1* LIBRARY 1 University lllLl/ll/Ifl/fl llll/llllllll/II/l/lI!!!I/I/I/NII/II/llllllll 93 10388 8445 meats This is to certify that the thesis entitled THE EFFECTS OF DREDGING AND PISCICIDE APPLICATION ON THE AESTHETIC CHARACTER OF AN ARTIFICIAL POND SYSTEM presented by G. DOUGLAS PULLMAN has been accepted towards fulfillment of the requirements for M- S - . Fisheries and degree 1n Wildlife @E7mbr’ljra/ Major professor Date 3/20/1980 0—7639 a ‘ ! pl._ .14 [Ia-“\\\ A ’ . ~ Warm" FNS: 25¢perdeypertten RETUMIIKS LIBRARY MTERIALS: Place in book return to remove charge from circulation record THE EFFECTS OF DREDGING AND PISCICIDE APPLI CATIm ON THE AESTHETIC CHARACTER OF AN ARTIFICIAL POND SYSTEM BY G. Douglas Pullman 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 1980 ABSTRACT THE EFFECTS OF DREDGING AND PISCICIDE APPLICATION ON THE AESTHETIC CHARACTER OF AN ARTIFICIAL POND SYSTEM BY G. Douglas Pullman The Dow Gardens artificial pond and stream system was characterized by excessive growths of aquatic plants, poor water transparency, an overabundance of fish and a conspi- cuous absence of zooplankton. A portion of this system was deepened by dredging to remove obnoxious growths of aquatic macrophytes and loose organic sediments. Fish were partial- ly eliminated from the pond system with a rotenone—based piscicide. The excessive predatory pressure exerted on the zooplankton populations by the overabundance of fish was diminished following the piscicide application, as evidenced by a modest recovery of zooplankton pOpulations. Data is given that shows that the overall effect of both management techniques, dredging and piscicide applica- ' tion, was a reduction in the primary productivity in the system and the subsequent improvement of its aesthetic appeal. to my wife and parents ii ACKNOWLEDGEMENTS I sincerely thank Dr. Clarence D. McNabb, my major professor, for directing me through this project and for his invaluable assistance in the preparation of this manu- script. I thank Dr. Charles Liston and Dr. Peter Murphy for serving on my graduate committee and for reviewing this manuscript. I thank Doug Chapman, Director of Dow Gardens, for his observations, willingness to assist in the collecting of information, and his-numerous suggestions. I am grateful for the assistance given me by the staff and students of the Limnological Research Laboratory and especially to John Newsted and Maureen Wilson for their help and for the conversations we had that shortened the distance between Lansing and Midland. Special thanks to Ted R. Batterson for his critical review of this manuscript, his example, encouragement and friendship. Finally, I thank Janet, my wife, for her unfailing support and understanding. This study was funded by a grant from the Herbert H. and Grace A. Dow Foundation, Midland, MI awarded to the Limnological Reserach Laboratory, Department of Fisheries iii and Wildlife, Michigan State University. Additional sup- port was provided by the Michigan Agricultural Experiment Station under project No. 959, Department of Fisheries and Wildlife, Michigan State UniverSity. iv TABLE OF CONTENTS Page LIST OF TABLES................................... vi LIST OF FIGURES..................................viii INTRODUCTION..................................... 1 METHODS.............................. ..... ....... 5 RESULTS AND DISCUSSION.............. .......... ... 10 CONCLUSIONS........ ..... . ..... ....... ........ .... 36 LITERATURE CITED.......... ....... .... ..... ....... 39 APPENDIX..... ..... . ........... .... ............... 44 Table LIST OF TABLES Page Aspects of the hydrologic budget of the Dow Gardens pond and stream system for the interval May 1, 1978 to October 31, 1978.00.00.0000000000......OOCOOO.........00011 Aspects of the hydrologic budget of the Dow Gardens pond and stream system for the interval May 1, 1979 to September 30, 1979.00.00.00000000000.000....0.0.0.00000000012 Aspects of the nutrient budget of the Dow Gardens pond and stream system for the in- terval May 1, 1978 to October 31, 1978.......l4 Aspects of the nutrient budget of the Dow Gardens pond and stream system for the in- terval May 1, 1979 to September 30, 1979.....16 Inorganic nitrogen concentrations in sur- face samples from the Dow Gardens pond and stream system during 1978 and 1979...........19 Phosphorus concentrations in surface sam- ples from the Dow Gardens pond and stream system during 1978 and 1979..................20 An analysis of the ratio of total inorganic nitrogen to totallphosphorus in the Dow Gar- dens pond and stream system during 1978 and 1979.00.00.00000000000O.......OOOOOOOCOOOOOOOZZ Mean surface pH, alkalinity, and free C02 in the Dow Gardens pond and stream system during 1978 and 1979.O.0.0.0.000000000000000024 Morphometric features of the Dow Gardens pond and stream system, l978............ ..... 44 Morphometric features of the Dow Gardens pond and stream system, 1979 ..... ............45 Mean surface water temperature, dissolved oxygen concentration, and percent oxygen saturation in the Dow Gardens pond and stream system during 1978............ ..... ...46 vi Table Page A-4 Mean surface water temperature, dis- solved oxygen concentration, and per- cent oxygen saturation in the Dow Gar- dens pond and stream system during 1979 ..... 47 A-S Water temperature, dissolved oxygen concentration, and percent saturation at 3.0 m depth in Area 12 of the Dow Gardens pond and stream system during 1979.00.00.00000000000000.000.000.0000. ..... 48 A-6 pH, alkalinity, and free C0 concentra- tions at 3.0 m depth in Area 12 of the Dow Gardens pond and stream system during 1979.................................49 A-7 Inorganic nitrogen concentrations at 2.5 m depth in Area 12 of the Dow Gardens pond and stream system during l979...............5O A-8 Phosphorus concentrations at 2.5 m depth in Area 12 of the Dow Gardens pond and stream system during 1979.............. ..... 51 A-9 Some events that were relevant to or that had a significant impact on the water quality of the Dow Gardens pond and stream system during 1979...............52 A-10 ZOOplankton concentrations in surface samples taken during 1979 from the Dow Gardens pond and stream system..............53 A-ll Zooplankton concentrations in samples taken from Area 12, at 2.5 m, in the Dow Gardens pond and stream system during 1979........................... ...... 55 vii LIST OF FIGURES Figures Page 1 The Dow Gardens pond and stream system with the subdivisions that are used to identify the various Areas within the system......................................2 2 A generalized diagram of the distribution of the principal macrophyte species and macrophyte species associations in the Dow Gardens pond and stream system during the early part of the 1978 growing season..26 3 A generalized diagram of the distribution of the principal macrophyte species and macrophyte species associations in the Dow Gardens pond and stream system during the later part of the 1978 growing season..27 4 A generalized diagram of the distribution of the principal macrophyte species and macrophyte species associations in the Dow Gardens pond and stream system early in the 1979 growing season.................29 S A generalized diagram of the distribution of the principal macrophyte species and macrophyte species associations in the Dow Gardens pond and stream system in the later part of the 1979 growing season......30 6 Locations of the loose organic sediments in the Dow Gardens pond and stream system during 1978.......OOOOIOOOOOOO00.00.000.00032 7 Locations of the loose organic sediments in the Dow Gardens pond and stream system during 1979.00.00.00.......OOOOOOOOO0.0.0.033 viii INTRODUCTION Dow Gardens is an ornamental garden located in Midland, Michigan. Development of the Gardens was begun in 1899 and it was opened to the public in 1930. A major reconstruction of the Gardens was begun in 1973 with landscape modification, introduction of new plant material, and the formation of ex- panded educational objectives. An artificial pond and stream system courses through the Gardens. It was constructed to enhance the aesthetic appeal and provide irrigation water for the Gardens. A scaled diagram of the pond and stream system is shown in Figure 1. The water level of the system was maintained at the crest of the spillway, zero stage, by replacement water influent from two municipal input sources. The total area of the system at zero stages was 15,082 m2. The average depth and volume during 1978 was 0.82 m and 12,709 m3 respectively. Areas 12 and 13 (cf. Figure 1) were deepended by dredging during the winter of 1978-1979. The mean depth and volume of the system was thereby in- creased to 1.02 m and 17,879 m3. The Dow Gardens pond system was connected end-to-end by a pump that could circulate the entire volume of the system at a rate greater than once every four days. Water was pumped from Area 12 to a waterfall at the head of a small cobble-filled stream channel through which it moved rapidly to Area 2. Water movement was barely perceptable Figure l. The Dow Gardens pond and stream system with the subdivisions that are used to identify the various Areas within the system. N Spillway + Orchard ln ut at“ p l3 l2 Circulating Wate rfdl t 4 \ Ornamental \ Waterfall I Input L J J O IOOln * Sampling station Figure l. along the main course of circulation. The system.contained several quiescent areas where water movement was not seen. These were Areas 1,2,4,6,11,12 and 13 (cf. Figure 1). The pond and stream system.contained overabundant growths of aquatic macrophytes and filamentous algae. It was also characterized by poor water clarity. These con- ditions were judged to be detrimental to the overall aesthe- tic and educational goals of the Gardens. A study was ini- tiated in April 1978 to recommend and, when possible, imple- ment freshwater management strategies that would rectify this situation. The intrinsic goals of this study were to 1) reduce biogenically-induced turbidity, 2) eradicate any biological pest species that were present in the system that were not consistent with the overall goals of the Gardens, 3) introduce new aquatic plant species that would be of educational and cosmetic interest, and 4) provide in- formation to the public on artificial pond management. This paper addresses only the first of these goals, as listed above. Information was compiled in the first year of this study to fonm a basis for the recommendation of aestheti- cally corrective management strategies for the pond and stream system. Because water from.the pond system was used for irrigation purposes, non-herbicidal management strategies were given preference. Based on these recommen- dations, dreding and biomanipulative piscicide application techniques were implemented during the winter of 1978- 1979. The efficacy of these treatments was monitored in the second year of this study. Particular emphasis was placed on the potential for the limitation of pri- mary production and nutrient cycling within the system as a result of these techniques. METHODS Hydrologic and nutrient budgets were constructed to identify the major sources of water and mineral plant nu- trient inputs to the system. These data were used in part, as‘ a basis for the management of the productivity in the Gardens ponds. Precipitation data were provided by Dow EnVironmental Services, Dow Chemical Company, Inc. , Midland, MI. Evaporation was estimated by isohyetal diagraming after a method for precipitation by Chow (1964'). Raw data for the calculation of evaporation were found in Climatologicaz Data, Vol. 93., Nos. 5 through 10 inclusive, National Oceanogra- phic and Atmospheric Administration, Environmental Data and Information Service, National Climatic Center, Asheville, NC. The water volume influent to the pond and stream system . via the orchard input was calculated from meter readings pro- vided by the City of Midland municipal water treatment plant. Water influent from the waterfall input was calculated by measuring its discharge rate and multiplying this value by its. estimated operating time. The area of the pond and stream system was estimated by planimetry based on contour maps made from aerial photo- graphs of Dow Gardens. Depth estimates were made in the field with a digital depth sounder (Heathkit, model MI-lOl) . These data were used to approximate the depth contours of the system which, in turn, were used to estimate the volume with planimetry . Water samples were taken periodically with a one liter polyethylene Kemmerer sampling device from the sampling stations shown in Figure 1. These samples were placed on ice and transported back to the laboratory for analysis. The following analyses were determined colorimetri- cally using a Varian Superscan 3 spectrophotometer. The methodology used is found in Standard Methods for the Exmrination of Water and Wastewater (APHA, 1975) . Water used for the deter- mination of total dissolved phOSphorus was passed through pre-ignited, acid washed Reeve Angel 984H glass fiber filters with a pore size of approximately 0.5 um. Total phosphorus and total dissolved phosphorus were determined by the ascor- bic acid single reagent method following an ammonium persul- fate acid digestion. Nitrite-nitrate nitrogen was determined from samples that were passed through cadmium reduction col- umns. Kjeldahl nitrogen was determined from digested samples after distillation and using Nessler's reagent. Ammonia was determined with Nessler's reagent after distillation. Particulate phosphorus concentrations were calculated as the difference between the total and total dissolved phosphorus fractions. Total inorganic nitrogen was calculated as the sum of nitrite-nitrate nitrogen and ammonia nitrogen. Ni- trogen and phosphorus concentrations and discharge measure- ments were used to calculate data in the nutrient budget tables. Total phosphorus and nitrite-nitrate nitrogen con- centrations in water from the orchard and waterfall inputs were furnished by the City of Midland municipal water treat- ment plant. Total atmospheric nitrogen and phosphorus in- puts were estimated from Chapin and Uttormark (1973). During 1979 atmospheric nitrogen and phosphorus collectors were set in triplicate near Area 10. Six liters of deionized, dis- tilled water were added to each of the three acid-washed lexan containers with a combined surface area of 0.78 m2. This water was allowed to stand in the covered containers for at least 24 hours to permit nutrient exchange between the water and the container walls. One liter of water was removed from each container just prior to their placement in the field. The three liters were composited into a sin- gle ”initial" sample that was taken to the laboratory for routine nutrient analysis. The fallout collectors were re- trieved after two weeks. The volume of the three containers was measured. Water was withdrawn from each container and composited into a "final" sample. Nutrient input to the 2 was calculated from a knowledge of the combined system per m total surface and total final water volume in the containers and the nutrient concentration in the fallout water as de- termined by the differnce between the "initial" and the "final" composite samples. pH was determined with a Beckman Expandomatic pH meter using a combination electrode with a silver/silver chloride reference element. It was standardized against pH 7 and 10 standard buffer solutions. This instrument was calibrated before each series of measurements. Total alkalinity was measured by the dual pH end-point acid titration method commonly used in limnological investigation (APHA, 1975). Free carbon dioxide concentrations were calculated from pH, temperature and carbonate-bicarbonate alkalinity data using the equations of Harvey (1957) and Park (1969). Dissolved oxygen, temperature, and percent saturation of oxygen data are presented in the appendix. Dissolved oxygen and temper- ature were measured in situ with a YSI (Yellow Springs In- strument Company, Yellow Springs, Ohio) model 54A oxygen meter with a pressure-compensated Clark-type polargraphic 'oxygen sensor with submersible stirrer. An integral ther- mistor permitted temperature readout and corrected for temperature-dependent membrane diffusion effects and for differential oxygen solubility with temperature. During January and February of 1979 dissolved oxygen was measured by the azide modification of the Winkler method (APHA, 1975). Percent dissolved oxygen saturation was determined from the tables and methods of Truesdale, Downing, and Louden (1949) and Mortimer (1956). Visual observations were used as a basis for the mapping of macrophytic distributions in the pond and stream system. Fish populations were also monitored by visual observations. ZoOplankton samples were collected in 1978 with a Student plankton net, towed just below the surface of the water. These samples were preserved in 70% ethanol. Mi- croscopic examination of these samples was performed to identify the dominant species. Quantification of samples taken in 1979 Was made possible by the use of a Schindler- Patalas plankton trap made from plexiglass to reduce avoid- ance by the zooplankton. It had a 50 liter capacity and was equipped with a No. 20 net with apertures of 0.076 mm. In the laboratory, the contents of each sample were diluted to between 80 and 150 ml, depending on the density of the animals. These known volumes were then randomized by gentle mixing with a magnetic stirrer. A subsample of 2-6 ml was removed with a wide-mouthed Hensen-Stempel pipette and placed in a chambered counting cell (Gannon, 1971). The entire cell was counted using magnifications of 14x to 60x (Yusoff, 1979). As a pond management technique, a rotenone-based piscicide was applied to the pond and stream system in February 1979. The piscicide was infused through the ice and paddles were used for dispersion. In November 1979 rotenone application was repeated. This time it was applied from a small boat and.mixing was accomplished by the turbulence created by the outboard boat motor. RESULTS AND DISCUSSION This long-term goal of this study was to recommend and, when possible, implement freshwater management techniques that might improve the aesthetic appeal of the Dow Gardens pond and stream system. Overabundant plant growth was the chief concern and was symptomatic of a nutrient-rich condi- tion. The nutrient dependence of primary productivity in lakes has been well-documented in the literature (Bachman and Jones, 1974; Hasler, 1947; Megard, 1972; Smith, 1979). Descriptive data were compiled as a basis for the recommen- dation of management techniques that would reduce nutrient concentrations in the pond and stream.system.and alleviate the symptoms of this condition. Nutrient Budgets Aspects of the hydrologic budget of the Dow Gardens pond and stream system were calculated for these portions of the growing seasons during which sampling for mineral plants nutrients was done. The results are given in Tables 1 and 2 for portions 1978 and 1979 respectively. Evaporation exceeded precipitation during both same pling periods, resulting in water deficits in the pond system of 7,238m3 in 1978 and 2,735 m; in 1979. water was also lost by withdrawal for irrigation. There was no water dis- charged over the retaining dam.during these periods (cf. Figure 1). water losses from the pond and stream system were replaced from.two sources such that zero stage was maintained. 11 Table l. Aspects of the hydrologic budget of the Dow Gardens pond and stream system for the inter- val May 1, 1978 to October 31, 1978. Inputs (+), Outputs (-), Source (m3) Total Precipitation1 + 882 Water entering via the orchard +19725 input2 Water entering via the waterfall nil input2 Evaporation3 - 8120 Irrigation and other losses4 -12487 Precipitation from Dow Environmental Services. See Figure 1. Evaporation by a modification of isohyetal diagraming and estimated from Climatological Data, Vol. 93, Nos. 5 through 10 inclusive, National Oceanographic and At- mospheric Administration, Environmental Data and Information Service, National Climatic Center, Ashville, N.C. 28801. This value is the sum of the input and output volumes based on the assumption that the pond and stream sys- tem was maintained at a constant elevation, the height of the dam, by precipitation and water entering the system via the orchard input. 12 Table 2. Aspects of the hydrologic budget of the Dow Gardens pond and stream system for the inter- val May 1, 1979 to September 30, 1979. Inputs(+), Outputs (-): Source (m3) Total Precipitation1 + 4260 Water entering via the orchard +14992 input2 Water enterin via the waterfall +11832 input 2: Evaporation4 - 6995 Irrigation and other losses -24089 1. Precipitation from Dow Environmental Services. 2. See Figure l. 3. Based on an input rate of 2.69 1 sec.‘1 and assuming that the input was operating for an average of 8 hrs. day-1 for 153 days. 4. Data from the U.S.D.A. Weather Service, Stephen P. Nesbitt Bldg., Michigan State University, E. Lansing, MI 48824. 5. This value is the sum of the input and output volumes based on the assumption that the pond and stream sys- tem was maintained at a constant elevation, the height of the dam, by precipitation and water entering the system via the orchard and waterfall inputs. The orchard input (cf. Figure l and Table 1) Was the principal source of replacement water during both years of this study. It contributed 96% of the total known water input in 1978 and 48% in 1979. Water was supplied to the orchard input through an aquaduct that originated in Sagi- naw Bay, Lake Huron. Water was also influent from an orna- mental waterfall located on the west side of the Gardens property and entered the pond and stream system in Area 5 (cf. Figure 1). This input was constructed in 1978 and operated only intermittently during that year. As a result, the total waterfall input volume was small and unmeasured. During 1979, however, the waterfall input contributed 38% of the known water input to the pond and stream system. It was supplied with water from the municipal water distribu- tion system of the City of Midland. The 1978 and 1979 nutrient budgets for the pond and stream system appear in Tables 3 and 4 respectively. The mean rate of input and total seasonal kilogram contribution are given for each of the sources described in these tables. The orchard input was the greatest source of total phosphor- us in 1978, and the waterfall input contributed the greatest amount in 1979. Polyphosphates are often added to municipal water supplies to prevent the accumulation of deposits in transport conduits (Hem, 1970). This would explain the re— latively high concentrations of phosphorus in the replace- ment water influent from the waterfall input. 14 Table 3. Aspects of the nutrient budget of the Dow Gardens pond and stream system for the interval May 1, 1978 to October 31, 1978. Mean Rate1 Nutrient of Input Accrual (+) or Export , Losses (-) Source Form (gm day'l) (kg) Atmospheric Total Phosphorus 1.653 + 0.304 Inputz Total Nitrogen 95.037 +17.4s7 Total Inorganic 53.717 + 9.884 Nitrogen Orchard Total Phosphorus 10.707 + 1.970 Input3v4 Nitrite + Nitrate 53.537 + 9.860 Nitrogen Waterfalls Total Phosphorus nil nil Input3:5 Nitrite + Nitrate nil nil Nitrogen Total Known Total Phosphorus 12.360 + 2.274 Inputs6 Nutrient Losses Total Phosphorus . 5.166 - 0.950 by Irrigation Nitrite + Nitrate 2.228 - 0.410 and Other Nitrogen Water Losses Nutrient Losses Total Phosphorus 7.196 - 1.324 in the System7 1. Mean Rate is calculated as the total nutrient input in grams divided by the number of days in the described interval. 2. Estimated from Chapin, J.D. and P.D. Uttormark. 1973. Atmospheric contributions of nitrogen and phosphorus. Tech. Rep. 73-2, Water Resources Ctr., Univ. Wis., Madison. 35pp. Nitrogen data from Madison, Wisconsin and Total P taken from middle of range proposed by Chapin and Uttormark and confirmed in our studies at Lake Lansing, Ingham Co., Michigan. 15 Table, 3 (cont' d.) 3. See Figure l. 4. These values are based on data provided by the water treatment plant of the City of Midland, Michigan. 5. These values are based on mean nitrogen concentrations from samples taken 7-31-78, 8-28-78, and 9-11-78, and mean phosphorus concentrations from samples taken 7-18-78, 7-31-78, 8-28-78, 9-11-78, 9-25-78 and 10-9-78. 6. Atmospheric Input + Orchard Input + Waterfalls Input. 7. Nutrient losses other than those that can be accounted for contained in known water losses from the system. 16 Table 4. Aspects of the nutrient budget of the Dow Gardens pond and stream system for the interval May 1, 1979 to September 30, 1979. Mean Rate Nutrient of Input Accrual (+) or Export Losses (-) Source Form (gm day-1) (kg) Atmospheric Total Phosphorus 13.634 + 2.086 Inputz Total Nitrogen 146.111 +22.355 Nitrite + Nitrate 6.176 + 0.945 Nitrogen Kjeldahl Nitrogen 141.882 +21.708 Orchard Total Phosphorus 13.719 + 2.099 Input3:4 Nitrite + Nitrate 140.118 +21.438 Nitrogen Waterfalls Total Phosphorus 50.268 + 7.691 Input3r4 Nitrite + Nitrate 35.059 +13.014 Total Kngwn Total Phosphorus 77.621 +11.876 Inputs Nitrite + Nitrate 231.353 +35.397 Nitrogen Nutrient Losses Total Phosphorus 8.784 - 1.344 by Irrigation Nitrite + Nitrate 3.719 - 0.569 and Other Nitrogen Water Losses Nutrient Losses Total Phosphorus 74.529 -11.403 in the System5 Nitrite + Nitrate 230.092 -35.204 Nitrogen 1. Mean Rate is calculated as the total nutrient input in grams divided by the number of days in the described interval. 2. These values were determined from samples taken from tri- plicate atmospheric fallout collectors with a total sur- face area of 0.78 ml placed near the orchard input (see Figure 2). 3. See Figure 1. 4. These values are based on data provided by the water treatment plant of the City of Midland, Michigan. 17 Table 4 (cont'd.) 5. Atmospheric Input + Orchard Input + Waterfalls Input. 6. Nutrient losses other than those that can be accounted for contained in known water losses from the system. 18 The orchard input contributed more nitrogen to the system than did the waterfall input during both the 1978 and 1979 nutrient sampling periods. Atmospheric and water- shed inputs, however, were probably the main sources of nitrogen contribution to the system. The land surrounding the Dow Gardens pond and stream system was a diffuse source of inorganic nutrients. These enter in runoff water following rain showers or irrigation, in seepage as leachates from soil, or as grass clippings and deciduous leaf litter. Leaf litter leachates and the subsequent contributions of nutrients from the microbial decomposition of this litter are often important sources of nitrogen in aquatic systems (Boling, 1975; Cumins et al., 1972). The leaf litter that carpeted much ofithe bottom was probably a significant source of nitrogen to the pond system. The principal conduit through which phosphorus and nitrogen were exported from the pond and stream system was through the removal of water for irrigation. It is note- worthy that this practice contributed to the available mineral nutrient pool of the terrestrial portions of the Gardens. The phosphorus and nitrogen that could not be account- ed for in the seasonal input or export volumes, and that were in excess of the amounts that were estimated to be contained in the water of the system (cf. Tables 5 and 6), were assumed to be lost to sinks within the system. These 19 Table 5. Inorganic nitrogen concentrations in surface samples from the Dow Gardens pond and stream system during 1978 and 1979. Total Nitrite + Inorganic Nitrate Ammonia Nitrogen Date (mg N 1‘1) (mg N 1’1) (mg N.1“1) 7-31-78 0.049 0.108 0.359 8-14-78 0.049 0.047 0.083 8-28-78 0.031 0.515 0.546 9-11-78 0.030 0.010 0.043 10-09-78 0.220 10-23-78 0.022 0.495 0.517 4-23-79 0.089 0.020 0.109 5-07-79 0.133 0.018 0.151 5-21—79 0.026 0.048 0.074 6-18-79 0.005 0.000 0.005 7-02-79 0.022 0.070 0.092 7-16-79 0.018 0.110 0.128 7-30-79 0.010 0.156 0.166 8-13-79 0.000 0.124 0.124 8-27-79 0.000 0.118 0.118 9-17-79 0.000 0.098 0.098 1. Concentrations for dates 7-31-78 through 6-18-79 inclusive are means calculated from concentration values determined for each of the four sampling stations identified in Figure 1. Concentrations for the remaining sampling dates were determined from a single sample composited in the field from samples taken from each of the same four sampling stations. 20 Table 6. Phosphorus concentrations in surface samples from the Dow Gardens pond and stream system during 1973 and 1979.1 Total Particulate Dissolved Total Phosphorus Phosphorus Phosphorus Date (mg P 1'1) (mg P 1'1) (mg P 1'1) 6-06-78 0.036 0.014 0.050 7-05-78 0.039 0.017 0.056 7-31-78 0.068 0.019 0.081 8-28-78 0.079 0.025 0.105 9-11-78 0.069 0.000 0.069 9-25-78 0.073 0.016 0.089 10-09-78 0.066 0.014 0.080 10-23-78 0.083 0.012 0.095 4-23-79 0.033 0.018 0.051 5-07-79 0.019 0.017 0.036 5-21-79 0.036 0.013 0.049 6-18-79 0.011 0.022 0.033 7-02-79 0.023 0.027 0.050 7-16-79 0.042 0.028 0.070 7-30-79 0.042 0.029 0.071 8-13-79 0.033 0.028 0.061 8-27-79 0.078 0.011 0.089 9-17-79 0.022 0.017 0.039 1. Concentrations for dates 7-31-78 through 6-18-79 inclusive are means calculated from concentration values determined for each of the four sampling stations indentified in Figure 1. Concentrations for the remaining sampling dates were determined from a single sample composited in the field from samples taken from each of the same four sampling stations. 21 nutrients were presumably incorporated into the macrophyte- epiphyte community (Mickle and Wetzel, 1979; Wetzel and Rough, 1973), adsorbed to the sediments (Harter, 1968; 1979; Rosenfeld, 1979; Shulka et al., 1971; and Williams et aL” 1971) or cycled between these two components of the system (Bristow, 1974; McRoy, 1972; Wium-Anderson, 1971). Nutrient Limitation Phosphorus and nitrogen concentrations in the surfi- cial water of the Dow Gardens pond and stream.system were determined periodically during 1978 and 1979. These data appear in Tables 5 and 6. Concentrations of the inorganic forms of these elements were two to three times higher than the levels generally thought to limit aesthetically unpleas- ing growths of aquatic plants (Sawyer, 1952; 1954). Phosphorus, nitrogen, and carbon are usually the three nutritional elements required by aquatic photosynthe- tic primary producers that may be in short supply from time to time, relative to their respective concentrations. The ratios of abundance of phosphorus and nitrogen in the pond and stream system, with regard to the relative requirements of aquatic plants, appear in Table 7. Assuming that no other element was lacking, this exercise revealed that ni- trogen concentrations were limiting to the growth of aquatic plants, relative to phosphorus. The concentrations of free carbon dioxide (sum of the equilibrium concentrations of C02 gas and carbonic acid) in Table 7. An analysis of the ratio of total inorganic nitro- gen to total phosphorus in the Dow Gardens pond and stream system during 1978 and 1979. Deviation Percent from Excess Observed TINzTP of Phosphorus2 Date TINzTP 16:1 (%) 7-31-79 4.43 -11.57 361 8-28-78 5.31 -10.69 308 9-11-78 0.62 -15.38 257 10-23-78 5.48 -10.52 249 4-23-79 2.14 -13.86 749 5-07-79 4.19 -11.81 381 5-21-79 1.51 -l4.49 1059 6-18-79 0.15 -15.85 10560 7-02-79 1.84 -l4.l6 870 7-16-79 1.83 -14.17 875 7-30-79 2.34 -13.66 684 8-13-79 2.03 -13.97 787 8-27-79 1.33 -14.67 1207 9-17-79 2.51 -13.49 637 1. Based on an assumed plant and algae nitrogen-phosphorus requirement as in King (1972) and Fuhs et aZ.(1972) and calculated as: Observed TINzTP - 16 = Deviation from TIN :TP of 16 . 2. The percentage of total phosphorus in the system found in excess of the hypothetical amount that would be re- quired to fix all total inorganic nitrogen found in the system. 23 the pond system were calculated. These data are reported in Table 8 and suggest that carbon dioxide may have occa- sionally been limiting to some of the photosynthetic organ- isms in the ponds during 1978. When free carbon dioxide concentrations are low (7.5 umole C02 1'1 or less), blue- green algae are thought to have a competitive advantage over other algal groups due to their greater affinity for carbon (King, 1972; Shapiro, 1973). Microscopic examina- tion of phytoplankton samples revealed the presence of one such alga, Anabaena sp. Obnoxious blue-green algal scums did not develop, however, on the ponds in 1978. At no time during 1979 were carbon dioxide concentrations so low as to impose limitations on the photosynthetic primary pro- ducers. The calculations of nitrogen-phosphorus ratios and the concentrations of free carbon dioxide in the system in- dicate that nitrogen was the principal nutrient element limiting to the potential for greater pirmary production and further degradation of the aesthetic character of the pond and stream system. Comparisons of 1978 and 1979 Water Qualities The mean phosphorus and nitrogen concentrations and the pH values determined for each sampling date were weight- ed arithmetically by the number of days between that date and the next sampling date. These weighted means were averaged over equivalent date-periods (ie. 6-1-78 to 7-31-78 and 6-1-79 to 7-31-79) for the comparison of 1978 and 1979 24 Table 8. Mean surface pH, alkalinity, and free CO in the Dow Gardens pond and stream system during 1978 and 1979.1 Alkalinity Free CO2 Date pH (mg Caco3 1'1) (umoles co2 1'1) 7-05-79 9.2 103 2.8 7-18-78 8.4 93 17.6 7-25-78 8.4 99 17.7 8-31-78 9.3 105 2.2 9-11-78 8.6 95 11.1 1-10-79 , 10.2 216 0.5 1-31-79 8.2 201 22.8 2-14-79 8.1 283 163.2 3-05-79 7.7 288 430.4 3-29-79 8.4 134 38.8 5-01-79 8.3 159 45.9 5-15-79 8.7 156 15.6 5-24-79 8.5 153 25.2 5-29-79 8.0 150 81.2 6-12-79 7.9 133 83.4 6-26-79 8.1 122 44.4 7-11-79 7.8 114 86.1 7-25-79 8.3 116 26.5 8-09-79 7.3 61 143.7 8-21-79 8.2 104 32.5 9-13-79 8.6 99 12.0 10-09-79 7.9 94 68.6 10-17-79 8.0 92 53.4 10-30-79 6.9 111 887.3 1. Means were calculated from values determined for each of the sampling sites identified on Figure 1. I'J Ul seasonal data. These comparisons follow in the text below. Comparisons of 1978 and 1979 data show an appreciable decline in the various forms of nitrogen and phosphorus in the pond and stream system. Concentrations of ammonia dropped 34%, nitrite-nitrate dropped 93%, and total inor- ganic nitrogen dropped 55%. Concentrations of particulate phosphorus and total phosphorus dropped 28% and 13% respec- tively. Total dissolved phosphorus concentrations, however, increased 38%. Pursual of the 1978 and 1979 nutrient input budgets indicate an internal cause for these differences. Two management strategies, the deepening of Areas 12 and 13 and biotic manipulation, are implicated as causative factors. Macrophytes covered approximately 90% of the bottom of the pond and stream system during the 1978 growing season. They were absent only from the deepest portions of Areas 2, 4 and 6 and from the firmer substrate areas (cf. Figures 2 and 3). Macrophytes, and their associated epiphytic flora, grew to the surface in Areas 12 and 13, forming unsightly mats. Deepening these areas by dredging was recommended to remove these nuisance growths and the underlying organic sediments. Dredging was accomplished during the winter months of 1978 and 1979, resulting in the complete removal of the aquatic plant community. It was intended that, once re- moved, aquatic plant growths would be eliminated from the central portions of these areas by light attenuation at Figure 2. A generalized diagram of the distributions of. the principal macrophyte species and macrophyte species associations in the Dow Gardens pond and stream system during the early part of the 1978 growing season. u... E'Zodea canadensis, Potcmogeton taxi fbliosus and Potamogeton pectinatus aaaaaaaaaaa ........... eeeeeeee 23:21:33 am Sp. tfi§§ Drepanooladas aduncus 2222 Myriophyl um spioatum 26 Spillway i 94- Orcnara Input Circulating Waterfall 1 N 6 5 Ornamental Waterfall Input L l J O IOOm Figure 2. Figure 3. A generalized diagram of the distribution of - the principal macrophyte species and macrophyte species associations in the Dow Gardens pond and stream system during the later part of the 1978 growing season. 9 EZodea canadensis, Pbtamogeton O O .. beiosus and Potamogeton pectinatus .0 eeeeeeeeeeeee ............. §§§§§ Myriophyllum spicatum 27 Spillway $1“— Orchard Input Circulating Waterfall t N a. L 0 Figure 3. increased depth. Recolonization of these areas during the 1979 growing season proceeded slowly (cf. Figures 4 and 5). By the end of the season, only a sparse band of vegetation, primarily Chara 4p. and Efodca canadensis, had re-established populations in the shallow areas. Dncpanoczadus aduncus, a bryophyte, established populations at the water-land inter- face around the edges of both areas. There is some evidence that aquatic macrophytes, with their associated epiphytes, may act as nutrient pumps, transporting inorganic nutrients held by the sediments, into the water (S. Wium-Anderson, 1971; Bristow, 1974; Wetzel and Rough, 1973). The removal of the macrophytes from.these areas may have been partly responsible for the decrease in the plant nutrient cancentrations observed during the 1979 growing season (cf. Tables 5 and 6). The sediments of ponds are reserviors for the mineral nutrients required for aquatic plant growth. They become enriched by the fallout of various inorganic and organic forms of these elements. Organic sediments tend to be richer sources of nutrients than inorganic sediments. This trend occurs, not because of higher concentrations of these elements (e.g. mg kg"1 ), but because they are more loosely adsorbed (Harter, 1969; Shulka et al., 1971; Rosen- field, 1979; and Williams et al., 1971). Furthermore, the .activity of greater numbers of decomposers (i.e. bacteria) on organic substrates promote high release rates of nutri- ents . Figure 4. A generalized diagram of the distribution of ' the principal macrophyte species and macrophyte species associations in the Dow Gardens pond and stream system early in the 1979 growing season. - :-.-.-. : ,Jdea comets/.323, A... .5. C C C I O 0 e 4 a s g . . . - Q , :flffl - - ‘. __ ' 0.20.5249 3. .... :9 AUTO/78 ,0?” rec ,2/1’2593 eeeeeeeeeeee eeeeeeeeeeee ............ ----------- eeeeeeeeeeee ............ ............ ............ 23 S pillway at Orchard Input 0 P e 23...... ‘3". a. 0‘2... . IO "e':e . . 'o C . . u": . .... 0.. ‘ . ' e \ 0. 0.. I I . :0 l2 Circulating Waterfall t a. Z f \ Ornamental Waterfall , Input 0 IOOm Figure 4. Figure 5. A generalized diagram of the distribution of the principal macrophyte species and macrophyte species associations in the Dow Gardens pond and stream system during the later part of the 1979 growing season. '4 I. V e g .- 333; ;.oaea oanaaensts, :o'tmoyeton O O O o . . . . “ 7 . .1 ‘ F ‘ ~ ‘ ° ‘ ° IO./LOS.I.S, an: :0'335’7’359-2 ,O/Z 38339.62 I. ’3 uuuuuuuuuuu eeeeeeeeeee ........... ........... gag? :repanooiadas adhrous spillway I Orchard Input so." j‘\ ........ ‘ “I AI Circulating Waterfall 3 l ( 46 I4 Stream Ornamental Waterfall Input IOOm Figure 5. 31 Maps of the sediments of the Dow Gardens pond and stream.system appear in Figures 6 and 7 and reveal two general types. A highly organic ooze mixed with, or overlain by, organic particles of terrestrial origin (leaf litter), was characteristic of the quiescent water areas. A firmer substrate of clay, with a thin surface layer of fine organic particles, was common in a channel that ran the main course of circulation within the system. It appears that this current is sufficient to prevent the accrual of loose organic sediments in the course of circu- lation. The removal of the organic sediments in Areas 12 and 13 exposed an expansive area of primarily inorganic clays. It follows that the removal of these sediments also re- moved a source of nutrient supply in this system. under aerobic conditions, clays can provide numerous sites for the adsorption of inorganic plant nutrients (Harter, 1968; 1969; Rosenfeld, 1979; Shulka et al., 1979). The exposure of these unbound adsorption sites could also help to ex- plain the decrease in nutrient concentrations observed in the system.from 1978 and 1979. Fish populations were manipulated in this study to indirectly reduce nutrient cycling between the water and sediments and to increase water transparency. Visual ob- servations made in 1978 revealed a great abundance of fishes. The codominant species were Canassiua auaatus, goldfish, and Figure 6. Locations of the loose organic sediments in the Dow Gardens pond and stream system during 1978. 32 Spillway i @" Orchard Input Circulating Waterfall N \L Ornamental Wderfall l npu t g L l O IOO m Figure 5. Figure 7. Locations of the loose organic sediments in the Dow Gardens pond and stream system during 1979. I.) LJ Spillway ‘k Orchard Input l3 l2 Circulati Watertarl‘l9 * 4L - Stream ' I Ornamental - -_ Waterfall 5 Input ' 2 L l J ‘ .-‘:: 0 IOOm 25L“ ' ::::K Figure 7. 34 Ictalurus sp., bullheads. Fathead minnows, Pimephaies promelas, were also abundant. Adult fish were observed roiling the bottom sediments, thus contributing to the turbidity of the overlying water. Nutrients loosely held by these sedi- ments were likely released to the overlying water by this activity. Furthermore, the digestive activity of fish with similar habits to these species have been found to contri- but to the nutrient loading of lakes (Lamarra, 1975). It is likely that the re-suspension of nutrient-rich sediments, and the nutrient loading effect of fish digestion contri- buted to the overall primary productivity in the pond sys- tem by the acceleration of nutrient cycling. Fish predation can virtually eliminate zooplankton populations from aquatic systems. Zooplankton feed on microscopic organisms and detrital particles that contribute to water turbidity. It follows then that, when fish preda- tory pressure is such that zooplankton populations are greatly reduced, there is a concominant increase in turbid- ity in these aquatic systems (Archibald, 1975; Helfrich, 1976; Hrbacek etafl., 1961; 1962; Pennington, 1944). The conspicuous absence of zooplankton, the great abundance of fish and a high level of turbidity in the system during 1978 led to the recommendation that fish be removed. Pro-Noxfish, a rotenone-based piscicide, was infused through the ice, which covered the system, in February 1979. Rotenone-based piscicides have been proven effective in warm 35 waters (Rounsfell and Everhart, 1953; Spitler, 1970), but little attention has been given to its use under ice (Hac- ker, personal communication). The treatment of Dow Gardens eliminated most of the fish from the system, but was not 100% effective. Bullheads and fathead minnows were present in the system during the 1979 growing season. Pro-Noxfish was applied once more during November 1979. There was a modest recovery of zooplankton populations in the pond and stream system following piscicide application. These data appear in Tables A-10 and A-ll. Zooplankton species that occurred in samples taken in 1979 were principally copepods and rotifers. The reasons for the absence of cladaoceran species is not clear, but may be explained by the predatory activity of the remaining fish or the composition of the phytoplankton or seston on which they feel (Goldman eteu., 1979). The return of zoo- plankton to the pond system was accomplished by an increase in water transparency. 36 CONCLUSIONS Based on the preceding data and the argument that follows, it appears that dredging Areas 12 and 13 and the removal of fish decreased the overall primary productivity of the pond and stream system from 1978 to 1979. The effect was to improve the aesthetic appeal of the system. The dredging project physically removed an obnoxious stand of aquatic macrophytes and rendered most of Areas 12 and 13 unsuitable for recolonization due to light attenua- tion at these increased depths. Removal of the fish and the excessive predatory pressures that they exerted per- mitted a modest recovery in the zooplankton populations. It is likely that the grazing activities of the zooplankton may have diminished some of the turbidity in the pond sys- tem. The elimination of fish also prevented the re-suspen- sion of nutrient-rich sediments by their activities. The overall decline in nutrient concentrations due to the improvement of internal nutrient sinks was also an im- portant factor in limiting of primary production in the pond system. This was accomplished by removing the organic sedi- ment in Areas 12 and 13 and, thereby, exposing inorganic clays to nutrient exchange and adsorption of nutrients in the overlying water. Evidence that primary productivity was decreased is also found in the relative concentrations of the various nutrient fractions. While all other phosphorus and nitro- gen fractions decreased from 1978 to 1979, total dissolv- ed phosphorus increased in the pond and stream system. It was stated earlier that nitrogen was limiting to photosyn- thetic organisms relative to phosphorus. This relative limitation was even more acute in 1979. As the nitrogen limitation to the plants increased, there was an accompany- ing decrease in the amount of phosphorus incorporated into the algae. This incorporated, or fixed, phosphorus is roughly equivalent to particulate phosphorus concentrations. The remaining phosphorus was left to the dissolved pool. Because phosphorus did not decrease at the same rate as nitrogen concentrations relative to the metabolic require- ments of the plants, the ratio of total dissolved to parti- culate phosphorus increased markedly from 1978 to 1979. Be- cause total phosphorus concentrations did not increase but, in fact, decreased during this time, it is very likely that the increase in this ratio is a reflection of decreased algal production in the pond and stream system. This was evidenced by an increase in Secchi disc transparancy mea- surements from a range of 90 to 110 cm in 1978, to 200 to 270 cm in 1979. Additional evidence of a decrease in primary produc- tion in the pond and stream system is found in the pH data. Comparison of weighted seasonal mean pH values show a de- crease of 8.6 to 7.8 from 1978 to 1979. Because aquatic plants are known to elevate the pH of small ponds as a 38 by-product of photosynthesis (O'Brien and de Noyelles, 1972), such a decline in pH could be explained by a reduction in the abundance of aquatic plants in the pond system during this period. Finally, observations of macrophyte distributions showed a 25% decrease in the percent coverage of the bot- tom of the pond and stream.system from 1978 to 1979. Deepening by dredging and the removal of an over- abundance of fish from the Dow Gardens pond and stream system resulted in an apparent decline in primary produc- tivity which was manifested in a reduction in biogenically- induced turbidity and the density of aquatic macrophytes. The overall effect was a significant improvement in the aesthetic character of the pond and stream system. 39 LITERATURE CITED American Public Health Association. 1975. Standard methods for the examination of water and wastewater. 14th edition. APHA, New York. Archibald, C.P. 1975. Experimental observations on the effects of predation by goldfish (Crassius auratus) on zooplankton of a small saline lake. J. Fish. Res. Bd. Canada 32:1589-1594. Bachmann, W. and R. Jones. 1974. Phosphorus inputs and algal blooms in lakes. Iowa State Journal of Research. 49(2):155-160. Boling, R.H., E.D. Goodman, J.O. Zimmer, K.W. Cummins, R.C. Petersen, J.A. VanSickle and S.R. Reice. 1975. Toward a model of detritus processing in a woodland stream. Ecology 56:141-151. Bristow, J.M. 1974. The structure and function of roots in aquatic vascular plants. Mimeo. Manuscript, 23 pp. Chapin, J.D. and P.D. Uttormark. 1973. Atmospheric contributions of nitrogen and phosphorus. Tech. Rep. 73-2, Water Resources Ctr., Univ. Wisc., Madison. 35 pp. Chow, V.T. 1964 ed. Handbook of hydrology. McGraw- Hill Book Co. New York. Cummins, K.W. 1977. From headwater streams to rivers. Am. Biol. Teacher 39:305-312. Cummins, K.W., M.J. Klug, R.C. Wetzel, R.C. Petersen, K.F. Suberkroppp B.A. Manny, J.C. Wuycheck and F.O. Howard. 1972. Organic enrichment with leaf leachate in experimental lotic ecosystems. BioScience 22:719-722. Cummins, K.W., R.C. Petersen, G.L. Spengler, G.M. Ward, R.H. King and D.L. King. 1978a. Microbial processing in a first order woodland stream. Oikos. F099, G.E. and W.D. Steward. 1965. Nitrogen fixation in the blue-green algae. Sci. Progr., 53:191-201. 40 Fuhs, G.W., S.D. Demmerle, E. Canelli and M. Chen. 1972. Characterization of phosphorus limited plankton algae. £3 Nutrients and Eutrophication. Spe- cial Symposia, The American Society of Limnology and Oceanography, Inc. Vol. 1. Gannon, J.L. 1971. Two counting cells for enumeration of zooplankton micro-Crustacea. Trans. Am. Microsc. Soc. 90(4):486-490. Goldman, C.R., M.D. Morgan, S.T. Threlkeld, and N. Angeli. 1979. A population dynamics analysis of the cla- doceran disappearance from Lake Tahoe, California- Nevada. Limnol. Oceanogr., 24(2):289-297. Hacker, V. 1978. Personal communication regarding the use of piscicides while ice is covering the surface of treated water bodies, State of Wis- consin, Department of Natural Resources, Oskosh, Wisc. Harter, R.D. 1968. Adsorption of phosphorus by lake sediments. Soil Sci. Soc. Am. Proc. 32:514-518. Harter, R.D. 1969. Phosphorus adsorption sites in soils. Soil Sci. Soc. Am. Proc. 33:630-631. Harvey, H.W. 1975. Chemistry and fertility of sea waters. 2nd edition. Cambridge University Press, Cam- bridge, England. 234 pp. Hasler, A.D. 1947. Eutrophication of lakes by domestic drainage. Ecology 28(4):383-395. Helfrich, L.A. 1976. Effects of predation by fathead minnows, Pimephales promelas, on planktonic commu- nities in small, eutrophic ponds. PhD Thesis, Mich. State. Univ., E. Lansing. 59 pp. Hem, J.D. 1970. Study and interpretation of the chemical characteristics of natural water, 2nd edition. Geological Survey Water Supply Paper 1472. U.S. Government Printing Office, Washington, D.C. 363 pp. Hrbacek, J. 1962. Species composition and the amount of zooplankton in relation to fish stocks. Rozpr. Cesk. Akad. Ved., Rada. Mat. Prir. Ved. 72:11-116. 41 Hrbacek, J., M. Duorakova, V. Korinek, and L. Prochazdova. 1961. Demonstration of the effect of fish stock on the species composition of zooplankton and the intensity of metabolism of the whole plankton association. Int. Ver. Theor. Angew. Limnol. Verh. 14:192-195. King, D.L. 1970. The role of carbon in eutrophication. J. Water Pollut. Cont. Fed. 42:2035-2051. King, D.L. 1972. Carbon limitation in sewage lagoons. In G. Likens (ed.), Nutrients and Eutrophica- Eion, ASLO Special Symp. 1:98-110. Lamarra, Jr., V.A. 1975. Digestive activities of carp as a major contributor to the nutrient loading of lakes. Verh. Internat. Verein. Limnol. 19:2461-2468. McRoy, CP., R.J. Barsdate, and M. Nebert. 1972. Phos- phorus cycling in an ecosystem. (Zostera marina L.) ecosystem. Limnol. Oceanogr. 17:58-67. Megard, R.O. 1972. Phytoplankton, Photosynthesis, and Phosphorus in Lake Minnetonka, Minnesota. Limnol. Oceangr. 17:68-87. Mickle, A.M. and R.C. Wetzel. 1978. Effectiveness of submersed angiosperm-epiphyte complexes on ex- change of nutrients and organic carbon in littoral systems. I. Inorganic nutrients. Aquat. Bot. 4:303-316. Mortimer, C.H. 1956. The 02 content of air-saturated freshwaters and aids in calculating percent sat. Mitt. Int. Ver. Limnol. 620 pp. O'Brien, J.W. and F. de Noyelles. 1972. Photosyntheti- cally elevated pH as a factor in zooplankton mortality in nutrient-enriched ponds. Ecology 53:605-614. Odum, E.P. 1971. Fundamentals of ecology. (3rd ed.). W.B. Saunders Co. Philadelphia, PA. 574 pp. Park, K. 1969. Oceanic C02 system: An evaluation of ten methods of investigation. Limnol. Oceanogr. 14:179-186. Pennington, W. 1944. The control of numbers of fresh- water phytoplankton by small invertebrate ani- mals. J. Eco. 29:204-211. 42 Rice, E.L. and S.R. Pancholy. 1972. Inhibition of ni- trification by climax ecosystems. Amer. J. Bot., 59:1033-1040. Rice, E.L. and S.K. Pancholy. 1973. Inhibition of ni- trification by climax ecosystems. II. Addi- tional evidence and possible role of tannins. Amer. J. Bot., 60:691.702. Rosenfeld, J.K. 1979. Ammonium adsorption in nearshore anoxic sediments. Limnol. Oceanogr. 24(2):356- 364. Rounsefell, G.A. and W.A. Everhart. 1953. Fisheries science: its method and application. John Wiley & Sons, New York. 251-255 pp. Sawyer, C.N. 1952. Some aspects of phosphates in relation to lake fertilization. Sewage and Industrial Wastes. 24(6):768-776. Sawyer, C.N. 1954. Factors involved in disposal of sewage effluents to lakes. Sewage and Industrial Wastes. 26(3):317-325. Shapiro, J. 1973. Blue-green algae: why they become dominant. Science 179:382-384. Shulka, S.S., J.K. Syers, J.D. Williams, D.E. Armstrong and R.F. Harris. 1971. Sorption of inorganic phosphate by lake sediments. Soil Sci. Soc. Am. Proc. 35:244.249. Smith, V.H. 1979. Nutrient dependence of primary productivity in lakes. Limnol. Oceanogr. 24(6):1051-1064. Spitler, R.J. 1970. An analysis of rotenone treatments for elimination of fish populations in southern Michigan lakes, 1957-1967. Michigan Academician. 3(1):77-82. Steward, W.D.P. 1973. Nitrogen fixation. £2.N°G- Carr and B.A. Whitten, eds. The Biology of the Blue Green Algae. Univ. of Calif. Press, Berkeley, 260-278 pp. Truesdale, G.A., A.L. Downing, and G.F. Lowden. 1955. The solubility of oxygen in pure water and sea water. J. Appl. Chem. 5:53-62. 43 Wetzel, R.C. 1975. Limnology. W.B. Saunders Co. Philadelphia, PA. 743 pp. Wetzel, R.C. and R.A. Hough. 1973. Producitivty and role of aquatic macrophytes in lakes. An assessment. Pol Arch. Hydrbiol. 20:9-19. Wium-Anderson, S. 1971. Photosynthetic uptake of free C02 by roots of Lobelia dortmanna. PhySiOl. Plant 25:245-248. Williams, J.D.H., J.K. Syers, R.F. Harris and D.E. Arm- strong. 1971. Fractionation of inorganic phosphate in calcareous lake sediments. Soil Sci. Amer. Proc. 35:250-.255. Yusoff, F. Md. 1979. Crustacean zooplankton of Lake Lansing, Michigan. Master's thesis. Michigan State University. 62 pp. APPENDIX 44 Table A-1. Morphometric features of the Dow Gardens pond and stream system, 1978. Site Area Mean Depth VOlume Numberl (m2) (m) (m3) 1 353 0.76 270 2 651 0.99 647 3 409 0.76 318 4 909 1.07 973 5 1180 0.84 991 6 833 1.45 1210 7 1175 0.76 898 8 937 0.76 716 9 1573 0.84 1323 10 1941 0.69 1336 11 731 0.69 503 12 2822 0.91 2589 13 1197 0.69 824 14 371 0.30 111 System Totals 15082 0.82 12709 1. As per Figure 1. 45 Table A-2. Morphometric features of the Dow Gardens pond and stream system, 1979. Site Area Mean Depth VOlume Number1 I (m2) (m) (m3) 1 353 0.76 270 2 651 0.99 647 3 409 0.76 318 4 909 1.07 973 5 1180 0.84 991 6 833 1.45 1210 7 1175 0.76 898 8 937 0.76 716 9 1573 0.84 1323 10 1941 0.69 1336 11 731 0.69 503 12 2822 2.00 5768 13 1197 2.35 2815 14 371 0.30 111 System Totals 15082 1.02 17879 1. As per Figure 1. 46 Table A-3. Mean surface1 water temperature, dissolved oxy- gen concentration, and percent oxygen saturation in the Dow Gardens pond and stream system dur- ing 1978. Temperature Dissolved Oxygen Percent Saturation Date (°C) (mg 02 1'1) (%) 4-12-78 7.8 12.3 109 4-28-78 14.3 12.7 131 5-10-78 12.1 10.9 107 5-24-78 19.3 9.9 114 7-13-78 21.0 7.3 86 7-18-78 21.7 6.9 82 7-25-78 24.9 9.4 119 8-06-78 23.5 9.9 123 8-31-78 20.6 9.6 112 9-11-78 22.0 7.8 99 9-21-78 . 17.5 8.9 99 10-11-78 11.3 10.4 95 10-18-78 9.0 10.7 '96 10-26-78 9.0 11.1 101 11-09-78 7.6 11.4 100 11-21-78 3.5 12.9 103 l. A mean of samples taken from depths from 0.5 m to the water surface at 2 to 8 stations in the pond and stream system. 47 Table A-4. Mean surface1 water temperature, dissolved oxy- gen concentration, and percent oxygen saturation in the Dow Gardens pond and stream system during 1979. Temperature Dissolved Oxygen Percent Saturation Date (0e) (mg 02 1'1) (%) 1-10-79 2.5 3.3 26 1-31-79 2.0 2-14-79 1.0 0.8 6 3-05-79 1.5 1.0 3-29-79 2.8 13.9 100 4-23-79 9.3 16.6 153 5-01-79 10.4 8.2 78 5-15-79 16.8 12.1 132 5-24-79 14.9 10.1 106 5-29-79 13.9 9.0 92 6-12-79 19.8 8.6 99 6-26-79 19.3 9.1 104 7-11-79 22.6 7.4 89 7-25-79 24.3 7.3 91 8-09-79 23.6 9.0 111 8-21-79 19.6 9.0 104 9-13-79 20.0 9.3 108 10-09-79 10.5 8.2 85 10-17-79 10.3 10.5 99 10-30-79 7.0 9.6 83 11-13-79 7.0 11.3 98 1. A mean of samples taken from depths from 0.5 m to the water surface at 2 to 8 stations in the pond and stream system. 48 Table A-5. Water temperature, dissolved oxygen concentra- tion and percent saturation at 3.0 m depth in Area 12 of the Dow Gardens pond and stream system during 1979.1 Temperature Dissolved Oxygen Percent Saturation Date (0C) (mg 02 1'1) (%) 4-16-79 5.0 1.2 10 4-23-79 5.0 1.2 10 5-01-79 6.5 2.1 18 5-24-79 6.5 0.8 6 6-12-79 13.0 1.3 13 6-26-79 16.0 1.2 13 7-11-79 17.0 1.3 14 7-25-79 18.5 0.6 7 8-09-79 19.0 0.2 2 8-21-79 18.0 0.2 2 9-13-79 17.3 2.5 28 10-09-79 11.0 7.4 71 10-17-79 8.7 8.3 75 1. See Figure 1. 49 Table A-6. pH, alkalinity, and free C02 concentrations at 3.0 m depth in Area 12 of the Bow Gardens pond and stream system during 1979. Alkalinity Free C02 Date pH (mg CaC02 1’1) (umoles C02 1'1) 7-11-79 7.4 134 276.6 8-09-79 6.8 93 246.4 8-21-79 7.7 113 115.3 9-13-79 8.5 97 15.5 10-09-79 7.9 91 65.8 10-17-79 8.1 92 44.1 1. See Figure 1. 50 Table A-7. Inorganic nitrogen concentrations at 2.5 m depth in Area 12 of the Dow Gardens pond and stream system during 1979. Nitrite- Total Inorganic Nitrate Ammonia Nitrogen Date (mg N 1—1) (mg N 1‘1) (mg N 1'1) 7-02-79 0.104 0.076 0.180 7-16-79 0.004 0.766 0.770 7-30-79 0.023 0.149 0.172 8-13-79 0.000 0.331 0.331 8-27-79 0.000 0.052 0.052 9-17-79 0.000 0.057 0.057 1. See Figure l. 51 Table A-8. Phosphorus concentrations at 2.5 m depth, in Area 12 of the Dow Gardens pond and stream system during 1979.1 Total Particulate Dissolved Total Phosphorus Phosphorus Phosphorus Date (mg P 1-1) (mg P 1’1) (mg P 1-1) 7-02-79 0.042 0.015 0.057 7-16-79 0.047 0.011 0.058 7-30-79 0.070 0.030 0.100 8-13-79 0.105 0.023 0.128 8-27-79 0.059 0.019 0.078 9-17-79 0.045 0.022 0.067 ' 1. See Figure 1. Table A-9. 52 Some events that were relevant to or that had a significant impact on the water quality of the Dow Gardens pond and stream system during 1979. Date 2-10-79 3-22-79 3-29-79 5-10-79 6-12-79 7-03-79 7-30-79 8-27-79 11-24-79 Event A fish toxicant was applied to all areas but Areas 12 and 13 which were drained to facilitate their being deepened at that time. Pro-Noxfish, a sulfoxide-synergized rotenone formulation with 10% active ingre- dients, was applied through the ice at 15 separate sites. The desired concentration of Pro-Noxfish was 1.69 ppm. Areas 12 and 13 were filled with water after being deepened to approximately 3.35 m. Fertilizer was applied to the lawns around the Gardens. Fifty lbs. of Aqua-Kleen, 2,4-D, were ap- plied to Area 10 for the eradication of .Myriophyllum spicatum. Bridge construction over Area 5 was begun. Dams were constructed to permit foundation work. Water was pumped from the south side of the site, over the dams, and into the northern portion of Area 5. This area was very turbid. Diquat, a contact herbicide, was applied to that pond system in the vicinity of the bridge between Areas 6 and 7 for the removal of a dense growth of E'Zodea. Within days this treatment appeared to have impacted most of the tracheophytes of the entire system se- verely diminishing these plant populations. Approximate concentrations of Diquat were calculated as follows; near the bridge 4.8 ppm, 1.46 ppm in Area 7, and 0.06 for the entire system. Bridge construction over Area 5 completed and dams and pumps removed. Fertilizer was applied to the lawns around the Gardens. Pro-Noxfish was reapplied at a rate of 2.07 ppm in the pond system. 53 .am oarowxeosm .mo creoronme .mo overuse .no mzsopmrb .mo ormsoom easoooz tomomoo moomomoo macawuooouom moomomou oeomoHo>u moomoooo oeoaaaau maum Hmlm bola mule Hath mule Nero vmlm mHlm Helm male Aluoqu mamoow>wosH moeoomm .Eoummm Emouum pom Odom mcooumo 300 any scum meme mcwuso coxou moHQEmm commune ca mc0eumuucoocoo couxcaaooou .oal¢ manna 54 a mooomuumo .nm cNNaeosaM MHlm Hmlm mmlh Help e~ue male elemueo metateeetee vmlm male A.©.HGOOV 0Hl< Canoe Table A-ll. Zooplankton concentrations in samples taken from Area 12, at 2.5 m deep, in the Dow Gar- dens pond and stream system during 1979. Individuals Liter"l Species 6-12 6-26 7-11 7-25 8-07 8-21 9-13 Calanoid 4 Copepods Cyclopoid 21 12 4 20 2 8 25 COpepods Copepod 18 12 2 93 3 27 33 Naupuli Bosmina 1 sp. AspZanchna 2 160 14 23 8 8p. Brachionus 3 141 125 6 1 3?: KerateZZa l 2 3p. "11111111111111