PHOSPHORUS CONCENTRATIONS ALONG THE WESTERN SHORE OF LAKE ERIE- Thesis for the Degree of M. S. MICHIGAN STATE UNIVERSITY CHARLES S. ANNETT 1977 - 1.-.---cgacvq- ‘ -7. cor—s....u.uoo quvfig‘fisflu‘q‘... ‘““Q‘voncvpa- -..;".'£:.‘.:.;“ 7?. "s I . .44‘. -A ' “1.... M; "T Tav- “ LVN-0311 8.3m xxzvcrsity » _ rw a m M a: mama .ddi 5 auwzam fia‘Eufiflfin uucwmwmmagw mnqwmnwm ".233. wvnvxrizcmmum: _. w. . . m mamanmmammmmmmw mmmmmmmmmmmmamamm am ”waamammmmwmmmmaawmmqammmammummmmammmcammmwmmmmmmmwmaa Em, 05.: an}; cuff. m; 033 652 mt: c-; mi: an en Q? m a," -~n~nn------~m------~fi-~.._~H--~_--~ mummmmmmwmwmmmmwmummmmmmgomwemmwmmmmmwmmmmmmmmmmumgmae mmmmmmmmmmmmmmmmmnmmnTmannannmmnmnnmmnmnnonmnnnmmmnmnm wowwwwwvuwvvvvvwqunwvqq..wvvvvwv~qu¢~¢¢ccvev¢vv wVvv "mnmmnmnnnmmnmmmnnnm mnnnmnnmmmmmmmmnnnmmmmmnnnmnmnm n N-----N-~NN~N--~N-NNNNNNNNNNNNNNNNNNNNN.Nu «N ______________~._____~_____________________—1.________ 2 2 2 : a. 2 : 2 N. z 2 3 3 S 3 S 3 3 .3 2 3 2 mm 2 an 3 3 R 3 G R a. 2. 3 m. S. 3 3 3 z. 3 on .n 3 an 2 z n... 2 2 3 2 2. Z aaaaaaaooaaccoeoeaaaaeaeaacaoaaaaoaoaaccaaaaa =.=a a: «m. PHOSPHORUS CONCENTRATIONS ALONG THE WESTERN SHORE OF LAKE ERIE by Charles S. Annett A THESIS Smeitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Fisheries and Wildlife 1977 F | E C _ .hd Ru m n e .n a m supp: .‘l 0‘ “' . OI-Ifll u A. i A .... I. Ian... ACKNOWLEDGEMENTS I wish to extend my appreciation to Dr. F.M. D'Itri and Dr. R.A. Cole for their assistance and guidance during this investigation. I am also indebted to Dr. N.R. Kevern and Dr. W.N. Mack for their contributions as members of my guidance committee and to Tom Ecker and the other graduate students and staff who provided necessary technical support. Financial support was provided by the Institute of Water Research and the Department of Fisheries and Wildlife and was greatly appreciated. Special thanks to my wife, Dianne, for her patience and assistance. Appreciation is also extended to my relatives and friends for their interest and concern. T. UL ABSTRACT PHOSPHORUS CONCENTRATIONS ALONG THE WEST SHORE OF LAKE ERIE The concentrationscfiTtotal and soluble phosphorus in the water and sediments near the west shore of Lake Erie were measured during 1970—1971. The analyses were performed to determine the effect of the heated effluent discharge from the Detroit Edison Monroe Fossil Fuel Power Plant on the aquatic ecosystem. Samples were collected at six lake stations, the Raisin River and the discharge canal from the plant. The study began one year before the plant became operational to obtain background data on the area. During 1971 the power plant experienced intermittant operation. The phosphorus loading of the Raisin River was determined and compared to previous years data and other tributaries to the western basin of Lake Erie. During 1971 the Raisin River had a decreased phosphorus loading which was caused by a reduced flow into the study area. However, in contrast the sedimentary phosphorus concentrations increased significantly at seven sta- tions during the same period. The increased phosphorus concentrations in the sediments were not related to temperature, dissolved oxygen concentra- tions, suspended solids or primary productivity. The Raisin River had significantly higher concentrations than all other stations. Approximately 35% of the sedimentary phosphorus was in an available form. During 1970 the waters of the Raisin River had significantly higher phosphorus concentrations than the other 8 stations. The lake stations and ii discharge canal had uniform concentrations with no depth variation. During 1971 significant increases occurred at all inshore stations and station 6 in the lake. Increases in the discharge canal were attributed to the diver- sion of nutrient rich water from the river to the canal. Changes in primary productivity,temperature, and dissolved oxygen concentrations caused no apparent changes in phosphorus concentrations of the water. The high phosphorus concentrations in the water and sediments of the study area largely prevented the determination of interaction between these concentrations and both chemical and biological changes in the study area. Algal blooms could be supported by a fraction of the phosphorus present in the water. Therefore, although the phosphorus in the water and sediment is in equilibrium, the sedimentary phOSphorus concentrations would seldom be affected by biological conditions. The discharge canal was the only area affected by the operation of the power plant. This resulted in elevated temperatures and depressed oxygen levels in 1971. However, the principle factor at these stations was the introduction of nutrient rich water from the Raisin River. This water contained twice the background levels of phosphorus and caused significant increases in the concentration of phOSphorus in the sediments and water of the discharge canal. iii TABLE OF CONTENTS LIST OF TABLES . . . . . . . . . . . . . . . . . . . . LIST OF FIGURES . . . . . . . . . . . . . . . . . . INTRODUCTION . . . . . . . . . . . . . . . . . . . . . DESCRIPTION OF THE STUDY AREA . . . . . . . . . . . General Description . . . . . . . . . . . . . . . The Monroe Power Plant . . . . . . . . . . . . Sampling Locations . . . . . . . . . . . . . . MATERIALS AND METHODS . . . . . . . . . . . . . . . AnaTysis for PhOSphorus in Natural Waters . . . . Analysis for Phosphorus in Sediments . . . . . RESULTS AND DISCUSSION . . . . . . . . . . . . . . . . Temperature . . . . . . . . . . . . . . . . . . . Dissolved Oxygen . . . . . . . . . . . . . . . . Suspended Solids . . . . . . . . . . . . . . . . Nitrogen . . . . . . . . . . . . . . . . . . Primary Productivity . . . . . . . . . . . Sediments . . . . . . . . . . . . . Major Tributaries to the Western Basin and Their PhOSphorus Loadings . . . . . . . . . . . Movement of Phosphorus Through the Western Basin of Lake Erie . . . . . . . . . . . . . . . Phosphorus Concentrations of the Waters . . . . . CONCLUSION . . . . . . . . . . . . . . . . . . . . . . LITERATURE CITED . . . . . . . . . . . . . . . . . APPENDICES . . . . . . . . . . . . . . . . . . . . . . iv Page vii 12 12 12 lb 1h 1h 15 27 31 3h 147 N9 53 Table 10. LIST OF TABLES Ava able phosphorus levels (ug/g-P dry weight) of sediment Saflflm? collected throughout the Lake Erie-Raisin River 8am} ing area 0 o o o o o o o o o a Q a Q q 0 Q 0 O Q Q 0 Average "available" phOSphorus levels (ug/g—P dry weight) of'swdiment samples collected throughout the Lake Erie- Rais.fl River salnpling area 0 o o o o o o o o o o o A co: parison of' 'available" and total phosphorus levels (ug/ -P dry weight) in sediment samples. Averages of trip— lica‘, 9 analyses 0 o o o o o o o o o o o o o o Tota- PhOSphorus loading of the Raisin River, 1970-71 . . . . Phosphorus loading in the western Lake Erie basin during 1970 and 1971 . . . . . . . . . . . . . . . . . . . Average phosphorus levels (mg/l-P) of water samples at 0.5 meters throughout the Lake Erie-Raisin River area during 1970 . . . . . . Average phosphorus levels (mg/l-P) of water samples at 2.5 meters throughout the Lake Erie-Raisin River area during 1970 . . . . . . . . . . . . . . . . . c011ecte sampling collected sampling Average total phOSphorus levels (mg/l-P) of water samples collected at 0.5 meters throughout the Lake Erie—Raisin River sampling area during 1971-2 . . . . . . . . . Average total phosphorus levels (mg/l—P) of water samples colleacted at 2.5 meters throughout the lake Erie-Raisin River“ sampling area during 1971-2 . . . . . . . . . Avereige soluble phosphorus levels (mg/l—P) of water samples colleacted at 0.5 meters throughout the Lake Erie—Raisin River“ sampling area during 1971-2 - . . . . - . . - Averaage soluble phosphorus levels (mg/l-P) of water samples COllECcted at 2.5 meters throughout the Lake Erie-Raisin River sampling area during 1971-2 - - - - - - . . - The a. verage ratio of total: soluble phosphorus of water sampl~; es collected throughout the study area during 1970 . The avverage ratio of total: soluble phosphorus of water sample es collected throughout the study area during 1971- 1972 . . . . . . . . . . . . . . . . . . . . . Page 20 21 22 30 30 35 36 37 38 39 MO Al A2 Appendices Al. A3. Ah. A5. A6. A7. A8. A9. A11. A12. Total phosphorus levels (mg/l-P) of water samples collected at 0.5 meters throughout the Lake Erie-Raisin River sampling area during 1970 . Total phosphorus levels (mg/l-P) of water samples collected at 2.5 meters throughout the Lake Erie-Raisin River sampling area during 1970 . Soluble phOSphorus levels (mg/l-P) of water samples collected at 0.5 meters throughout the Lake Erie—Raisin River sampling area during 1970 . Soluble phosphorus levels (mg/l-P) of water samples collected at 2.5 meters throughout the Lake Erie-Raisin River sampling area during 1970 . Page 59 61 . . . . . . . . . . . . . . . . . . . . . . . 63 Total phosphorus levels (mg/l-P) of water samples collected at 0.5 meters throughout the Lake Erie-Raisin River sampling area during 1971-2 . . . . . . . . . . . . . . . . . . Total phosphorus levels (mg/l-P) of water samples collected at 2.5 meters throughout the Lake Erie-Raisin River sampling area during 1971-2 . . . . . . . . . . . . . . . . . . . . Soluble phOSphorus levels (mg/l—P) of water samples collected at 0.5 meters throughout the Lake Erie—Raisin River sampling area during 1971—2 . . . . . . . . . . . . . . . . . . . Soluble phosphorus levels (mg/l-P) of water samples collected at 2.5 meters throughout the Lake Erie-Raisin River sampling area Mean Mean Mean Mean during 1971—2 concentration concentration concentration concentration of soluble phosphorus in mg/l by station of soluble phosphorus in mg/l by station Of total phOSphorus in mg/l by station of total phosphorus in mg/l by station vi . 65 . 67 . 69 . 71 - 73 - 75 - 77 . 79 . 81 LIST OF FIGURES Figure Page 1. Map of the study area in relation to western Lake Erie . - - - . 5 2. Map of the study area with the location of sampling stations.- . 6 3. Temperature and oxygen concentrations during 1970-1971 . . . . . 13 h. Water movements throughout Lake Erie . . . . . . . . . . . . . . 32 5. Water movements in the western basin of Lake Erie . . . . . . . 33 6. Total phOSphorus concentrations throughout the study area . . . hh vii | ‘1 1’1 Iii. Ph Ph; 1.: .11 INTRODUCTION A Detroit Edison fossil fuel steam electric plant is under construc- tion near the mouth of the Raisin River at Monroe, Michigan. The plant can generate up to 3,200 megawatts andrequiresrq>to 85 m3/sec of water for its once through cooling system. The first of the plants four units was com- pleted in March, 1971, and was operated intermittently throughout that year. During that period the temperatures of the cooling waters drawn from the lake and river increased a maximum of 10°C. The construction of the plant and the long term increasing phOSphorus loadings to the western basin of Lake Erie has introduced the possibility that the heated effluent discharges would affect the complex interactions of algae and fish with regard to nutri- ent uptake and metabolic rates. This research is part of a comprehensive ecological study of natural phosphorus levels in the water and sediments of Lake Erie's western basin. These data will be used to explain seasonal or related variations due to physical alterations, especially from the once—through cooling system on the Raisin River. Lake Erie has gradually become a disposal basin for assorted anthro- pogenic wastes which raised the nutrient levels in that waterway. Verduin (196h) reported that the soluble phosphorus levels increased from 7.5 to 36.0 Ug/l between 1950 and 1961. The Federal Water Pollution Control Administration also reported an increase in soluble phosPhorus concentra- tions from 90 to 120 pg/l in the western basin of Lake Erie between 1963 and 1968. Various nutrients, broadly classified as micro or macronutrients, are essential to the metabolism of algae and aquatic macrophytes; and high levels stimulate their growth. The macronutrients are often the limiting factors. They include nitrogen, phosphorus, and carbon. For example, a relationship has been demonstrated between the growth of algae and the up- take of phOSphorus. Thus, the growth of algae could be controlled if the input of phOSphorus was reduced by regulating such uses as in detergents and eliminating the input from domestic and industrial wastes. With the continual nutrient enrichment of Lake Erie, the annual phyto- plankton crOps have also increased (Arnold, 1969); and the lake has become more eutrophic. As the massive growths of algae blooms die and decay, they deplete the oxygen supply so young fish cannot survive either (Round, 1970). Furthermore, enriching the water with phosphorus also encourages the growth of large filamentous green and blue-green algae at the expense of small diatoms. The larger species are inferior food sources because they cannot be consumed by small zooplankton, an important link in the food chain between algae and fish. The higher water temperatures shift the equilibrium between sediment and water concentrations and increase the solubility of nutrients in the water. In addition, the rate of organic decomposition and, therefore, of nutrient release is consequently accelerated. During the first year of the study, background or natural nutrient levels were measured to facili- tate later comparisons of data when the heated effluent discharge began to elevate temperatures in the waterway. DESCRIPTION OF THE STUDY AREA General Description The western basin of Lake Erie is a relatively small, shallow basin covering an area of 3,108 km2 with an average depth of 7.3 m and a maximum depth of 19.2 m. A rocky island chain separates it from the larger central basin, which covers 16,317 km2 with an average depth of 18.3 m (Chawla, 1970). The shallow western basin is generally well mixed and homothermous due to persistent wind driven water movements. Seiches, generally of less than 1 m, occur twice daily with an occasional movement of approximately 2 m. The total water movement results in thorough mixing, frequent resus- pension of sediments, and general high turbidity. While the western basin comprises only 5 percent of the total Lake Erie volume, it receives 95 percent of the total tributary flow (Nalepa, 1972). The Detroit River contributes the majority of the inflow. The discharge averaged 5,800 m3/sec during the study period (National Ocean Survey, 1969—1971). Other signifi— cant contributors include the Maumee River averaging 156 m3/sec (USGS—Ohio, 1970-1971) and the Raisin River with an average of 21 m3/sec (USGS-Michigan, 1970—1971). The interaction of the Detroit and Maumee Rivers, combined with the prevailing winds from the southeast, generally result in a counterclockwise water movement in the southwestern corner of the basin (Andrews, 19h8) and a flow-through time of about two months (Verduin, 1969). The water velocity depends upon the depth and wind velocity. It averaged 1.0 cm/sec over a six—month period in 1970, while the wind velocity averaged 0.85 km/day. Although the water generally moves counterclockwise, the Raisin River discharge into the basin is an exception. Where it enters the lake, the water flows in a southerly direction before Joining the major current. The Monroe Power Plant The Monroe Power Plant consists of four 800 megawatt power units. Each unit requires 3 pumps to circulate cooling water to condense steam from the turbine operation. Cooling water is supplied by pumping from the Raisin River. To facilitate discharge of the heated effluent, a discharge canal was constructed to carry the water to Lake Erie. The first unit of the plant was completed in March, 1971. While the cool- ing water was pumped fairly consistently throughout the year, the power generations and, therefore, heating of the water‘wasljnfiixxiand sporatic. Sampling Locations The Specific Lake Erie studyznfifiicenters on the mouth of the Raisin River near Monroe, Michigan, and includes 16.1 km of near shore lake water. Six lake stations (1 to 6) were positioned l to 2 km offshore (except No. 6 at 3 km) along a 25° azimuth parallel to the prevailing northeast current and north and south of the river mouth (See Figures 1 and 2). The stations were positioned far enough from shore to be representative of the lake and yet close enough that most would be gradually exposed to the warm.water plume. Stations 1 and 6 were located where they could serve as controls throughout the project. The stations were generally 1.5 km apart except for station 6 which was 5.5 km southwest of station 5. The water depth at the lake stations was 5‘m361nexcept for station A which averaged 3 to h m. DETROIT IIVEI ," 7” -- f, g YOLEDO _ 3", Q o ('3 I ' CD v" 6- ' 4m .fl’I"I' 0 fl ,’ 2m ' I .. O fwd. IKm H Figure 1. Map of the study area in relation to western Lake Erie. 5 Stations: 41-9 1‘“ 6‘ *1 Monroe are“) 1° Bay b‘° ' ., 4+2 379 P Plum Q A Creek k " 7‘47"" *\ P Discharge 8 I “I «. Canal +4 (J LAKE ”to / ERIE *5 5 La Plaisance Bay ‘—-—J 1 kilometer Figure 2. Map of the study area with the location of sampling stations. 6 an: don mai Plum Creek is a shallow embayment with a width of approximately 1 km, an average depth of l to 2 m, and flow of <1 m3/sec into the discahrge canal. Station 7 is located near the intersection of the creek and the discharge canal. The discharge canal was constructed south of the mouth of the River in 1969-1970 to carry the heated cooling water effluent from the steamrelectric plant to the lake. The steep sided canal is approximately 150 m wide and 2,500 m long. It has been dredged to a depth of 6 to 7 m, and station 8 is located near its confluence with Lake Erie. The Raisin River received substantial amounts of industrial and domestic pollution. Thus, the lower section must be dredged annually to maintain its 7.5 m depth. Since the power plant requires 120 m3/sec of cooling water for peak capacity operation, the entire flow of the river (21 m3/sec) is required with the remainder coming from Lake Erie. Station 9 was located on the river slightly upstream from the plant. —'-——‘—-— MATERIALS AND METHODS The sampling period extended from May 1, 1970, to February 18, 1972. Samples were collected at approximately two—week intervals from May 1 to November 7, 1970, at all nine sampling stations. During the winter, incom- plete collections were made on January 23 and February 18, 1971, at stations 1, 2, 7, and 8. More regular sampling was resumed on April 16 and continued through November 11, 1971, with the following exceptions. No samples were collected in early July, and those collected June h and August 17 were not analyzed. Partial collections were taken on December 2, 1972. Triplicate water samples were usually taken from each station at both 0.5 and 2.5 m, except for station 7 where only a 0.5 m sample was collected. The lake stations were marked by buoys, and replicate samples were taken approximately 30 m apart. The water samples were collected in clear Plexiglas, 8.1 liter Van Dorn Bottles. Then 1 liter of each was transferred to 1 liter amber polypropylene bottle. The remaining sample was reserved for phytoplank- ton and zooplankton analyses. During 1970 the samples were preserved with 2 ml of 8 N sulfuric acid as recommended by Charpiot (1969). However, with this procedure the total soluble phosphorus concentration was overestimated. Apparently the acid caused hydrolysis of organic phosphorus forms, lysis of cells, increased solubility of absorbed phosphorus, or some combination of these (Annett and D'Itri, 1973). Consequently hO mg/l of mercuric chloride was then used as a preservation and produced more accurate measurements. At each station triplicate sediment samples were collected with a Ponar dredge during April, July, and September of 1970 and during May, August, and October of 1971. The samples were then stored in glass bottles at h°C until they were analyzed. Analysis for Phosphorus in_Natural Waters Natural waters contain both inorganic and organic phosphorus in par— ticulate and dissolved forms. Therefore, the analyses were divided into two methods. Total phOSphorus can be measured with an acid hydrolysis of all organic, metaphosphate , pyrophosphate , and other polyphosphates to ortho- phosphate. The total soluble phosphorus fraction is obtained by filtering the sample through a 0.h5 u Millipore filter and hydrolyzing the filtrate. Orthophosphate can be determined by analyzing an unhydrolyzed, unfiltered sample directly. To measure phosphorus by the spectrOphotometric method, the phosphorus atom is reacted with molybdate ions as a coordinating group. Because arsenic, silicon, germanium, and phosphorus all react similarly with molybdate to form heteropoly acids, the heteropoly acid of interest is separated from the interfering substances with a solvent extraction. Such methods of extracting these complexes into amyl alcohol were used as early as 1920. Since then, this important technique for extracting heteropoly acids has been applied with the following solvents: esters ketones, aldehydes, ethers, and chloroformébutanol (Olsen, 1967). The chloroformAbutanol extraction mixture was chosen for this study because of its selectivity for the phos- phomolybdic acid complex in the presence of arsenic, silicon, and germanium. The method used in this research is a modification of the procedure of Wadeli: and Mellon (1953) and Sugawara and Kanamore (1961). 1J1! Iljl: .quf ”q Analysis for Phosphorus in Sediments The phosphorus concentrations in natural waters depend on how much is released from the sediments or introduced from other sources. The sedimen- tary phosphorus is generally bound in various solid phases, all of which have different solubility equilibria. They are affected by changes in temperature, pH, redox potential, and the concentration of other compounds. The rates and cycles for the transfer of phosphorus from sediments to water and the reverse have been determined (Mortimer, 19h1). However, they are at least approximate and only apply in selective cases. The biological processes in the sediments also affect the phosphorus interchange (Gahler, 1969). Benthic organisms alter the sediments, and microorganisms can facilitate dissolving otherwise insoluble inorganic phosphates. In shallow waters physical processes such as wave action from winds, seiches, boats, and the natural flow of water all stir the sediments and may alter the phosphorus balance. Generally, total phosphorus or fractions in soils or sediments have been analyzed with methods described as availability indexes. They have been widely accepted to measure the quantity of sedimentary phosphorus available for plant growth. With availability determinations the fractions of phosphorus in the soil have been correlated with crop response on acid soils . The phosphorus extracted by dilute solutions of strong acids can be correlated with the crop yield respond to phosphate fertilizers (Jackson, 1958). How- ever, the degree of correlation has been much lower with neutral or alkaline soils. Nelson et a1, (1953) found that a dilute hydrochloric-sulfuric acid mixture was the most effective of nine extraction solutions for three soil 10 types. Olsen and Dean (1965) describe an extraction method with a 0.05 N hydrochloric acid and 0.025 N sulfuric acid mixture. Olson and Dean's (1965) technique was used in this research project. However, after filtration through Whatman No. A2 filter paper, the sample was neutralized and run through the extraction process. The total phos- phorus in the sediments was determined with the sodium carbonate fusion technique described by Jackson (1958). In preparation for each analytical technique, the sample was mixed in a Waring blender for two minutes. Then a separate aliquot of the homogenized mixture was oven dried at 110°C to determine its moisture content. 11 p4 P) RESULTS AND DISCUSSION Temperature The lake stations exhibited similar seasonal trends, warming more slowly than the inshore stations in the spring and cooling more slowly in the fall (Figure 3). The discharge canal and Plum Creek began to show the affects of the intermittent heated effluent discharge after the plant began opera- tion in March, 1971. Similar, positive responses are apparent in June, July, and late August. At times the temperature increase approached 10°C at the discharge canal; however, the overall average was much lower due to the interrupted plant operation. Since station9 was upstream from the plant, it was not affected by the heated effluent. The temperature closely paralleled the lake stations which were quite uniform throughout both years. Some temperature variations could be accounted for by sampling over an 8 to 10 hour period. Dissolved Oxygen Dissolved oxygen levels in the lake varied uniformly throughout both years with a general slight decrease from surface to bottom. Stratification was generally minimized by wind induced mixing (Cole, 1972). The Raisin River had depressed dissolved oxygen levels through summer and fall of each year, reflecting the heavy organic loading it receives (Figure 3). During 1971 the plant operation resulted in depressed oxygen levels in the discharge canal and Plum Creek. The cooling waters frequently have low initial dis— solved oxygen levels which are accentuated by the heating before discharge. .Hnmfllonmfi Anofi 62—d30 ZO_Pxo QZ< wdDHoH mahommmong :oanmaflo>< .m canoe 21 Table 3. A comparison of "available" and total phosphorus levels (ug g-P dry weight) in sediment samples. Averages of triplicate analyses. "Available " Total Station Phosphorus Phosphorus % Available 1 137 361 38 2 265 780 31+ 3 77 208 37 h 88 251 35 5 19h 587 33 6 307 901+ 31+ 7 273 781 35 8 A20 1106 38 9 656 1988 33 35 - Average 22 Protection Agency (1973) determined that the total phOSphorus levels of the sediments in the central and eastern basins averaged 865 pg/g dry weight of which an average of 75 percent was inorganic phOSphorus. The total phos- phorus concentration of the sediments at the six lake stations in this study area averaged 515 ug/g (dry weight) and ranged from 208—90h pg/g. A pair- wise comparison of means (p<0.05) of the total phOSphorus data revealed the following relationships between stations: 3, h, l, 5,72, 7, 6, 8, 9. The total phosphorus content of river station (9) is significantly higher than all the other stations while Plum Creek (7) is significantly higher than three of the lake stations. The discharge canal (8) contained more phos- phorus than four of the lake stations. Among lake stations the levels decreased slightly with the progression from the mouth of the Maumee River. The average levels declined to the mouth of the Raisin River where they again increased. Then they declined again farther to the north. Apparently, the northerly currents sweep the nutrient loads of the rivers northward. Little accumulation is evident in these lake sediments, and the water action appears to be sufficient to suSpend much of the material and sweep it from the area. A comparison of the percentages of clay and silt at the various stations reveals striking similarities. The stations are listed in order of decreasing magnitude for each parameter as follows: Total phosphorus: 9, 8, 6, 7, 2, 5, l, h, 3 Percent clay and silt: 9, 6, 8, 7, 2, 1, 5, 3, h Thus, the total phosphorus is closely linked to the clay and silt fraction of the sediment and an identical comparison was made with the available phos- phorus levels. A pairdwise comparison (p<0.15) of the available phOSphorus data revealed the following relationship between stations: A, 3, l, 2, 5, 23 6, 1;_§, 9. All three inshore stations are significantly higher than the lake stations. Among the latter, the concentration decreased northward from the mouth of the river, similar to that of total phosphorus. Table 3 indi- cates the relative percentage of total phOSphorus which is available. For Lake Mendota, Wentz and Lee (1969) used the same extraction technique to determine that 50 percent of the total phosphorus was in the available form. In this study the average was 35 percent, and it was stable throughout all stations. The available phOSphorus levels primarily reflect the amounts of soluble and calcium phosphates. Certain iron bound phosphate compounds are not included in the mixed acid extractions. These complexes could be of great importance because under anaerobic conditons the phosphorus may be released to the overlying water. Although the index represents only a portion cm” the available phosphorus and not the total available phos— phorus, the sediment represents a significant reservoir of phosphorus for the lake basin. The levels of sedimentary phOSphorus in the study area are affected by numerous factors including the amount of mixing in the water, temperature, productivity of the overlying water, and the input of allochthanous phosphorus. While most of these variables could cause seasonal changes in the sedimentary phosphorus concentrations, none were apparent in this study. The Environmen- tal Protection Agency (1973) reported seasonal variations in Lake Erie and related the variations to either redox potential in the sediment or phytoplankton uptake . Shock and Britt (1969) also reported that the iron and phOSphorus content of the sediments decreased in Lake Erie due to high temperatures and low oxygen levels. Sample determinations revealed uniform diurnal variations in dissolved oxygen levels at the lake stations. During 1970 the Raisin River 2h has consistently lower levels of dissolved oxygen while those in the discharge canal and Plum Creek more closely approximated the lake stations. During 1971 the Raisin River retained its characteristic low levels of dissolved oxygen while the discharge canal and Plum Creek exhibited lower levels in reSponse to the initial use of the condensers. Variations with depth were reported for the lake stations. Some deficiency had occurred near the bottom in June, 1970, and remained until October 10, 1970. During stratification the deficit was more pronounced. Normal diurnal changes occurred at all stations. The oxygen depletion and resultant change in redox potential should decrease the sedimentary phOSphorus levels due to translocation to the overlying water. This would most likely occur in either the discharge canal or the Raisin River because of their severe oxygen deficiencies in the summer and fall. The discharge canal had its highest levels of sedimentary phosphorus in April or May each year, followed by a drop in concentration by July and August and the maintenance of these levels through September and October. The Raisin River experienced high levels in April and September of 1970 and August of 1971. There was no apparent relation between dissolved oxygen levels and sedimentary phOSphorus levels. The Environmental Protection Agency (1973) reported that the sedimentary phOSphorus content was negatively correlated with temperature. Therefore, phosphorus should be released from the sediments when the temperature increases in the overlying waters as occured at inshore stations during 1971. Elevated temperatures were more often measured in the discharge canal and Plum Creek due to the intermittent operation of the power plant (Cole, 1972). Contrary 25 to expectations, the sedimentary phosphorus levels at these stations were significantly higher (p<0.01) during 1971. Apparently factors other than temperatures have a dominant influence on the sedimentary phOSphorus con- tent. The amount of mixing of the water also affects the sedimentary phos- phorus levels as the process suspends varying amounts of phosphorus con- taining material. The levels of suspended solids at the lake stations were highest in the spring and decreased on a gradient from south to north. This correlated with the decreasing concentration of total sedimentary phosphorus levels along the same gradient. Both apparently reflect the heavy loading of phosphorus from the Maumee River as it is carried north- ward by the prevailing currents and gradually diSpersed. Despite decreased phosphorus loading rates for the western basin in 1971 there was a significant (p<0.05) increase in the sedimentary phosphorus levels. All stations experienced increased levels and the analysis of variance indicated significant increases (p<0.01) at all stations except 3 and 9. During 1971 the cooling waters drawn from the Raisin River were diverted toward stations 7 and 8 and it was expected that these stations would experience increased sedimentation and sedimentary phOSphorus levels. The levels in the Raisin River and station 3, off the mouth of the river, were essentially unchanged in 1971. Increased levels at the other lake stations were unexpected and are apparently unrelated to temperature, dissolved oxygen levels, and loading rates. 26 Major Tributaries to the Western Basin and Their Phosphorus Loadings The four major tributaries to the western basin are the Detroit River, Huron River, Raisin River, and Maumee River. The four comprise essentially the entire water input to the basin and thereby determine its water quality. Because of their effect on the study area, the general characteristics and phosphorus loading of each will be discussed. The Detroit River is dominant in the western basin in terms of quantity of flow, nutrient loading, and current influence. The river begins with the Lake Huron outflow and thereafter receives tributary drainage discharged to the St. Clair - Detroit River systems. Natural drainage water from through- out the various basins as well as extensive municipal and industrial wastes are discharged to the river from throughout the Detroit Metropolitan Area. Bahr (1972) estimated that during 1970 and 1971 the Detroit River contributed 97.5 percent of the total flow into the basin and 83.h percent of the total phosphorus. Approximately 20 percent of the phosphorus was in the Lake Huron outflow while the remainder was added before the water reaChed Lake Erie. Municipal sources account for 55 percent of the total phosphorus, industrial sources 10 percent, and agricultural and assorted runoff 35 percent (IJC, 1969). During the study period the average discharge of the Detroit River was 212,000 cfs which contained a total of 30,655,260 lb of phosphorus in 1970 and 23,808,771 1b of phosphorus in 1971 (Bahr, 1972). When compared with the 27 estimate of 35,200,000 1b of phosphorus discharged in 1966 (IJC, 1969), a gradual decrease in phosphorus loading is indicated. The Huron River contributes a minor portion of both flow and phosphorus to the western basin. Although its drainage basin includes large areas of Metropolitan Detroit, Ann Arbor, and Ypsilanti, it accounted for only 0.25 percent of the total flow and 1.15 percent of the total phOSphorus discharged during the study period. The Maumee River contributed only 1.98 percent of the total flow to the western basin but lb.3 percent of the total phosphorus. During 1970 the Maumee River had a total phOSphorus load of 5,23h,78l lb and 3,082,h79 lb during 1971 (Bahr, 1972). The river is the largest source of suspended solids to the basin and accounts for hO percent of the total tributary output. The primary source is a large eroded sediment load from surrounding agricultural areas and also municipal wastes. The Raisin River has a drainage area of 1.0h2 sq mi and contributes 0.2h percent of the entire flow to the western basin. It receives municipal effluent from the City of Monroe and various industrial wastes including reprocessed paper waste and plating plant discharges. Approximately A7 per- cent of the phOSphorus loading is from municipal-industrial sources, and 53 percent is from assorted runoff. A yearly dredging operation is maintained in the last 2 km of the river to remove the organic sludge buildup (Kreh, 1973). With flow data from the U.S. Department of the Interior, Geological Survey, and phosphorus concentrations determined in this study, the amounts of phOSphorus flowing into the study area from the Raisin River were calcu- lated. The average daily flow rate for the Raisin River was 588 cfs and h51 cfs respectively for 1970 and 1971. The average flow rates on sampling 28 days were h05 and 179 cgs respectively. Therefore, the phOSphorus loading (TableIM3)WaS calculated from the average daily flow rates and phosphorus concentrations. Bahr gt_§l, (1972) determined a total phosphorus loading for the Raisin River with flow data from the Geological Survey and phosphorus concentrations reported by various federal and state agencies. For 1970 and 1971 they determined that the loadings were 356,833 and 320,611 lb of phos- phorus respectively. The major sources of differences between calculations in the two studies were the concentrations of phosphorus. Bahr gt_gl, (1972) also calculated the total phosphorus loading for the entire western basin of Lake Erie(TébleJ£H- Flow data were taken for the mouths of the individual rivers, and the average phosphorus concentrations were obtained from several federal and state agencies. The four major tributaries carry significant waste loads consisting of municipal and indus- trial effluents and agricultural runoff. Municipal—industrial wastes account for 83 percent of the total phOSphorus . Other minor sources of phosphorus include vessel wastes , dredging spoils and atmospheric fallout . Dredging Spoils now add less than previously because they are taken to diked areas instead of being dumped in deep water disposal sites away from the river channel. The phosohorus loading decreased in each of the four rivers over the study period. The total loading to the basin reflected this as did a comparison with an estimated load of 30.1 short tons of phosphorus in 1967 (IJC, 1969). During 1970 and 1971 the western basin had loading rates of 0.63 gP/mB/year and 0.h7 gP/mB/year respectively. Shannon and Brezonik (1972) studied the relationship between lake trophic states and phosphorus loading rates. A comparison with their values indicated a hyper eutrophic situation. 29 asa.smm.sm msa.mam.mm ass.mwo.m ams.smm.m ac.a mm.m mos.m mam.s steam chess: aam.omm mmw.mmm om.o mm.o am: mam so>am sauaam owm.mmm asm.oss mm.o no.0 sss saw steam cones ass.mow.mm omm.mmm.om a.so ma.sm ooo.oam ooo.mom steam paospoo asaa osma asoa osaa asaa osaa osaa Amsaosamonm nonpomv poPSDaapaoo Ammov maapmoq sonEmoapm & opmm 30am .Amsma .uzom sousv asma paw osma weapap aamop oasm mama nympho: opp ea weaoooa mahommmomm .m oapme cem.mmm oom.msm oes.ssm assosaaosa sass sod messoa 0mm an: wwm Ammov Spas zaaop omoso>< mm.o mm.o :m.o Amla\wev coapapuaooaoo owaao>¢ HmpOB HbmH ONQH .asuosaa .sosam cauasm has so meaeaoa ashosaaosa aspos ..l oases 30 Movement of Phosphorus Through the Western Basin of Lake Erie Water movement in the western basin of Lake Erie is dominated by the flow of the Detroit River. Its influence is sometimes recognizable as far as the Ohio shore of the lake. The river flows through the middle of the basin and separates the Canadian and American influent waters. Inputs from the Canadian rivers are contained along the northeast area of the basin while those from the American rivers are contained in the southern and western areas (Figures h and 5). As a result, the waters from the Maumee and Raisin Rivers are restricted to coastal areas and remain relatively rich in nutrients. In the western basin outside the immediate influence of the Detroit River, the currents vary in direction and speed in correlation with the direction and intensity of the wind and seiches. The water flows in a northerly direction along the Michigan shore under all winds except those from the north, north- west, and northeast. After flowing almost due south into the basin, the dominant flow of the Detroit River progresses east toward Pelee Passage on the Canadian site and the water quality improved by dilution. The Interna- tional Joint Commission (1969) reported that the average total phosphorus concentration in the western basin ranged from 160 ug/l at the mouth of the Detroit River to 50 ug/l at Pelee Point. Approximately 8h percent of the influent phOSphorus remains in the lake primarily in the western basin. Bahr (1972) estimated that the influent phosphorus levels decreased 60 to 70 per- cent during passage from the western to eastern basin. This loss was pri- marily due to translocation to the sediments. 31 ha. .m_am mxOZ mms<3 .m mm:0_u moz~m meD_m _m_~m sHomswo 33 PhOSphorus Concentrations 2£_the Waters The phosphorus concentrations of the waters in the study area are dependent upon numerous factors. These include the loadings of tributaries into the study area, the phosphorus content of the sediments, temperature, dissolved oxygen concentrations and other biological and Chemical conditions. In addition to concentration, the "availability" of the phosphorus is impor- tant. To estimate the amount of phosphorus readily available for biological uptake the soluble phosphorus fraction is generally measured. However, because organically bound phosphorus may be biologically or chemically con- verted to soluble forms, this fraction must be measured and considered a reservoir of phOSphorus along with the sediments. To Obtain an accurate estimate of the phOSphorus content of the waters in the study area both total and soluble phOSphorus determinations were performed. Phosphorus concentra- tions are compared at different stations over the study period, and their relationship to biological and chemical changes discussed. The data along with ratios of the two fractions are presented in Tables h-ll and Appendix III. Phosphorus is an essential element in the growth of aquatic organisms. Phosphrous levels in the water have been related to numerous biological factors. Wong (1968) found that phosphorus uptake was related to primary productivity levels and temperature. Weiss (1969) demonstrated that algae quickly incorporate phosphorus into organic matter and that algae secrete organophosphorus materials. The zooplankton consuming the phytoplankton concentrate the phOSphorus further and return a portion of the ingested phosphorus as fecal pellets (Rigler, 1961). Bacteria also quickly absorb phosphorus and provide food for zooplankton. Watt §t_§l, (1963) determined that both bacteria and zooplankton incorporate dissolved organic and 3h 10 ll 12 13 1’4 15 1970. Collection Number during ing area River sampl lSln Average phosphorus levels (mg/l-P) of water samples collected at 0.5 meters throughout the Lake Erie-Ra Solublegphosphorus Table 6, Station # omsoosmgoomra OOOOr-i OON OOOOOOOOO NOFODFFCDL‘UN r4c>c>czc>c>c>c>s4 <3 c>c>c>c>c>c>c>c> 888888888 c>c>c>c>c>c>c3c3c3 8888 888i c>c3c3c3c3c3c3c>c> [\-O\O\H®O\ [\Lfl OOOHOO ON c3c3c3c3c3c3c3c3c3 sgsmmmmww 0 0000000 000000000 wmmoa 0am oaaaa Ham 00000 000 838mmme mo 0 OOOOOm ooooooooo Ln888888851? 666666666 oaoémgo 8H OOOOOOOOO mgmmmMJMO O OOOOOOr-i OOOOOOOOO o8888888a c3c3c3c3c3c3c3c3c3 O\b—U\b— C>c>c>c>€5<3§80 c3c3c3c3c3c3c3c3c3 oxb—c>oxw3«3nwm C>C>HHC>r1r4r4r4 C3C3C3c3c3c3c3c3c3 s4c>oia s1 s4r—a) s4s4s4s4ol s4c>s4 c>c3c3c3c3c3c3c3c3 l 2 ML!” MO [\(I) O\ 10 11 12 13 la 15 Collection Number Total phosphorus Station # OO\U\COOOOOO\OO r—IOHOHOOr-im OOOOOOOOO mHOONPChOOr—i r—lr—lOr—lOOt—‘lr—IN 000000000 005ng oooxm OO CO COM 000000000 OONOOO mm Door—4888001 OOOOOOOOO (\lr-ICDMN POM r—iHOHH Or-im OOOOOOOOO mo 0\ Ohm-O: 0.480 OHHm OOOOOOOOO u—Ioommm .3010 Hl—ir-Ir—lr-l t—ln—IN 0000 000 LA 00 oosoomxo O O OOOr—im OOOOOOOOO :N 88aa 8‘ 000000000 .10 .08 .2 .1 .2- 888888898 000000000 88888888: 000000000 88888 288 000000000 888888888 000000000 JNMJMJCDL‘H t-ir-lt-lr-Ir-lt—lt—lr-IN OOOOOOOOO b—\DO\OMC\JO\M[\ HHHNNHHI—IN 000000000 1 2 3 h Lr'\\0[\(DO\ 1n8 ing area dur' l 1ver samp R Average phosphorus levels (mg/l-P) of water samples collected at 2.5 meters throughout the lsin 1970. 03 CE I G) '4-1 7-4 [:1 (D '33 b; d) :3 C6 E-I Soluble phosphorus Collection Number 15 1h 13 12 ll 10 Station # EJ%3%38 00000 F [\-[\\0 O OOH 00000 0.09 0.07 0.05 0.07 0.09 0.05 0.07 0.07 0.06 0.06 0.10 0.07 0.10 0.08 0.05 0.05 0.07 0.05 0h .06 .19 55555558 00000000 88888883 00000000 .33.: COO-80.30 OOOOOOOO MJLR :LflmO COO 0004—! 00000000 CO 08888 00000000 88888888 0000000 FCOFNHCRCO OOOr-lr—iOO OOOOOOO O\O\Lr\m.d'Lf\I—l OOI—lr—lr—{Or-l 0000000 0.13 0.07 0. r-ICUMJLRKOCIDO 36 Totalgphosphorus Collection Number 13 1h 15 0.07 0.13 0.12 0.12 0.07 0.08 0.11 0.09 12 0.06 0.16 0.08 0.11 0.07 0.08 0.15 0.09 11 10 Station # 7 0.09 0.1M 0.09 9 0.30 0.19 0.33 .07 0.08 0.06 0.27 0 2 .06 0.09 0.11 0.08 0.08 0.07 0.08 0.11 .10 0.05 0.07 0.09 0.09 0 0 0 0 12 .ll 11 23 c>c3c>c3c3c3 1 1h 12 10 23 6 .09 0.1a 0.1 1 1 0.1M 0.23 0.30 0.3 0 0 0 0 u u 0 0 .06 .07 I11 0 0 0 0 0 09 10 08 09 09 08 15 22 0 0 0 0 0 0 0 0 8838) 0000 U'\O\r-I CO 0000 (Db-(DQCDQO: OOOOOOn—lr—I C3c3c3c3 C>uxb~a3 r4c>c>c> C>c>c>c> 01r4q>d> PiFiFiri C>C>C>C3 «auxoun r4r4r4r4 OOOO Hmm: c3c3c3c3 b— cnxo <318<3r4 c>c>c>c> uxr4;r 44.44433 c3c3c3c3 H:\OU\ OJririQJ c>c>c>c> U\\D< om.H :m.H m:.H mm.H mm.H mH.H -- mm.H m mm.H mm.H Hs.H mH.H m:.H ms.H mo.H o:.H m Hm.H ms.H mm.H 4;.H mm.H mo.H HH.H mm.H m mm.H wH.H mH.H sm.H mm.H Hm.H :m.H H:.H m m:.H :m.H mm.H :m.H NH.H mH.H mm.H 2:.H : mw.a :m.a mm.H Hm.H mo.H :H.H :H.H :©.H m mm.H om.H mm.H om.H mm.H mm.H HH.H :m.H m mm.H mH.H om.H mm.H mw.H mm.H mm.H am.H H .>02 mm .900 OH .poo am .pamm mH .pamm H .pamm wH .ws< ; .msa coHpspm mm.H mm.H sm.H mm.H Hm.H mm.H sm.H mmwpm>< mm.H mm.H OH.H om.H mH.H ww.H sm.H a NH.m ms.H :o.m sm.H NH.H mm.H mw.H m NH.H Hs.H m;.H mm.H mm.H HH.H as.H m :m.H sm.H mm.H mm.H om.H ms.H Hm.H m Hm.H mw.H ms.H mm.H sm.H ::.H mm.H : om.H mw.H mH.H :m.H mo.H so.m m:.H m ms.H ms.H :H.H sm.H -- -- Hm.H m ss.H oo.H mm.H mm.H :m.H sm.H mo.H H Hm sHss s sHsa gm mesa OH mass pm as: mH as: H as: coHpmpm .osmH mcHsso amps madam map pdonm50p59 wopomaaoo moamfidm pops: mo masonmmosm odeHOmunpOp Mo oflpwu ommhmbd one Awfi manna M2 mm.H ss.H mm.H mm.H om.H om.H sm.H 0:.H mmwpm>< mm.H .. em.H -- HH.m mm.m ms.H 0:.H m m:.H ms.H am.H :m.H mm.H Hm.m mm.H ms.H w -- -- -- m:.H mm.H mm.H m:.H mm.H m -- -- -- m;.H mm.H ::.H o:.H mm.H m -- :m.H sw.H mH.H om.H mw.H mm.H mm.H s sm.H :o.m om.H mo.H mm.H mm.H :m.H mm.H m -- -- -- :H.H mm.H ms.H m:.H mm.H m ms.H -- :m.H mo.H ss.H mm.H m:.H H:.H H mH .nma HH .can 0H .omm NH .>oz .om .poo mH .poo .poo mH .pamm :oprpm om.H mm.H mm.H am.H H:.H mm.H mm.H measm>< mH.H om.H mm.H m:.H mm.H mm.H ws.H a :m.H mm.H om.H s:.H m:.H om.H m:.H w mH.H mH.H mm.H mm.H HH.H mH.H mm.H m aH.H Hm.H sm.H :m.H mm.H om.H mm.H m mo.H mm.H :m.H mm.H sm.H mm.H m:.H : mm.H NH.H PH.H :m.H 0:.H mm.H m:.H m mm.H mm.H mm.H Hm.H m;.H mm.H mm.H m mm.H mm.H mm.H mm.H mm.H mm.H sm.H H m .pamm mm sHss mH sHsa NH «can om as: H has mH HHpaa coprpm .mbmanabma wcfihsu cogs harpm opp psonwsounp dopomaaoo mmHQEwm pmpwz mo mahonmmozm oHQZHOmHprov kc mowpmh wwwhm>w 05B .MH oHan dissolved inorganic phOSphorus into particulate phOSphorus and then release both dissolved forms. Al—Khaly (1969) determined that phosphorus is absorbed across the gills of fish and is deposited in the bones and muscle. Macrophytes also take up mainly inorganic phosphorus with probable luxury storage (Gossett, 1971). The total and soluble phOSphorus levels in the study area were generally high andeumwfljxrranging from 0.06 mg/l to 0.53 mg/l (Figure 6). The analysis of variance indicated no significant (p<.01) difference in concentration between the 0.5 m and 2.5 m depths. During 1970 the total and soluble phosphorus concentrations were uniform throughout stations 1 through 8 (Tables A9 to A12). Station 9 was significantly (p<.05) higher than all otherstationscmlall bum two collection dates. DeSpite the decreased 1971 phosphorus loadings from the Maumee and Raisin Rivers, significant increases occurred at stations 6, 7, 8 and 9 during 1971. The increased concentrations at stations 7 and 8 were attributed to the diversion of nutrient rich water from the river to the discharge canal. The increased concentration at sta— tion 9 was attributed to lower flow rates and higher phosphorus concentra— tions in the Raisin River. Throughout 1971 station 9 was significantly higher in concentration that the lake stations. After June of 1971 sta- tions 7 and 8 also had concentrations generally significantly (p<.05) higher than the lake stations which were again uniform throughout. The lake sta- tions had relatively high phOSphorus concentrations in the Spring of 1970, possibly due to spring runoff containing high phosphorus loadings. The Raisin River also had high concentrations at this time. The phosphorus concentrations, then cycled from a gradual decrease, to a peak concentration in August, and.a. gradual. decrease once again. During 1971 data are lacking M3 .51.»? >095 mIF PDOIGDOaIF mZO1H<~1HZmUZOU mDmQ1n1len1 .1<.1.0F .o unsoln mama lama oamH 2.1L...oez_o.mw.1m /. x 1 1 .\ /.\. 1m... 1 1 Ni... .1 1c. ..on. hh for the spring period, however, a similar cycle appears to have occurred in the lake stations. Beginning with low concentrations in April a gradual increase occurred until the June-July peak and gradual decrease thereafter. The inshore stations exhibited a disruption in the pattern due to the diversion of flow to the discharge canal during 1971. The discharge canal experienced gradually increased phosphorus concentrations from 0.06 mg/l to 0.25 mg/l and the maintenance of these levels. Plum Creek experienced a cycle similar to 1970 with the exception that high levels were maintained in the fall except for one October sample. The Raisin River had high erratic values throughout 1971. Significant increases in total and soluble phosphorus occurred during the August 1970 phytoplankton bloom. In 1971 the phosphorus levels were higher throughout the months of April to October. Although phosphorus con- centrations were elevated during periods of increased primary productivity, the two factors are not necessarily related. During periods of increased biomass it was expected that large amounts of phosphorus would be incor- porated into organic matter, thereby increasing the total:soluble phosphorus ratio. The ratios were higher for inshore stations and varied inconsistently throughout the study periods. There was no significant correlation of the total:soluble phOSphorus ratios and primary productivity. Because of the rapid uptake and excretion of dissolved phosphorus by algae, it is possible that totalzsoluble ratios could remain similar under bloom conditions. Dur- ing the periods of increased primary productivity, there was no evident decrease in soluble phosphorus concentrations and no apparent loss of phos- phorus from the sediments. With the loss of dissolved oxygen from the water to the point of decreas- ing sediment redox potentials, it is possible to experience a loss of 145 phosphorus from the sediment to the overlying waters. When comparing the dissolved oxygen values and phosPhorus concentrations of this study, the only apparent relationship occurred in September of 1970 in the Raisin River. Upon the depletion of dissolved oxygen a coincident increase of phosphorus concentrations was determined. Because of the nature of the Raisin River with fluctuating phosphorus loadings it is difficult to definitely correlate the two factors. During 1971 there was no apparent change in phosphorus values upon oxygen depletion. It is also difficult to correlate the phosphorus concentrations and temperature changes. The only stations directly affected by increased temperatures from the plant Operation were 7 and 8. These stations were also subjected to the constant input of high nutrient water diverted to the discharge canal. Thus, although significant increases in phosphorus con- centrations did occur at the stations it is extremely difficult to attribute these increases wholly to one factor. The increased concentration of phos- phorus in the sediments of the stations would indicate that temperature was a minor factor. Assuming a constant phosphorus loading the phosPhorus con- centration of the water would be expected to rise as the water temperature increased, with a resulting decrease in the sedimentary phosphorus levels. The simultaneous increase of phosphorus concentrations in both water and sediments would indicate a greatly increased phosphorus loading to the area which makes it difficult to evaluate the actual effects of the temperature changes in the system. 146 A? CONCLUSION Phosphorus loadings to the study area decreased during 1971 and may provide encouragement for the future of the region. Phosphorus loadings had undergone gradual, long term increases causing the present eutrophic state. Continued decline could indicate a response to improved wastewater treatment facilities. Despite decreased phosphorus loading the sedimentary phosphorus levels increased significantly at seven stations in 1971. These increases could not be directly related to primary productivity, dissolved oxygen or temperature. Because the power plant experienced limited operation in 1971 the effects of the heated effluent were limited to stations 7 and 8. These stations bothexperienced.significantly increased sedimentary phos- phorus concentrations. The increases were attributed to the increased phosphorus loading to the discharge canal during 1971. The increased loading resulted from the diversion of water from the Raisin River to the discharge canal. Influent concentrations after the diversion were approxi- mately double the background levels of the discharge canal. Significant increases in the phosphorus concentrations of the waters at stations 6, 7, 8 and 9 occurred in 1971. These increases were unrelated to primary productivity, dissolved oxygen levels or temperature. Increased concentrations at station 9 were attributed to the reduced flow of the Raisin River providing a lack of dilution. The increased levels at stations 7 and 8 were caused by the diversion of high nutrient water from the river to the discharge canal. Station 6 was the only lake station having a significant change in concentration, and the cause was unexplained. The high phOSphorus concentrations in both the water and sediments of the study area prevented the determination of interaction between phos- phorus concentrations and chemical and biological changes in the study area. Algal blooms could be supported by a fraction of the phosphorus present in the water and not affect the sedimentary phOSphorus levels. As a result there was no significant relationship between primary productivity and phosphorus concentrations . During the study period temperature affects were limited to the discharge canal. However, an overriding factor at these stations was the introduction of high nutrient, cooling water. The occasional dissolved oxygen depletion at some stations could have caused the release of some sedimentary phosphorus. These equilibrium shifts were not of sufficient magnitude to cause a significant change in the high phOSphorus concentrations of either the water or sediments. Therefore, the affect of the power plant has been the diversion of cooling water from the Raisin River to the discharge canal and the resul- tant increase of phOSphorus concentrations at stations 7 and 8. Because the power plant experienced limited operation during the study period, these observations are of limited use in determining long term affects. As the heated effluent plume extends into Lake Erie perhaps more pronounced developments may occur. The high background phOSphorus concentrations in the study area indicate that very limited, additional phOSphorus related damage will be caused by the heated effluent discharge. h8 LITERATURE CITED b9 LITERATURE CITED Al—Kholy, A., M.M. Ishak, Y.A. Youssef and S.R. Khalil. 1970. PhosPhorus uptake from water by Tilapia Zillii. Hydrobiologia 36(3)3571-h78. AndreWS,3PJF- l9h8. Temporary changes of certain limnological conditions in western Lake Erie produced by a Windstorm. Ecology 29(h):501-505. Annett, C.S. and F.M. D'Itri. 1973. The comparison of preservation techniques on total soluble phOSphorus, pH and susPended solids. Proc. 16th Conf. Great Lakes Res., pp. 2lh—220. Arnold, E.E. 1969. The ecological decline of Lake Erie. New York Fish and Game J. 16(1):27—h5. Bahr, T.G. 1972. Ecological assessment for wastewater management in south- eastern Michigan. Tech. Rep. 29, Inst. of Water Res., Mich. State Univ., East Lansing, Mich. 281 pp. Charpiot, R. 1969. Preservation technique for sea water samples for phosphate, nitrite, silica and boron determinations. Cahiers Oceano- graphique 21:773-793. Chawla, V.K. 1970. Changes in the water chemistry of Lakes Erie and Ontario. In; Proceedings of the conference on changes in the chemistry of Lakes Erie and Ontario. Bull. Buffalo Soc. Nat. Sci. 25(2):31-6h. Cole, R.A. 1972. Physical and chemical limnology along the western shore of Lake Erie. Tech. Rep. 13, Inst. of Water Res., Mich. State Univ., East Lansing, Mich. 120 pp. C018, R.A. 1973. An ec010gical evaluation of a thermal discharge: summary of early postoperational studies. Tech. Rep. 32.0, Inst. of Water Res., Mich. State Univ., East Lansing, Mich. A3 pp. Curl, H.C. 1951. The distribution of phosphorus in western Lake Erie and its utilization by natural phytoplankton populations. M.S. Thesis. Ohio State Univ., Columbus, Ohio. Environmental Protection Agency. 1973. Phosphorus release from lake sedi- ments. Office of Research and Monitoring. Washington, D.C. 185 pp. Fitzgerald, G.P. 1970. Aerobic lake muds for the removal of phosphorus from lake water. Limnol. Oceanogr. 15(h):550-555- Gahler, A.R. 1969. Sediment-water nutrient interchange. Proc. Eutrophi— cation Biostimulation Assessment WorkshOp, Berkeley, Calif., pp. 2A3- 257. Gossett, D.R. and W.E. Norris, Jr. 1971. Relationship between nutrient availability and content of nitrogen and phosphorus in tissues of the aquatic macrophyte, Eichornia Crassipes (Mart.) Solms. Hydrobiologia 38(1):15-28. Harter, R.D. 1968. Adsorption of phosphorus by lake sediments. Soil Sci. Soc. Amer. Proc. 32:51h-518. Hayes, F.R. 1955. The effects of bacteria on the exchange of radiophos- phorus at the mud-water interface. Verh. Internat. Ver. Limnol. 12: 111-116. Hayes, F.R. and J.G. Phillips. 1958. Lake water and sediment IV Radio— phosphorus equilibrium with mud, plants, and'bacteria under oxidized and reduced conditions. Limnol. and Oceanogr. 3:h59-h75. Holden, A.V. 1961. The removal of dissolved phosphate from lake waters by bottom deposits. Verh. Internat. Verein. Limnol. lhz2h7-251. Hynes, H.B.N. and B.J. Greeb. 1970. Movement of phosphate and other ions from and through lake muds. J. Fish. Res. Bd. of Canada 27(h):653-668. International Joint Commission(reportto). 1969. Pollution of Lake Erie, Lake Ontario, and international section of the St. Lawrence River. Vol. 2 - Lake Erie. 316 pp. Jackson, M.L. 1958. Phosphorus determinations for soils. 12} Soil Chem- istry Analyses. Prentice Hall Inc., Englewood Cliffs, N.J. A68 pp. Kemp, A.L.W. 1969. Organic matter in the sediments of Lake Ontario and Erie. Univ. of Mich. Great Lakes Res. Div. Proc. 12th Conf. on Great Lakes Res., pp. 237-2h9. Kemp, A.L.W. and C.F.M. Lewis. 1968. A preliminary investigation of chlorophyl degradation products in the sediments of Lakes Erie and Ontario. Univ. of Mich. Great Lakes Res. Div. Proc. 11th Conf. on Great Lakes Res., pp. 206-229. 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. M.S. Thesis, Mich. State Univ., Tech. Rep. 32.1, Inst. of Water Res. 92 pp. Li, W.C. and D.E. Armstrong. 1973. Measurement of exchangeable inorganic phosphate in lake sediment. Environ. Sci. and Technol. 7(5):h5h-h57. Marcus, M.D. 1972. The distribution of phytoplankton and primary produc- tivity near the western shore of Lake Erie. M.S. Thesis, Mich. State Univ., Tech. Rep. 1h, Inst. of Water Res. 96 pp. 50 Mortimer, C.H. l9hla. The exchange of dissolved sUbstances between mud and water in lakes. J. Ecol. 30:1h7-20l. Mortimer, C.H. l9hlb. The exchange of dissolved substances between mud and water in lakes. J. Ecol. 29:280-329. Nalipa, T.F. 1972. An ecological evaluation of a thermal discharge, Part III: The distribution of zooplankton along the western shore of Lake Erie. M.S. Thesis, Mich. State Univ., Inst. of Water Res., Tech. Rep. 15. 112 pp. National Ocean Survey. 1969-1972. U.S. Dept. of Commerce, Lake Survey Center, Detroit, Mich. Nelson, W.L., A. Mehlick and E. Winters. 1953. Soil and fertilizer phos- phorus in crop nutrition. Vol. h, Agronomy: A Series of Monographs. Academic Press, Inc., New York., pp. Olsen, S. 1967. Recent trends in the determination of orthophosphate in water. In; Chemical environment in the aquatic habitat. H.L. Golterman and R.S. Clymo., Eds., N.V. Noord, Hollandsche Vitgevers Maatschappij, Amsterdam, pp. 63-105. Olsen, S.R. and L.A. Dean. 1965. Phosphorus. lg; Methods of soil analysis, Part II. Amer. Soc. Agronomy, Madison, Wis., pp. 1035-10h9. Olson, F.C.W. 1950. The currents of western Lake Erie. Ph.D. Thesis, Ohio State Univ., Columbus, Ohio. Pinsak, A.P. 1967. Water tranSparency in Lake Erie. Proc. Tenth Conf. Great Lakes Res., Inter. Assoc. Great Lakes Res., Ann Arbor, Mich., pp. 309-321. Pomeroy, L.R., H.M. Mathews and H.S. Min. 1963. Excretion of phosphate and soluble organic phOSphorus compounds by zooplankton. Limnol. Oceanogr. 8(1):50-55. Rigler, F.E. 1961. The uptake and release of inorganic phOSphorus by Daphnia Magna Straus. Limnol. Oceanogr. 6:165-17h. Round, F.E. 1970. The biology of the algae. Edward Arnold Ltd., London. 269 pp. Shannon, E.E. and P.L. Bregonik. 1972. Relationships between lake trophic state and nitrogen and phosphorus loading rates. Environ. Sci. and Technol. 6(8):719-725. Shock, E.J. and W. Britt. 1969. Monthly variation in phosphate and related chemicals found in the sediments in the island area of Lake Erie, 1967-1968 with reference to samples collected in 196A, 1965 and 1966. Univ. of Mich. Great Lakes Res. Div. Proc. 12th Conf. on Great Lakes Res., pp. 325-3h0. 51 Stumm, W. and J.O. Leckie. 1971. Phosphate exchange with sediments; It's role in the productivity of the surface waters. Proc. 5th Int. Water Pollution Res. Conf., pp. 26/1—26/16. Sugawara, K. and S. Kanamori. 1961. Spectrophotometric determination of submicrogram quantities of orthOphOSphate in natural waters. Chem. Soc. Jap. Bull. 32(2) 258—261. U.S. Department of the Interior. 1969-1972. Water resources data for Michi— gan. Part I. Surface water records. Geol. Survey, Water Res. Div., Lansing, Mich. U.S. Department of the Interior. 1969—1972. Water resources data for Ohio. Part 1. Surface water records. Geol. Survey, Water Res. Div., Columbus, Ohio. Verber, J.L. 1955. Surface water movement in western Lake Erie. Ohio J. Sci. 51(1):h2-h6. Verduin, J. 196A. Changes in western Lake Erie during the period 19h8-1962. Verh. Int. Verein. Limnol. 15:639-6hh. Verduin, J. 1969. Man's influence on Lake Erie. Ohio J. Sci. 69(2):65-69. Wadelin, IL and M.G. Mellon. 1953. Extraction of heteropoly acids with application to determination of phosphorus. Anal. Chem. 25:1668-1673. Watt, W.D. and F.D. Hayes. 1963. Tracer study of the phosphorus cycle in sea water. Limnol. Oceanogr. 8:276-285. Weiss, C.M. 1969. Relation of phosphates to eutrophication. J. Amer. Water Works Assoc. 61(8):387-391. Wentz, D.A. and G.F. Lee. 1969. Sedimentary phosphorus in lake cores - analytical procedures. Environ. Sci. and Technol. 3(8):750-759. Wong, S.L. 1968. The measurement of primary production and its relation to inorganic phosphate absorption in a freshwater lake. Hydrobiologia, PP- 378-391. 52 APPENDICES \n L APPENDIX I Procedure for the Analysis of Phosphorus in Natural Waters When using the chloroform-butonal extraction solvent for phosphorus analysis , both the relative proportion of butanol and chloroform and the acidity of the aqueous solution are critical. A large prOportion of butanol causes high sensitivity but also increases interferences. Sugawara (1961) deter- mined a crucial normality range of O.h to 0.8 N for the extraction. There- for, both aqueous volume and the amount of concentrated hydrochloric acid must be carefully controlled to determine the proper pH. The following equipment, reagents, and procedures were used to analyze for phosphorus in natural waters. Apparatus: l. Burrell wrist action shaker 2. 500 ml pear—shaped separatory funnels 3. Flat bottom, round 300 m1 boiling flask h. Boiling chips 5. Graduated cylinders 6. Millipore filter apparatus and O.h5 u filters 7. Beckman DK-2A spectrophotometer Reagents: 1. Stock phOSphorus solution — Dissolve O.h39h g of potassium dihydro- gen phosphate (KH2POh), which has been dried overnight at 105°C, in distilled water and dilute to 1 liter. 10. ll. 12. Working phosphorus standard solution - Dilute 10 m1 of stock phos- phorus solution to 1 liter with distilled water. 1 ml of this solution is equal to 1 ug of phosphorus as P. Concentrated hydrochloric acid. Concentrated nitric acid. Sulfuric acid (3.6N) - Add 10 ml of concentrated sulfuric acid to 90 ml of distilled water. Sodium hydroxide (l N) - Dissolve h g of sodium hydroxide in 100 ml distilled water. Sulfuric acid.UDJ2N)-Add 2.8 ml concentrated sulfuric acid to A97 ml distilled water. Ammoniumnmflybdatcesolution (lO percent)-—Dissolve 10 g of ammonium molybdate ([NHh16 M0902h-AH20) 90 ml distilled water. Phenolphthalein indicator solution - Dissolve 5 g of phenolphthalein (C2OH1hOh) in l 2 of 50 percent ethyl alcohol. Neutralize with 0.02 N sodium hydroxide. N4butyl alcohol. Chloroform4butanol solution - Mix 300 ml n-butyl alcohol with 700 ml chloroform. Strong acid solution — Add 300 m1 concentrated sulfuric acid to 600 ml distilled water. After cooling add A m1 concentrated nitric acid and dilute to 1 liter with distilled water. Preliminary Treatment: To analyze for total phOSphorus, a 50 ml sample is quantitatively transferred to a 300 m1 flat bottom boiling flask. The graduate is then rinsed with 10 ml of concentrated nitric acid, A ml of 3.6 N sulfuric acid and 2cn°3 boiling chips. The sample is heated until white sulfuric acid fumes evolve. At this point only a l or 2 m1 slurry remains 5h in the flask and all forms of phOSphorus have been converted to orthophos- phate. To measure total soluble phoSphorus, the sample is initially passed through a O.A5 u Millipore filter. Then the filtrate is treated in the man- ner described for total phosphorus. For an orthophOSphorus determination, the sample does not require any preliminary treatment. Extraction Procedure: Sincetflmaquantitative extraction of the phospho— molybdic acid complex into the chloroform—butanol mixture is a function of the pH of the aqueous solution, Special precautions must be taken to insure that the acidity of the sample is correct. Following preliminary treatment the aqueous sample is neutralized. Then A m1 of concentrated nitric acid are added, and the total volume is brought to 50 ml with distilled water. For either the total phosphorus or total solUble phosphorus analysis, approximately 10 m1 of distilled water and 2 drops of phenolphthalein indi- cator are added to each flask. Next the solution is titrated with 1N sodium hydroxide to the pink endpoint. Then it is back-titrated to a colorless endpoint with 0.2 N sulfuric acid. The neutralized sample is then transfer- red to a 50 ml graduate cylinder, and the boiling flask is rinsed with A ml of concentrated hydrochloric acid and two 10 ml portions of distilled water. They are also added to the graduate cylinder. The sample is then diluted to 50 ml and transferred to the separatory funnel. For the orthophosphate determination A6 ml of the sample and A m1 of concentrated hydrochloric acid are transferred directly to the separatory funnel. For these tests the samples were always checked to insure that the solutions were neutral. How- ever, the natural waters were usually in the pH range where no neutralizing procedure was required. The following steps in the determinations are iden— tical for all phosphorus forms. First , 15 ml of the chloroform-butanol solution is addedtoiflmzsolution. Thenifluafunnelis Stoppered and Shaken for five minutes 55 with a pause to relieve the pressure. After phase separation the lower organic layer is drained and discarded. A second 15 ml aliquot of the chloroformrbutanol solution is added. Then shaking is continued for an additional five minutes. Afterlflmumaseparation the lower layer is again discarded. At this point the aqueous phase containing the orthophosphate is saturated with chloroform-butanol while interferring colored complexes have been extracted into the organic phase and removed. Saturation is important because the final volume of chloroformebutanol is critical. For each sample, exactly 10 ml of chloroform-butanol mixture must be retained throughout the extraction without loss to the aqueous phase. Otherwise, the concentration would change. The final step is to add 10 ml of the chloroform-butanol mixture and A ml of the 10 percent ammonium molybdate solution. The mixture is then shaken for five minutes. After phase separa— tion the absorbance of the lower layer is measured at 310 nm. To establish a standard curve with the working standard solution, pipet O, 3, 7, 10, l3, l7 and 20 pg of phosphorus as P into separate 50 ml gradu- ated cylinders. Add A ml of concentrated hydrochloric acid to the samples and then fill to volume with distilled water. The samples are then trans- ferred to separatory funnels and carried through the extraction procedure. In these tests after a standard curve was established, the O and 10 pg stan— dards were checked daily for possible contamination and to insure that the instrument was operating properly. The standard curve was very stable. The absorbance of the samples was determined with a Beckman DK—2A spectrophoto- meter. The scale expansion feature of this instrument made it possible to detect 0 to 20 ug phosphorus with a sensitivity of 0.2 ug. During the development of the analytical procedure, the following para- meters were refined to optimize the sensitivity: 56 Wavelength: A wavelength analysis confirmed the maximum absorbance for the phosphomolybdic acid complex was in the range of 306 to 311 nm (Wadlin and Mellon, 1953). As a result, 310 nm was used to analyze the phosphomolyb- dic acid complex. Reproduceability: The standard curve was exceptionally stable through- out the period of analysis. During the multistep procedure in the extraction process, the major source of error is likely to be the technician. When the analytical procedure has been mastered, 10 pg replicate standards are easily reproduced within 1 0.005 absorbance units or 0.1 pg. Several spiked samples demonstrated 90 to 100 percent recovery. Interferences: The major interferences in the determination of phos— phorus are arsenic, silicon, and germanium. They are of Specific concern in the selective extraction of the phosphorus heteropoly acid. Therefore, 10 pg standards of phosphorus Spiked with 50 pg of arsenate and silicate were analyzed. Because the absorbance readings of the spiked samples equaled the unspiked standards, clearly, the high levels of arsenate and silicate did not interfere. Only the phosphomolybdic acid complex was selectively extracted. Loss of phosphorus during hydrolysis: Two sets of standards, each con- sisting of O, 2, A, 6, 8, and 10 pg-P samples, were established from the standard working solution. One set was hydrolyzed and neutralized according to the procedure described above while the other was analyzed directly. The absorbances for each set were essentially identical, showing no loss upon hydrolysis. Normality: The normality depends upon the amount of acid and the final volume of the aqueous solution. Sugawara and Kanamori (1961) reported a peak efficiency of the extraction procedure from a O.A to 0.8 N solution. 57 In a similar experiment, as the normality increased, so did the extrac- tion efficiency until an aqueous volume of only 1A ml was reached. The use of a 50 ml volume was a compromise based both on necessity and practicability. To transfer all of the neutralized sample from the boiling flask to the separatory funnel, at least 30 ml was required. The 50 m1 volume was easily measured and resulted in a favorable absorb- ance range for the standard curve. Preservative: Sulfuric acid was used as a preservative in the first year of the study and A0 mg/l mercuric chloride was substituted thereafter. As reported by Annett and D'Itri (1973) sulfuric acid caused a positive error in the determination of total soluble phosphate due to the hydrolsis of other phosphorus compounds. The total soluble phOSphorus levels increased substantially after the acid was added. However, with a mercuric chloride preservative, the soluble phosphate concentrations were stable for at least two weeks. The trends were similar in a study conducted with Lake Erie samples. Contamination: Since the most likely sources of contamination were the various chemical reagents, these were checked daily. The use of Millipore filters introduced another possible source of contamination in the total soluble phOSphorus determination. Therefore, on three occasions five filter pads from three different packages were rinsed with distilled water, and the rinsing water was analyzed for phosphorus. In each instance the results indicated no contamination. 58 APPENDIX II Table A1. Total phosphorus levels (mg/l-P) of water samples collected at 0.5 meters throughout the Lake Erie-Raisin.River sampling area during 1970. May 15 May 27 June 10 June 2A July 7 July 21 August A y 1 Station # \J'I \L‘ CO 0000 OOOOOOOOOOOI—IHHNNN OOOOOOOOOOOOOOOOOOOOOOOOOOO 8F® m.:r0\r-IO\C\IO\HHOO\CDO\L\:NU\NL\-.:THNM OO OOOHOHOHHHOOOONNNHHr—INNN OOOOOOOOOOOOOOOOOOOOOOOOOOO O OOOOOOOOOOOOOOOOH HNNN OOOOOOOOOOOOOOOOOOOOOOOOOOO GOO GOO 000 00000 0000 H seeseeaasssseessaeeaeaaeo 0.10 0.10 CO 0000 O OOHOOr—lr—ir—JO Hr—‘IN 00 6666666666 eeeseasaaasaee ONOF—Lflhm CDO\O\Lr\ .d'l.‘ b—L‘mmd) [\CDFO HOHOOOOBSOOOO‘SOOSBOOOOOOr—{r-lr-l OOOOOOOOOOOOOOOOOOOOOOOOOOO Lr\ :cumazzxomzxozzmmmmmxowbmxomao r-i HHHHHHHHHHHHHHHHHHHHr—lHNNN OOOOOOOOOOOOOOOOOOOOOOOOOOO Jr-iMJKOJCDOONOMHOL‘NHMNJOONCDLAN—If HNHHHHHHNHHNMNHHHHNHNHHHNMN OOOOOOOOOOOOOOOOOOOOOOOOOOO Total phosphorus levels (mg/l-P) of water samples collected at 0.5 meters throughout the Lake Erie-Raisin River sampling area during 1970. Table A1 (cont.) October 10 October 25 November 7 September 15 September 27 September 1 August 18 Station-# HH HH (56 H NO 00 Ln 0 CO 0.11 l O\[\O‘\C\JOCJ\OHHO\®OOML\OO HL‘OOOOHMLR OOOHHHH HOOHHMOO HOOHHOMMN c5c5c3c$c5c>C>c>c>c>c>c>c>c>c>c>c>c>c>c>c>c>c>c>c> OOOO (DCOCDCDCOQL‘CDb—HO OHCD mmmOm OHH OOOOHOOOOHH HHO HOHNN oo'o'o'cSo'o'o'o'o'o'o'o'o'o'o'o'o'o'o'o'o'o'o'o' O\b— b—uxdluxul :rb-b» c~ «Db—t~cnd3a3 nwc~t~ <318<3<3<3<>c> <318<><>c>c>c>c> dfldflfll c3c3c3c>c>c>c>c>c>c>c>c>c>c$c>c>c>c>c>cnc>c5c5c5c$ a SSSS SSSSS SSSSSSSSSSSS C>c>c>c$c5c$c5c5c>c>c>c> c$c3c§c$c3c5c5c3c3c3c>c> HESS-3‘8 HHSQHHH‘HHHBS‘OHHS‘Sccég OOOOOOOOOOOOOOOOOOOOOOOOOO 8910 c>c3 ONfiOOOChOL‘ L‘LflHMHL‘r-lmfimw HCOJOCh HOOHO OHr-IHr-IOHO HH HOM—‘ICU o'o'cSo'o'o'do'o'o'o'o'do'o'o'oo'oo'o'o'o'o'o' OOQDSQfi—SWFJMN [\OJHMHCDHF HCUHH HHHHHH HHHHHHNMN OOOOOOOOOOOOO 000000000 10 2A 2B 20 3A 3B 30 AA AB Ac 5A 5B 5C 6A 613 60 7A 7B 70 8A 813 80 9A 9B 9c Total phosphorus levels (mg/l-P) of water samples collected at 2.5 meters throughout the Lake Erie-Raisin River sampling area during 1970. Table A2- July 21 August h 7 JUly May 1 May 15 May 27 June 10 June 2h Station # 61 (D l‘ NCDF-b-Ln t‘CDFLn [\NONJH: 08088800000 0000 0HHH(\J(\I(\J 000000000000000000000000 000HOH000H0000H 00HHHH mmwomapmmowmbwm wmhxmmgg c3c5CSCSCSCSCSCSCSCSCSCSCSCS(Scic5c>c>c>c>c> CD61) [Vb EFF [\(DCDL‘LR b—NHMLRKOM 0000880008800000 0HHHNNN 000000000000000000000000 Lnln Lr\ b—LflLfl O\O\ CO Lr\L\C\JO\O\r-IN 800 080008008806800HO0HH 000000000000000000000000 CDL‘wg—gb-amHCDCDOL‘CowCDOhr-lmfib—JH 000 0 0HO0H0000HOHHONNN 000000000000000000000000 Hoomm L‘ b—O\CDCD Q35 N 005mm: 00 080000800880800HHH 000000000000000000000000 MMNHNHQJFNOQJOJHHO—fl'lflmwwzf r—IHHHHHHHHHHHHHHHHHHHHHHH 000000000000000000000000 \Olnb-wln HCO O\.:T'HO\_:I‘L\-H «1.330(1) Lr\..:f\0.:1' HHHHH (\JHHHNHNHNHHHHHHNNN 000000000000000000000000 River sampling area during 1970. Total phosphorus levels (mg/lAP) of water samples collected at 2.5 meters throughout the lsin Lake Erie-Ra Table A2 (cont.) September 27 October 10 October 25 November 7 September 15 September 1 August 18 Station-# 62 O\.0CDCDO\O\(D[\(\JO\MC\JMO\c>c>c>c>c>c>c5c3c3c> 0.06 0.07 O 0.10 O 0 CONN HO\000\—d'.:r HHHOH HHH HOHHOHH HHHHH cSo°o'o°o'o'o'o'o'o'o°o'o'o'o’oo 0.11 mmHfi-H830wm NMCDJLACDOOH HHHOH HHOHHHHHOHOH 000000000000000000 NNMJMQMQOJMWOM: HHHHHHHHHHHHHHH 000000000000000 O\HU‘\HC\! Or-Immm (566666 0.07 0.07 0.0 0.3 0-3 0.26 Lf\C\l \D\OU\ 0H NOON o'o'o'o'o'o' aw aw aw 0.28 0% 0.37 MJQNNO HHHMNM 000000 Soluble phosphorus levels (mg/l-P) of water samples collected at 0.5 meters throughout the Lake Erie-Raisin River sampling area during 1970. Table A3. July 7 July 21 August h June 2% May 1 May 15 May 27 June 10 Stationl# 00 00 0 00 00000000 00NC\JH 666666ddddddooddddddodddddd 88886858888888888888888€32fi 666666666666ddddddddddddddd 8688 8 8888688866888688 982 066666666666doodddoddoddddd 886888688888886688888688238 oddddoddddooodd666666660000 00 00 000 000 0 0000 0HHH 0000000000 0000000000000000 wb bbdhmb [\Ln mmmmb [\CDb-LhW—fl' 00§8000000 00 0000088000HHH 000000000000000000000000000 LV ©0f>- O\0H00\O\0m.-:f MMNNOM H—d' 808001-10 OHHHOOHHH HHHHHHSIHH 666666666660ddddddddddddddd HMQDOMCDJHOONHOer-iml‘mOO/W b—HNHH HHOHHOHHHHHHMHHHOOOHH OHNCUH 000000000000000000000000000 .b—II' ling area during 1970. 1ver samp R Soluble phosphorus levels (mg/l-P) of water samples collected at 0.5 meters throughout the 18in Lake Erie-Ra Table A3 (cont.) September 15 September 27 October 10 October 25 November 7 September 1 August 18 Station # 6L 838883888 88888 88288888388 000000000000000000000000000 HCDL‘OOCDNNL‘KOOCD [\F mooobtxoofixom (\100H00000000 00 0 0H0000 Hr-l 000000000000000000000000000 88888888888888m88888 88$ 000000000000000000000000000 88888888888 88 88888 88825 66666666666666 666666666666 [\L‘L‘C00\0\00\O\NHH O\0c>i§c>c3§8<3c>c>c> c>c> C>OJQJOJ c>c>c>c>c>c>c>c>c>c>c>c>c><>c>c>c>c>c>c>c>c>c>c> “8888888888660060 088 O c5c3c5c3c3c3c3c5c5c5c5c>c>c>c>c>c>c>c> 0.18 0.21 0.18 COO 0000 OOr-irC-DIOOOOOO ONNM c>c>c>c5c5c3c3c$c5c>c>c>c>c>c>c>c>c>c>c>c>c>c>c> O\OC\L\-O\ MCDCDOOJOOCDLREQQ come-moxr—I OHOOO HOOr-lr-lr-IOHOO OO Om O c>CSCSCSCSc3c5c5c5c>c>c3c>c>c>c>c>c> GOOMJLRMKOr-IONMHFO (\Jr-ICUO\O\O Or-IHHHr-ir-Ir—lr-IHHHr-{OH HHHMNN OOOOOOOOOOOOOOO OOOOOO I “‘1'. v .D Id - I I u . .11, L I ( ...! n~14‘a\rr(o\ lCFEr-GU Lev-HEP .. ( rrh F \LLr: U. . ..- .. . . .. x \ Tux—Cw USLCERmCSL. d ‘ H ”75,. .m< 0:22. 0.13 0.1h 0.10 0.11 0.11 0.12 0.09 0.12 Total phosphorus levels (mg/l-P) of water samples collected at 0.5 meters throughout the Lake Erie- 0.07 Raisin River sampling area during 1971-2. Station # January 23 February 18 April 16 May 1 May 20 June 17 July 15 July 29 September 2 September 16 Table A5. 67 MO\ mNNNOHOHOOmmOOFmHMn—i HOHOHHHHHHHOHNNNMNNMMM QC OOOOOOOOOOOOOOOOOOO OOmOMCIDmQOOCDmfi'CDJNN—i—d'F-LVQ HHHHHOHOHHOOHNNNMNNN—d’m OOOOOOOOOOOOOOOOOOOOOO OHQOHNONNHHHJOQMJL‘NLRNO OHOOHHHHHHHHHNNNNNNMMJ OOOOOOOOOOOOOOOOOOOOOO Hmmmwmbmamamwmanmomaa: HHHHHHHHNHNOONMNHNNNMJ OOOOOOOOOOOOOOOOOOOOOO m:m0.:r_:r.:r.:r\o\om LANMOv-INL‘QON Hr-lHt—IHHHHr-lr-IH HNNNNNHNMM OOOOOOOOOOOOOOOOOOOOOO mmbommommmomamhmxoomam HOOHHHHHHOHHHOOHHNNNN 000000 00000000000000 OO O OOOr-IOOOu-lr-h—ir-ICUNM OO OOOOOOOOOOOOOOOOOOOOO OO omeOonmmmHooonomozmc—ixomza t-lr-l OOOOHHOHHOI—IOI—IHHHl—Ir—INNN OO OOOOOOOOOOOOOOOOOOOOO r-IOCO mmcu O O NMCDCDF-N (\ICUNOOO OOOOOO mom HHH OHOHHH mmmmmmmmm 000 000000 ooooooooo m Hammoomw H mmmmmmam 6 06060006 we no m5h©®flm03000b®10®3 2 60 OH oooooaaaaaamaaamam a oooooooooooooooooooooooo 0 88868859668888 8‘8 2:58:21 $533 81% 666666666666666666666666666 COOHCDNO\O\ O\L\- U\CDLF\O\L\ NOQMOLRKONO Or-ir-iOr—lOO 0088000008NNHNNHHMM OOOOOOO OOOOOOOOOOOOOOOOOOO b-J‘JJHCDO r-iI-lO\r-IO\OOO\OL\.:2'(\I\OL\\D\OCDC\J r-l OH88HHOHOHHOHNNNNNNMM: O 6666666666666666666666 FIDO CDC) mo¢moc> 0.08 0.0 0.1 0.11 0.11 0.25 0.33 0.29 0.30 0.36 0.33 0.11 0.09 0.26 0.25 0.23 0.28 0.12 0.112 0.10 0.11 0.38 0.26 0.18 0.20 0.1m 0.2M 0.17 0.11 0.28 0.27 0.21 0.33 0.31» 0.31 0.07 0.12 0.21 0.17 0.19 0.31 0.27 0.25 0.07 0.07 0.111 0.13 0.111 0.214 0.22 0.21 7 7 Total phosphorus levels (mg/l-P) of water samples collected at 2.5 meters throughout the Lake Erie- Raisin River sampling area during 1971-2. Table A6. Station-# January 23 February 18 April 16 May 1 May 20 June 17 July 15 July 29 September 2 September 16 2B 20 3B 30 MA MB hc 5A 5B SC 6A 6B 6C 8A 8B 80 9A 913 90 Total phosphorus levels (mg/l-P) of water samples collected at 2.5 meters throughout the Lake Erie-Raisin River sampling area during 1971-2. Table A6 (cont.) Station # October 2 October 15 October 30 November 12 December 2 December 19 January 11 February 18 ‘8‘8‘8 666 91:13 000 6882688 66666666 519139151? 511 M3 r—lr-lI-l 1B 10 0.07 00 O\COL\t-i OOOr-i I.‘ H 666666 0.1 0.0 0.10 0.12 0.10 0.10 (DCD CO OO O H 0.111 O\H(\J Or-lu-ir-it-lOr-lr-lt—IMI—IN '666666666666 LnO\U\ OOO OOOOOOOOOOOO L\-O\CDCOO\OO OOOOOO c>c>c>c>c>c>c3c3c3c3c3c$ r-lr-JOOO\OL\r-l HHHHOHCOr-l OOOOOOOOOOOO 2B 2C 3A BB 3C M 1+8 1+0 70 HNO\ODr-i 00.33:? (\JCUCU 666 0].:1' O\r—4 L‘L‘b—Chb-QNN OOOO O\c> OC\[\ @0008 r—IOO OOu—l c3c$c5c5c5c>c5c5 [\O\@L\Lr\ OOOOO (YMCDr-i O\C\JO‘L\- Or—lOOr-ir-lOr—IOO OOOOOOOOOO Lr\COCDO\L\O\ONCD OOOOOOHOO 0000000000 [‘88 (I)U\L{\®OL\ OO OOOOHO c3c5c$C5c5c> 35380858 666666 868 c$c$c5 00000000000 0 \OMN HMHNM HHr—I NI-INNN 000000 0 gfgmom—Hn Ezm OOHr—{r-lr—{r-l OOOOOOOOO OSSH c5c5c>c5c$c>c5c>c> [symmooomHmNJonxoo r-ngmbmm OOOOOHOHOOHOOO r-l Or-lu-ir-l OOOOOOOOOOOOOOOOOOOOO 60 0.2 0.2 0.2 (1300] r-iNCU OO c3c3c$c>c5c> 7A 7B 70 8A 8B 80 9A 9B 90 Soluble phosphorus levels (mg/l-P) of water samples collected at 0.5 meters throughout Table A7 (cont.) ing 1971-2. ea dur 1ng ar 1ver sampl R lsin the Lake Erie-Ra Station # October 2 October 15 October 30 November 12 December 2 December 19 January 11 February 18 888 666 888888 888888 666666 888888 666666 0.12 OFNNNHO C>C>C>C>C>F1C> —~] TO 82 b~t~co c>c>r4 666666666666666666 “HMO/1.5.3.21“ 000 00 66666666666666 88888 8 88888 c>c>c$ 6 sseeessesaeesees e (SCSCSc5c5c>c>c5c>c>c>c5c5c$c$c5 asamagewmt O LAO 000 03—! b—q>b— OOO 91:1 6 b-uxc>U\q>b—C>b«o rir1r4r4r4r4éffn(n C>C>C>C>C>C>C>C>C> 03d) FkDCD b—mcu rifiririrlriflHN C>C>C>C>C>c>c>c> b—qu—uxuxu3r4uxdw wiriririririolojoj C>c>c>c>c>c>c>c>c> \ot~\0\o\o\ocncn Fiririririririfll C>C>C>C>C>c>c>c> b-t~;¢Lnt~03 gr rir1r+r+r+ri .H C>C>C>C>C>C> C) b— Ch Ch;rcnr4 C)%3€SCD%§C>F4CDF4 666666666 O\O\r-IO\E‘- b—Hm OOHOO Ol-ll-i 666666666 OMLflLflNNL‘ r-ir—lr-‘lt-iCUNN 666666666666666666666666666 fififififiR §m0 b—b—t~ 1971-2. River sampling area during Soluble phosphorus levels (mg/léP) of water samples collected at 2.5 meters throughout the Lake Erie- lsin Ra Table A8. September 16 Station # January 23 February 18 April 16 May 1 May 20 JUne 17 July 15 July 29 September 2 HONO®O\ODO\O\8H O\ N (\l O\O\ COCDCDCDqDChb-O O\O\r-1CD O\O\c> II\c3 [\O O\CDL\80 U\Lr\L\O NEG O\OML\- O H OOOr-i r-IOO Or—ir-lt-l O 666666666666666666666 boom Lr\L{\L\-COO\ [Fm b- OOHOOOOO OO O O c>c3c3c3c3c3c3c3c3c3c3c> 0.17 1 1 0.2h 0.17 0.19 000 O O (\lr-I OOOOOOOI—it-IOc-ir-ll-i 666666666666666666666666 see 538 c>c3c> c>c>c> Soluble phosphorus levels (mg/l-P) of water samples collected at 2.5 meters throughout the Lake Erie-Raisin River sampling area during 1971-2. Table A8 (cont.) Station # October 2 October 15 October 30 November 12 December 2 December 19 January 11 February 18 mag MN L{\U'\\OC\O(ID O OO r—ir—lt—IMJM GOO 000 000000 agngm \ONL‘MN O OO r—lHr—imm 000000 000 O [‘5 Ln: [\L‘N Ln\OLnr—l.:rm 00 CO 000 r—ir—ir—INNN 000 000000 000000 01 00805-0 r—l HHI—‘ICUm 0 000 O bgoogflflbcgooooom—iboo [\wame U\ O 0 H00 OOOHOOOHOOHHH (\J OOOOOOOOOOOOOOOOOOOOO 0 “88888888888 o'o'cSo'o'o'o'o'o'o'o'o' MMJMLRLA .80 0 000000 00 O 88 88888888888 888 8883 OOOOOOOOOOOOOOOOOOOOOO HOOOOOO O {:2 OOOOr—lt-lr-lm OOOOOOOOOOOOOOOOOOOOOO 1A 1B 1 2A 2B 2C 3A O