates) and water
temperatures for afternoon samplings of

1972-73.

 

68

increase in density and volume at the plume stations
(15 and 16) in June, but since the lake station (17)
also had somewhat high values, the plume increase may
be due to mixing of the discharge with a more produc-
tive Lake Erie.

Anacystis incerta and Aphanizomenon gracile: Des-

 

pite some heterogeneity of variances of abundance and
volume for A. incerta and A. gracile, the two-way AOV's
were performed. For both species the AOV's had sig-
nificant («10.05) interactions appear between the main
effects.
The coccoid blue-green alga, A. incerta, showed
little, if any, significant entrainment effects as
seen in Figure 17. Only the June and September results
had significant («10.01) station mean differences
which were usually seen as decreases in density and
volume in the discharge canal relative to the intake,
but abundance was so low that those results may not
be considered reliable. Statistically insignificant
(«>0.05) decreases in abundance and volume were seen
on August 9th, but the upper discharge canal station
(12) values were so much above the intake's that a
patchy distribution of the species could explain this.
A. gracile's results in Figure 18 were even more
variable between stations than those of A. incerta.
Despite high summer volumes, almost no station means

for A. gracile were statistically («10.05) different

TEMPERATURE-C

ABUNDANCE
L00'0(I/HL+1)

VOLUME
Loam (m3 /ML+I)

Figure 17.

30

20

ID

69

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

11-10-72 01-21-73 011-05-73 06-12-73 08-09-73 09-29-73
. ...m..|||“||l“”"” 1|“

" < <

2 2

O O

I I 3 ll 13

< <

‘ 2 2

O O

O O

‘ I . l I”

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I718 815 91211I16
STATIONS

Anacystis incerta abundance and volume

 

(means of five replicates) and water
temperatures for afternoon samplings of

1972-73-

 

Figure 18.

70

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

u II-Io-72 0I-2I-73 01-05-73 06-12-73 08-09-73 09-29-73
.1130!
K
at
(20"
I:
z .
m
~ III II...m..m|l 3 I i
3.
“3'.
oz 2‘ r
2\
(in
av
2°
:— < <
GIN-9 I- I-
(O I: < <
.l O G
[I o o
z 2
I II I l I I I , L I
6‘
A 51
I
z I-
U\
In
3 SE 3-
2‘1,
u—z" : If
0 < <
.l O Q
" “III I ° °
II = I |=
n 18r8'15'l'9rrl'2t1h16
STATIONS
Aphanizomenon gracile abundance and volume

 

(means of five replicates) and water
temperatures for afternoon samplings of

1972-73.

 

71

from one another. Yet, June's sampling results offered
some indication of greater abundance and volume at some
discharge canal and the inner plume stations (8, 1H,

and 15).

Mean SpeCimen Volume Changes for Selected Species

 

So far, results have been presented to address the
question of whether entrainment influenced the relative
growth or mortality rates of the algal classes and
species. Another consideration was the change in cell
size or mean specimen volume (MSV) of a species in
response to the stresses of entrainment. Limited
evidence (e.g., Margalef, 195“) indicated that a reduc-
tion in cell size might occur after a rise in tempera—
ture for some species. Furthermore, the specimen size
of a colony or filament might be reduced by fragmenta-
tion due to turbulence with passage through the power
plant condensers.

These new questions were examined by considering
the seven selected species Just discussed (Table 7).

To insure reasonably accurate estimates of the MSV,
only annual means of afternoon sampling stations are
given. The intake station, 18, was a theoretical
station and had no MSV's estimated for it.

Of the seven species, only g. subtillissima, a
filament, showed a sizable decrease in its MSV in the

discharge canal. However, these changes for this

72

 

 

 

H.0mm H >.mmm H 0.0mm H m.Ho: H p.33: H w.mmm H m.mzm H AHcmsmHHcv
MHmm HmmH NwMH mmzm cmmH mmsH mesH mHHome cocoEoHHcaca<
m.mHH H m.mo H m.mmH H >.om H m.mmH H m.wm H AscoHoov
osH u: 3mm 5mm mHm me mam mppoocH mHHmsomca
p.5mH H :.oom H o.mmH H m.:m H m.~mH H w.NMH H H.mHH H AucmsmHHov
:cmH HMOH ems mm» saw pom mmoa msHmmHHHHHnsm prnuoH:
m.om H H.0m H H.3m H w.m H m.Hm H m.mH H =.~H H AHmHnocooov mcHamecoH
OHN mmH smH moH mmH omH mmH .Hm> mosmoHHomsc mzsmmcwcmom
>.omm H o.mmm H o.mm H m.mmH H :.mw H o.H= H o.ozH H AscoHoov
:om om: Ham osm som mmH mmm ssHamnona asHpomcqmosHmHo
m.zmw H m.mHm H m.mmm H m.~oH H o.~m~ H m.:mH H m.mmH H AHHmov
mme HmzH omMH mmmH mmma mHHH oemH acchstocms «HHmHoHoso
w.m:m H 2.53m H ~.H- H m.=mm H :.moo H o.NNOH H m.moo H AHHmoV
:omm mmmm omom . mmms ammo :mooa mmm» msochmH msomHoocHomoo
SH ma :H m NH m NH meaz mmHomam
mesam mezam mwpwnomfia wwpmzomfio mmngomam Lm>fim oqu
Louzo poccH pwzoa mfiooaz Lona:

 

.mmfioodm Hmem ompoawm co>wm mo meHHQEmm coocpouum mwlmwma pom coaumum comm um A.m.mHv mossao> Hamo com: .5 mange

73

species were still within one or two standard errors
of the means for the intake region (i.e., stations 17

and 9).

Seasonal Changes in Species Diversity

 

 

As a last consideration of the phytoplankton com-
munity structure in this study, species diversity indices
were evaluated as a means of determining changes in the
relative dominance of some species due to entrainment.
Margalef's index, the Shannon-Wiener or simply Shannon's
index, and equitability were computed from species data
for each station's replicates. Indices for abundance,
volume, and biomass were obtained. Density and volume
versions of Shannon's index and corresponding equita-
bility are illustrated in Figure 19. The 95% confidence
intervals are indicated about each station mean.

Margalef's index did not prove too useful for
comparing intake-discharge differences due to the
index's high dependence upon the number of species in
a sample. The intake station was always inflated, as
a result, since it was a theoretical combination of
species at the lake and river stations. Shannon's
index was not so sensitive to the number species factor
and seemed to be the more conservative measure of spe-
cies diversity.

For November, Shannon's index for abundances

increased slightly at the lower discharge and two

Figure

SNANNON'S INDEX
DENSITY

SHANNON'S INDEX
VOLUME

DENSITY

EQUITADILITY

EQUITADILITY
VOLUME

724

 

 

 

 

 

 

 

 

 

 

 

 

 

2.0 "
II‘IO'7Z OI'ZN'73I 0h-05‘73 05-I2'73 03-03'73 09'29'73
9 a 3.3
.Ba B. ..-I. 33.88-. 3883888 8 BE 3 33.9;
I.04 BB.— 9 B a
o o
z z
2.0'l
B--- J ..B.- O B. E E
a- " ' In I" B a .0 a
I.0- .II -' BB II a
I399 '3 ’I ' B: {'3' 2
a
I .0 .. B- ' < <
III h h
H - " -'l|fla.BB'l.iBaBB‘BgJBBB'BBg - .I.g§
883- Ba - o B o
z z
0.5‘
I .0 -
- .;- a
- ---.
.. B H - .. I‘D.-.I If- g- If
BB I 888 <1 B Il<
M a on .-g° . - °
9 3 3
fiflhiélfsi Igi‘lzllxrlaillrilll (11T11IIIIIIIrIII Wit1lll
STATIONS

Shannon's species diversity and equitability
indices for algal density and volume for
afternoon samplings of 1972-73.

 

75

plume stations (14, 15, and 16) compared to the intake
(18) but decreased there over 25% using the volume
index. Equitability density and volume results were

similarly'.affectedq Since the species volume

diversity decreased to a great extent while the number
of species did not change at the lower discharge and
plume, apparently dominance in volume of a few large—
sized species was greater here. As was seen earlier in

the section of seasonal species results, Coscinodiscus

 

radiatus, a very large-sized species, increased volume-

 

trically while the smaller sized Cyclotella meneghiniana

 

decreased at these same stations which supports the
conclusion of a change in dominance. Similar station
changes in the diversity indices were observed for the
morning and evening periods of November. However,
since the lake station (17) species volume diversity
index was also low in November, the decline at the
lower discharge canal and plume may still be attributed
to mixing with the open lake.

January's results were overall higher in magnitude
than November's, but the volume results showed a simi-
lar pattern in the discharge. The plume stations again
had lower diversity than the intake or all discharge
canal stations. In this case, however, the lake sta—

tion volume diversity was not similarly low which

76

indicates Open lake mixing might not have been the
cause of the plume diversity decreases.

The species diversity of April varied little
between the discharge and intake stations. Then,
however, the lake station had a very low species vol—
ume diversity which did not reduce the plume values
through mixing as suggested for November's samplings.

On June 12th another decline at the plume stations
in both species density and volume indices was observed.
Equitability was similarly affected. These declines
may be only partially attributed to mixing with the
open lake since somewhat low volume indices were also
indicated for the lake.

Results of August and September were more complex.
For the August 9th data, Shannon's volume diversity
index and volume equitability for all discharge canal
stations were considerably below the intake's levels.
This was not observed for abundance diversity or
equitability. The opposite situation occurred on
September 29th when the discharge canal stations had
substantially higher species volume diversity and
volume equitability. For both of these seasonal sets,
the diversity changes were seen immediately at the
upper discharge canal station (12) with little further

change beyond that point.

77

Entrainment Impact gpon Primarnyroductivity

 

One problem with examining possible growth responses
to a change in environment is that the algae may require
hours or days to react. However, a more immediate
response of algae to environmental perturbations might
be seen in their metabolic processes, in particular the
photosynthetic rate. The gross primary productivity
(GPP) and community respiration (H) were, therefore,

examined.

Annual Mean Changes in the GPP and fl

 

 

Table 8 summarizes the station GPP and R results
averaged for each diel period over the study year and
also averaged for those sampling dates with an ambient
water temperature below 16°C (winter) and for those
dates above 16°C (summer). The 16°C figure is used
since some studies indicated depressions of net primary
productivity occurs with algal entrainment when the
ambient temperature is above this value. The winter
averages include data from November, January, and March—
April seasonal sets while the summer means are from
measurements during the remaining sets.

Table 8 gives evidence of sharp declines in GPP at
the discharge canal stations (12, 8, and 1“) during
morning and afternoon periods. These are restricted
to the "summer" averages, however. In addition, a

recovery of the GPP occurred to a level similar to that

78

 

 

mH0.0I m20.0l 00.0 00.0 No.0: mm0.0 m00.0 mm0.0 mwmpo>< wcaco>m

H0.0I 00.0: H0.0 00.0 m0.0| 30.0 No.0 No.0 Awmuwav owmgo>< pw553m

m00.0 mH0.0 00.0 00.0 00.0 mH0.0I mm0.0| mm0.0 Aoalzv owmpo>< Loucaz
02H2m>m

NmH.0 ma.0 0H.0 00.0 HH.0 HH.0 No.0 HH.0 owmpo>< coocampm<

0m.0 Hm.0 0H.0 NH.0 Hm.0 mm.0 mH.0 0m.0 Ammnmav owmho>< Lo563m

«00.0 50.0 m0.0 m0.0 H0.0 00.0 H0.0 20.0: Aoanmv owmpm>< gonna:
zoozmmem<

0:.0 mm.0 mm.0 "mm.0 0H.0 0m.0 mm.0 02.0 owapo>< wcficpoz

05.0 m0.0 m:.0 0m.0 nm.0 00.0 0m.0 0>.0 Ammumav mmmpm>< amassm

Ho.o mo.o mo.o Hoo.o mo.o 00.0 mo.o mo.o AHHumv mwapm>< HchHz
oszmoz

>BH>Heoaaoxm ~m<szm mmomo

0H mH 3H 0 NH 0H m NH A0. HcoHos< co mwcmmv

madam mezam ompmcomfio ompmzomdo owamzomaa oxmp0H Lo>am oqu mpom Hmcommom omaoom
Lopzo LoccH pmzoq 0H2 Loan: Qonmm

mcoapmum

 

.Apsoc\poufia\~0 we ca mosam> Hamv munmmma no mpmm HMCOmmom
A.uoOI.qum ocm ..w:< .mcz0v LoEESm 0cm AHHLQ<Icome ucm ..cm0 ..>ozv hoped: pom ommmpm>m mcofiu
Imam Empmzm wcfiaooo on» Lou :ofiumpadmop mpficzeeoo cam apa>auosoogn agmefipa mmopw cofipmum 0mm: .0 magma

79

.mpumouHH EOHH «Han xoaH OHHH 0H new mH oHsz msnomnmo EOHH «Han somH 0H o:H.mH .0H .m .5H mcoHHmeH

.muuoHIHH Ho mums mosHocH Ho: mmoaH
.mpuooI3o Ho «Han mosHocH Ho: moons

 

 

 

mm0.0a m30. mo.0 m0.0 00.0 m30.0 m30.0 m30.0 mwmpm>< maficm>m

30.0: 30.0 30.0 50.0 00.0 m0.0 00.0 m0.0 Ammumav ownsm>< LoEEJm

«00.0 mm0.0 00.0 m0.0 m0.0 mm0.0| mm0.0I mm0.0I A0313v mmmgm>< pmucfiz
02H2m>m

~m0.0 30.0 03.0 00.0 03.0 00.0 03.0 0H.0 wwwgo>< coocnmu0<

00.0 HH.0 00.0 m0.0 ma.0 HH.0 0H.0 00.0 Awmlwav ommpm>< goeszm

«00.0 No.0: ma.0 HH.0 30.0 30.0 m0.0 03.0 Aoalmv omwpm>< Loucfiz
zoozmmem<

30.0 00.0 00.0 300.0 m0.0 00.0 00.0 30.0 wwwpm>¢ maficpoz

0H.0 00.0 wo.0 00.0 m0.0 00.0 30.0 00.0 Ammumav owmpm>< Loessm

H0.0| m0.0 m0.0 ~m0.0 30.0 30.0 m0.0 00.0 AHHIMV owmgm>< amped:
oszmoz

on9<mHmmmm >EH202200

ma ma 3H 0 NH 0H 0 NH A00 pcmfins< 00 mwzmmv

mssam @8330 mwhmcomao ompmzomfio mmpmzomfio mxwucH Lo>Hx oxmq muom Hmcommmm cmaoom
Louso LwccH 90304 03: Load: oonmm

mcofipmpm

 

.A.o.HccoV 0 «Hams

8O

expected for the open lake based on the lake station
(17) means. Evening GPP's displayed no measurable
photosynthesis, as expected. The "winter" GPP's were
very low in magnitude. At this time of the year GPP
changes in the discharge were not well defined.

The R was very low throughout the year and,
surprisingly, had only slightly different averages
for winter or summer. Although the morning winter R
results were inconclusive, the afternoon and evening
averages indicated a slight stimulation of R in the
discharge canal. In contrast, morning and afternoon
periods of summer showed modest depressions of R at
some discharge canal stations. In nearly all measure—
ments, the plume R results were similar to that of the

lake station (17) and probably the open lake too.

Annual Mean Changes in the P/R Ratio

 

 

When the GPP/R or, more simply, P/R ratios were
computed at each station for the morning and afternoon
periods, the resulting values were quite variable and
of questionable reliability due to the presence of zeros.
To minimize this the ratios were averaged into winter
and summer means as shown earlier for Table 8. The
winter mean ratios were still too erratic to show
changes in the discharge. The summer mean P/R ratios,
however, did have interesting results. Intake values

averaged highest at 8.25 in the morning period of summer

81

while the afternoon intake mean value was only 2.00.
Substantially lower P/R values occurred at all dis-
charge canal stations for morning which ranged from
4.50 to 6.80. For the same period the plume stations
showed a recovery to 6.89 and 7.90. No such changes
in P/R appeared in the discharge for the afternoon

summer means .

Seasonal Changes in the GPP and R

 

 

Gross Primary_Productivity: To better visualize

 

the more significant data, Figures 20, 21, and 22 por-
tray the summer GPP's of June, August, and September-
October, respectively, for the morning and evening
periods. The water temperature, phytoplankton biomass,
and the GPP are indicated for each station. The 95%
confidence intervals are given about biomass and GPP
means. A brief note of sky conditions on each date
of GPP measurements is included although more complete
weather data is given in Appendix AM.

For the first three seasonal sets of measurements,
GPP was usually negligibly different from zero at most
stations based on 95% confidence intervals of station
means. Relatively high sampling variability, low
algal biomass, poor light conditions, and perhaps too
deep an incubation depth (1/2 m) for GPP measurements

contributed to the lack of significant winter results.

TEMPERATURE-C

BIOHASS
ug C/NL

GPP, mg 02/LITER/NOUR 0F INCUBATION

3D

82?

 

20

O
n

IHHWHHHHWHWW

 

3 d

.gB-=EBBEHBBBBHEB

 

06-13-73 MORNING
(o750-12h2 EST)
(MOSTLY suuuv)

 

06-12-73 Arrsnuoou
(1328-1805 :51)
(HEAVILY ovencAsr)

 

 

 

 

w BB B
BB B EB
-

W B a BBB
I T I I I r T'TI I I I I T I
I7 9 18 I2 ”I IS 16 I7 9 I8 I2 8 It IS 16

STATIONS
Figure 20. Station water temperatures, algal biomass,

and GPP for June, 1973 measurements.

 

E33

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U
H 30‘__ __ __ - '1 __ .3 '1 '1 __
3 1 '1 "I ‘I '1
: ZOI
‘
III
; I0-
I"
.—

$
““0 B BEBE
In:
53 =- E E El E!
1; 2 I53 E53 nun unluwu

" E53
285'2-22."°::II° 2?;22'332'E5I?°°"
o z - o -
z'° noser suauv) (HEAVILY OVERCAST)
2 --I
O
.7.
g‘Sq
i B I
II.
o d
2 I.o-
D
O
z
\
g B
u
P B
3 E! El BB
\
N
B BB
° B BE
E
J
3
0.01
I; 5 I3 I; 3 I? I? I3 *II §7 IE I} 5‘ {I {577%

STATIONS

Figure 21. Station water temperatures, algal biomass,
and GPP for August, 1972 measurements.

 

TEMPERATURE-C

BIOHASS
ug C/NL

GPP. mg OzlLITER/NOURS OF INCUDATION

Figure 22.

8M

 

30¢

amnnnnnmmmmn

l

 

N
I

888388 a
B EEEBBENODATA

 

I0-0I-73 NORNING 09-29-73 AFTERNOON
o . (0726-Ihzo £51) (I250-I756 EST)
(noser CLOUDY) (OVERCAST)

BBEBHBB=B BEBBEB

 

 

 

 

I l I I 1 V

T I r T I
I7 9 I8 I2 8 I“ IS I6 I? 9 I8 I2 8 IO IS 16
STATIONS

Station water temperatures, algal biomass,
and GPP for September-October measurements
of 1973.

85

No obvious changes or trends in the GPP were seen in
the discharge during this time period.

In contrast, inspection of Figures 20, 21, and 22
show not only significant GPP's above zero but also
substantial reductions in the primary productivity at
the discharge canal stations (12, 8, and 1a) compared
to the intake (18). The depressions of GPP occurred
on at least two or, perhaps, threeoccasions--June 13th
(morning), August 10th (morning), and September 29th
(afternoon). In each case an immediate drop in th GPP
was observed at the upper discharge canal station (12).
The relatively low productivity was more or less sus-
tained in the discharge canal followed by an apparent
recovery in the plume. The recovery, however, may be
more related to mixing with open lake water and the
plume than to a return of the entrained algal produc-
tivity to pre-entrainment levels.

The largest absolute decrease in GPP was about
0.7 mg Oz/liter/hour which occurred on August 10th
while the largest percentage drop was on June 13th
where a 75% drop in the rate was found in the discharge
as compared to the intake. The depressions showed no
relationship to the temperature increases experienced
by the phytoplankton since the other diel period of the
same seasonal set had no depressions despite similar
ambient temperatures and At's. A poor correlation was

also seen for the observed GPP and the corresponding

L13
O\

station biomass in Figures 20, 21, and 22 although it
may be related to low river (9) and high plume station
(15 and 16) GPP's. The depressed discharge canal GPP's
were not associated with unusually low biomass.

Light may have been a significant factor in con-
trolling when the GPP depressions took place. The
largest decreases of June and August occurred on sunny
days. Most cloudy and overcast days which had produc-
tivity measurements had no depressions except Septem-
ber 29th when it was cloudy and raining. However, due
to substantial variability in the intake GPP estimate
and the small size of the discharge decrease in the
rate, September 29th's results are certain.

Community Respiration: As for primary productivity

 

the R data of November, January, and March-April indi—
cated that respiration was negligible and without trend
in the discharge. R during the summer was still barely
measurable by the oxygen change method. Variability
was such that June's measurements were negligibly dif—
ferent from zero. For that seasonal set there was a
substantial but insignificant (based on 95% confidence
intervals) drop in R of up to 0.07 mg Oz/liter/hour at
the lower discharge canal station (in) for morning and
afternoon. In contrast, August sampling dates had R
values that increased in the discharge above the intake
levels. This was most evident on August 8th (evening)

when the intake station had virtually no R while the

87

upper discharge canal station (12) rate was 0.19 mg
Oz/liter/hour. The September—October measurements
had rather large but probably still insignificant
declines in R within the discharge for afternoon and
evening periods while morning results showed no such

change.

DISCUSSION

Community Structural Changes

 

In the introduction, several hypotheses were
introduced pertaining to predicted effects of entrain-
ment upon the phytoplankton structure. In essence,
four questions were asked about the impact of entrain-
ment. First, does it stimulate the growht of phyto-
plankton in general? Second, can entrainment affect
the survival and growth of certain types of algae
differently than for others leading to shifts in dom-
inating forms? Third, is the species diversity
affected? Finally, does entrainment alter the sizes
of algal individuals? The following will attempt to
consolidate and interpret the results in light of
these hypotheses.

Algal Growth: The results of extensive measure-

 

ments of density and volume of algae to the species
level often showed statistically significant changes
in the discharge canal. These were most pronounced
for the total algae, the three major classes (diatoms,
green algae, and blue—green algae), and two of the
seven algal species examined, 9. radiatus and g. mene-

hiniana.

88

89

Some of the differences between stations in abun-
dance and volume could be attributed to phytoplankton
patchiness since no attempt was made to sample the same
water mass as it passed through the cooling system.
Indeed, samples of the upper discharge canal station
were usually taken prior to the samplings of the intake
region. Thus, for example, the sharp increase in den-
sity and volume observed for diatoms for the evening
period of the March—April seasonal set was probably
due to algal patchiness. Similarly, abrupt increases
or decreases in numbers observed immediately at the
upper discharge canal station are suspected to be from
patchiness. Such abrupt changes were observed in the
annual means of total algae and the August abundance
of A. incerta.

Therefore, emphasis was necessarily placed on
trends along the discharge of gradually increasing or
decreasing abundance and volume in relation to
increased exposure time of entrained biota within the
effluent. Presumably, stimulation or inhibition of
algal growth would lead to increasing or decreasing
values with longer exposure to the environmental change.
Since the discharge stations were set at points to
reflect this exposure time factor, a typical trend
might be increasing abundance along the flow of the

discharge with the least change at the upper discharge

9O

station and the greatest difference at the lower dis-
charge station or plume.

The trends in November and January, at first glance,
indicated a strong proliferation of the algae for most
taxon's examined. This rise in abundance and/or vol-
ume of algae was observed at the lower discharge and
plume stations for total algae and diatoms but only in
November for green algae and blue-green algae. However,
as pointed out earlier, density and volume at the lake
station, which was not affected by the discharge, were
usually quite similar to those values at the plume.
Although the one lake station was not necessarily an
accurate representation of true open lake conditions,
the values obtained at that station indicated the
increases noted above were largely a product of mixing
discharge water with a more productive Lake Erie.

Such a large difference between the discharge's
algal assemblage and that in the open lake is under-
standable since the Raisin River, with a river-type of
algal flora, made up a large proportion of the water
entering the power plant's intake in November and
January. An examination of the major species found at
some stations for November and January could clarify
this question. Table 9 lists the relative percentage
of major species at selected stations. The intake

station (18) in Table 9 represented mostly river water

91

 

 

II 3.3 II II II II II II II II 003000232 .2
II II II m.3 II II II II II II 2300000 .2
II II 0.3 II II II II II II II 000030000 .2
II m.m m.3 m.3 II II II II II II 0302000000300 03:03>0z
3.0 II m.33 0.0 0.m II 3.0 m.m3 0.33 II 020300> .:
II II II II 3.3 II II 3.m II m.m 003020303 .2
II II II II II II II 3.m m.3 II 000332000 .2
II II II II II II 3.3 II 3.3 II 03000000 .2
II 0.3 0.3 II II II II II II II 0303220 00300302
II II 3.3 II II II II 3.m m.3 II 330002000 050300030
II 3.m II II II II II II II II Es3s>000 .0
II 0.m 0.3 m.3 3.m II II 3.3 0.3 II Es0o0>33o 0202020200
0.3 II 0.33 II II II II 0.3 II II .000 .0
0.0 II II 0.0 3.3 II II II II II 03020200000 0300330000
II 0.m II II II II II II II II 000033> .0
II II II m.m II II II II II II .00 0200030
II II 0.m II 0.3 II II 0.m 3.3 II 00300 003030000500
3.0 0.mm m.3 m.m3 0.03 3.3 m.3 0.3m m.3m m.m 020323200202 .0
II II II II II II II 0.m II II 02030230033 .0
II 0.0 3.3 3.3 II II II II II II 000002030 0330003030
3.3m 3.0 0.3 m.03 0.0m 0.33 m.0m II 0.3 0.33 00003000 0000300230000
II II 3.3 II II II II II II II 0300200030 030200000
0.3 II m.3 3.3 3.m m.m II II 3.3 II 0002000 03302030000<
03 33 03 03 33 03 33 03 03 33 0030000
02:30 000020030 000020030 030023 0300 02:30 000020030 000020030 030023 0300
00030 00300 0000: 00030 00300 00000
m3I3mI30 m3I03I33

 

.02030000 00000300 00 0E:30> 2003203000020 30000 020 00 0000200000 0>300300 03020 2033
3002330200 2002000000 3000200 020 00220>02 23 300030 00 0E:3o> 30000 020 00 03 0230000x00 0030000 30030 0000: .0 03209

92

 

 

 

II II II II II II II II II m.3 003U0I0030 202050032020<
m.m II II 0.3 3.m II II II II II 0000000200 0300330209
II 3.m II II II II II II II II 003002030> .m
0.0 0.m 0.33 m.3 m.m II 3.3 0.0 m.m m.3 0233 .0
II 3.3 II II II II II II II II 0300 .0
II II II II II II II II II 0.0 003020300 .00> 0003000 .0
II II II 3.3 II II II 3.3 0.3 II 000>0 033003030
0.3 II II II II 0.0 0.3 II II II .00 .0
0.03 0.00 II m.m3 0.00 0.30 0.00 II II 0.33 0000003: .0
3.03 0.0 0.3 0.m 0.m 0.0 0.3 II m.m 0.33 0000000 03003002020000
II 0.0 II m.3 II II II II II II 000>030 0320200003020
0.3 II II II II II II II II II 03020300 0320300320
II II 3.m m.3 II II II II II II 00230 0300332230
II II II II II II II 0.0 m.m II .000 .2
II II II 3.3 II II II II II II 05030 .2
II 0.0 0.3 3.0 0.3 II II II II II 03330000 .2
II 0.0 m.3 3.0 II II II II 0.3 II 0350003330 .2
II 0.3 II II II II II II II II 0300330300 032000032
II 0.m II II II II II II II II 0330303> .2
II 3.m 3.m 0.3 II II II II II II 000230300 03:03>0z
II 3.m 3.3 0.3 II II II II II II 003035 .2
II 0.3 3.m II II II II m.m 0.3 II 03020000202320 .2
03 33 N3 03 33 03 33 N3 03 33 0030000
05330 000020030 000020030 0x0023 0x00 05330 000020030 000020030 0x0023 0303
00030 00300 00000 00030 00200 0000:
m3I3mI30 m3I03I33

 

.3.0.0:oov 0 03000

93

algae as an estimate of the initial algal assemblage
being entrained. Since the discharge water was mostly
river water, one would expect a similar group of algae
between the intake station and the upper discharge
canal station (12). In contrast, if the terminal dis-
charge stations were similar to the open lake in algal
content, one would expect for the plume stations to
have a similar assemblage to that at the lake station
(17). Indeed, Table 9 showed this to be the case. For
November 10th a key species was g. radiatus which was
highly productive at the lake station and the lower
discharge canal and plume stations (14 and 16). g.

meneghiniana was rare at those locations but common at

 

the intake and upper discharge canal stations (18 and

12). Another species, Melosira varians, was a river

 

species seen at the intake and upper discharge canal
but rare elsewhere in the study area.

On January 24th and most other sampling dates,
these distinctions are less clear because a greater
proportion of lake water entered the cooling system.

Nevertheless, g. radiatus was common at the lake sta-

 

tion and the outer plume on that date but relatively
scarce at the other stations. Also, more rare species
were observed at the intake, upper discharge canal,
and lower discharge canal than at the lake or outer

plume stations.

9“

To expand on this further for all sampling dates,
chloride distribution at the various stations was used
to indicate the degree of mixing of discharge water in
the plume with the open lake (M.S.U., 1976). Typically,
the discharge canal chloride levels were higher due to
a high river input and lower in the open lake. The
plume waters were always intermediate to these extremes
which indicates mixing was common.

Although the arguments presented above do not prove
that all changes in algal abundance in the plume were
due solely to mixing with Lake Erie, certainly the
largest increases of November and January were mostly
a product of this phenomenon. This suggests that the
plume was an unreliable place to find evidence of an
entrainment effect on algal growth or survival. By
ruling out the plume stations as indicators of changed
abundance or volume, virtually all of the significant
differences producing recognizable trends of popula-
tion growth are eliminated. June, in particular, was
the other sampling seasonal set showing such trends of
increased density and volume for total algae, per-

haps green algae, g. radiatus,and g. subtillissima.

 

However, these trends were largely confined in the
plume and, therefore, are questionable indications of
stimulated growth. Other seasonal sets lacked signifi-
cant trends of any kind largely due to erratic vari-

ability of algal station results.

95

For the most part, evidence for stimulated growth
of phytoplankton or any single algal group was not
apparent. Increases were common beyond the confines
of the discharge canal, but these were likely a con-
sequence of plume mixing with the receiving waters.
Within the canal itself, almost no significant trends
were indicated.

Why was stimulation of the algal growth not
observed more conclusively? The responses of algae to
temperature changes, such as they experience in the
discharge, has been discussed by Eppley (1972) and,
more recently, by Goldman and Carpenter (197“).' At
sublethal temperatures, a fairly predictable increase
in growth follows a temperature increase. The change
in growth rate may vary for different species or
groups and under different environmental conditions.

To explain the lack of evidence of increased
growth at the Monroe Plant, keep in mind that the maxi-
mum passage time of cooling water through the discharge
canal was estimated to be only 11.“ hours. This is not
sufficient time for most algae to develop detectable
changes in abundance or volume. To illustrate, con-
sider a fast growing species having 2 doublings per
day at the intake, a Q10 of 2 for its growth—temperature
relationship, and no lag time in the growth response.
An increase in temperature of 10°C with entrainment

would mean its growth rate would reach U doublings per

96

day. Thus, if 100 entrained individuals entered the
intake, by the time they reached the lower discharge
stations there would be somewhat less than “00 indi-
viduals. However, the normal growth rate would have
produced 200 individuals by the end of the discharge
canal. So the increase in abundance was actually
100%. Of course, this is a highly simplistic model
but for many species a 100% increase in abundance was
not statistically significant! Even in the case of
total algae, an increase in abundance from that at the
intake of 50% or more was needed to show a significant
change at a discharge station. Such would be rare,
indeed, over a period of eleven hours or less. In
addition, most algae display a lag phase in responding
to changing environments which may last hours or even
days for some slow growing species. Furthermore,
conditions for growth in the study area were far from
idea, primarily due to a poor light environment, which
would hinder algal growth.

Shifts in Algal Dominance: Entrainment could

 

create shifts in the relative importance of various
phytoplankton forms. In extreme cases some species
might be killed by a temperature beyond its upper
tolerance limit. Although there was no attempt during
this study to assess the death of algae, some effort
was made to determine whether there were major shifts

in dominating classes. Cases of blue-green algae and

97

green algae replacing dominant diatoms when temperatures
exceeded 30°C have been reported (Cairns, 1956; Patrick
gt al., 1969; Rankin 32 al., 197a). Such temperatures
were encountered at the Monroe Power Plant discharge
canal in August samplings.

The only evidence of a major shift in relative pro—
portions of the algal classes occurred in June when
green and blue-green algae increased 10% at the expense
of diatoms. The maximum temperature at this time in
the discharge was 27°C. This change was primarily a
plume response and not a spatial trend along the dis-
charge. Mixing of the plume with the open lake having
different proportions of algae might also serve to

explain this shift.

Changes in Species Diversity; Results of species

 

diversity indices calculations showed the plume to be
the principal region of reduced species diversity for
November,January, and June. For November and January,
the lake station also displayed low species diversity,
indicating that mixing with the open lake might explain
reduced species diversity in the plume.

For June, however, results were not related to
mixing since there was apparently little similarity
between the lake station and plume diversity estimates.
To explain the plume results, it is important to bear
in mind that species diversity is weighted by both

equitability between species and the species richness

98

(i.e., the number of species in a sample). A sharp
change in either component of diversity may change

the species diversity index obtained. During June,
equitability decreased in the plume but not as much as
the species richness. At the lower discharge canal
between station volume equitability was 0.63, and the
number of species there was found to be 59. However,
at the inner plume station these values became 0.58

and 47, respectively. Obviously, the number of species
lost between these two stations was the major reason
for the drop in the species diversity. The loss in
species richness was primarily limited to the diatoms
which may also explain the decreased importance of
diatoms in the plume discussed for June in the previous
section. However, since these observations were
restricted to the plume with no evidence of trends
earlier in the discharge, it is impossible to be cer-
tain how the above changes are related to entrainment
without more data to support it.

April, August, and September afternoon species
diversity results showed no clear entrainment impact.
The latter two months had sizable variations in volume
species diversity and equitability at the discharge
canal stations, but these were abrupt changes most
likely due to patchiness of algae.

Changes in the Sizes of Algae; A limited amount

 

of data was examined for possible changes in the sizes

99

or mean specimen volumes of algae. Of seven species
considered with different morphologies, none showed
unusual changes beyond natural variability. This
indicates that turbulence in the power plant condensers
had a minimal effect on fragmentation of certain colo-

nial or filamentous algal forms.

Algal Metabolic Changes

 

Among the stated hypotheses three dealt with
effects upon algal metabolism. First, stimulation of
the GPP would be expected in the discharge when the
ambient temperature was below 16°C, but a depression
of the GPP would occur above this ambient temperature.
This hypothesis was largely based upon the conclusions
of Morgan and Stross (1969) and Warinner and Brehmer
(1966) discussed earlier. The second hypothesis was
that respiration of phytoplankton would increase during
entrainment. This follows from the fact that respira—
tion is largely a temperature dependent enzymatic
reaction. The last hypothesis was that the GPP should
decline in the discharge in response to chlorination
activities at the power plant. Morning GPP measure—
ments were intended to test this aspect of entrainment
impact.

Evidence Q; GPP Simulation 9; Depression: The GPP

 

 

measurements taken when ambient temperatures were below

16°C (November, January, and March-April sets) showed

100

no increases anywhere in the discharge compared to

the intake. However, almost all the GPP's observed

at these times were also negligibly different from
zero. The method used to measure primary productivity
may have lacked the sensitivity to detect an increase
in the rate.

An explanation of the low GPP during these months
was that biomass at this time of the year was very
low—-averaging only 17% of the algal biomass for the
warmer months. Furthermore, the light conditions for
photosynthesis were poor on the days the measurements
took place. Only January 18th (afternoon), during the
winter GPP measurements, had a sunny day, but even then
the primary productivity was negligible.

In contrast, the GPP was high in June, August, and
September-October when ambient temperatures exceeded
16°C. Half the daylight GPP measurements showed no
significant change in the GPP at the discharge stations
compared to the intake stations. However, the morning
measurements of June and August and the afternoon
measurements of the September-October set displayed
sharp reductions in the GPP at all the discharge canal
stations. In each case of GPP depressions, the plume
stations showed recovery of the primary productivity.

The reasons for the GPP depressions on some days
and not others was difficult to understand. Biomass

and temperature differences were small between the two

lOl

daylight diel periods of a given seasonal set. Light
conditions may have been related to the differing GPP
results since on two of the three days when depressions
were observed, the skies were sunny. All other summer
daylight GPP measurements were on days of poor light
conditions due to overcast skies. The depressions of
GPP for the afternoon in the September-October set

were observed on an overcast day, but these were also
the smallest GPP reductions compared to other dates.

The reductions in GPP at the Monroe plant were
generally consistent with the declines in net primary
productivity (using C1“) observed for artifically
illuminated samples of several different power plant
effluents (Morgan and Stross, 1969; Warinner and
Brehmer, 1966; Gurtz and Weiss, 197“). However, in
all of these published studies no recovery followed
the depressions. At the Monroe plant site, GPP
recovery in the plume was seen although there was
evidence that this was more a response to mixing with
the open lake water which already had a high GPP than
to actual improvement of the discharge rate.

Kreh (1973), in an earlier study on phytoplank-
ton in the vicinity of the Monroe Power Plant, observed
depressions in 1971 for lg gitg GPP. Furthermore, he
experimented by transferring sampled water from the

discharge canal to the open lake and vica versa along

 

with similar exchanges between the intake and discharge

102

canal and then measured the GPP of these samples in
sitg. At the time these were done, ambient temperatures
were 25°C at the intake, 33°C in the discharge, and 22°C
in Lake Erie. His results showed GPP depressions for
all samples incubated in the discharge canal but which
had been collected elsewhere. In contrast, discharge
canal samples that were incubated at the intake or Lake
Erie showed no GPP depressions. Samples collected in
the discharge canal and also incubated there did show
lower primary productivity. Apparently, there was
nothing inherently different in the photosynthetic
capacity of algae in the discharge canal, intake, or
open lake.

One could interpret Kreh's observations of
depressed GPP in the above experiments as temperature
related since it was the only environmental parameter
that differed between the intake, discharge, and Lake
Erie. Effects of chlorination and mechanical stress
were eliminated. The ability of discharge canal
samples moved elsewhere for incubation at the ambient
temperatures to have GPP's as high as that expected
of the open lake or intake indicated recovery of the
depressed primary productivity was possible.

None of the published power plant studies men-
tioned nor Kreh's (1973) work were designed to offer
a mechanistic explanation for the depressions of net

or gross primary productivity. Likewise, the data

103

presented in this thesis on GPP depressions say nothing
about the physiological changes in the incubated phyto-
plankton that might explain their lowered productivity.

Since the depressions were observed at tempera-
tures as low as 25°C in June and even lower in other
published investigations, outright death of algae in
sufficient numbers to reduce the photosynthetic capacity
seems a remote possibility. The evidence of a recovery
of the GPP both in this study and Kreh's indicates the
capacity for photosynthesis was not impaired. However,
apparently no literature has dealt with possible shock
of algae due to an abrupt rise in temperature which
might temporarily impair photosynthesis. This might
be a factor particularly due to the acclimation of the
entrained algae to an ambient temperature. However,
At's on days when the GPP decreases occurred were 3.0
for June 13th and August 10th and 8.2 for September 29th
at the surface. Since other summer dates with no
depressions had similar At's, the explanation must be
more complicated.

Since light was a factor for two of the three days
when GPP was depressed and since water samples were
incubated near the surface, perhaps increased suscep—
tibility of algae to photoinhibition followed an abrupt
rise in temperature. For example, photoinhibition at

high light levels was more common for Thalassiosira

 

nordenskioldii, a marine diatom, when its photosynthetic

 

IOU

temperature optimum was exceeded (Durbin, 197”).
However, little is known about the effect upon photo—
inhibition with abrupt temperature changes.

Photorespiration can also lead to reduced primary
productivity. This process is light dependent consump-
tion of 02 and release of C02 with production of
glycolic acid (Tolbert, 197“). It is promoted by
saturated 02 concentrations, low 002 and a pH between
8 and 9. However, these conditions existed to a sig-
nificant degree only in the open lake. Highest 0
concentrations were found there, and after the primary
productivity incubations, supersaturation was most
pronounced for Lake Erie measurements. The pH in
summer was between 8 and 9 and 002 was near zero in
Lake Erie. The discharge had lower 02 concentrations,
lower pH, and relatively high C02 during the summer
(M.S.U., 1976). Therefore, photorespiration should
have been more common in the open lake than in the
discharge canal where the depressions of GPP were
actually observed.

Although the effect of chlorination has yet to be
discussed, the cause of the GPP depressions cannot be
answered with the data made available in this study.
Regardless of why decreases in GPP were seen, the impact

was a reduction in the rate of carbon fixation. P/R

ratios in the discharge were reduced but still exceeded

1.00 over the incubation periods. So, the net effect

105

of entrainment upon primary productivity was a loss in
net production during possibly half the summer days but
not to the point of being heterotrophic during daylight.

Change $3 the Community Respiration: Community

 

respiration estimates were so low at all times of the
year that typical results were negligibly different
from zero even during summer. Based strictly on 95%
confidence intervals of station mean community respira-
tion, no significant difference in respiration could be
demonstrated between the discharge and the intake.

Chlorination Impact gpon GPP: The use of chlorine

 

by power plants can also sharply reduce algal produc-
tivity in the cooling water effluent (Hirayma and
Hirano, 1970; Brook and Baker, 1972). The depressions
in GPP observed at the Monroe plant discharge canal may
be partially explained by this. There is, however,
uncertainty as to the impact because the exact times
when chlorination commenced and finished on a given
day were not recorded by plant operators. Also,
residual chlorine concentrations were calculated, not
measured, from amounts added to the cooling system.
Supposedly chlorination began at 0700 E.S.T. for
June, August, and September—October seasonal sets. The
application of chlorine was to be of 1/2 hour duration.
Residual chlorine concentration during these times were
estimated at 0.90 ppm in June samplings and 1.35 ppm

for later ones.

106

Based on the above information, the decrease in GPP
on June 13th may have been related to chlorination,
especially at the upper and middle discharge canal
stations. These stations were sampled at 0750 and
0802 E.S.T., respectively. Assuming a certain amount
of delay in the discharge flow reaching these stations,
these stations should have been in the chlorinated water
mass. On August 10th when the largest decline in GPP
occurred, only the middle discharge canal station should
have been affected since it was sampled at 0825 E.S.T.
when the chlorinated water mass might have reached it.
The upper discharge canal station on this date was
sampled one hour after chlorination supposedly ceased
in which case the affected water mass probably had
passed.

However, the depression on September 29th can hardly
be related to chlorination since sampling was done 5 to
6 hours after chlorine application ceased. This seems
particularly true at the upper discharge canal station
which was sampled first but had the strongest depression
in GPP in the canal.

Chlorination might explain some but not all the
GPP depressions. At best, the evidence given here is
tenuous due to the reasons just stated. Further, as
mentioned earlier, Kreh (1973) showed depressions can

be entirely independent of chlorination.

107

Entrainment Impact Upon Western Lake Erie

 

 

It is important to put some of the changes seen,
regardless of their reason, in perspective of the
receiving waters, i.e., western Lake Erie. The wes-
tern basin can be distinguished from the rest of the
lake by a line of islands on the basin's eastern side.
The basin, including Sandusky Bay and the islands,
occupies 3u11 km2 (Wright, 1955). I estimate its
volume to be about 25 x 1012 liters. It is strongly
influenced by the Detroit River which accounts for
97% of the basin's inflow (using the 1936-1971 average
for a total Detroit River inflow of 16H x 1012 liters/
year). Other rivers such as the Raisin, Portage, and
Maumee account for most of the remaining input. Out-
flow is to the east.

If the Monroe Power Plant's discharge were con-
sidered to be entirely an inflow into the western basin,
it would account for about 1.0% of the total input for
the year. Of course, an estimated ”1.2% of the plant's
discharge during 1972-73 had its source already from
the lake, so real input to the lake was that of the
Raisin River (0.98 x 1012 liters/year for the study
period) or less than 1% of the basin's inflow. In
terms of the power plant's discharge into the basin,
it is of small importance from strictly a hydrological

point of view. The discharge's input of entrained

108

phytoplankton should be, likewise, small relative to
that of, for example, the Detroit River.

To press the argument further, results of the
population data can be used to estimate an impact for
the basin. The average biomass, in terms of organic
carbon, drawn through the intake station was 1.7“ x 106
kg C/year for the study year. Using the lower discharge
canal station results rather than the plume data, to
avoid the problem of mixing of thedischarge with the
open lake, the plant's effluent had an increased bio-
mass of 1.89 x 106 kg C/year. Thus, 0.15 x 106 kg C/
year was added to the lake above that of no entrainment
effect at all. Since the extra biomass would eventually
decompose, more oxygen from the water would have to be
used. For the entire basin this increase in biomass
would consume an additional 0.017 mg/l of dissolved
oxygen on a cummulative basis across the entire year.

Of course, the effect of oxygen depletion may be
more localized than this. Consider a lake area circle
extending from the discharge canal at a 9.“ km radius.
This would have a lake area of 166.5 km2 and a volume
of roughly 620 x 109 liters. Such an area was selected
by geographic barriers to the discharge effect (for
example, the Stony Point penninsula to the north was
0.“ km away). For this volume the biomass increase pre-
viously noted would lower the dissolved oxygen only

0.69 mg/l over the entire year. Such a drop, while

109

considerably more than for the entire basin, is still
negligible on a daily basis. Furthermore, I assumed
no atmospheric exchange and no mixing with the rest of
the lake. The impact of simple increased biomass is,
thus, extremely small.

Ecological impact need not be simple the quantity
of change but can also be a qualitative effect. Other
studies have suggested thermal discharges increase
blue-green and green algae at the expense of diatoms
at temperature extremes. No definitive evidence of
such a class shift was demonstrated here. Short
exposure to the increased temperature and the slow
algal response was the probably reason.

Although the entrainment effects here were minimal,
some caution must be added. I have considered this
plant's impact without regard to other facilities
along the western basin of Lake Erie. Entrainment of
phytoplankton at these other locations may have a com-
bined effect on the basin's ecology above that of any
one plant alone. Therefore, an effect should be made
to assess the total effect of all once-through cooling
systems for the entire basin including new facilities

contemplated in the future.

SUMMARY

Overall increase in abundance and volume of algae
were observed only in the plume of the discharge
during November, January, and June. However, the
November and January increases were primarily a
result of mixing of a lower productive discharge
with the more productive receiving waters of Lake
Erie. The June increase, although still probably
caused by mixing, could be evidence of stimulated
growth.

Diatoms were the most prominent algal class and
demonstrated increases in abundance and volume in
November and January only in the plume. The rea-

son for this was mixing with productive Lake Erie.

Green and blue-green algae had significant increases

in November only and then only in the plume for the

same reason as diatoms.

Shifts in the relative dominance of classes were

rare. Only in June was there evidence of increased

green and blue—green dominance at the expense of

diatoms in the discharge. No statistical

significance was found for this shift, however.

110

111

Diatom species dominated the cooling system over
most of the year. Of seven algal species studied
in detail representing the major classes, only

the diatoms Coscinodiscus radiatus and Cyclotella

 

 

meneghiniana showed change in the discharge. The

 

former species showed increases in abundance and
volume in the plume in November, January, and June
with only the change in June not being clearly

demonstrated as a mixing effect. For g. meneghiniana

 

there were decreases in November and increases in
January of density and volume in the plume due to
mixing.

Species volume diversity declined in the plume in
November, January, and June. For November and
January, the decreased values were due to mixing
with a volumetrically less diverse open lake. How-
ever, decreased diversity during June in the plume
was not a mixing effect and appeared to be caused
by a loss of diatom species.

No observed change in the mean specimen volume of
species was observed due to entrainment.

No stimulation of gross primary productivity was
observed. Decreases were seen in the GPP in
mornings of June and August in the discharge canal,"
possibly due to chlorination. Another depressed
GPP in the discharge canal appeared in an afternoon

of September. Other measurements showed no

112

significant change in discharge GPP possibly due

to poor light conditions. The depressed GPP's may

be explained by abrupt temperature increases, photo-
inhibition, or other factors.

Community respiration was negligbly different from
zero over most of the year. No significant change

in respiration in the discharge was demonstrated.

The impact of the power plant on algae in the western
basin of Lake Erie or in the near-shore area was

considered negligible.

APPENDICES

113

.Lo>fim :fimfimm on» Low mopooos .m.o.m.: anm mama owpmcomac Lo>Hm
g

 

 

 

:.HH o m.m o.m: m.mm o.mm s.0H 0.5 ms\ao\oa
:.HH m m.m o.m= H.mm o.>m m.HH o.m m~\mm\mo
:.HH 0 m.m o.m: m.Hm m.wm w.w ~.m m~\wm\oo
:.HH c m.m o.m: :.H> 0.0m o.mm o.mH m>\ofi\mo
:.HH w m.m o.m: o.m> m.Hm o.mm m.oa ms\oC\mo
=.HH o m.m o.m: m.m> o.am m.om o.HH m>\mo\mo
m.» m m.m o.mw m.mo 0.0: m.mm o.mm mu\ma\©o
m.> m m.m o.mm m.mw o.mz ~.Hm 0.0m m~\ma\oo
m.» m w.m o.mw H.mm o.H: m.:m o.mm mn\~a\oo
m.» m m.m o.mw 5.0m o.mm m.om o.mm m~\oo\:o
m.> m m.m o.m© >.Hm o.om m.wc o.m: m~\m0\zo
m.> m m.m o.mm o 0.0 00H o.mo mw\om\mo
m.s m m.m o.mo m.om o.m~ w.mo 0.2: ms\mm\fio
m.» m w.m o.mm o.mm m.om o.wo m.m: m>\:m\ao
m.> m w.m o.m© o.mw m.m: o.Hm 2.0H ms\mfi\ao
m.~ m m.m o.mo :.mm c.m= m.~m :.NH msxwfi\ao
:.HH 0 m.m o.m: o 0.0 oca o.mm m>\oH\HH
:.HH 0 m.m o.mz o 0.0 OOH =.>m m>\oO\HH
Amazomv amazm Aomm\Eov Aomm\mEV Lopmz Aoom\msv Loam: Aoom\msv mama
oEHB do zuwoon> owgmnomfio mxmq Loom: L0>Hm ~Loam:
mwmmmmm Lonezz ompmcomfic kuoe acmosom oxmq pcoopom Lo>fim
Loan: pmumSHumm pmumEapmm

 

.Hmcmo mmgmzomfio mcu cwzoszu moEHu mwmmmmd cam mama owsmzomfio
cufiz wcoam 30am oxmocfi oz» 0» mcfiusnfipucoo Loam: mxma new Lo>HL no mpcsosm o>HuwHop oopmefiumm

.H< xficcmaa<

11“

Appendix A2. Schematic representation of sampling plan.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

STA #1 (Lake) 5 SAMPLES
._STA #2 (River) 5 SAMPLES
L—STA #1-2 (Theoretical Intake) 5 SAMPLES
MORNING -STA #3 (Upper Discharge) 5 SAMPLES
F-PERIOD
r—STA #“ (Middle Discharge) 5 SAMPLES
-—STA #5 (Lower Discharge) 5 SAMPLES
-STA #6 (Plume) 5 SAMPLES
L-STA #7 (Plume) 5 SAMPLES
r—STA #1 (Lake) 5 SAMPLES
-STA #2 (River) 5 SAMPLES
SEASONAL h—STA #1-2 (Theoretical Intake) 5 SAMPLES
SAMPLING
(Once AFTERNOON -STA #3 (Upper Discharge) S SAMPLES
every b'-_PERIOD
two -—STA #“ (Middle Discharge) S SAMPLES
months)
-STA #5 (Lower Discharge) 5 SAMPLES
t—STA #6 (Plume) 5 SAMPLES
L—STA #7 (Plume) 5 SAMPLES
STA #1 (Lake) 5 SAMPLES
[STA #2 (River) 5 SAMPLES
~STA #l-2 (Theoretical Intake) 5 SAMPLES
__EVENING -STA #3 (Upper Discharge)—————————— 5 SAMPLES

 

PERIOD

 

 

PSTA #A (Middle Discharge) 5 SAMPLES
eSTA #5 (Lower Discharge) 5 SAMPLES
-STA #5 (Plume) 5 SAMPLES
LSTA #7 (Plume) 5 SAMPLES

 

 

 

Appendix A3.

115

Sampling and primary productivity dates

of field collections to be included in
this report.

 

 

Sampling
Number Period Date Type of Data
1 Morning 11/09/72 Algal samples, primary
prod.
Afternoon 11/10/72 Algal samples, primary
prod.
Evening 11/09/72 Algal samples, primary
prod.
2 Morning 01/25/73 Algal samples
01/19/73 Primary productivity
Afternoon 01/2“/73 Algal samples
01/18/73 Primary productivity
Evening 01/18/73 Algal samples
01/25/73 Primary productivity
3 Morning 0“/06/73 Algal samples
0“/05/73 Primary productivity
Afternoon 0“/05/73 Algal samples
03/30/73 Primary productivity
Evening 03/30/73 Algal samples
0“/05/73 Primary productivity
“ Morning 06/13/73 Algal samples, primary
prod.
Afternoon 06/12/73 Algal samples, primary
prod.
Evening 06/11/73 Algal samples, primary
prod.
5 Morning 08/10/73 Algal samples, primary
prod.
Afternoon 08/09/73 Algal samples, primary
prod.
Evening 08/08/73 Algal samples, primary
prod.
6 Morning 10/01/73 Algal samples, primary
prod.
Afternoon 09/29/73 Algal samples, primary
prod.
Evening 09/28/73 Algal samples, primary

prod.

 

 

116

 

 

 

N.NH m 0.0H om OH mm\HO\OH
O.mH mz O.m OOH O m>\mm\mo
m.wH m >.HH OOH O m>\mm\mO
m.mm 3 w.mH om OO m>\OH\wO
~.Om 3m m.mH O» mo m>\OO\OO
H.Om m :.HH O: NO m>\mo\mo
m.wH z >.HH Om Hm m~\MH\OO
O.mm 3m z.mH cm 5: m5\mH\OO
w.~m 3m :.mH ON OO m>\HH\OO
~.HH 3m O.Hm O: OO m>\Oo\:O
5.0 3 H.Om O» m: m>\mo\:O
0.0H 3m >.mH OOH m m~\Om\mo
w.m 3m H.Om O OOH mp\mm\HO
N.NI 3m m.mH O: HO m~\:m\HO
m.m 3 m.>m OOH O m~\OH\HO
H.HH m 0.0H OO 2m m>\OH\HO
w.m m :.mH OOH O NN\OH\HH
O.m mz O.HH OOH O m>\mo\HH
HOov COHpompHO H.pn\exv Ommam po>oo mmO pom mama
mLSBmLmQEoB ccHz OCHz mwmhm>< mxm a ochmcsm
LH< mwmpw>< wCHHHm>oum mHnHmmom a

 

.AmkumAmHv zesem mfiee ca emeemeefi co meeee mefi>fieeeeoee
Ocm coaxcmHa on wchHmpme COHumELOHCH HmonOHopmpmz

.:< xHocoaa<

117

Appendix A5. List of all phytoplankton species and
unknowns enumerated during the 1972—73
study year.l

 

CLASS BACILLARIOPHYCEAE

Achnanthes clevei Grun.

 

A. flexella (Kutz.) Brun.

A. lanceolata (Bréb.) Grun.

 

A, minutissima Kutz.

 

|3>

. sp.

Amphora ovalis Kfitz.

 

A. ovalis var. pediculus Kfitz.

 

*Asterionella formosa Hass.

 

Caloneis bacillum (Grun.) Cleve.

 

C. sp.

9. ventricosa (Ehr.) Meist.

 

Cocconeis diminuta Pant.

 

g. disculus (Schumann) Cleve.

 

g. pediculus Ehr.

 

*9. placentula Ehr.

 

*Coscinodiscus radiatus Ehr.

 

Cyclotella antiqua W. Smith

 

Q. bodanica Eulenst.

IO

. comta (Ehr.) Kfitz.

:0:
IO

glomerata Bachmann

 

at
In

. kutzingiana Thwaites

 

3:
IO

. meneghiniana Kfitz.

 

IO

. michiganiana Skv.

 

 

Appendix A5 (cont'd.).

 

g. ocellata Pant.
9. sp.

*Cyclotella stelligera Cleve. and Grun.

 

*Cymatopleura solea (Bréb.) W. Smith

 

Cymbella affinis Kfitz.

 

Q. microcephala Grun.

 

IO

. prostrata (Berk.) Cleve.

IO

. sinuta Greg.

spp.

an:
IO

9. ventricosa Kfitz.

*Diatoma elongatum (Lyng.) Agardh

Q. hiemale (Lyng.) Heiberg

*2. sp.

*2. vulgare Bory.

*Diploneis oblongella (Naeg. ii Kutz.) Ross
2. sp.

Eucocconeis sp.

Eunotia pectinalis (Kfitz.) Rabh.

E. sp.

Fragilaria brevistrata Grun.

E. capucina Desm.

*E. crotonensis Kitton

 

[“12]

intermedia Grun.

[’11

leptostauron (Ehr.) Hust.

 

119

Appendix A5 (cont'd.).

 

*3. spp.

Gomphonema acuminatum var. coronata (Ehr.)
W. Smith

 

 

*G. angustatus (KUtz.) Rabh.

 

G. constrictum Ehr.

 

 

g. gracile Ehr.
*G. olivaceum (Lyng.) Kutz.
*g. parvulum (Kfitz.) Grun.

 

Gomphonema sp.

 

*Gyrosigma acuminatum (Kutz.) Rabh.

 

G. kutzingii (Grun.) Cleve.

 

*G. sp.

9. spencerii (Quek.) Griff. & Henfr.

 

Hantzschia amphioxys (Ehr.) Grun.

 

H. sp.

Mastogloia grevellei W. Smith

 

M. smithii Thwaites EE- W. Smith

M. smithii var. amphicephala Grun.

 

*Melosira ambigua (Grun.) O. Mfill.

 

*M. arenaria Moore

M. binderana Kfitz.

 

:0:
l3

granulata (Ehr.) Ralfs

 

islandica O. Mull.

an
IE

 

*
l3

italica (Ehr.) Kfitz.

:0:
I3

sp.

 

120

Appendix A5 (cont'd.).

 

*N. varians Agardh.

Meridion circulare (Grev.) Agardh

 

Navicula anglica Ralfs

 

N. bacillum Ehr.
*N. canalis Patrick

N. cari Ehr.

 

 

 

N. cincta (Ehr.) Ralfs

N. contenta Grun.

*N. cryptocephala Kutz.

*N. cuspidata (Kfitz.) Kfitz
N. decussis Ostr.

N. exigua (Greg.) 0. Mfill.

 

*Navicula gastrum (Ehr.) Kfitz.

 

 

 

 

 

 

N. hungarica Grun.

N. integra (W. Smith) Ralfs
N. krasskei Hust.

N. menisculus Schumann

N. minima Grun.

N. minuscula Grun.

*N. mutica Kfitz.

N. muticopsis Van Heurck
N. perigrina (Ehr.) Kfitz.
N. placentula (Ehr.) Kfitz.
N. pupula Kfitz.

 

F4
R)
H

Appendix A5 (cont'd.).

 

3“
l2 I'Z l2 IZ IZ

Iz

*

*N.

:2

. pygmaea Kth.

radiosa Kutz.

rhynchocephala Kutz.

 

salinarum Grun.

 

scutelloides W. Smith

 

sp.
tripuncta (O. F. Mfill.) Bory

 

virdula Kfitz.

Neidium dubium (Ehr.) Cleve.

 

*Nitzschia acicularis (Kfitz.) W. Smith

 

I2

a:
IZ

*N.

. amphibia Grun.

angustata (W. Smith) Grun.

 

commutata Grun.

 

dissipata (Kutz). Grun.

 

filiformis (W. Smith) Hust.

 

gracilis Hantz.

Nitzschia hungarica Grun.

 

*
l2 IE: NZ l2: ”3 l2

[2

kutzingiana Hilse

 

lacunarum Hust.

 

palea (Kfitz.) W. Smith
sigma (Kfitz.) W. Smith

sigmoidea (Ehr.) W. Smith

 

sp. #1

sp. #2

 

122

Appendix A5 (cont'd.).

 

*N. sp #3
*N. spp.

N. stagnorum Rabh.

 

Iz

tryblionella Hantzsch

 

IZ

tryblionella var. victoriae Grun.

 

 

Ophephora martyi Herib.

 

*Pinnularia gibba Ehr.

 

P. sp.

*Rhizolenia eriensis H. L. Smith

 

*Rhoicosphenia curvata (KUtz.) Grun.

 

Rhopalodia gibba (Ehr.) O. M011.

 

Stauroneis anceps Ehr.

 

S. smithii Grun.

S. sp.

*Stephanodiscus astraea (Ehr.) Grun.

 

*S. niagarae Ehr.
*S. sp.
S. tenuis Hust.

*Surirella angusta Katz.

 

*S. ovata Kfitz.

 

*S. robusta var. splendida (Ehr.) Van Heurck

 

Surirella sp.

 

Synedra actinastroides Lemm.

 

*S. acus Kfitz.

 

Appendix A5 (cont'd.).

123

 

Meist.

 

Sm
S.

§. sp.
*8

*S.

 

parasitica (W. Smith) Hust.

. ulna (Nitz.) Ehr.

vaucheriae Kfitz.

*Tabellaria fenestrata (Lyrg.) Kfitz.

 

*Unknown
Unknown
Unknown
Unknown

*Unknown
Unknown
Unknown

Unknown

centric
pennate
pennate
pennate
pennate
pennate
pennate

pennate

CLASS CHLOREBACTERIAE

filament
#1
#2
#3
#“
#5
#6
#7

Pelogloea bacillifera Lauterborn

 

E. chlorina

CLASS CHLOROPHYCEAE

Actinastrum gracillimum G. M. Smith

 

A. hantzschii var. fluvitile Schroeder

 

 

Ankistrodesmus convolutus Corda

 

 

A. falcatus (Corda) Ralfs

 

A. falcatus var. mirabilis (W. & G. S. West)

 

*Binuclearia eriensis Tiffany

 

 

12“

Appendix A5 (cont'd.).

 

Carteria klebsii (Dang.) Dill

 

Characium limneticum Lemm.

 

Chlamydomonas sp. #1

 

9. sp. #2

IO

sp. #3

IO

Spp
Chlorella sp. #1

 

9. sp. #2
*9. sp. #3

Closteriopsis longissima Lemm.

 

Coelastrum microporum Naegeli

 

Cosmarium abbreviatum Raciborski

 

*9. formulosum Hoffman

 

0. sp.

9. subcrenatum Hantzsch

 

Crucigenia alternans G. M. Smith

to

apiculata (Lemm.) Schmidle

 

crucifera (Wolle) Collins

IO

 

IO

fenestrata Schmidle

 

IO

irregularis Wille

 

IO

lauterbornei Schmidle

 

IO

qgadrata Morren

 

IO

rectangularis (A. Braun) Gay

 

IO

sp.

 

125

Appendix A5 (cont'd.).

 

g. tetrapedia (Kirch.) W. & G. S. West

 

Dictyosphaerium ehrenbergianum Naegeli

 

*D. pulchellum Wood

 

Elaktothrix gelatinosa Wille

 

E. viridis (Snow) Printz

Errella bornhemiensis Conrad

 

Franceia droescheri (Lemm.) G. M. Smith

 

Geminella minor (Naeg.) Heering

 

Gloeocystis gigas (Kuetz.) Lagerheim

 

Golenkinia radiata (Ched.) Wille

 

G. radiata var. brevispina Tiffany and
Ahlstrom

 

Hematococcus lacustris (Girod.) Wittrock

 

Kirchneriella contorta (Schmidle) Bohlin

 

N. lunaris (Kirch.) Moebius

IN

lunaris var. dianae Bohlin

Ix

obesa (W. West) Schmidle

Ix

obesa var. aperta (Teiling) Brunnthaler

IN

obesa var. major (Bernard) G. M. Smith

 

Ix

sp.

IN

subsolitaria G. S. West

 

Lagerheimia genevensis var. subglobosa
(Lemm.) Chodat

 

 

A. longiseta (Lemm.) Printz

 

L. quadriseta (Lemm.) G. M. Smith

 

 

126

Appendix A5 (cont'd.).

 

A. subsalsa Lemm.

A. wratislawiensis Schroeder

 

Micractinium pusillum Fresenius

 

N. quadrisetum (Lemm.) G. M. Smith

 

*Mougeotia elegantula Wittrock

 

 

*Pandorina morum (Mue11.) Bory

Pediastrum boryanum (Turp.) Meneghini

 

A. duplex Meyen

 

A. duplex var. gracillimum W. & G. S. West
N. simplex (Meyen) Lemm.

N. simplex var. duodenarium (Bailey) Rabh.

 

Pediastrum tetras (Ehr.) Ralfs

 

Pharotus lenticularis (Ehr.) Stein

 

Planktosphaeria gelatinosa G. M. Smith

 

Polydriopsis spinulosa Schmidle

 

 

Quadrigula closteriodes (Bohlin) Printz

 

Q. lacustris (Chodat) G. M. Smith

 

Scenedesmus abundans (Kirch.) Chodat

 

S. abundans var. brevicauda G. M. Smith

 

IUJ

abundans var. longicauda G. M. Smith

 

IUJ

acuminatus (Lagerh.) Chodat

 

IUD

acutiformis Schroeder

 

IUD

anomalus (G. M. Smith) Ahlstrom & Tiffany

IUJ

arcuatus var. platydisca G. M. Smith

 

 

127

Appendix A5 (cont'd.).

 

lm Im H0 Im l03 H9 lm IU3 ND lm l03 H0

IC/J

Mn one

IUD

armatus (Chod.) G. M. Smith

bernardii G. M. Smith

 

bijuga (Turp.) Lagerheim

bijuga var. alternans (Reinsch) Hansgirg

 

bijuga var. flexuosos (Lemm.) Collins

 

brasiliensis Bohlin

 

denticulatus Lagerheim

 

dimorphus (Turp.) Kuetzing

 

hystrix Lagerheim
longus Meyen

opoliensis P. Richter

 

quadricauda (Turp.) de Brébisson

 

quadricauda var. alternans G. M. Smith

 

 

quadricauda var. longispina (Chodat)
M. Smith

 

 

quadricauda var. maximum W. & G. S. West

 

quadricauda var. parvus G. M. Smith

 

Scenedesmus quadricauda var. westii G. M. Smith

 

S.

sp.

Schroederi setigera (Schroed.) Lemm.

 

Selenastrum bibraianum var. gracile (Reinsch)

 

Tiffany and Ahlstrom

_S_.

S.

minutum (Naeg.) Collins

westii G. M. Smith

 

128

Appendix A5 (cont'd.).

 

Sorastrum spinulosum Naegeli

 

Sphaerocystis schroeteri Chodat

 

Staurastrum chaetocerus (Schroeder) S. M.
Smith

 

 

N. paradoxum Meyen

 

Stylosphaeridium stipatum (Bachm.) Geitler
and Gimesi

 

Tetradesmus wisconsinense G. M. Smith

 

 

Tetraedron arthrodesmiforme (G. S. West)
Woloszynska

 

2. assymetricum Prescott

 

2. caudatum (Corda) Hansgirg

 

2. enorme (Ralfs) Hansgirg

T. EEEEE (Teiling) G. M. Smith
2. minimum (A. Br.) Hansgirg
E. muticum (A. Br.) Hansgirg
2. sp

Tetrastrum glabrum (Roll) Ahlstrom and Tiffany

 

N. heteracanthum (Nordst.) Chodat

 

N. staurogeniaeforme (Schroeder) Lemm.

 

Trochisia granulata (Reinsch.) Hansgirg

 

*Ulothrix subtillissima Rabenhorst

 

Unknown colony #1
Unknown colony #2

Unknown filament

 

129

Appendix A5 (cont'd.)

 

Unknown green algae-damaged
Unknown unicell #1
Unknown unicell #2

Westella botryoides (W. West) de Wildemann

 

N. botryoides var. major G. M. Smith

 

CLASS CHRYSOPHYCEAE

Dinobryon sp.

 

Mallomonas alpina Pascher and Ruttner

 

N. pseudocoronata Prescott

 

Ophiocytium cochleare (Eichw.) A Braun

 

 

CLASS CRYPTOPHYCEAE

Cryptomonas ovata Ehrenberg

 

CLASS CYANOPHYCEAE

Agmenellum quadriduplicatum Bréb.

 

A. trolleri (Bachmann) Drouet and Daily

Anabaena sircinalis Rabenhorst

 

A. spp.

Anacystis cyanea Drouet and Daily

 

A. dispersus (Keissl.) Drouet and Daily

 

 

A. grevellei (Hass.) Drouet and Daily
A. incerta Drouet and Daily

A. marina Drouet and Daily

A. minimus (Keissl.) Drouet and Daily

 

130

Appendix A5 (cont'd.).

 

A. montana f. minor Drouet and Daily
A. montana f. montana Drouet and Daily

A. thermalis f. major (Lagerheim) Drouet
and Daily

 

Aphanizomenon flos—aquae (L.) Ralfs

 

*A. gracile ? Lemm.

Coccochloris clathrata (G. S. West) Drouet
and Daily

 

g. peniocystis Drouet and Daily

 

C. stagina Sprengel

Dactylcoccopsis fasicularis Lemm.

 

Gomphosphaeria gponina Kfitz.

 

G. dubium (Grunow) Drouet and Daily

g. lacustris Chodat

 

Marssoniella elegans Lemm.

 

*Oscillatoria spp.

 

g. tenuis C. A. Agardh

Rhaphidiopsis curvata Fritsch and Rich

 

Spirulina laxissima G. S. West

 

Unknown blue—green alga-damaged
Unknown colony-Chlorococcales
Unknown filament-Nostocales
Unknown filament-Oscillatoriales

Unknown unicell

 

131

Appendix A5 (cont'd.).

 

CLASS DINOPHYCEAE

Glenodinium sp.

 

Gymnodinium varians

 

CLASS EUGLENOPHYCEAE

Colacium vesiculosum Ehrenberg

 

Euglena acus Ehrenberg

 

*E. gracilis Klebs

E. minuta Prescott
Euglena sp.

E. viridis Ehrenberg

Trachelomonas dybowskii Drezepolski

 

 

 

 

T. hispida (Perty) Stein

T. pulchella Drezepolski

T. pulcherrima var. mlggg Playfair
T..sp.

*T. volvocina Ehrenberg

 

 

 

1An asterick (*) before a name indicate that
species had 1% or more of the total station
volume for at least one sampling seasonal
set.

LIST OF REFERENCES

132

LIST OF REFERENCES

Altman, P. L. and D. S. Ditmer, Editors. 1973. Tolerance
to temperature extremes: plants. Pp. 808—810, In
Biology data book, 2nd ed., Vol. II. Federation—5f
American Societies for Experimental Biology, Bethesda,
Md.

American Public Health Association. 1971. Standard
methods for the examination of water and wastewater.
13th ed. Washington. 875 p.

Aruga, Y. 1965. Ecological studies of photosynthesis and
matter production of phytoplankton. II. Photosyn-
thesis of algae in relation to light intensity and
temperature. Bot. Mag. (Tokyo) 78:360-365.

Brook, A. J. and A. L. Baker. 1972. Chlorination at power
plants: impact on phytoplankton productivity. Science
l76:l“l“-1“15.

Cairns, J., Jr. 1956. Effects of increased temperatures
on aquatic organisms. Indus. Wastes l(“):150.

Castenholz, R. W. 1967. Environmental requirements of
thermophilic blue-green algae. Pp. 55-79, lg Envi-
ronmental requirements of blue-green algae. Pacific
Northwest Laboratory, Richland, Washington.

Drouet, F. and W. A. Daily. 1956. Revision of the coc—
coid Myxophyceae. Butler Univ. Bot. Stu. 12:1-218.

Durbin, E. G. 197“. Studies on the autecology of the
marine diatom Thalossiosira nordenskioldii Cleve. 1.
The influence of daylength, light intensity, and
temperature on growth. J. Phycol. 10:220-225.

 

Environmental Protection Agency. 197“. Methods for
chemical analysis of water and wastes. EPA-625-/6-
7“-003. Methods Development and Quality Assurance
Res. Lab., National Environmental Research Center,
Cincinnati. 298 p.

Eppley, R. W. 1972. Temperature and phytoplankton growth
in the sea. Fish. Bull. 70(“):106“-108“.

133

Goldman, J. C. and E. J. Carpenter. 197“. A kinetic
approach to the effect of temperature on algal growth.
Limnol. Oceanogr. 19:756-766.

Gurtz, M. E. and C. M. Weiss. 197“. Effect of thermal
stress on phytoplankton productivity in condenser
cooling water. P. “90-507, TA Thermal ecology. J.
W. Gibbons and R. R. Sharitz, Editors. CONF—730505.
U. S. Atomic Energy Comm.

Hirayama, K. and R. Hirano. 1970. Influences of high
temperature and residual chlorine on marine phyto—
plankton. Marine Bio. 7:205-213.

Hoogenhout, H. and J. Amesz. 1965. Growth rates of photo-
synthetic microorganisms in laboratory cultures.
Archiv. Microbiol. 50:10-2“.

Hustedt, F. 1930a. Die Kieselalgen. TA Kryptogamen-
Flora von Deutschland, Osterreich, und der Schweiz.
L. Rabenhorst, ed. Teil 1-3. Akademische Verlags—
gesellschaft m.b.h., Leipzig. (Johnson Reprint Co.,
New York.)

Hustedt, F. 1930b. Bacillariophyta. TA Die Susswasser-
Flora Mitteleuropas. A. Pascher, ed. Heft 10.
Gustav Fisher, Jena. (University Microfilms, Ann
Arbor, Xerox.)

Kreh, T. V. 1973. An ecological evaluation of a thermal
discharge. Part VII: Postoperational effects of a
power plant on phytoplankton and community metabolism
in western Lake Erie. Tech. Rpt. 32.1, Inst. Water
Res., Michigan State Univ., E. Lansing, Mich. 92 p.

Lansa, G. R. and J. Cairns, Jr. 1972. Physio-morphological
effects of abrupt thermal stress on diatoms. Trans.
Amer. Micros- Soc. 91:276-298.

Lund, J. W. G. 1965. The ecology of freshwater phyto-
plankton. Biol. Rev. “0:231-293.

Margalef, R. 195“. Modifications induced by different
temperatures on cells of Scenedesmus obliquus
(Chlorophyceae). Hydrobiol. 6:83-9“.

Margalef, R. 1968. Perspectives in ecological theory.
Univ. Chicago Press, Chicago, 111. 111 p.

McNabb, C. D. 1960. Enumeration of freshwater phyto-
plankton concentrated on the membrane filter.
Limnol. Oceanogr. 5:57-61.

13“

Michigan State Univeristy. 197“. Mass transport of
biological material through a once-through cooling
system on western Lake Erie. An annual progress
report to the U. S. Environmental Protection Agency.
Institute of Water Research/Department of Fisheries
and Wildlife, Michigan State Univ., E. Lansing,
Mich. 106 p.

Michigan State University. 1976. The impact of thermal
discharge from the Monroe Power Plant on the aquatic
community in western Lake Erie. Tech. Rpt. 32.6,
Inst. Water Res., Michigan State Univ., E. Lansing,
Mich.

Miller, R. G., Jr. 1966. Simultaneous statistical
inference. McGraw-Hill Book Co., New York.

Morgan, R. P. and R. G. Stross. 1969. Destruction of
phytoplankton in the cooling water supply of a steam
electric station. Chesapeake Sci. 10:165—171.

Nielsen, E. S. and E. G. Jorgensen. The adaption of
plankton algae I. General part. Physciol. Plant.
21:“01—“13.

Patrick, R. 1969. Some effects of temperature on fresh-
water algae. Pp. l6l-185, TA Biological aspects of
thermal pollution. P. A. Krenkel and F. L. Parker,
Editors. Vanderbilt Univ. Press, Portland, Ore.

Patrick, R. 197“. Effects of abnormal temperatures on
algal communities. Pp. 335—3“9, TA_Therma1 ecology.
J. W. Gibbons and R. R. Sharitz, Editors. CONF-
730505. U. S. Atomic Energy Comm.

Patrick, R., B. Brum, and J. Coles. 1969. Temperature
and manganese as determing factors in the presence
of diatoms communities in similar ecological condi-
tions. Amer. Natur. 102(92“):173-183.

Patrick, R. and C. W. Reimer. 1966. The diatoms of the
United States. Vol. I. Acad. Nat. Sci. Phila.
Monogr. 13. 688 p.

Phinney, H. K. and D. McIntire. 1965. Effect of tempera-
ture on metabolism of periphyton communities developed
in laboratory streams. Limnol. Oceanogr. 10:3“1-3““.

Pielou, E. C. 1969. An introduction to mathmatical
ecology. Wiley, New York. 286 p.

Prescott, G. W. 1970. Algae of the western Great Lakes
area. W. C. Brown, Dubuque, Iowa. 977 p.

135

Rankin, J. S., J. D. Buck, and J. W. Foerster. 197“.
Thermal effects on the microbiology and chemistry
of the Connecticut River--A summary. Pp. 350-355,
J. W. Gibbons and R. R. Sharitz,

In Thermal ecology.
CONE-730505, U. S. Atomic Energy Comm.

Eaitors.
Phytoplankton of the inland lakes of
and Nat. Hist. Survey

Smith, G. M. 1920.
2“3 p.

Wisconsin. Wisconsin Geol.
57, Series 12, Madison, Wisc.

(Bull.
1969. Biometry. W. H.

and F. J. Rohlf.
776 p.

Sokal, R. R.
Freeman and Co., San Francisco, Calif.

Kinetic studies of temperature effects

Sorokin, C. 1960.
Biochim. Biophys. Acta 38:

on the cellular level.

197-20“.

Sorokin, C. 1971. Calefaction and phytoplankton. Bio-
science 21:1153-1159.

Starr, J. F. 197“. Plankton entrainment by the condenser
systems of nuclear power stations on Lake Ontario.
Pp. 291-295, Lg Thermal ecology. J. W. Gibbons and
R. R. Sharitz, Editors. CONE—730505, U. S. Atomic

Energy Comm.
1967. Estimating the organic carbon

Strathmann, R. R.
content of phytoplankton from cell volume or plasma
volume. Limnol. Oceanogr. 12:“11-“18.

Taft, C. E. l9“5. The desmids of the west end of Lake
Erie. Ohio J. Sci. “5:180-205.

and C. W. Taft. 1971. The algae of western

Taft, c. E.
Bull. Ohio Bio. Survey “(1):1-189.

Lake Erie.
Editor. 19“2. Das Phytoplankton des

Thienemann, A.,
Susswassers, Die Binnengewasser. Ban XVI, Teil I-V.
E. Schwiezerbart'sche Verlagsbuch-handlung, Stutt-
(Stechert, New York, reprinted 1962.)

Tolbert, N. E. 197“. Photorespiration. Pp. “7“—50“, TA
W. D. P. Stewart,

Algal physiology and biochemistry.
Editor. Univ. California Press, Los Angeles.

Warinner, J. E. and M. L. Brehmer. 1966. The effects of
thermal effluents on marine organisms. Air & Water
Poll. Int. J. 10:277—289.

I. 1971. A guide to the common diatoms at
U. S. Environ-

Weber, C.
water pollution surveillance stations.
mental Protection Agency, Cincinnati. 101 p.

gart.

136

Westlake, D. F. 1969. Interpretation of results: units
and comparability. Pp. 113-117, TA A manual on
methods for measuring primary production in aquatic
environments. R. A. Vollenwieder, Editor. Blackwell
Scientific Publications, Oxford, England.

Wright, S. 1955. Limnological survey of western Lake
Erie. Spec. Sci. Rpt.-Fisheries, No. 139, U. S.
Dept. of Interior, Fish and Wildlife Service, Wash-
ington, D.C.