”V was}. .. .3“: . ..._ 1!... . .0 to. . m '1 . .fli.» . a an?» . .r I” .. . . . ... mfwi-u u..ImWMI- I. u... t. . r _. l I IJW on .m-blo. ', I ..§m.hB "my 5.34.4 I (L. . I .; 2.4.5..an .n . n? V Ix“. 0.4, 9. . .J" . - r :, . ‘1 " ' I 0 v‘ . . I" I o ‘w _ . I . I“l g. -. II‘OUI , 0 O - ' . hL.I¥o1.flIuL-Ingq¢¢.|1 I "'.‘ I O IooIHaIOn-IUO.’olollhfl..ll o . . .Olou .'.I0 I. IIOfIIIn‘O" l 0". I’l I I I ~1- ' I | | O I I r I ‘1 Iii“: I .1 s' " I,‘I '! [I I | I II' I I I I 0 }'vi‘ '.§,.l I.‘ ' ‘- +~m A" ' I_._‘.- , | V‘ ' v ' , . I I I H ' d “ | o I .I. o" . . ‘ c O a. LII“ I ..,I .J I I“. .l 'I... 5 I h I I I .‘u o .t I I ILI-. 125A IL II . -..| I‘I I t 1.. is: a” "It . I I I O VII" “III I. .I j .IIOO a fifi‘f'oI'! .fr‘hf IIl' Col ‘0’}- 'I ‘II' a IDIOI'III IIOIIJ' II..O~‘I!'IIQ||6 no oIII'oII'u‘a‘I' I. I'D'-‘IO‘ “ c I I.) 0 'vI'II. I I I l . I I ‘ "#1 AV K . In: I If I I ’ I I I I I Q «MW. . s -\ - ' . . . .' —. '3‘ " .. . .:. .' u n I ' I o o II - Il.’ - - __ ' O O I I I ' I OIII I I. I . . . all ! 0 - - I - 1 . . III I -o ‘.| O In! 0 I. I I? II. o‘l‘l J I I I I I II I II I I II II. -_.IIIII I I. n ‘r I ' ' II. I ‘- {I 'IIII .’ - I . I I - I‘- I r‘ll. 13"...- I ' I II , I. III II. I o I I. I I. I ' .I O . . | -I - |\ I I v.‘lfI"I.I- '0‘.- _ I. II - ‘ - I .- ‘- ."‘I I . I .l I I I I ' III .‘v-H‘I‘V“! THE FERTILIZATION OF A MARL LAKE By GAYLORD RAY ALEXANDER A THESIS submitted to the School of Agriculture of Michigan Stateg University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Fisheries and Wildlife 1956 ..%f .t" I.’ fr: 'II ACKNOWLEDGMENTS I wish to express my sincere appreciation and indebtedness to: Dr. Robert C. Ball who directed the graduate work; Dr. F. F. Hooper for guidance in the. study; Alfred B. Grzenda, with whom the field work was carried out; Dr. D. W. Kayne for assistance with the statisti- cal analysis; Dr. Gordon E. Guyer for assistance with the bottom fauna chassification; Dr. E. W. Roelofs and Thomas P. Waters for suggestion on the manuscript; Edward H. Bacon, Gerald F. Myers and Mrs. Alfred R. Grzenda for their assistance in the collection of field data; my wife for her assistance and encouragement in the preparation of this thesis. Financial assistance for this work was received from the Institute for Fisheries Research of the Michigan Department of Conservation. This thesis gives the results of part of a project undertaken Jointly by the Institute for Fisheries Research and the Department of Fisheries and Wildlife and.Agricultural Experiment Station of Michigan State University. 11 ABSTRACT Hoffmn Lake, a 120 acre marl lake in northern Michigan, was fertilized twice during the summer of l95h with inorganic commercial fertilizer. The additions of the fertilizer resulted in immediate increases in the concentrations of total and soluble phosphorus, ammonia nitrogen, and sulfate. However, these increases were only temporary. Light penetration decreased at all depths immediately following each application of fertilizer, but shortly thereafter increased until the transparency of the water was greater than before treatment. This response was due either to a flocculation or precipitation res action that occurred following each application of fertilizer. A ten-to thirtyfold increase in periphyton at the outlet of the lake occurred after fertilization, however these was no increase in the plankton of the lake. The standing crop of macroscopic benthos was sampled throughout the summer. It was found that the burrowing mayflies comprised more I than 90 percent of the total number and volume of organisms. The generation of mayfly nymphs of the genus Ephemera produced after fertilization appeared to grow more rapidly than the generation present prior to fertilization. The game fish, except for the largemouth bass, were growing at a less than average rate. Bass were growing at a rate somewhat above average. 111 TABLE OF CONTENTS INTRODUCTION................................................. DESCRIPTION OF THE LAKE AND STUDY AREA....................... METHODS AND EQUIPMENT........................................ Fertilization.............................................. Sampling................................................... Physical................................................. Secchi disk............................................ Underwater photometer.................................. Turbidity.............................................. Temperature............................................ Chemical................................................. Hydrogen ion concentration............... ...... ........ Alkalinity............................................. Ammonia nitrogen....................................... Phosphorus............................................. Sulfate................................................ Biological............................................... Plankton............................................... Periphyton............................................. Macroscopic benthos.................................... Fish................................................... RESULTS...................................................... &mplin80000000000000000OOOOOOOOOOOOOOOCOOOOOOOOOOOOOOOOOOO iv Page CDCDCD—qszw 12 12 12 12 12 12 13 13 l3 l3 13 2o 23 2h 27 27 Physical................................................. 28 Secchi disk............................................ 28 Photometer readings.................................... 28 Turbidity.............................................. 3h Temperature............................................ 3h Chemical................................................. 39 Hydrogen ion concentration............................. 39 Alkalinity............................................. 39 Ammonia nitrogen....................................... 39 Phosphorus............................................. h3 Sulfate................................................ h? Biological............................................... 51 Plankton............................................... 51 Periphyton............................................. 6h Macroscopic benthos.................................... 72 Fish................................................... 97 Interrelationships between physical, chemical, and biological characteristics of Hoffman Lake............... 123 SUMMARY...................................................... 128 11me GIMOOOOOOOIOOOOOOOCOOOOOOOOOOOOOOOOOOOOOOOOOOOOO 130 VJ . Q a L‘. 10. 11. 12. 13. 11+. 15. 16. ‘ 17. 18 .0 LIST OF TABLES Theoretical concentration of chemicals in Hoffman Lake after fertilizatIODOOCCOO0.0.0...0.0.0...0.0.0.0000... Mean Secchi disk and photometer readings.............. Surface turbidity (p.p.m.)............................ Air and surface water temperatures (°C.).............. Ammonia nitrogen (p.p.m.)............................. Soluble and total phOSphorus (p.p.b.)................. Sulfate (p.p.m.)...................................... Total and acid insoluble suspended solids, their losses on ignition, and carbonate fraction (p.p.m.)... Determinations for phosphorus, calcium ion and total hardness made from plankton samples................... Production of periphyton on bricks and shingles placed in outlet or Heffmn mkeOOOOOOOOOOOOOOOOOOOOOOOOOO0.0 Enumeration of macroscopic benthos from station 1..... Enumeration of macroscopic benthos from station 2..... Analysis of variance of differences between the stand- ing crop of macroscopic benthos from station 1 and Station 2......0.0.000....0.O.OOOOOOOOIOOOOOOOOOOOOOOO Enumeration of total volume of macroscopic benthic organisms, (milliters, per Ekman dredge sample,)...... Grouped macrosc0pic benthos from station 1 and 2...... Size distribution of Ephemera simulans (grouped in one-tenth inch frequency classesI................%.... Number and mean length of Ephemera simulans used for the calculation of instantaneous rates of growth and mortality...’...0....OOOOOOCOOOICOOOOOOIOO0.0.0.000... Absolute growth of yellow perch from Hoffman Lake, vi PAGE 33 37 38 In 1+6 50 55 60 65 78 82 83 88 92 93 100 TABLE 19. 20. 21. 25. 26. 27. Mean instantaneous rate of growth for yellow perch from HOffmn lake, lgshOOOOOOOOO00.0.0000...0......O. Absolute growth of rock bass from Hoffman Lake, 195A. Mean instantaneous rate of growth for rock bass from HOffmn um, 1951+...o0......-OOOCCOCIOOOOIOOOOOOCOOO Absolute growth of common sunfish from Hoffman Lake, 1954........................ ..... .................... Mean instantaneous rate of growth for common sunfish from Hoffman Lake, 1954.............................. Absolute growth of common sucker from Hoffman Lake, 195k................................................. Mean instantaneous rate of growth for common sucker fromHOffma-n IAke’ 1951*0000OOOOOOOOOOOOOOOOIOOOO.0... Absolute growth of largemouth bass from Hoffman Lake, l95h................................................. Mean instantaneous rate of growth for largemouth bass from HOffman hke’ 1951‘.OOOOOOOOCOOOO.00.00.000.00IO. vii PAGE 101 10h 105 108 109 116 117 118 12k w, HI... h 10. 11. 12. 13. 11+. 15. 16. LIST OF FIGURES Hoffman Lake, from east to west, showing the marl deposition on Bubmrged 1035......-coo-000000.00...o Map of Hoffman Lake giving the locations of sampling sutionsooooonOOOo00.00000000000000000000000000000. The method of collecting periphyton by use of a Shingle substramOOOOoeOOIOOOOOOOOOOOOOOOOOOOOOOOOOO The method of collecting periphyton by use of a briCk S‘JbStrateOOOOOOOOOOIOOOOOOIOOI0.0.0.0000...... Mean Secchi disk readings, in feet.................. Percentage of surface illumination reaching various depthSIOOOOOCOOOOOOOOIOOOOOOOOO.OOOOOCICCOCOOOOOOOO. Turbidity of the surface water on various dates. Values plotted are averages for 2 stations. . . . . . . . . . Ammonia nitrogen (p.p.m.)........................... Total and soluble phosphorus (p.p.b.)............... sulfate ion (popome)eoe00000000000000.oeoeooooooooeo Relationship between total and acid insoluble suspended solids and their volatile fraction........ Relationships of phOSphorus in plankton samples to the total phosphorus less soluble phosphorus in lake water, and to carbonate8............................ Relationship between calcium ion and total hardness 1n plankton SampleSOOOOOO...OOOOOOOOOOOOOOOOOOOOOOOO The appearance of a shingle substrate after a 30 day exposure period prior to fertilization......J....... The appearance of a shingle substrate after a 30 day exposure period following the application of fertilizerOOOIO0.0...0.00000IOOOOOOOOOOOOOOOO0.00... Periphyton nearly completely covered this pair of shingle substrata, which were exposed for a 30 day period following fertilization, the yellow patches are where the periphyton was scraped.off of the ShingleSOOOOOOOOOOOOCOCOOOOOIOOOOOOOOOOOOOOO0.0.0... viii PAGE 11 15 18 3O 32 36 no “5 1&9 5h 59 63 67 69 71 FIGURE 17. 18. 19. 20. 21. 22. 23. 2h. 25. 26. ———— — ._-.- . — m __ ,____ ax: Percentage composition of the total number of macro- scopic benthos collected from stations 1 and 2...... The number and volume of macroscopic benthic organisms per square foot of lake bottom............ Frequency distribution of the number of Ephemera simulans collected weekly from Hoffman Lake......... Number and mean length of Ephemera simulans taken each week from Hoffman Lake; instantaneous rates of growth and mortality were determined from the slope of the lines........................................ Length-weight relationship of the yellow perch. Curve A shows the absolute values; curve B shows the 108’108 tmnSformtioneooonce-00.090000000000000 length-weight relationship of the rock bass. Curve A shows the absolute values; curve B shows the log- 108 tranSformtionOOOOOOO0.000000000000IIOOOOOOOIOOO length-weight relationship of the common sunfish. Curve A shows the absolute values; curve B shows the .log-log transformation.............................. Length-we ight relationship of the common sucker. Curve A shows the absolute values; curve B shows the 108’108 tmnsrormtioneoeeoooeoeeococo00000000000000 lengtheweight relationship of the largemouth bass. Curve A shows the absolute values; curve B shows the 108-106 transromtionoe0.0.0000.000000000000000.IO. Gravimetric instantaneous rate of growth of various species. Mean rate is plotted on semi—log scale.... ix PAGE 75 86 91 96 103 107 113 115 120 122 INTRODUCTION Michigan has ever-increasing numbers of fishermen. In the last forty years their numbers have nearly doubled every ten years, and at the present time there are approximately 1,200,000 licensed fisher- men utilizing the waters of the state. It has become necessary to make the best possible use of the state's lakes and streams to satisfy the public's needs. In an effort to maintain and improve the fishing, attempts are underway to find management procedures for these waters which will increase fish production. Chemical nutrients are necessary to build the living protoplasm of plant cells. It is believed that the addition of the basic nutrients in the form of inorganic fertilizer is a practical method for increasing the production in natural waters. Bacteria, protozoa, algae, and higher aquatic plants synthesize these nutrients into protoplasm which in turn is utilized as food by animal life, including fish. In this country artificial fertilization of lakes and streams is a comparatively new practice. The Chinese, however, fertilized carp ponds more than 2,000 years ago. In EurOpean literature, ferti- lization dates back to the nineteenth century. Summaries presented by Davis and.Wiebe (1930), and Smith (193A) indicated that the first experiments were directed toward the production of plankton in relation to carp culture. Early American eXperiments were directed along similar lines by Embody (1921) and Wiebe (1930). Later work by Smith and Swingle (1939), SurbBr (1915), Swingle (1917), Smith (19%), 2 Langford (19h8), Ball (19u8), Patriarche and Ball (19u9), and Ball and Tanner (1951) have shown that increases in the growth of higher aquatic plants, plankton, bottom fauna, and fish result from the addi- tion of fertilizer. The more important American and some of the BurOpean literature dealing with aquatic fertilization has been sum- marized'by Maciolek (195h). float of the fertilization has been done on lakes under 30 acres in size and little on largerlakes or streams. The obJect of this investigation was to test the hypothesis that an addition of fertilizer to a lake would increase the produc- tivity within the lake, and would also bring about an increase in the productivity of a stream fed by the lake. The lake fertilized was Hoffman Lake, Charlevoix County; Additions of fertilizer were traced within the lake and down the West Branch of the Sturgeon River, the outflowing stream. Results were evaluated in terms of physical, chemical, and biological changes occurring following fertilization. The over-all program of study was planned for a period of three years to permit evaluation of the slower responses and long range effects of ferti- lization. This thesis deals with the work done on Hoffman Lake during the summer of 195% (first year of fertilization). The field work on the lake and stream was carried out Jointly with.Mr..Alfred R. Grzenda. His thesis Grzenda (1956) entitled "The Biological Re5ponse of a Trout Stream to Headwater Fertilization," deals with the findings from the stream. DESCRIPTION OF THE LAKE AND STUDY AREA Hoffman Lake is located in Hudson Township, Charlevoix County (T. 23 N., R. h W}, Sec. 26, 27, 3h, 35). It lies about 7 1/2 miles west of Vanderbilt, Michigan, in a valley among prominent hills. It is a shallow marl lake having a surface area of 120 acres. The basin has three minor depressions which are approximately 22 feet in depth; this is the maximum depth of the lake. More than 75 percent of the lake is less than 15 feet deep. Thermal stratification was not detected during the summer except in the depression off the south shore which, in June, contained water a few degrees cooler than the remainder of the lake. The water temperature was nearly homothermous throughout the lake for the remainder of the study. The surrounding soils are composed of sandy glacial drift which has an abundance of calcium and magnesium. The waters of the area are generally alkaline. Alkalinity or the lake was consistently about 130 p.p.m., mostly in the bicarbonate form. A water sample collected September 3 had a total hardness of 155 p.p.m., of which .100 p.p.m. was due to calcium salts. The pH varied from 8.2 to 8.5. Except for small patches of sand adjoining the shore, the bottom of the lake is light gray marl containing very little organic matter. The shore line development was 1.2. The water has a bluish-green cast which is characteristic of marl bottom lakes. Turbidity of the surface water was less than 5 p.p.m. The principal water supply is furnished by numerous springs entering the south and west shores. Several of these springs unite Figure l. Hoffman Lake, from.east to west, showing the marl deposi- tion on submerged logs. ”4.3—. ff“? ‘3. L. s O D. .m to form the inlet which enters at the west end of the lake. The watershed of the lake is small due to the hilly topography, and prob- ably contributes little water to the lake as surface runoff (Roelofs, 19h1, mimeographed report). The chief vegetative type of the drainage area is second growth hardwoods with scattered clearings. Some areas are being utilized for farming and the grazing of livestock. Cedar swamps occupy the low lands adjacent to the lake, and some of these areas are being cleared and filled for cottage sites. The bulrush (Scirpus sp.), was the predominant aquatic plant and it occurred in water 1 to 5 feet deep. In the deeper water scattered patches of pondweed (Potamggeton sp.) and stonewort (Chara sp.) were found. There was one small patch of white water lilies (Nymphaea sp.) at the west end of the lake. The vegetation was extremely Sparse and the submerged parts of the plants were heavily coated with marl, which may have a decided effect upon plant abundance. Burrowing mayflies (Ephemeridae) composed the bulk of the bottom organisms. Other forms of aquatic insects were not abundant. Game fish found in the lake were largemouth bass (Micropterus salmoides), rock bass (Ambloplites rupestris), common sunfish (Lepomis gibbosus), yellow perch (Perca flavescens), and brook trout (Salvelinus fontinalis). One species of coarse fish, the common sucker (Catostomus commersoni) was taken. Forage species were log perch (Percina caprodes), Iowa darter (Etheostoma exile), common shiner (NotrOpis cornutus), mimic shiner (Notropis volumellus), creek chub (Semotilus atromaculatus), and bluntnose minnow (Pimephales notatus). A4 Judging from the reports of local residents, the lake in the past furnished good fishing for bass, perch, and trout but the fishing success has reportedly decreased within the past twenty -years. All Species of game fish except the largemouth bass were growing at a below average rate at the time of this study. Numerous attempts to establish trout in Hoffman Lake have been made. One thousand brook and 1000 rainbow trout were planted in 19h1 with little success. Montana grayling were planted in 1926 but apparently did not survive. Two brook trout were taken in trapping operations on the lake during the summer of l95h. Fry and fingerlings of brook trout were abundant in the springs which feed the lake. These fish presumably would stock the lake if conditions were favorable for trout. According to the lake classification of the Michigan Department of Conservation the lake was designated as a trout lake in 195k, but has since been removed from that status. The lake has about a dozen cottages around its south shore and more are being built at other locations at the present time. In Michigan, lakes, other than marl lakes which have similar bottom conformation and depth, tend to be relatively high in productivity, but apparently the influence of the marl deposit and the lack of organic deposition result in a meager production of aquatic life. METHODS AND EQUIPMENT Fertilization Commercial inorganic fertilizer with an analysis formula of 10- 10-10 (N-P-K) was applied to Hoffman Lake twice during the summer of 8 l95h. The fertilizer contained nitrogen in the form of ammonium sul- fate, phOSphorus as super-phosphate, and potassium as potassium chloride. The fertilizer was spread from a moving boat. It was released slowly from the bags to decrease the possibility of its falling to the lake bottom before being completely dissolved. Most of the chemical was spread in shallow water (under four feet deep) so that wave agitation aided mixing. The actual quantities of fertilizer applied were: 3200 pounds on July 30 and 2700 pounds on.August 9. The theoretical concentration to be expected in the lake as a result of each application may be found in Table 1. In these calculations it was assummed that the fertilizer dissolved completely, and was evenly distributed through- out the lake. The lake volume used in these calculations was h5,000,000 cubic feet. Sampling Five sampling stations were established on Hoffman Lake; these are shown in Figure 2. Stations A, B, and C are locations at which chemical samples were taken. At stations 1 and 2, which were marked by bouys suspended from posts driven into the bottom of the lake, turbidity, plankton, and macroscopic benthos were sampled. PHYSICAL Secchi disk. This instrument was employed as one measurement of light transmission. Secchi disk readings are not actual measurements of light penetration, but are useful meaSurements when.umed under standard conditions. According to Welch (l9h8) this measurement can be used to compare light conditions in one body of water at different times. Readings were taken throughout the study. Table 1 Theoretical Concentration of Chemicals in Hoffman Fertilizer Nitrogen Ammonia Sulfate Phosphoric acid Phosphorus Potassium oxide Potassium Lake After Fertilization Concentration (p.p.m.) First application (3200 pounds) 1.139 0.1139 0.1h6h 0.h026 0.1139 0.0h98 0.1139 0.09h5 Second application (2700 pounds) 0.968 0.0968 0.12hh 0.3h21 0.0968 0.0hZh 0.0968 0.0803 10 Figure 2. Map of Hoffman Lake giving location of sampling stations. .ann NNdN Uum 3.3.. .ZNMF 240.10.: .00 x_0>wJ¢433 CNN—Array". CNN—Jr—kmn— ,.om om 2n. poem“ mm .2 \\I\<\/ H \0— \\l\<|/ .w. . \o .0 n , @0333 0. ON om O? on 00 Ch 00 00 oo— lNEDBBd Table 2 Mean Secchi Disk and Photometer Readings Secchi Photometer Date disk (percentage of surface illumination reaching (feet) various depths in feet) 3 6 9 12 15 18 21 July 23 6.0 6u.1 33.8 23.2 16.5 11.2 8.h 2.9 30* ... ... ... ... ... ... Aug. 2 h.0 u8.1 26.7 18.5 11.1 7.6 u.8 0 u h.5 50.6 30.1 17.1 11.0 h.6 2.0 0 5 u.3 u8.1 27.2 16.9 10.6 6.6 3.9 1.3 6 5.3 51.7 32.0 19.7 12.2 7.9 u.9 0.1 9* 7.0 6u.u 3u.9 26.8 21.9 17.0 10.0 0 12 6.5 55.h 32.8 23.0 15.9 11.3 7.8 5.5 13 6.3 56.7 32.5 21.6 1u.9 7.8 u.u 0 16 7.0 65.2 35.9 21.6 10.h 1.3 2.9 0 17 7.0 52.3 33.9 21.5 13.h 6.5 5.0 1.8 20 7.0 59.0 32.0 20.00 12.0 7.7 5.0 2.8 30 7.5 72.6 h9.h 31.2 19.8 16.5 9.5 0 ‘ * Dates of application of fertilizer 33 3b fertilization. This phenomena occurred following each application of the fertilizer. Turbidity. Prior to fertilization surface turbidities were u to 5 p.p.m. Immediately after the first fertilization the surface tur— bidity was reduced to about 2.8 p.p.m. After this initial reduction, turbidity increased steadily and reached the prefertilization level by the time of the second fertilizer application. Immediately following the second fertilizer application the turbidity fell to 2 p.p.m. and remained at this point for the duration of the study period. Fluctu- ation in the surface turbidity averaged for various stations on each date during the summer are shown in Figure 7. Temperature. Surface water temperatures varied between 68° and 79° F. for the study period. Records of air and surface water temper- atures are tabulated in Table 9. In general, water temperatures were the highest in the latter part of June, and decreased during July and August. This general trend was also evident in the records of air temperatures. Most of the water temperatures were taken at the surface, and were for the most part representative of temperatures throughout the lake since the water was in nearly complete circubation. The depression off the south shore contained water at a temperature of 66° F. during June. This may be attributed to the cooler denser waters settling in this depression from the numerous small springs entering the lake in this area. Surface spring had temperatures ranging from 5h° and 58° F. throughout the summer. 1.- iJ ' Figure 7. Turbidity of the surface water on various dates. Values plotted are averages for 2 stations. 34" 1| Fm303< >42. 854.5 new: FPCUJ NN G. 0_ 9 O. h V _ m fl N fl t 3 = fl 1. q q u q q . O . Table 3 Surface Turbidity (p.p.m.) Date Station I Station II July 8 h.5 5.2 12 h.9 h.l 2O h.h 9.0 27 5.0 h.1 30* Aug. 2 2.6 3.0 h 3.8 3.8 5 1+.0 3.8 6 3.8 h.0 9* 10 3.8 h.0 11 2.h 2.5 12 3.0 2.5 13 2.3 2.2 16 2.9 3.1 18 2.0 2.0 20 1.9 1.8 22 2.0 2.0 27 2.h 2.3 Sept. 8 - 1.8 2.3 10 2.0 2.1+ M W * Dates of application of fertilizer Table h Air and Surface Water Temperature (0°) Date Water temperature Air temperature June 17 25 27 18 26 27 19 25 28 2h 22. 21 29 22.5 20 July 5 20 18 7 20 18 8 22.5 20 12 21 23 15 18 23 22 23 20.5 26 2h 23.5 JKug. 6 22 20 10 18 1h 12 18.5 1h 19 23.5 20 29 20 19 Sept. 3 19 18 38 3 * r3414- 39 CHEMICAL Hydrogen ion concentration. The pH of the lake water varied between 8.2 and 8.5 during the study. There was no evidence that fertilization affected the pH of the lake although there could have been changes of short duration in the area of application of the fertilizer. Alkalinity. Alkalinity varied from 128 to 133 p.p.m. within the period of study. About 10 p.p.m. of this was due to carbonate and the remainder was attributed to bicarbonate. Marl particles (CaCO3) could be seen suspended in the water and these were undoubtedly responsible for a large pr0portion of the carbonate. Fertilization did not seem to alter the alkalinity of the lake water although car- bonates are believed to have been flocculated or precipitated in the lake following each application of fertilizer. Ammoniam nitrogen. There was an increase of ammonia nitrogen following each application of fertilizer. Hoffman Lake was fertilized July 30 and again on August 9. Prior to fertilization the concentra- tion of ammonia was 0.06 p.p.m. (Figure 8). This is slightly lower than concentrations found in surface water of seven Wisconsin lakes during June, July, and Augustby Domogalla, Juday, and Petersen (1925). One day following the first application of fertilizer the concentration of ammonia was 0.0h p.p.m. for stations A and B, and 0.03 p.p.m. for station C. These are lower than the prefertilization concentrations and this may be due to error in measurement, or the normal decline of ammonia nitrogen in lake waters which occurs at this time of year. p1 39 Figure 8. Ammonia nitrogen (p.p.m.) d. 20.55 Fawm HWDUD< . >43fi 85.4.53 8522mm Umj am em om o. o. o m ”Una om J . M .w E w. 0 .mo. .9. .2. U 20:25 .om. Id, 3 E Eu -2. .9. m 20.25 . .no. .2. -m... W Table 5 Ammonia Nitrogen (p.p.m.) Date Station A Station B Station C July 26 0.06 0.06 0.06 30* .. 31 0.0h 0.0h 0.03 Aug. 3 0.11 0.10 0.03 6 0.01 0.01 0.01 9* . 10 0.12 0.09 0.20 12 0.06 0.06 0.06 16 0.0M 0.05 0.05 18 0.03 0.01 0.03 20 0.03 0.00 0.01 2h 0.01 0.01 0.03 27 0.01 0.01 0.01 Sept. 3 0.01 0.01 .0‘01 10 0.01 0.01 0.01 * Dates of application of fertilizer 1.1 #2 According to Domogalla gt_§l. (1925), a decline in ammonia, nitrites, and nitrates in the surface zone occurs in the late summer and early fall. Four days following the first application.ammonia had increased to 0.11 p.p.m. for stations A and B but remained at 0.0% p.p.m. for station C. Eight days following the first application of fertilizer ammonia was 0.01 p.p.m. at all stations. 1 One day following the second application ammonia concentrations increased at stations A and B to 0.12 and 0.09 respectively. The theoretical concentration, assuming even distribution throughout the lake, was calculated to be 0.12 p.p.m. At station C ammonia increased to 0.20 p.p.m. theoretical concentration. This phenomena was also Observed in the case of phosphorus and it is believed to be due to the high winds present at the time of the second application, which moved the fertilizer waters to the east end of the lake, in the vicinity of station C. Three days after the second application the samples contained 0.06 p.p.m. ammonia at all three stations, indicating a nearly homogeneous mixture in the lake. Ammonia disappeared rapidly until August 27. .After this date only traces of ammonia could be found. Following the first application of fertilizer the increase in ammonia was not detected until feur days after fertilization, whereas ammonia increases were detected on the day following the second appli- cation of fertilizer. This might indicate that the windy'weather helped to dissolve the ammoniam sulfate. Sulfate analysis also showed the same general trend. h3 The ammonia disappeared rapidly after each application of ferti— lizer. This has been the case in many other eXperiments (Hayes, 19h?) and others. The rapid reduction could be due to the uptake of ammonia W -‘.i. ,4— If by plants, oridation'by nitrites and nitrates, flocculation or precipi- tation and to a lesser degree, dilution of the lake water. Phosphorus. The concentration of soluble phosphorus prior to fertilization was 1 p.p.b. (microgram per liter) at the three chemical stations (A, B, C). One day following the first application 8 p.p.b. was detected at station.A, 7 p.p.b. at B, and h p.p.b. at C. (Figure 9). Laboratory tests showed that phosphorus in the fertilizer dissolved in a few minutes. In the lake, however, the soluble phosphorus made up only a small fraction of the total phosphours one day after ferti- lization. It is believed that the phosphorus in the fertilizer went into solution immediately upon its addition to the lake, and then combined with calcium, carbonate, and possibly others to bring about a flocculation or precipitation reaction; this would account for the rapid reduction of soluble phosphorus to prefertilization levels. The second application increased the concentration of soluble phosphorus at station.A to 5 p.p.b., station B to 2 p.p.b., and station C to 12 p.p.b. These data and the ammonia nitrogen (Figure 8), both show the highest concentrations of nutrients at station C following the second application. Two days later the concentration of soluble phosphorus was again at the prefertilization level at all stations. Part of the decrease in soluble phOSphorus could have been due to activities of plankton, periphyton, and higher aquatic plants, but hh Figure 9. Total and soluble phosphorus (p.p.b.) I JULY lJUJLLJ M W AUGUST trl 0 l2 I6 ERTILIZED STATION A ‘ H STATION 8 STATION C - SOLUBLE PHOSPHORUS [:1 INSOLUBLE PHOSPHORUS J1 20' m. 2? 3 SEPT Table 6 Soluble and Total Phosphorus (p.p.b.) JDate Station;A Station B Station C Soluble Total Soluble Total Soluble Total July 26 l 1+ l h l 2 30* 31 8 36 7 V 36 u 20 Iitaeg. 5 2 2h 2 28 2 28 6 1 27 2 28 2 18 1o 5 18 2 19 12 27 12 2 3h 3 25 1 79 16 0 22 O 26 0 22 18 1 3h 2 32 * 3 26 2O 1 16 1 16 1 13 2h 0 13 1 1h 0 18 27 O 15 O 15 O 26 Sept. 3 o 10 o 10 1 11 ~ * Dates of application of fertilizer l+7 it is believed that most of the phOSphorus was precipitated to the bottom or was being held in suspension as an insoluble form. Before fertilization there was a concentration of total phosphorus of 5 to 8 p.p.b. at the three chemical stations. One day following the first application Of fertilizer the total phOSphorus was 36 p.p.b. at station A and B, and 20 p.p.b. at station C. Total phosphorus as determined by tests was about 70 percent of the calculated theoretical concentrations one day after fertilization. Four days after the first application total phosphorus concentrations ranged from 2h to 28 p.p.b. It decreased only slightly from these levels up to the time of the second application on August 9. One day following the second application there was only a slight increase in total phosphorus at station C and concentrations present at There was stations A and B were lower than before the application. however increases in soluble phosphorus. Three days later total phosphorus increased to 31+ p.p.b. and 25 p.p.b. at stations A and B. At station C there was a concentration of 79 p.p.b. which was nearly double the theoretical concentration for the\ entire lake assuming Complete mixing had taken place. This higher concentration was eVident in ammonia and soluble phosphorus determinations also. Sulfate. There was an increase in sulfate ion following each application (Figure 10). Prior to fertilization there was’about 0.1 19.13.11. of sulfate at all chemical stations. One day after fertilization the concentration had changed very little. Four days after fertilization the concentration Ind increased to 0.51 p.p.m. at station A and 0.27 h8 I',_r i Figure 10. Sulfate ion (p.p.m.). Hdmw . .5303 52, 033:5... 85.1.53 N. am em om o. e. m. o; o n 89 em 0 r. E r. C C 2 a c : C :1. O 2925 1m. 2 ... c c n ; , c o a E C : z. _. 1N. E c m 20.55 -m C I c I C C = a c ”V IN. E [0. 1e. L ...... no. ,4 29.2.5 'W'd Table 7 Su1fate (p. p. In.) Date Station A Station B Station C July 26 0.10 0.10 0.09 50* . . 31 0.07 0.0h 0.13 Iktuge 3 0.51 0.27 0.0h 6 0.12 0.09 0.03 9* 10 0.25 0.10 0.15 12 0.12 0.10 0.07 16 0.12 0.08 0.13 18 0.00 0.01 0.08 20 0.01 0.02 0.01 2h 0.0h 0.0h 0.02 27 0.01 0.01 0.01 Sept. 3 0.09 0.07 0.0LI * Date of application of fertilizer 51 p.p.m. at station B. NO increase was detected at station 0. Three days later concentrations were again nearprefertilization levels at all stations. By the first day following the second application sulfate had increased to 0.25 p.p.m. at station A and 0.15 p.p.m. at station B. No significant increase occurred at station C. Two days later sulfate concentrations were again at prefertilization levels. They remained at this point until August 18 when they dropped to a trace. Only a trace could be detected until September 3, when they rose to preferti- lization levels. The changes in sulfate concentration were similar to changes in ammonia. After the first application Of fertilizer increases in ammonia and sulfate were not detected until the fourth day, whereas increases occurred one day after the second application. This differ- ence may have been due to the high winds which agitated the water and resulted in a more rapid dissociation Of the ammonium sulfate following the second application. BIOLOGICAL Plankton. This section of the discussion is primarily chemical in nature since no detectable increase in the plankton was observed fellowing fertilization. The plankton samples, however, did show a Visible increase in cloudiness which was due to a material that was rlocculent in nature. Analysis Of the plankton samples were under- tElwin to determine the relationship of the flocculent material to the addition of‘fertilizer. The methods used have been discussed 52 previously. In the following discussion total suspended solids, volatile fraction, phosphorus, calcium ion, and total hardness were determined from the centrifuged plankton samples. This is not neces- sarily the total amount that was suspended in the water at the time of sampling, since part Of the material was presumed to be lost in centrifugation. Thus the results Of these analyses may be lower than the actual concentrations in the lake at the time of sampling. To what extent the volumes are low was not determined. Only relative abundance Of a substance from one date to another is indicated by these analyses. Analyses of the total suspended solids in the centrifuged plankton samples showed increases after each application of ferti- lizer (Figure 11). For 20 days preceding fertilization the total suspended solids ranged between 8 and 9 p.p.m. Four days after the first application Of fertilizer the total suspended solids increased to 23 p.p.m. Two days later they had decreased to nearly the pre- fertilization level. This decrease in suSpended solids can be Correlated with photometer readings taken on the same date for the 3-and 6-foot depths. It should be kept in mind that the plankton 8Buliples were surface samples and presumably the waters would show faster clearing at the surface than at the deeper levels. At the time of the second application of fertilizer the total SuSpended solids were near the prefertilization level (Figure 11). Three days after the second application the total suspended solids had increased to 15 p.p.m. Six days later (August 17) levels were again 53 Figure 11. Relationships between total and acid insoluble suspended solids and their volatile fraction. .49” _ fkT Had unemDJOmZ QU< ........... n0 20:05... Had M 4m DJOWZ _ UIE. 0.9.. no ...... mQDOm aozwdmbm 43.0... WQZOm 2958 I390... lllll no zomwgn MI..._. monow 302$me 45.0.» I._ --: 55 .soueaaphou no downtowaams no aspen * .moHHOm oucsoagsm «HosHOmefl dead one moaHOm oucnoomsm HepOp no eowpaewa mood umoa Oceanus oonosuuuao ** II JIFF|HI E s.m H.H m.m w.: m.m om :.m m.o m.H m.: m.@ em :.m m4 :.m or: o.m :m o.m w.o m.H m.: o.m om mam To 04 ...: w.» 5 m: o; o.m :6 mos 8 o.» o.H w.H o.m m.ma «H o.: m.o s.s w.: m.m 0H s.: e.o o.a m.m >.m_ so 0.: m.o m.H :.m m.m o o.m H.H e.a m.: w.o~ m o.m m.H w.a m.: 0.0H : m.wa :.H ~.m m.om o.mm m .ws¢ one so. no. nos so. *om e.m s.o m.H m.m H.> em o.m m.H m.m :.: m.m om m.m m.H o.H 0.: o.m ma e.m m.H m.: m.m m.m o ease dossasms mosses nonsense sesaos steoapoouh no ooosoomsm so ooeeommsm open opmsopnso whoa vansaomoa mmOA aspoa shoe E A.a.o.ov .eoHpuwhh openonuso one .eoapaan no memmOA sauna .sosaom soosoooom oaooaomsH osoe_ooe Hesoa a sea 56 near the prefertilization level and they remained there for the duration of sampling. The volatile fraction of the total suspended solids gave an estimate of the organic matter and carbonates present. Organic matter and carbonates lose weight during ignition by the loss of carbon dioxide. It my be seen from Figure 11 that the volatile fraction (ash-free dry-weight) follows the same general pattern as the total suspended solids. Therefore variations in suspended solids probably reflected variations in either carbonate or some form Of organic matter. To test whether these variations were due to a carbonate or ' Organic material, an aliquot of the plankton sample was treated with 0 -05 N HCl to dissolve acid soluble compounds that were present in the precipitate. A total suspended solids determination was then nude on the remaining acid insoluble residue or "floc." This determin- ation gave the p.p.m. Of inorganic material plus the organic matter. Burning this residue above at dull red heat in a muffled furnace gives 8- loss in weight due to organic nutter. ‘ The results from the above procedure showed that the larger share or the total suspended solids went into the acid solution. By burning the acid insoluble precipitate the organic fraction was determined. It showed little variation throughout the summer. These data support the belief that there was no increase in plankton and suggest that the suspended material was some form Of carbonate. It is doubtful that there was any increase in bacteria. The centrifuge used does not remove all bacteria but normally removes large bacteria which 57 should have been present in the organic fraction of the determination. Since there was no increase in the organic fraction there is no reason to suspect that the suspended material was bacteria. Analysis of the acid extract also revealed the content of phOSphorus, total hardness and calcium present in the suspended material. TO be sure that all the phosphorus and calcium had been dissolved by the 0.05 N BCl, the residue remaining after burning the acid insoluble precipi- tate was treated with concentrated EDI. This solution was tested for phosphorus and calcium. Tests showed that these two substances were absent and indicated that the 0.05 N HCl completely dissolved the acid soluble salts. Determination Of the phOSphorus content of the suspended material showed that its phosphorus content increased following each fertiliza- tion and fluctuated in the same way as the phosphorus content of the lake water. This is shown in Figure 12 which compares the phosphorus content of the precipitate with insoluble phosphorus of the lake water. The quantity Of phosphorus in the precipitate was not as great as the insoluble phosphorus in the lake water but was a proportionate fraction of it. It is not likely that all the suspensoids were centrifuged out 01' tr: water and, if they had been, it is believed that the insoluble Phosphorus content of the lake water would agree with the phosphorus content of the suspended material in the plankton samples. The analyses of the acid extract of the plankton samples for total ha~2I:‘<1ness and calcium showed a reduction in these substances following ea~<:h application of fertilizer. Before fertilization the calcium 58 Figure 12. Relationships Of phosphorus in plankton samples to total phosphorus less soluble phosphorus in lake water, and to carbonates. PmDODJ. >4 3o 3E om em 9 8355.? snow mete mm a__ m. ...... _ _ .. I ....... l _ _ .. x \ - o. l \ m \ III, 7 \ vI \ 1 xx \ .. om / ......II .II.\ «\ loo 0! // e I 2 .on ..dw x. .d on. W0. A m. .8 a- ms<2omm e.ea om.m om.m oe.m mo.H mm.o mm.o oa.a os.H oo.H mm.H .......Aneoeeaaaaeav namaeumuo nasao> Hmpoa *m.mm s.oo m.mw o.mm s.mm o.m o.m o.m o.mH w.w m.oa .....eooe census and mamfienwno Ho Hoeaez Ham and we age Hm om m em 0m mm em ...........usueouwuo moaned annoy 00mm new new new mew new new new new new mom 000.000A900H ggdmv 6038mm cons H.309 ooH OH OH 0H OH OH 0H 0H 0H 0H 0H .....moaosue no wonssz Heeoa m em om ma m on mm 6H m, m . sonsuemom puswse ease [in open soeeooaaoo H nogmpm aonm monpeom camoomOhom—z Ho mofipduoaqam .3” 0H 968 77 «Haw: owcpgd a II ”I! fl! no. no. coo eo- ooo coo H co. co. coo-cocooeoOoCUflfidfihflm m ... ... ... ... ... H ... ... .............nco&n&u< ... ... ... m a ... ...........3odnoom:o ... H m ... .... ... ... ... ... ......e.......0d.©.nv.nom m m mm m ... H m H e ..........oueHeosHesoa i: H M N 000 H co. 0.. o... oeeoeooooeeeemw MHH‘Hm 4.. H H H .0. N H H N oooeeeeeoeeeovsnwflmgoo pm. om XMH Tm: ow mm nrma m m ensure aHse open soHeooHHoo Heusersoov HH oHsee ' ,".~.'M—-r‘.,‘ _ 78 Aomsereoov m. .0. 0.0 N coo .0. H .0. on. no. so. oQQIQOooeemgfigfln—“Opfig no. .00 900 can no. co. 00. ee- ooo no. 00. oooceogm ngoflgamofiflom one .00 .0. no. no. no. .0. so. so. so. so. eoeeeeoegm flflwhgufldg m on. H H N so. oo- oo. co. 00. H econ-Jag 0mm sea mom mmm mm mm HH ma mm om em .....msmastw suusunmm soe.o oo.H om.H wo.H em.o so.o om.o mm.o mm.o «v.0 m:.o .....eoou season use msdemwuo no manao> ©.>H 0m.m oo.m o>.m oo.H oo.H om.o mm.o 0m.a ow.H om.H .......AmhopHHHHHHsv mamHommuo ussHo> Hmpoa so.em o.mm m.em e.ooH o.mm m.sH m.m m.m m.OH «.mH m.mH .....eooe pauses nod msmHemmuo noessz new msH me wow am am 4H mm em mm mm ...........nsuHsemso Hansen Havos o.mm m.m m.m m.m m.m m.m m.m m.m m.m m.m m.m .......Heoou oeusunv doaaamm done Hmpoa OH 0H 0H 0H 0H 0H 0H 0H 0H 0H 0H .....mmaasmw no hmnssz Hence m hm om ma no 0m mm; ,0H m N sossusmum pummme aHse all. opus soHeooHHoo m soHpcpm soak monpeom 6Haoomonodz no eoHpehuasem NH manna 79 F - fl'll N .0. 000 00 e 000 0.0 unstM ommhm>¢ * I 1| IHII .............mmdwufihwm .............mdoaHnas< ...........mumm£oowHHO ..............0dc«mamm oeeoeoeooemddfidvmfidgmfi ecoeaooeoeeoomm WHHwHw oeoeeoeoooeeowgfiggaow ampoe om ma sneeze (ma hash dune soHeooHHoo Admseapmoov NH manna 80 of Hexaggnia nymphs. He found that these nymphs could not burrow successfully in clean sand taken from.a wave swept shore, but that they could burrow in marl, or a sand and marl mixture. However he gave no reference to the compactness of the marl used in his experi- ment. Needham (1920) observed Ephemera simulans nymphs during several seasons in Lake Michigan and Lake Ontario. In both localities the bottom was sandy, not muddy, and Hexaggnia was not observed. Burks l (1953) states that Ephemera simulan.n mphs are found near the shore I of lakes having considerable wave action and their characteristic habitat is small rivers with a fairly rapid flow. Hunt (1953) found ) Ephemera simulans abundant in sandy-mud bottoms of Big Silver and Gun lakes in southern michigan. He concluded that bottom type is of great importance in determining the local distribution of Hexagenia nymphs. Hexagenia nymphs are usually found in large numbers only in bottoms composed of soft marl, mud or clay and are largely restricted to a substratum which is soft, yet firm enough to permit maintenance of a burrow. Hexagenia do not ordinarily inhabit sand, gravel, rubble, peat or a bottom which is flocculent. It appears from.the literature that Ephemera simulans is a stronger digger than Hexaggnia and can dig and maintain burrows in harder bottoma. The difference in the distribution of these genera in Hoffman.lake is prdbably related to the slight difference in bottom texture noted above. Currents and agitation may also influence their distribution. 81 Some studies indicate that Hexagenia nymphs are more available than Ephemera nymphs. Ieonard (l9h7) found that Birch Lake, an oligotropic lake in southern.Michigan, supported populations of Hexagenia and Ephemera in about equal numbers, as shown by bottom sampling. Hexaggnia were commonly utilized by rainbow trout through- out the study, but Ephemera were rarely taken by the trout, other than at the time of mass emergence. The author concluded that E, simulans spends its nymphal life too deeply imbedded in the substrate to be~ available to bottom feeding rainbow trout and that Hexaggnia nymphs, on the other hand, either leave their burrows occasionally or at least come near enough to the surface of the lake bottom to be consistently taken by trout. .Assuming that other bottom feeding fish are not more successful in capturing Ephemera than rainbow trout, then the majority of the volume of bottom organisms in Hoffman Lake are not readily available to the fish, except at the time of emergence. To summarize, there is a difference in the distribution of Ephemera simulans and Hexagenia limbata in Hoffman Lake, and this is presumed to be due to a slight difference in bottom compactness; The preceding discussion indicates the need for a comprehensive study of the mayflies, particularly the genus Ephemera, to determine their availability and utilization by fish. The weekly variations in total number and volume of macroscopic benthos from station 1 and 2 may be seen from Figure 18, .Analysis of variance was used to test the null hypothesis that there was no statistically significant difference in the total volumes of organisms 82 Table 13 VquM" Analysis of Variance of Differences Between the Standing Crop of Macroscopic Benthos From Station 1 and Station 2 _ — Source Degrees Sum Mean of of of square "F" ratio variability freedom squares Total 199 33.8059 Stations 1 .h910 .h910 51.68* 1 Weeks 9 13.6h80 l. 5161; 159.62* “ Stations x Weeks 9 1.6906 .1878 19.77* Error 180 17.076 3 .0095 I * Significant at the 1 percent level. Nng' CW‘LK\&V<‘°/\> lH-x'b Tab’4 Ave W ovvuw . $4.4: WTTW‘L‘ ‘J '\\"*QT - 83 oH.o 0m.0 m0.0 00.0 0H.0 0 0 00.0 00.0 0H.0 .0H 0m.0 0m.0 m0.0 0m.0 00.0 0 0 0H.0 0m.0 0H.0 .0 00.0 04.0 00.0 00.0 m0.0 0 mH.0 0H.0 00.0 0H.0 .0 0m.0 0m.0 0m.0 0H.0 00.0 0 0 00.0 00.0 0H.0 .> 00.0 0H.0 00.0 no.0 00.0 no.0 0m.0 0H.0 0H.0 00.0 .0 0m.0 0m.0 04.0 00.0 0 0e.0 00.0 0H.0 00.0 0H.0 .m 00.0 0e.0 00.0 m0.0 00.0 mH.0 0H.0 00.0 0H.0 mH.0 .4 00.0 0e.0 0m.0 0H.0 no.0 00.0 no.0 0H.0 0m.0 0H.0 .m 00.0 00.0 0m.0 0m.0 00.0 no.0 no.0 0H.0 0H.0 mH.0 .0 0H.0 0m.0 0m.0 0H.0 00.0 no.0 0H.0 0H.0 0H.0 0H.0 .H Hop—use madamm 00330 00.0 00.0 0H.0 m0.0 0 0 0H.0 0H.0 0H.0 no.0 ..0H 00.0 0m.0 0H.0 m0.0 0 0 0m.0 00.0 0H.0 00.0 .0 00.0 00.0 00.0 0H.0 0 0 mH.0 0H.0 0H.0 0H.0 .0 0m.0 00.0 00.0 no.0 0H.0 0 0H.0 0H.0 0H.0 0H.0 .s 0m.0 00.0 00.0 00.0 m0.0 0 0H.0 00.0 0H.0 0H.0 .0 0e.0 0H.0 0m.0 m0.0 00.0 no.0 mH.0 00.0 0H.0 00.0 .m 00.0 0H.0 mH.0 0H.0 0 no.0 0H.0 0H.0 0H.0 0m.0 .e 0H.0 0e.0 0H.H 00.0 0m.0 no.0 0H.0 0H.0 0H.0 0H.0 .m 0m.0 00.0 mH.0 00.0 0H.0 no.0 no.0 00.0 0H.0 no.0 .0 0m.0 0m.0 00.0 no.0 0H.0 no.0 no.0 0H.0 0H.0 no.0 .H hogan: mamamm H soHeoem m a0, 00 MH ,0 0m m07 0H 0 0 weesoemom ensms< aHse ease soHeooHHoo HoHosum oweosa spasm son usoeHHHHHHzV .msuHeemso «Henson oHeoouosou: 0o uazH0> H0009 H0 nofipmnuazum :H 0.”an 8h between the two sampling stations or between the weeks of sampling. The: analysis showed that there was a highly significant difference in total volume between stations 1 and 2. Station 2 had a higher standing crOp of organisms than station 1. The standing crop does not neces- sarily mean that station 2 is more productive than station 1, but because the writer believes that predation by fish on most of the bottom fauna of Hoffman lake was insufficient to alter the general POpulation trends, it may be assumed that the larger crop at station 2 indicates higher production at this station. The analysis showed a highly significant difference between weeks of sampling (Table 13). This phenomena is of common occurrence in bottom fauna data because, normally, bottom organisms are at a low abundance during the summer because of emergence at this time. Figure 1.8 shows that minimum numbers and volumes occurred about July 30. This was due to the emergence of Ephemera simulans. It may be seen from Figure 18 that there was a very rapid increase in both numbers 4 and volumes after July 30. This was due to the appearance of newly hatched myfly wmphs in the samples. Ephemera and Hexagenia nymphs Present in Hoffman lake were small as compared with individuals of the same species which have been found in southern Michigan lakes. The largest Ephemera found was 0.8 inches and the largest Hexagenia “8 0.9 inches and both of these genera are commonly over an inch long at the time of maturity in southern Michigan. Nomenclature used in this paper for mayflies is given by Burks (1953). 85 Figure 18. The number and volume of macroscopic benthic organisms per square foot of lake bottom. A...’ REX HO IOO so so 70 so so 40 so :20 IO __-VOLUME ___NUMBER l L ML. no mo 90 80 70 60 50 40 30 20 J0 2 9 lb 23 m) 6 JULY 3 20 m' AUGUST 3 SEPT “this 87 To evaluate the effects of fertilization instantaneous rates of growth and mortality were calculated from the weekly standing crOp data. Howell (19h2) and Patriarche and Ball (1919) report significant increases in bottom organisms resulting from fertilization. If ferti- lization enhances more favorable conditions for Ephemera in Hoffman Lake it should be reflected in the rates of growth and possibly mortality. The changes in the production of a benthic organism can- nOt always be determined from a measure of the standing crop, because the production may be cropped off by fish. In this study no effort was made to establish total production figures for Hoffman Lake, because the data from the two stations showed that the bottom fauna was not distributed homogeneously throughout the lake, and not enough is known about the distribution of the organisms in relation to the different types of marl bottom to Justify the estimte. Because the population of Ephemera simulans is believed relatively free from predation by fish, this population affords an excellent o'Pportunity to estimte the natural mortality rates and growth of a burrowing mayfly population. Natural as used here means mortalities a11d. growths not affected by fish predation. Although the analysis or variance showed a difference in volumes between the two sampling Stations the. data for E. simulans has been clumped to compute mortality and growth rates. This is believed Justifiable because the same s"Hi-tions will be used for sampling in following years of investigation and thus the data will be comparable. -. wan-w I 1 88 enema“ omwa0>.0 00.0 ms.0 w.m 0.0 s.HH 0.0H 0.MH 0H 0: R 00 00 peck ohmsdm Hon whopHHHHHHs ussao> Auoaaswm poem unmade my whopHHHHHfis eH msmHemmao no masao> H0909 poom oamsdm nod Honssz Acoagsmm poem unmadm my msmHemwao ho unease H0909 HmpoB Hoesovmom s0 00 mH m vmdmm< 0m m0 70H m 0 mass wand aofipooaaoo N can a eoapmpm soak monpsom camoumoaomz someone ma oant 89 Figure 19, a frequency distribution, shows that the lowest numbers of E. simulans occurred around July 30. This was due to an emergence at this time. There are two different p0pulations of E. simulans represented in the data and they are designated as life cycle (generation) 1953-5h and life cycle (generation) l95h-55. It may be seen from Figure 19 that the 199-55 life cycle first appeared on August 6. Samples contained nymphs of the l953-5h life cycle until about August 20. July 30 is about in the middle of the emergence period of the l953-5h life cycle and it appears from the data that emergence probably began about July 16 and continued until August 20. In a southern Michigan lake Leonard and Leonard (l9h6) found E, simulans emerged in late_may, whereas emergence in Hoffman Lake was in late July. .After July 30 most of the E, simulans represented in the bottom samples belong to the 195h-55 life cycle. Leonard (19h7) found that E. simulans has an annual cycle and the data from Hoffman Lake supports this conclusion (Figure 19). Estimates of the instantaneous rates of mortality and growth have been computed from Figure 10. The instantaneous rate of mortality, based on reduction in numbers of organisms, was-(L187 per week for the 1953-5h life cycle. The gravimetric instantaneous rate of growth was calcudated to be 40.073 per week for the 1953-51: life cycle. This computation was made from the semi-log plot of the average lengths of nymphs. weight was computed from length by multiplying this logarithm of the length times 3. .IF"-'"'t . . 90 Figure 19. Frequency distribution of the number of Ephemera simuLans collected weekly from Hoffman Lake. NO. EPHEMERA 1 O 0 >J3o 23 HWDOD< 7 2 qum .3 .4 .5 .6 .7 INCHES .2 Table 16 Size Distribution of Ephemera simulans. (Grouped in One-tenth Inch Frequency Classes.) Collection Frequency classes in tinths of inches date 0.1 0.2 0.3 m 0.5 0.6 0.7 0.8 July 2 ... ... h 18 16 7 ... ... 9 ... ... 3 17 26 5 1 ... l6 ... ... ... h 22 1 ... ... 23 ... ... ... h 12 8 1 ... 30 ... ... ... 2 5 7 ... . Aug. 6 ... 6 ... 2 12 19 3 ... l3 3 22 32 10 15 9 ... ... 20 ... 103 1&0 7h 1h 19 ... ... 27 ... 17 60 107 3h 12 ... 1 Sept. 3 ... 2 38 15h 67 16 1 ... 92 93 Table 17 Number and Mean Length of Ephemera simulans Used for the Calculation of Instantaneous Rates of Growth and Mortality Life cycle l953-5h _Life cycle l95h-55 Collection Number Mean Number Mean date length length (inches) (inche§)_ July 2 h5 0.h6 ... ... 9 52 0.h7 ... ... 16 27 O.h7 ... ... 23 25 0.52 ... ... 30 1h 0.5h ... ... A“? 6 6 37 0.5 0.20 13 17* 0.52* 79 0.30** 20 ... ... 350 0.32 27 ... ... 231 0.39 Sept. 3 ... ... 278 O.h2 M * One-half frequency group 0.5 and all larger. ** One half frequency group 0.5 and all smaller. 9h The instantaneous rate of mortality for the 195h-55 cycle was computed to be -O.l92. This computation was made from the descending right limb of the catch curve (Figure 20). Since this curve was fitted by inspection to only three points; it gives a rough estimate, but shows that the mortality rate of the young individuals of the l95h-55 life cycle is nearly the same as the nearly mature individuals of the 1953-59 life cycle. The biological significance of this is not known. The numbers of Ephemera nymphs of the l95h-55 life cycle that were taken in samples during the latter part of the summer appear to form a typical catch curve when plotted on semi-log paper. Such a curve results from the escapement of smaller individuals from the catch, either in the process of washing or in sorting. Figures 19 and 20 illustrate such a phenomena. In Figure 20 it appears in the ascending left limb of the catch curve of the l95h-55 life cycle. In Figure 19 it appears as a ch0pping off of the smaller Sizer from a normal frequency distribution. The instantaneous rate of growth for the 195h-55 life cycle was computed to be +0.519 and this is much higher than the older numphs of the 1953-5h cycle. The primary use of the instantaneous rate of growth and mortality will be to compare with the rates computed from later years of sampling. It may be seen from Figure 20 and Table 17 that the mean length of the l953-5h life cycle of nymphs taken on July 2 was 0.h5 inch, and the mean length of nymphs taken at the end of the summer of the 195h-55 life cycle was O.h2 inch. Thus nymphs hatched in mid- summer were nearly as large by the end of the summer as nymphs taken in samples at the beginning of July which hatched the preceding summer. 95 ev—fi" M‘ Figure 20. Number and mean length of Ephemera simulans taken each week from Hoffman Lake; instantaneous rates of growth and mortality were determined from the slope of the lines. I 000 IOO NUMBER IIIT I III] IIIII r7 LIFE CYCLE I953-54 . MEAN LENGTH + NUMBER LO 0 1 L111] LIFE CYCLE l954-55 A MEAN LENGTH 0 NUMBER 1 l l 1 J 1 l l L 9 l6 23 3O 6 I3 20 27 3 JULY AUGUST SEPT. LENGTH IN INCHES 97 Whether this indicates exceptional growth of the l95h-55 life (2ch (due to fertilization) or that there is little or no growth of Ephemera from September to July could not be decided from the data at hand. £133. The primary objective of fertilizing natural waters is to increase the production of desirable fish. Fish cannot utilize inorganic nutrients directly, but do so indirectly through plankton, periphyton, benthos, and other forage groups. The fisheries biologist can determine whether or not fertilization increases fish production entirely from sampling the fish, but this approach does not give any information as to the succession of events responsible for additional production. Determining changes induced by fertilization in the physical, chemical, and biological conditions of a body of water may reveal factors that are limiting the production of fish. With this information management methods may be employed to produce the maximum of desirable fish. Fertilization may increase the production of fish in one of two ways: (1) The growth rates of the individual fish may increase. (2) The population any increase in size. Fish were collected through- out the summer for age and growth studies. Species taken were large- mouth bass, common sunfish, rock bass, common suckers, and yellow Perch. Sampling suggested that except for yellow perch the fish P0pulations were not large. All captured fish were marked by fin clipping and returned to the lake. During subsequent sampling many 01' the sunfish and rock bass, and a few suckers and largemouth bass I “ n; 98 were recaptured. Of the 57 largemouth bass marked during trapping operations eleven were reportedly caught by anglers during the summer. No game Species under 3 inches in length were taken or even seen in the lake. TVice during the summer the lake was seined in an attempt to obtain the smaller fish. A bag seine 150 feet long, 6 feet deep, and having a one-quarter inch mesh size was used. All seining was carried out in water less than 11 feet deep. Using this procedure sunfish, rock bass, suckers, largemouth bass, and yellow perch, all of which were over 3 inches long were collected. It did not seem likely that the small game fish escaped through the mesh of the seine, because numerous snail shiners and darters were captured. Due to the paucity of fish food, and the lack of cover for young fish, the scarcity of young fish may have been due to the predation of larger fish. The principal objective of sampling fish was to establish growth rates and length-weight relationships for the game species of fish in Hoffman lake. These determinations will be considered to be characteristic of conditions prior to fertilization and will be used at a later date to determine if the fertilization resulted in changes in growth. No attempt was made to estimte the size of the various thish populations. There is the possibility that fertilization may Produce conditions which are more favorable for the survival of young fish, and may result in an increase in pepuJation density. Yellow perch were probably the most numerous of the gene Simecies. In general they exhibited slow growth as compared with p... ...; 99 average growth of various age groups of Michigan yellow perch (Beckman 191%). The largest Specimen taken was 13.6 inches in length. Most fish were from age groups I to IV. Very few older fish were present. These older and larger fish exhibited faster growth in their early years of life than other fish. Absolute growth and annual growth increments for yellow perch are found in Table 18. The length-weight relationship was computed to be Loge W = -2.0965 + 3.0855 Loge L and is shown graphically in Figure 21. Mean instantaneous rates of growth for age groups II through V are given in Table 19. Of the game species rock bass were believed to be second in abundance. This species exhibited very slow growth. On the average they did not reach a length of 6 inches until their seventh growing season. Most fish were in poor condition and were heavily parasitized with Neascus sp. The largest Specimen taken was 10.0 inches in length and belonged to age group XII. A wide ranging habit was exhibited by a rock bass; one fish 9.3 inches long was marked after being trapped at the west end of the lake and the next day this fish was trapped at the east end of the lake. Age groups Iv through XII were represented in the scale samples. Absolute growth and annual increments of growth for rock bass may be found in Table 20. The length-weight relationwhip was computed to be Loge W :- -O.53hl + 2.6558 Loge L and is shown graphically in Figure 22. Mean instantaneous rates of growth for the last complete years growth are given in Table 21. Sunfish were common and probably furnished the best fishing of any Species. In the sample taken by trapping age group V and VI were Table 18 Absolute Growth of Yellow Perch From Hoffman lake 195h Number Mean total size Increment growth Age of length. Weight Length Weight group fish (inches) (grams L finches) (grams) I 8 3.8 7.3 3.8 7.3 II A6 h.6 13.6 0.8 6.3 III 28 5.0 20.“ 0.h 6.8 IV 13 5.5 27.9 0.5 7.5 V b ' 8.0 91.0 2.5 63.1 ‘VIII 1 13.6 h6l.0 ... ... 101 Table 19 ldkean Instantaneous Rate of Growth for Yellow Perch From Hoffman Lake, 195h Coefficient lxge Number Linear Gravimetric Standard of egzroup of rate of rate of deviation variability fish growth growth (fi) II h6 0.h3 1.32 0.317 2h.0 ‘III 28 0.26 0.79 0.197 2h.9 Iv 13 0.21 0.611 0.116 18.1 V h 0.19 0.58 0.095 l6.h VIIII l 0.17 0.52 ... ... 102 Figure 21. Length-weight relationship of the yellow perch. Curve A shows the absolute values; curve B shows the log-log transformation. hhhhh WEIGHT IN GRAMS Lose LENGTH o I 2 I00 1 u 7 so - 5 so - 5 7o - 4 so - 3 50 r- 2 B 40 h ' so - 0 A .. 20 1— . -| I0 ‘2 1 1 1 1 1 1 1 1 = 0o I 2 3 4 5 s 7 s 93 TOTAL LENGTH IN INCHES LOGe WEIGHT 1011 Table 20 Absolute Growth of Rock Bass From Hoffman Lake 19511 -L_ ‘— Number Mean total 8 ize Increment growth Age of length We ight length We ight goup fish (inches L (gems) (inche 5) (grams) I 8 2.1* u.2** 2.1 the” II 8 3.0* lo.8** 0.9 6.6** IIII 8 3.9’ 21.8** 0.9 ll.o** 1v 2 u.7 3u.o 0.8 l2.2** v 15 5.3 50.8 0.6 16.8 v1 32 5.7 60.7 O.h 9.9 ‘VII 26 6.1 72.8 o.u 12.1 \IIII 10 6.8 107.7 0.7 3u.9 Ix 10 7.h 125.9 0.6 18.2 x 3 8.5 18u.7 1.1 58.8 x1 1 9.3 23u.0 0.8 u9.3 XII 1 10.0 3h8.0 0.7 11h.0 * Back calculation from scales. ** Calculated from Loge w . -0.53h1 + 2.6558 Loge L. ‘81 ills-“Hr We. .- “-1.0 ‘ 105 Table 21 lfiean Instantaneous Rate of Growth for Rock Bass From Hoffman Lake, 195k Coefficient .Age Number Linear Gravimetric Standard of agroup of rate of rate of deviation variability fish growth growth ($) IV 2 0.29 0.78 0.120 15.h v 15 0.21 0.56 0.132 23.5 VI 32 0.12 0.33 0.085 25.8 VII 26 0.10 0.27 0.066 2h.h \lIII 10 0.09 0.2h 0.077 32.1 IX 10 0.08 0.22 0.050 22.7 X 3 0.08 0.20 0.033 16.5 XI 1 0.06 0.16 ... .. XII l 0.03 0.08 .. . . RI.“ ‘1 106 Figure 22. Length-weight relationship of the rock (bass. Curve A shows the absolute values; curve B shows the log-log transformation. WEIGHT IN GRAMS L0Ge LENGTH I 2 3 a i a, I00? Y I T 1 l l 1 3 «4 5 G 7 8 9 IO TOTAL LENGTH IN INCHES LOGe\NaGHT‘ 108 more numerous than age groups III and IV. This could be interpreted to mean that trapping selected the larger fish but this was also evident in fish caught by hook and line. Sunfish were growing slightly slower than the state average (Beckman 9p. sit.) and appeared to be in average condition. About one-half of the sunfish were heavily parasitized with Neascus sp. The largest specimen taken was 7.1 inches in length. Age groups III through VII were represented in the scale samples. Absolute growth and annual increments for common sunfish are shown in Table 22. The length-weight relationship was computed to be Loge W = 4.32211 + 3.1370 Loge L and is shown graph- ically in Figure 23. Mean instantaneous rates of growth for the various age groups may be found in Table 23. Common suckers were taken throughout the summer but the relative abundance of this Species is not known. Suckers were taken in about equal numbers in traps set at all depths. In water over 15 feet in depth they were the Species trapped most frequently. Only four other fish (two large yellow perch and two brook trout) were taken in.water deeper than 15 feet. The suckers were in poor condition; they had a thin body which narrowed abruptly behind a head that was dispr0por- tionately large for the body size. Since suckers feed mostly on organisms which are low in the food chain and as they are at present in extremely poor condition, they may respond more rapidly to ferti- lization than other species. Age groups III through VIII were repre- sented in the Scale samples. Absolute growth and annual increments __ A ., all l! -.r“; .. ..r Table 22 Absolute Growth of Common Sunfish From Hoffman Lake, 195h Number Mean total size Increment growth Age of Length Weight length Weight groupf fish (inches), jgrams) (inches) (grams) I 2h 2.u* u.2** 2.h h.2** II 2h 3.5* 13.6** 1.1 9.u** III 8 h.7 35.1 1.2 21.5** IV 12 5.6 61.7 0.9 26.6 V 38 5.8 65.5 0.2 3.8 VI 37 6.3 85.8 0.5 20.3 VII 7 6.9 118.3 0.6 32.5 * Back calculation from scales. ** Calcudated from Loge W = -l.322h + 3.1270 Loge L. 109 110 Table 23 Mean Instantaneous Rate of Growth for Common Sunfish from Hoffman Lake, 195h Coefficient Age Number Linear Gravimetric Standard of group of rate of rate of deviation variability ‘ fish growth growth (1:) III 8 0.39 1.22 0.393 32.2 IV 12 0.18 0.55 0.132 2h.0 V 38 0.16 0.h9 0.103 21.0 'VI 37 0.13 0.hl 0.07h 18.0 VII 7 0.09 0.27 0.0h7 17.l+ 111 Figure 23. Length-weight relationship of the common sunfish. Curve A shows the absolute values; curve B shows the log-log transformation. WEIGHT IN GRAMS Looe LENGTH O l 2 I40 _ T 5 IZOI- .- -I 4 I00- 'I 3 sob s 2 B 60r- -I I A 40- 'I 0 20!- 8". o l 4 1 1 '1 J l -2 O l 2 3 4 5 6 7 8 TOTAL LENGTH IN INCHES LOGe WEIGHT 113 for suckers may be found in Table 2h. The length—weight relation- ship was computed to be Log! W a -O.h388 + 2.3852 Loge L and is shown graphically in Figure 2h. Mean instantaneous rates of growth may be found in Table 25. largemouth bass were probably the least abundant of the game fish. Their growth was below the state average for the first two growing seasons, but following their second year their growth rate was above the state average. All largemouth bass taken from Hoffman Lake were in excellent condition. The larger bass were probably the only group of fish in the lake that have an abundant food supply. The largest specimen taken was 18.6 inches in length and weighed h 3/h pounds. Some bass were heavily parasitized with Neascus sp. Age groups II through VIII were represented in the scale samples. Absolute growth and annual increment for largemouth bass may be found in Table 26. The length—weight relationship was computed to be Loge w . 2.0813 + 3.2765 Loge L and is shown graphically in Figure-25. Mean instantaneous rates of growth for the last complete growing season for the various age groups may be found in Figure 26. Two brook trout were taken from the traps placed in the depression off the south shore. One was 11+ inches long and the other one 12 inches long, and both were in excellent condition. Growth rates were not determined for this species. The instantaneous rate of growth for all Species were the high- est for the youngest age group, and they decreased for each succeding age group, showing that as fish get older their rate of growth 11’: Figure 21+. length-weight relationship of the common sucker. Curve A shows the absolute values; curve B shows the log-log transformation. WEIGHT IN GRAMS 500 400 200 I00 LUGe LENGTH O 2 3 -__\/L 1 I ’ ‘ 8 h "I 7 I- .4 6 I- -I 5 I— B 4 4 .1 .. -‘ 3 A >- ‘I 2 b .1 | n- u o 44 J l 1 1 1 L 1 -| O 7' 9 II I3 I5 TOTAL. LENGTH IN INCHES LooexNaoHT 116 Table 2b Absolute Growth of Common Suckers From Hoffman Lake, 195u Number Mean total size Increment growth Age of Length Weight Length Weight group fish (inches) (grams) (inches) (grams) 1 18 u.8* 27.0** u.s 27.o** II 18 7.8* 86.0** 3.0 59.9** III 7 9.9 175.7 2.1 89.7** IV 13 11.0 199.7 1.1 2h.0 V 38 11.8 250.8 0.8 51.1 VI 8 12.7 307.0 0.9 56.2 VII h 13.5 33h.0 0.8 27.0 VIII 2 1h.2 389.0 0.7 55.0 117 Table 25. Mean Instantaneous Rate of Growth for Common Suckers From Hoffman Lake, 195k Coefficient .Age Number Linear Gravimetric Standard of group of rate of rate of deviation variability fish growth Agrowth Ci) III 7 .3h .81 .167 20.6 IV 13 .20 .h7 .115 2h.h V 38 .16 .38 .069 18.2 VI 8 .11 .26 .oh7 18.1 VII h .10 .25 .029 11.6 VIII 2 .09 .19 .050 26.3 Table 26 Absolute Growth of Largemouth Bass From Hoffman Lake, 1958 Number Mean total size Increment_growth Age of Length Weight Length Weight group, fish (inches) (grams) (inches) (grams) I 21 h.8* 21.5" h.8 21.5" II 23 8.6 151.7. 3.8 130.2** III 15 11.h 380.0 2.8 228.3 IV 7 13.7 672.5 2.3 292.5 V 8 1h.6 830.8 0.9 158.3 VI 2 15.9 106u.0 1.3 233.2 VII 1 17.3 12u8.0 1.u 18h.0 VIII 1 18.6 2213.0 1.3 965.0 * Back calculation from scales. ** Calculated from Logé w = -2.0813 + 3.2765 Loge L. Figure 25. Length-weight relationship of the largemouth bass. Curve A shows the absolute values; curve B shows the log-log transformation. IN GRAMS WEIGHT L0Ge LENGTH O I 2 I 750 , T I500 - I250 - '000 I' 7 . q 750 I- 500 5 ° - 250.» L 4 1 1 1 L l 1 L L L 00 8 IO I2 I4 I. I. TOTAL LENGTH IN INCHES U N LOGe WEIGHT 1 I N 1 O 1 Figure 26.. Gravimetric instantaneous rate of growth of various species. Mean rate is plotted on semi—log scale. INSTANTANEOUS RATE OF GROWTH | 0.0 I.0 IIIT I TTTT I 1 -....PERCI-I ..-- ROCK BASS SUNFISH .... SUC KER ...... LARGEMOUTH I IIIIINY'EIUIYIIIIIXII. AGEGROUP 123 decreases. Variability in the rate of growth was greater among fish of the younger age groups than among the older fish. Mean instant- taneous rates of growth for all Species are shown in Tables 19, 21, 23, 25, and 27. Condition factors of the fish were not computed, but the rela- tive state of condition (robustness) may be shown from the constant, 3, derived from the length-weight relationship. This constant (Slope of the log-log transformation, Figures 21, 22, 23, 2k, and 25) is usually near 3. A value of 2 higher than 3 means the fish is heavier in relation to its length than normal. A fish with an 3 value less than 3 has less weight in relation to its length. Hoffman Lake fish had n_va1ues as follows: largemouth bass 3.28, sunfish 3.1h, perch 3.09, rock.bass 2.66, and suckers 2.39. The n values for Hoffman Lake perch and sunfish were nearly the same as the state averages which were determined by Beckman (19h5). Hoffman Lake largemouth bass were much higher and rock bass much lower than state average. INTERRELATIONSHIPS BETWEEN PHXSICAL, CHEMICAL, AND BIOLOGICAL CHARACTERISTICS OF HOFFMAN LAKE Because of immediate decreases in transparency after each application of fertilizer, followed by a rapid clearing of the water which resulted in a greater transparency after fertilization than before fertilization, it was concluded that fertilization caused a flocculation or precipitation reaction. Following this 12h Table 27 Mean Instantaneous Rate of Growth for Largemouth Bass From Hoffman Lake, 195a Coefficient Age Number Linear Gravimetric Standard of group of rate of rate of deviation variability fish growth growth (5) II 23 0.7M 2.h1 0.h69 19.5 III 15 0.h0 1.32 0.190 lh.h IV 7 0.20 0.65 0.076 11.7 V 8 0.17 0.56 0.125 22.3 VI 2 0.15 0.h8 0.017 3.5 VII 1 0.10 0.33 .. .. VIII 1 0.08 0.26 ... ... 125 decrease in transparency at all depths, the upper 6 feet of water cleared and simultaneously there was a further decrease in trans- parency of the bottom waters. These transparency changes may be explained by assuming there was a homogeneous mixture of suspended material in the lake water immediately following fertilization that settled out of the upper strata and accumulated in the lower levels. The rate of settling of the suspensoids would depend on the specific gravity of the material and the amount of mixing due to wind action. Records of wind action, other than a note on the windy condition during second application of fertilizer, were not taken. Some workers in evaluating fertilization experiments upon hard water lakes have used decreases in transparency, as measured by the Secchi disk, as an indication of a biological response to fertili- zation in the form of a plankton bloom. The Hoffman Lake experiment suggests that some of these workers may have arrived at erroneous conclusions by the use of this measurement. The rapid loss of added nutrients from fertilized lakes has been assumed by some workers to be due to the increased biological activities of organisms transforming the added nutrients into living protoplasm. Hayes (1951) has demonstrated by the ume of radioactive phosphorus that decreases in added nutrients can and does occur by ion exchange. It has been concluded from many experiments that phosphorus becomes precipitated by calcium.in the form of tricalcium phosphate in hard water lakes. The experiment on Hoffman Lake neither proves or disproves this, but suggests the formation inorganic 126 precipitates containing phosphorus. Determinations point to the possibility of ammonium carbonate complexes being formed when ammonia is added to a hard water lake. It is possible that such an ammonia complex, if formed, would not be stable, but could account for the immediate and temporary decreases in water transparency. Loss of the fertilizer by drainage through the outlet is believed to be small. The outlet stream had an average flow of 3 cu. ft./sec. It was calculated that it would take approximately 173 days for the entire volume of water in the lake to drain through the outlet. Assuming no mixing and no loss of fertilizer by flocculation, pre- cipitation, ion exchange or uptake by organisms, it is calculated that 3h pounds of fertilizer would have left the lake each day as a result of both applications of fertilizer. The fertilizer that left the lake was sufficient to produce an increase in periphyton for about 10 miles downstream on the west Branch of the Sturgeon River. By the use of standard chemical methods increased amounts of ammonia in the stream.were detected three miles below the lake after the second application of fertilizer. Increases in phosphorus were not detected more than one mile below the lake following either application. This may indicate that the suspended material containing the phosphorus was being settled or strained out of suspension whereas the ammonia was either soluble or a more bouyant form of insoluble material than the phosphorus and consequently was carried further downstream. 127 Biological increases occurred in the form of periphyton following fertilization. These increases were measured quantitatively by chlorophyll extraction. Increases in periphyton were observed on logs that had fallen in the lake, on patches of bottom in shallow areas, on the submerged parts of bulrushes, and on the trap nets used to collect fish samples. Except on the bulrushes, periphyton was not evident prior to fertilization. The reason for the appreciable increases in periphyton and little or no increase in plankton are not known. Possible explanations may include: (1) There was sufficient seed stock of periphyton to utilize the nutrients, but no enough plankton stock because plankton organisms may have been flocculated out of suSpension. (2) Nutrients may have precipitated and settled too rapidly to be of much use to plankton organisms, but the insoluble flocculent material Settled upon the substrate occupied by periphyton organisms and these organisms were in some way able to utilize the insoluble material. 128 SUMMARY 1. Inorganic fertilizer was applied to Hoffman Lake, a 120- acre marl lake located in northern Michgan. A study was made of the physical, chemical, and biological characteristics of the lake before and after fertilization. ‘ 2. Transparency of the water decreased immediately after each application of fertilizer, thereafter the transparency increased to higher values than existed before the fertilization. This response from fertilization was due to the formation of a flocculent material which formed immediately after each application of fertilizer. 3. No change in the pH or alkalinity of the lake was found following fertilization. h. Concentrations of ammonia nitrogen, total and soluble phosphorus, and sulfate ion increased after each application of fertilizer, but these increases were only temporary and concentra- .tions returned to prefertilization levels within a week. 5. No detectable increase in phytoplankton or zooplankton was found. 6. Determinations made on water samples collected for plankton extraction showed increases in suspended material after each.appli- cation of fertilizer and the increase was due to a flocculent material which contained carbonates, phosphorus, and calcium. 7. The standing crop of periphyton produced during a 30~day period following the first fertilization was 10 to 30 times greater than the crop produced during a 30-day period before fertilization. 129 8. The standing crops of macroscopic benthos were sampled and measured for future evaluation of fertilization upon this group. No immediate measureable change in the benthos was expected the first summer, however, the rate of growth of the l95h-55 life cycle of Ephemera is possibly higher than the l953-5h life cycle which were produced before fertilization. 9. Fish, like macroscopic invertebrates, were not expected to Show a detectable response to fertilization the first summer. Data has been compiled for future evaluation of changes in growths which may occur following fertilization. 130 LITERATURE C ITED American Public Health Association 19h6. Standard methodshfor the examination of water and sewage. 9th ed., New York, 286 pp. Ball, Robert C. l9h8. Relationships of lake productivity to total fish production and to fish feeding habits. Mich. State Coll., Agric. Exper. Sta. Tech. Bull., 206 pp. Ball, Robert C. and Howard Tanner 1951. The biological effects of fertilizer on a warm-water lake. Mich. State Coll., Agric. Exper. Sta. Tech. Bull. 223, 32 pp. Barrett, Paul H. 1953. Relationships between alkalinity and adsorption and regeneration of added phosphorus in fertilized trout lakes. Trans. Am. Fish. Soc., 82: 78-90. Beckman, William C. 19h5. The length-weight relationship, factors for conversions between standard and total lengths, and coefficients of condition for seven Michigan fishes. Trans..Am. Fish. Soc., 75: 237-256. Beckman, William.C. l9h9. The rate of growth and Sex ratio for seven Michigan fishes. Trans. Am. Fish. Soc., 76: 63-81. 131 Burks, B. D. 1953. The mayflies, or Ephemeroptera, of Illinois. Bull. of the I11. Nat. Hist. Surv., 26: 1-211. Davis, H. and A. Wiebe 1930. Experiments in the culture of the black bass and other pondfish. U. S. Bur. Fish., Doc. 1085: 177-203. Domogalla, B., C. Juday, and W. Peterson 1925. The forms of nitrogen found in certain lake waters. Jour. Biol. Chem., *3(2): 269-285. E1115, I4. NI. 1937. Detection and measurement of stream pollution. Bull. 22, U. 8. Eur. Fish. 58: 365—u37. Ellis, M. M., B. A. Westfall, and M. D. Ellis l9h6. Determination of water quality. U. S. Dept. Inter., Fish and Wildlife Serv. Research Rept. No. 9: 199. Embody, G. 1921. The use of certain milk waste in the prOpagation of natural fish food. Trans. Am. Fish. Soc., 51: 76-79. Greenbank, John l9h5. Limnological conditions in ice-covered lakes, especially as related to winter-kill of fish. Ecol. Monogr., 15: 383-392. — Grzenda, Alfred R. 1956. The biological reSponse of a trout stream to headwater fertilization. Masters thesis Michigan State University. Gumtow, Ronald B. 1955. An investigation of the periphyton in a riffle of the West Gallatin River, Montana. Trans. Amer. Micros. Soc., 12h(3): 278-292. Harvey, H. W. 193%. Measurement of phytoplankton. Journ. Mar. Biol. Assoc. 19: 761-773. Hayes, F. R. 1951. On the theory of adding nutrients to lakes with the object of increasing trout production. Canad. Fish. culto’ 10: 1-70 Howell, Henry H. l9h2. Bottom organisms in fertilized and unfertilized fish ponds in Alabama. Trans. Am. Fish. Soc., l9hl, 71: 165-179. Hunt, Burton P. 1953. The life history and ecomonic importance of a burrowing mayfly, Hexagenia limbata, in southern Michigan lakes. Bull. of the Institute for Fisheries Research No. A, Mich. Dept. of Cons., 129 pp. 133 Lagler, Karl F. 1952. Fresh water fishery biology. Wm. C. Brown Co., Dubuque, Iowa, 360 pp. Langford, R. R. l9II8. Fertilization of lakes in Algonquin Park, Ontario. Trans. Am. Fish. Soc., 78: 133-lhh. Leonard, Justin W. 19A7. Differences in the occurrence of nymphs of two Species of burrowing mayflies in fish stomachs. Ann. Ent. Soc. Amer., MO: 688-691. Le0nard, J. W. and F. A. leopard 1996. An analysis of the feeding habits of rainbow trout and lake trout in Birch Lake, Cass County, Michigan. Trans. Am. Fish. Soc., 76: 301-31h. Lyman, Earle F. l9h3. Swimming and burrowing activities of mayfly numphs of the genus Hexagenia. Ann. Ent. Soc. of Amer., 36: (2). Maciolek, John A. 195h. Artificial fertilization of lakes and ponds-«A review of the literature. U. S. Dept. of Int., Fish. and.Wild- life Serv., Spec. Sci. Rept., Fish No. 113: hi. 13A Needham, James G. 1920. Burrowing mayflies of our larger lakes and streams. Bull. U. s. Bur. Fish., 36: 267-292. Neese, J. 19A9. Development and status of pond fertilization in central Europe. Trans. Am. Fish. Soc., 76: 335-358. Patriarche, Mercer H., and Robert C. Hall l9h9. An analysis of the bottom fauna production in fertilized and unfertilized ponds and its utilization by young-of— the-year fish. Mich. State Coll., Agric. Exper. Sta. Tech. Bull. 207: 35 PP. Patrick, Ruth l9h9. A proposed biological measure of stream auditions based on a survey of Conestaga Basin Lancaster County, Pennsylvania Pro. Acad. Nat. Sci. Phil., 101: 277-3h7. Roelofs, Eugene l9hl. Fisheries survey of Hoffman Lake, Charlevoix County Michigan. Report No. 698. Institute for Fisheries Research, Michigan Dept. of Conservation. Mimeograph Report. Rounsefell, G. A. and W. H. Eveth 1953. Fishery science: its methods and applications. John Wiley and Sons, New York. huh pp. 135 Smith, E. V. and H. S. Swingle 1939. The relationship between plankton production and fish production in ponds. Trans. Am. Fish. Soc., 68: 309-315. Smith, M. W. 193k. Physical and biological conditions in heavily fertilized water. Jour. Biol. Bd. Canada, 1: 67-93. Smith, M. W. 19h8. Fertilization of a lake to improve trout angling. Note No. 105, Prog. Rept. Atl. Biol. Sta., Fish. Res. Ed. Canada, A8: 3-6. Snedecor, George W. 19u6. Statistical methods. hth ed. The Iowa State Coll. Press, Ames, Iowa, A85 pp. Surber, E. W. l9h5. The effects of various fertilizers on plant growths and their probable influence on the production of small- mouth bass in hard water ponds. Trans. Am. Fish. Soc., 19h3: 73: 377-393. Swingle, H. S. l9h7. Experiments on pond fertilization. .Ala. Exp. Sta. Ala. Poly. Inst. Bull. No. 25h: 23. Theroux, Eldridge, and Mallman l9h3. Laboratory manual for chemical and bacterial analysis of water and sewage. 3rd. ed., McGraw-Hill, New YOrk, 27h pp. 136 Tucker, Allen 19A9. Pigment extraction as a quantitative analysis of phyto- plankton. Trans..Amer. Micros. Soc., 68 (1): 21-23. Welch, P. S. 19h8. Limnological Methods. Blakiston Co. Philadelphia, Toronto, 381 pp. Wiebe, A. 1930. Investigations on plankton production in fish ponds. U. s. Bur. Fish., Bull., us (1982): 137-176. Young, 0. W. 19A5. A limn010gica1 investigation of periphyton in Douglas Lake, Michigan. Amer. Micros. Soc., 6h (1): 1-20. ROOM USE ONLY Date Due I Demco-293 I III III l l l II III I l I I III I. III! III II II I l l II l l l I I l l l ' III I l l' l l I l l l I ll. 3 1293 03056 0860