US ISSN 0073-4918 J:LLJ:NOJ:S Natural History Survey BULLETJ:N Richard E. Sparks William C. Starrett STATE OF ILLINOIS An Electrofishing Survey of the Illinois River, 1959-1974 DEPARTMENT OF REGISTRATION AND EDUCATION NATURAL HISTORY SURVEY DIVISION URBANA, ILLINOIS VOLUME 31, ARTICLE 8 AUGUST, 1975 STATE OF ILLINOIS DEPARTMENT OF REGrSTRATrON AND EDUCATION BOARD OF NATURAL RESOURCES AND CONSERVATION RONALD E. STACKLER, J.D., Chairman; THOMAS P-ARK, Ph.D., Biology; L. L. SLoss, Ph.D., Geology; HERBEBT S. GuTOWSKY, Ph.D. , Chemistry; ROBERT H. ANDERSON, B.S.C.E., Engineering; W. L. EVERITT, E.E., Ph.D., Repre­ aenling the Pre,ident of the University of Illinois; JOHN C. GUYON, Ph.D., Representing the President of Southern lllinoia University. NATURAL HISTORY SURVEY DIVISION, Urbana, Illinois SCIENTIFIC AND TECHNICAL STAFF GEORGE SPRUOEL, JR., Ph.D., Chief ALICE K . ADAMS, Secretary to the Chief Section of Economic Entomology WILLIAM H . LUCKMANN, Ph.D., Entomologist and Head WILLIS N . BRUCE, Ph.D., Entomologiat WAYNE L. HowE, Ph.D., Entomologiat STEVENSON MOORE, Ill, Ph.D., Entomologist, Extension JAMES E. APPLEBY, Ph.D., Associate Entomologist EDWARD J. ARMBRUST, Ph.D., Associate Entomologist MARCOS l(ooAN, Ph.D., Aasociate Bntomologist JOSEPH V. MADDOX, Ph.D., Associate Entomologist RONALD H. MEYER, Ph.D., A,.ociate Entomologist ROBERT D. PAUSCH, Ph.D., Associate Entomologist RALPH E. SECHRIEST, Ph.D., As,ociate Entomologiat JOH~ K. BOUSEMAN, M.S., Assistant Entomologist GEORGE L . GODFREY, Ph.D., Assistant Bntomologiat MICHAEL E. IRWIN I Ph.D., Assi&tant Entomologi'Jt DONALD E. KUHLllfAN, Ph.D., Assistant Professor, Extension R oscoE RANDELL, Ph.D. , Assistant Professor, Eztenaion ·w1LL1AM G. RUESINK, Ph.D., Assi&tant Entomologist JAMES R . SANBORN, Ph.D. , A,sistant Entomologist DOUGLAS K. SELL, Ph.D., Assistant Entomologist C. ROBERT TAYLOR, Ph.D., Assistant Entomologist JOHN L . WEDBERG, Ph.D., Assistant Entomologist CLAnENCE E. WHITE, B.S., Assistant Entomologist Tu1 COOLEY, M.A., Assistant Specialist, Extension KURT E. REDB0R0, M.S., Ass-istant Specialist Jom, F. WALT, M.S., Assistant Specialist, Extension JEAN G. WILSON, B.A., Supervisory Assistant STEPHEN ROBEHTS, B.S., Junior Professional Sciefl..tist JOHN T. SHAW, B.S., Junior Professional Scientist DANIEL P. BARTELL, Ph.D., Research Associate BBTTINA FRAN CIS, Ph.D., Research Associate MARGARET ANDERSON, B.S., Research Assi.,tant RoBl!:RT J. BARNEY, B . S ., Research Assistant Tzu-SUAN CHU, M.S., Re,earch Assistant STEPHEN D. COWAN, B.S., Research Assi,tant STEPHEN K . EVRA.RD, B.S., Research Assistant MARION FARRIS, M.S., Research Assistant BONNI& lnw1N, M.S., Research Assistant JENNY KOGAN, M.S., Research Assistant GLENN L&VlNSON, B.S., Research Assistant ROSE ANN MECCOLI, B.S., Research Assistant BRIAN MELIN, B.S., Research Assistant CELIA SHIH, M.S., Research Assistant KATHY Woon, M.S., Research Assistant Jo ANN AUBLE, Technical Assistant Low&l~L DAVJS, Technical Assistant CHARLES G. HELM, M.S., Technical As,istant LINDA ISENHOWER, Technical Assistant Lu-P1NG LEE, M.S., Technical Assistant Section of Botany and Plant Pathology Cuus GRUNWALD, Ph.D., Plant Physiologist and Head ROBERT A. EVY.Rs, Ph.D., Botanist EUGENE B. HIMELICK, Ph.D. , Plant Pathologist R. DAN NEELY, Ph.D., Plant Pathologist D. F. SCHOENEWEISS, Ph.D., Plant Pathologist J . LELAND CRANE, Ph.D., Associate Mycologist WALTER HARTSTIRN, Ph.D., A,sistant Plant Pathologist BETTY s. NELSON, Junior Professional Scientist GENE E. REID, Technical Assistant Section of Aquatic Biology D. HOMER BUCK, Ph.D., Aqnatic Biologist WILLIAM F . CHILDERS, Ph.D., Aquatic Biologiat R. WELDON LARIMORE, Ph.D., Aquatic Biologiat ROBERT C. HILTIBRAN, Ph.D., Biochemiat ALLISON BRIGHAM, Ph.D., Assistant Aquatic Biologist WARREN U. B1t1GHAM, Ph.D., Assiatant Aquatic Biologist RICHARD E. $PARKS, Ph.D., A88iltant Aquatic Biologist TED w. STORCK, Ph.D., A,siatant Aqnatic BiOlogist Jo11N TRANQ0ILLI, Ph.D., A88istant Aquatic BiOlogist MAR~ FRANCES BIAL, Junior Profe,sional Scientiat CARL M. THOMPSON, Junior Profeasional Scientist RICHARD J . BAUR, M.S., Research A880Ciate DoNALD W . DuF,oRn, M.S., Research A88ociate JOHN M. McNURllEY, M.S., Re,earch As,ociate HARRY W. BERGMANN, B.S., Re,earch A,siatant KURT T. CLEMENT, B.S., Research Assistant LARRY W. COUTANT, M.S., Research A&Sistant HERBERT M. DREIER, M.S., Research Assistant MICHAEL A. FRAKES, M.S., Research Assistant THOMAS E. HILL, M.S., Research Assistant EARL THOMAS JoY 1 JR. 1 M.S., Research Assiatant RICHARD KOCHER, B.S., Research Assittant ROBERT MORAN, M.S., Research Assistant KATHRYN EwrNG, B.S., Technical Assistant SUSAN MOORE, Technical As.tUtant FLORENCE PARTENHEB-IER 1 B.A., Technical Assistant C. RussELL RosE, Field Assistant Section ot Faunistic Surveys and Insect Identification PHILIP W. SMITH, Ph.D. , Taxonomist and Head WALLACE E. LABERGE, Ph.D., Taxonomist MILTON W. SANDERSON, Ph.D., Taxonomist LEWIS J. STANNARD, JR., Ph.D., Taxonomist LARRY M. PAGE, Ph.D., Assistant Taxonomist JOHK D. {!NZICKER, Ph.D. , Assistant Taxonomi8t DONALD W. WEBB, M.S., Assistant Taxonomist BERNICE P. SWEENEY, Junior Professional Scientist CRAIG W. RoNTo, Technical Asmtant Section of Wildlife Research GLEN C. SANDERSON, Ph. D., Wildlife Specialist and Head F'RANK C. BELLROSE, B.S. , Wildlife Specialist JEAN W. GRABER, Ph.D., Wildlife Specialist RICHARD R. GRABER, Ph. D., Wildlife Specialist HAROhD C. HANSON, Ph.D., Wildlife Specialiat RONALD F. LABJSKY, Ph . D., Wildlife Specialist WILLIAM L. ANDERSON, M . A., Associate Wildlife Specialist W. W. CocHRAN, JR., B.S., As,ociate Wildlife Specialist WILLIAM R. EDWARus, Ph.D., Associate Wildlife Specialist G. BLAIR JOSELYN, M.S., Associate Wildlife Specialiat CHARLES M. NIXON, M.S., Associate Wildlife Specialist KENN~TH E. SMITH, Ph.D. , Associate Chemist . RICHARD E. WARNER, M.S., Associate Wildlife Specialist Ro1uLD L. WESTE>JAN D. LEVINE, Ph .D., Profeasor of _Vete':'nary Parasitology Veterinary Research and Zoology and Director of the Center for Human Ecology, Univernty of lllinoia; EZ:ToMOLOOY, ROBERT L. METCALF, Ph.D., Professor of Zoology and of Entomology, University of lllinoia; and GILBERT P. WALDBAUER, Ph.D., Profe,sor of Entomology, University of lllinoia; STATISTICS, HORACE W. NORTON, Ph.D., Profe.,or of Statiatieal Design and Analysis; University of Illinoia . CONTENTS ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317 PROCEDURE . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 RESULTS .................................... . .. . ....... ....... .... .. 319 Physical-Chemical Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 Electrofishing Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 Historical Changes in the Fish Populations of the Illinois River .... .. 332 Future Impacts on the Fish Populations of the Illinois River . . . . . . . . 342 SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344 LrTERA TURE CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377 INDEX .... • ............. ... .......................... . .............. 378 This report is printed by authority of the State of Illinois , IRS Ch. 12"1, Par. 58 .12. It is a contribution from the Section of Aquatic Biology of the Illinois Natural Histor11 Survey. Richard E. Sparks is an Assistant Aquatic Biologist, and the late William C. Starrett was an Aquatic Biologist, at the Illinois Natural History Survey. (66938-4M-8-75) ~)1 An Electrofishing Survey of the Illinois River, 1959-1974 FROM AS FAR BACK as historical ac­ counts are available, the Illinois River Valley has been described as unusually productive of fish and wildlife. The French explorer Marquette wrote in 1673 ( Mills, Starrett, & Bellrose 1966: 3--4): "We have seen nothing like this river that we enter, as regards to its fertility of soil, its prairies and woods; its cattle, elk, deer, wildcats, bustards, swans, ducks, parroquets, and even beaver." When Illinois was still a territory, the Illinois River Valley was considered one of the important sources of furs in the northwest part of the United States ( Starrett 1972: 139). There are older residents of the valley who recall the importance of fish and wildlife to some of the river towns in the early part of the century. Hugh Bell, Super­ intendent of the Illinois Department of Conservation Fisheries Field Head­ quarters at Havana, as a young man worked at filling specially constructed tank cars with fish to be shipped by rail from Havana to Chicago. At one time live fish also were shipped regu­ larly to Boston and New York, and the Illinois River ranked as a major inland commercial fishery. There was a U.S. government fisheries station at Mere­ dosia ( Forbes & Richardson 1920:XVI) . During that same period a train called the Fisherman's Special ran between Springfield and Havana, and there were many people in Havana who made their living outfitting and guiding fishermen and duck hunters. Because of their importance as unique resources, the Illinois River and its bottomland lakes were studied in­ tensively by the Illinois State Labora­ tory of Natural History and its succes- 317 Richard E. Sparks William C. Starrett sor, the Natural History Survey, from 1874 to 1927 ( Forbes 1928:387). More recently, surveys of the fish populations of the river have been conducted regu­ larly from the 1940's to the present. Various types of sampling gear have been employed in these surveys, for various purposes. For example, min­ now seines were used regularly in mid­ summer to collect small fish and there­ by gauge the spawning success of species which spawn in the spring. Hoop nets were used to collect large fish in backwaters and bottomland lakes. The present report concerns pri­ marily the electrofishing surveys, which have been conducted regularly in the Illinois River in the fall, from 1959 through 1974. ACKNOWLEDGME.NTS The electrofishing survey of the Illi­ nois River was conceived and carried out, for the most part, by Dr. William C. Starrett, Aquatic Biologist, Havana Field Laboratory, Illinois Natural His­ tory Survey. Dennis L. Dooley worked on the electrofishing survey, and other Illinois River studies, for 9 years. Robert Crompton, Howard Crum, and Ron Barker also assisted in the project un­ der Dr. Starrett' s direction. Following Dr. Starrett's death in De­ cember, 1971, the electrofishing survey was resumed in 1973 by the writer and Kenneth Walker, with assistance in locating stations and following previ­ ously established methods from Mr. Dooley. Carl M. Thompson assisted with the 197 4 electrofishing and helped compile and analyze data for this re­ port. We thank Lloyd LeMere for drawing the figures, Dr. R. Weldon Larimore 318 ILLINOIS NATURAL HISTORY SURVEY BULLETIN Vol. 31, Art. 8 for reviewing the manuscript, 0. F. Glissendorf for final editing, and Judith L. Breckenridge who did the typing. We are grateful to all the students and other assistants who helped with the program from 1959 through 1974. Finally, the electrofishing survey could not have been continued in 1974 without the support of the St. Louis District and the Waterways Experi­ ment Station of the U.S. Army Corps of Engineers. PROCEDURE Twenty-four sampling sites were chosen in 1959 that provided good habitat for adult fish and that were fairly well distributed throughout the length of the river ( Table 1). The same sites were usually sampled in succeeding years, except that one addi­ tional station, Big Blue Island Chute, was sampled in 1974. Most of the sites are in chutes, that is, side channels of the river, and contain brush piles, un­ dercut banks, and "holes" where vari­ ous species of fish are apt to congregate. The four exceptions to this general de­ scription are ( 1) the station above Pekin where both sides of the main channel were fished, ( 2) the station along the shore of Lower Peoria Lake, ( 3) the station in Middle Peoria Lake where docks and riprapping in various marinas were fished in the 1960's and where riprapping at a state conserva­ tion landing in Detweiller Park was fished in the 1970's, and ( 4) a station in the Des Plaines River where the wide mouth of the Du Page River and a boatyard were fished. The stations are located most accurately by river mile 0 -the exact number of miles up­ stream from the mouth of the river at Grafton, based on the Corps of En­ gineers' chart book of the Illinois Waterway ( U.S. Army Engineer Dis­ trict, Chicago 1970). A river mile designation shows the approximate area that was fished. For example, at the • Stations are located by river miles rather than by kilometers because existing rlver charts and navigation aids along the river use mileages. first station listed in Table 1, we fished that part of Mortland Island Chute which extended from mile 18.7 to mile 19.4. Pools in Table 1 refer to the waters impounded behind the dams and locks for navigation. Throughout this paper, references are made to these pools as convenient geographic locations of the various sections of the river. The lower part of the Illinois River is under the in­ fluence of the Alton Dam on the Missis­ sippi. The dams forming the other pools, in upstream order, are: La Grange (river mile 80.2), Peoria (mile 157.6), Starved Rock (mile 231.0), Marseilles (mile 247.0), and Dresden (mile 271.5) . Be­ cause the upstream pools are shorter than the downstream. ones, there are fewer stations in the upstream pools. The Illinois River begins at the con­ fluence of the Des Plaines and Kanka­ kee Rivers, and a distance of only 1.4 miles ( 2.25 km) separates the conflu­ ence and Dresden Dam. The Dresden Pool extends into the Des Plaines and Kankakee Rivers, and our one sampling station in the Dresden Pool is actually located in the Des Plaines River. The Kankakee is a relatively unpolluted stream, while the Des Plaines River receives municipal and industrial efflu­ ents from the Chicago metropolitan area, via the Chicago Sanitary and Ship Canal. The Des Plaines station is ex­ cluded when results from the Illinois River stations are used to compute average yearly catches per unit effort for the whole Illinois River ( Tables 3-27). The navigation dams help to main­ tain a 2.74-m deep navigation channel by impounding water during low-flow periods. When the water is thus im­ pounded the river behind the dam is said to be at pool stage. In order to sample under similar environmental conditions from year to year, electro­ fishing was conducted at the same time every year, from late August to the middle of October, and only when the river was in pool behind each of the navigation dams. Not all stations could Aug., 1975 SPARKS & STARRETT: ELECTROFISHING SURVEY OF ILLINOIS RIVER 319 be fished every year, because of high water levels, and no stations were fished in 1971 and 1972 due to high water. In addition, the Des Plaines River sta­ tion was fished only in 1959, 1962, 1973, and 1974, because it is not part of the Illinois River proper and was omitted whenever there was a limited amount of time available for sampling. Several . physical-chemical measure­ ments were made at each station be­ fore sampling of the fish populations began. Dissolved oxygen concentra­ tions at a depth of .91 m and at the bottom in the deepest part of the sta­ tion were measured by the Winkler azide method and, in 1974, with a YSI Model 57 dissolved oxygen meter. Sur­ face water and air temperatures were measured with a mercury thermometer. Wind direction and velocity and cloud cover were noted. Transparency was measured with a Secchi disk. In addi­ tion, turbidity of the river was mea­ sured with a Jackson turbidimeter dur­ ing some surveys. Fish populations were sampled by means of electrofishing. Fish were stunned by an electric current pro­ duced by a 230-volt, 180 cycles/sec, AC generator ( Homelite 9HY-l), and transmitted through the water via three cables suspended from booms in the front of a 5.49am aluminum boat. The stunned fish were dipped from the water and placed in plastic garbage cans containing water. Electrofishing was conducted in 15-minute segments, and a total of 60 minutes was spent electrofishing at most stations. In small chutes, or where an abundance of fish was collected quickly, only 30 minutes were spent electrofishing. Fish were identified, counted, weighed, checked for disease, and returned to the river. The few fish that died were buried on shore. RESULTS PHYSICAL-CHEMICAL RESULTS Physical-chemical results for the fall of 1974 are shown in Table 2. Since the dissolved oxygen levels at both the .91-m depth and on the bottom were approximately the same at every station, the water was presumably well mixed. The dissolved oxygen concen­ tration was 77-97 percent of saturation in the Alton Pool, 65-122 percent of saturation in La Grange and Peoria Pools, and 47-104 percent of saturation in Starved Rock, Marseilles, and Dres­ den Pools. At Ballard Island Chute (mile 247.8-248.2) and in Lower Peoria Lake (mile 163.0-163.4), the atypically high oxygen values ( greater than satu­ ration)· were probably due to algal photosynthesis, since the waters had a greenish or brownish tinge. Ballard Island Chute is shallow, and has a large surface area, slow current, and a very dissected shoreline, with many marshy blind pockets. Thus, it should be a likely spot for phytoplankton to develop. The Secchi disk visibility here was much lower than in the river al­ though some of the turbidity on' the sampling date can be attributed to wave action on the shallow bottom as well as to phytoplankton. ' The upper river in 1974 was gen­ erally more transparent, as measured by the Secchi disk, than the lower river. Starrett ( 1971 :273) found that turbidity readings with a Jackson tur­ bidimeter were higher in the lower three pools than in the upper three pools in the period 1963-1966. The Alton, La Grange, and Peoria Pools are generally more turbid than the upper pools, presumably because the lower pools have soft mud bottoms and re­ ceive heavy silt loads from tributary streams that drain agricultural areas. The river above Hennepin ( mile 207.5) generally has a rocky bottom, although the rock is overlaid with mud sand and/ or gravel in some sections. ' ' Towboats ( several barges pushed by a diesel-powered boat) have a marked effect on turbidity in the Illinois River. Fig. 1 shows that the turbidity in mid­ channel at mile 25.9 was increased by about 100 Jackson turbidimeter units ( JTU) as towboats passed on three 320 ILLINOIS NATURAL HISTORY SURVEY BULLETIN Vol. 31, Art. 8 180 70 7 NOVEMBER 1963 0 170 MILE 25,9 MID-CHANNEL 160 ~ (/) 65 150 f- ~ z: => z: 140 0:: C> w f- f- w ex: ~ 0: 130 e => f- ex: 60 J::Q (/) 0: => .... 120 f- z: C> z: (/) w llO ""' <.!) u >- ex: X ~ C> 55 100 >- f- Q 90 J::Q 0: => f- 80 5 70 900 1000 UDO 1200 1300 1400 1500 CENTRAL STANDARD TIME OXYGEN= o---OSURFACE ~ MID-DEPTH 0 BOTTOM t BARGE PASSAGE ....... TURB ID ITV Fig. I .-Dissolved oxygen concentrations and turbidity in the middle of the navigation channel of the Illinois River at mile 25.9, during passages of towboats on 7 November, 1963. Symbols for dissolved oxygen are circles for at the surface, triangles for at mid-depth, and squares for at the bottom. Turbidity is indicated with black dots. The time at which each towboat passed mile 25.9 is marked by an arrow. occasions on 7 November, 1963. It took approximately 2½ hours for the tur­ bidity to return to background levels following passage of towboats. A Natural History Survey crew took a few dissolved oxygen readings in midchannel on 6 and 7 November, 1963, before, during, and after tow­ boats had passed ( Fig. 1 and 2). One might expect turbulence from move­ ment of the hulls and from the pro­ pellers to aerate the water. Surpris­ ingly, oxygen levels at the surface de­ clined and then recovered following passage of a towboat on 6 November. On 7 November, oxygen levels at both the surface and bottom declined. The declines are significant; oxygen levels at the surface on 6 November and at the bottom on 7 November declined by 0.4 mg/1, and the standard deviation of the method used ( azide modification of the Winkler method) is 0.1 mg/I, even in the presence of appreciable interference. The decline in dissolved oxygen and the increase in turbidity are both attributable to the resuspension of sediment caused by towboats mov­ ing in the relatively shallow naviga­ tion channel ( 2. 7 4 m deep). Sediments in the Illinois River exert an appreciable oxygen demand, and the demand in­ creases 7-fold to 10-fold when the sedi­ ments are disturbed. For example, Butts ( 1974:12) reported an oxygen demand of 2.8 g/ m2/day for sediment at mile 198.8, under quiescent condi­ tions, and 20.7 g/ m2/day when the sediments were disturbed. The dis­ turbance was produced by water cur­ rent within a special chamber which Butts had constructed to measure in Aug., 1975 SPARKS & STARRETT: ELECIBOFISHINC SURVEY OF ILLINOIS RIVER 321 7 70 z: 0 I- ~ ::::, I- ->< 0 6 ~ 1300 1400 1500 1600 CENTRAL STANDARD TIME 1700 150 1110 130 120 110 100 90 80 70 60 50 40 V) I- 6 NOVEMBER 1953 z: ::::, MILE 25.9 °" MID-CHANNEL UJ I- UJ ~ Q "" OXYGEN °" ::::, I- 0----0 SURFACE z: b,. 0 MID-DEPTH U) ""' D--0 BOTTOM u ~ ~ ~ "' ~ er., "tl ~ V) ~ er., I t:rj I er., c ~ ..,: 0 "'.I -I ~ < !ri ~ 1959 60 61 62 63 64 65 66 67 68 69 70 73 74 1959-1974 w Nl ~ 1:~ : I I : I I I I I I I I ---1.,.._ ~ < w c:: I- en c.. DRESDEN ::, - - ---- ..... 10~ t"' t"' z 0 ~ MARSEILLES : • • z - - - - - - - - - - - ---- > 1:~ 2 !:ti STARVED > t"' ROCK I ::i:: I I • - -I - --- ~ - - -- - - ,-J 0 1:~ !:ti >< rJl PEORIA C ::0 • • <: - • -- • • tTl - - - - - - ---- >< 1:~ ti::, C t"' LA GRANGE t"' t'l ::l z - - - - - - - - - - - - ---- ~ 1:~ < w ALTON c:: I- en < z 3:: £. 0 "T" , I .,. _.,.._ A I I I I I I I I I I 1959 60 61 62 63 64 65 66 67 68 69 70 73 74 1959-1974 w ..... • Fig. 4.-The number of carp x goldfish hybrids taken per 30 minutes of electrofishing in the Illinois River, arranged by pool and year. The .... :-'" average numbers taken during the years 1959-1974 are shown in the last column. When electrofishing was conducted, but no fish were taken, 00 a very small bar is shown on the figure. Where no electrofishing was conducted, there is no bar. To determine whether a small number of fish or no fish were taken, refer to the text or the tables. I ~ DRESDEN --= UJ a: .... CJ) ~ MARSEILLES ~ --= UJ a: .... CJ) z 3: STARVED ROCK PEORIA LA GRANGE g ALTON 1959 60 61 62 63 64 65 66 67 68 69 70 20 ~ I I 1111 I I I • I I I ' I 03 2 ~ • - I • I • I • I • • • ~ - I I I I • I I • - - I 40~ : • • I I I I • I I I I I 4 :~II .• ,,.,,, •. 1959 60 61 62 63 64 65 66 67 68 69 70 73 - • - 74 1 • • • ._J_ u r 73 ' 74 1959-1974 ---1,_ -•- _.__ ...L _L J_ _._ 1959-1974 > C: ~ ...... CD -l Cll r:JJ ~ ~ V, R" r:JJ .., ;i., ,, ,, 9 ~ t"' t'1 ~ 0 ~ V, :i:: ~ r:JJ C: ,, < t'1 -< 0 "1 ..... t"' t"' z 8 "' c' ~ Fig. 5.-The number of carp taken per 30 minutes of electrofishing in the Illinois River, arranged by pool and year. The average numbers taken during the years 1959-1974 are shown in the last colum~. (Gizzard shad, like carp, were abundant throughout the river. ) When electro- ~ fishing was conducted, but no fish were taken, a very small bar 1s shown on the figure. Where no electrofishing was conducted, there is no bar. C1l To determine whether a small number of fish or no fish were taken, refer to the text or the tables. 326 ILLINOIS NATURAL HISTORY SURVEY BULLETIN Vol. 31, Art. 8 ( 1928: 285). At present, carp and giz­ zard shad are the only species that occur abundantly in our electrofishing collections in all pools of the river ( Fig. 5). Carp and bigmouth buffalo comprise the bulk of the commercial catch in the Illinois River. The carp catch from the Illinois River was 213, 000 pounds ( 104,000 kg) in 1973. River Carpsucker, Quillback Carpsucker (Tables 11 and 12) The greatest number of quillback carpsuckers ( Carpiodes cyprinus) was usually taken in three pools of the Illi­ nois River : Marseilles, Starved Rock, and Peoria. In contrast to the quillback, the most river carpsuckers ( Carpiodes carpio) were generally taken in the three lower pools, Alton, La Grange, and Peoria, prior to 1973. In 1973 and 1974 most were taken in Starved Rock Pool, so their distribution in the river may have changed after the high-water period 1971-1973. The quillback and river carpsuckers are both commercial spe­ cies. Smallmouth Buffalo (Table 13) The largest numbers of smallmouth buffalo ( lctiobus bubalus) were taken from Peoria and La Grange Pools. An unusually large number of smallmouth buffalo were taken from Starved Rock Pool in 1974. The smallmouth buffalo is a commercial species. Bigmouth Buffalo (Table 14) Like the smallmouth buffalo, the big­ mouth buffalo ( lctiobus cyprinellus), was most commonly taken in Peoria and La Grange Pools. Prior to 1974 no bigmouth buffalo had been taken from Dresden and Marseilles Pools, and bigmouth buffalo had been taken in Starved Rock Pool in only one year, 1966. In 1974 they were taken in both Starved Rock and Marseilles Pools. It is surprising that few buffalo were ever taken in Alton Pool, and that no buffalo were taken there in 1974. Sev­ eral commercial fishermen at Kamps­ ville Landing and Godar Landing on the Alton Pool said that they also were catching very few bigmouth buffalo in 1974. Bigmouth buffalo rank second to carp in the commercial catch from the Illinois River. Black Buffalo (Table 15) The black buffalo ( I ctiobus niger) is a commercial species. It was not abun­ dant in the Illinois River electrofishing collections, and was taken only in the lower three pools prior to 1974. It was most commonly taken in Peoria and La Grange Pools. In 1974, the few black buffalo taken all came from Starved Rock Pool. Shorthead Redhorse (Table 16- Discussed under "Species Infrequently Taken") Black Bullhead (Table 17) The black bullhead ( lctalurus me las) is considered a commercial species, but most of the bullheads in our elec­ trofishing collections were quite small. Most of the black bullheads were taken froni one station, Ballard Island Chute ( river mile 247.8-248.2) in Marseilles Pool ( Fig. 6), which was described earlier as being an unusually shallow, broad, marsh-fringed area, with very little current. The black bullhead probably prefers this type of habitat. Black bullheads were collected occa­ sionally in the main navigation channel, by means of an otter trawl. For ex­ ample, on 26 August, 1964, 51 black bullheads averaging 18 cm in total length were taken in 49 minutes of trawling at mile 193. Yellow Bullhead (Table 18 - Discussed under "Species Infrequently Taken") Channel Catfish (Table 19) Channel catfish (lctalurus puncta­ tus) were taken in Marseilles Pool for the first time in 197 4. Also, the sec­ ond largest number and weight of fish were taken in the river in 1974 ( Fig. 7). Most channel catfish were taken below Beardstown ( river mile :E 1959 60 61 62 63 64 65 66 67 68 69 70 73 74 1959 -1974 ct > LJ.J : I ' : I I I I I I I I _j__ c:: ]:~ C I- 20 qq (/) c.. ...... ::::, (D DRESDEN ----l (Jl_ ----]:~ r:r, '"(I > I :0 ~ I I (/) MARSEILLES I I _L ~ - • • - • • • r:r, .., l:~ ~ :0 STARVED t'1 ROCK ~ - - • - - - • - - - - - - - ---- tr1 l:j t"' t'1 n .., :0 0 PEORIA ::1 (/) - - -- - - - - - - - - --- - --- ::i: l:~ z (j r:r, C: LA GRANGE :0 < t'1 - ,< - - - - - - - - - --:E 0 ct l:~ "'1 LJ.J c:: ...... I- t"' (/) t"' z z 3: ALTON 0 0 0 H 'T" 'T" T" 'T" "T'" .....,._ (/) I I I 'T" T" r T I I ~ 1959 60 61 62 63 64 65 66 67 68 69 70 73 74 1959-1974 < t'l :0 Fig. 6.-The number of black bullheads taken per 30 minutes of electrofishing in the Illinois River, arranged by pool and year. The average w numbers taken during the years 1959-1974 are shown in the last column. (The black bullhead was the only species restricted primarily to one station N) within one pool.) When electrofishing was conducted, but no fish were taken, a very small bar is shown on the figure. Where no electrofishing ----l was conducted, there is no bar. To determine whether a small number of fish or no fish were taken, refer to the text or the tables. 1959 60 61 62 63 64 65 66 67 68 69 70 73 74 1959-1974 w ::;: 1: ~ : I I : I I I I I I I I __L_ Nl < 00 UJ a:: I- CJ) 0.. DRESDEN ::, ----- 10~ --t'" z 8 MARSEILLES : (/) - z 1~~ > .., c:: STARVED :,; > ROCK t'"' - - ::c - - - - - - - - - - - -- .... (/) 1:~ .., 0 :,; ..,: rJ) PEORIA c:: :,; < - - - - - - - - - - - - - - ---- t'l 1~~ ..,: ttl c:: t'"' LA GRANGE I t'"' t'l • • • • .., - - - -- - - --- z ::;: l:~ I < UJ a:: ' J I- ALTON CJ) ' • z ' ' ' ' < 3: • 0 Cl I I I I ~ 1959 60 61 62 63 64 65 66 67 68 69 70 73 74 1959-1974 w ...... Fig. 7 .-The number of channel catfish taken per 30 minutes of electrofishing in the Illinois River, arranged by pool and year. The average > numbers taken during the years 1959-197 4 are shown in the last column. ( Short nose gar, bowfin, goldeye, mooneye, flathead catfish and white ..., bass showed a similar pattern of increasing numbers in the downstream direction, toward the Mississippi River.) When electrofishing was con- :-'" ducted, but no fish were taken, a very small bar is shown on the figure. Where no electrofishing was conducted, there is no bar. To determine whether 00 a small number of fish or no fish were taken, refer to the text or the tables. Aug., 1975 SPARKS & STARRETr: ELECTROFISHINC SURVEY OF ILLINOIS RIVER 329 88.5). They were taken occasionally from the main navigation channel by trawling. On 13 November, 1964, 68 young channel catfish averaging 9 cm in total length were taken in 53 minutes of trawling in the channel at mile 156. Prior to 1973, the numbers and weights of channel catfish taken appear to be unrelated to water levels. Channel cat­ fish have declined in the Illinois River since 1899 as evidenced by the follow­ ing commercial fishing statistics: 241, 000 pounds (109,316 kg) in 1899, 105, 554 pounds (47,878 kg) in 1950, about 98,000 pounds ( 44,452 kg) in 1964 ( Mills, Starrett, & Bell rose 1966: 17) , and 45,000 pounds (20,412 kg) in 1973. ( Larry Dunham, Fishery Biologist, Illi­ nois State Department of Conservation, personal communication.) Flathead Catfish (Table 20) Flathead catfish ( Pylodictis olivaris) are a desirable commercial species and often reach weights of 9-18 kg. Flat­ head catfish were never abundant in the electrofishing collections, and were confined to the lower two pools. An 8.16-kg individual was taken in La Grange Pool and several 1- or 2-year­ old flatheads were taken at several stations in both Alton and La Grange Pools in 1974. White Bass (Table 21) The white bass ( M orone chrysops) is a game species. The largest number of white bass was taken from the river in 1974, but the greatest catch by weight was in 1968. White bass popu­ lations generally increased in the down­ stream direction, with the largest num­ ber and greatest weights usually taken in Alton Pool. Green Sunfish (Table 22) Green sunfish ( Lepomis cyanellus) are considered game fish by some people, although they do not grow as large as their relative, the bluegill. The green sunfish was taken in the Des Plaines River in two of the four years this station was sampled, whereas the bluegill was never taken from this sta- tion. The largest numbers of green sunfish were generally taken in Peoria Pool. The number of green sunfish taken did not increase dramatically after the high-water period 1971- 1973, as did the number of bluegills. Bluegill (Table 23) The largest number and greatest weight of bluegills ( Lepomis macro­ chirus) per 30 minutes of electrofishing were taken in 1974. Bluegill popula­ tions generally increase in the down­ stream direction, with either Alton or La Grange Pools having the greatest number and weight. However, in only one year, 1969, were more bluegills obtained in Starved Rock Pool than in the next pool upstream. Largemouth Bass (Table 24) The largemouth bass ( Micropterus salmoides) is a game species. Large­ mouth populations generally increase in the river in a downstream direc­ tion ( Fig. 8), with the greatest num­ bers taken from La Grange and Peoria Pools. However, fewer bass were taken at the two stations in Starved Rock Pool than at the three stations in the next pool upstream, Marseilles. Bass popu­ lations in the river as a whole reached their peak in 1960 and 1961, then showed a drastic decline during and following the drought years 1962- 1964. The recent increase in largemouth pop­ ulations follows the high-water years 1971-1973. Crappies (Tables 25 and 26) The largest catch of both black crappie ( Pomoxis nigromaculatus) and white crappie (Pomoxis annularis), in weight and numbers, was taken in the river in 1974, following the high-water years 1971-1973. Populations of both species showed a steady decline in the years 1962--1965, during a drought pe­ riod. Prior to 1973, few crappies were taken in the upper three navigation pools, but increased numbers of both species were taken in the Starved Rock and Marseilles Pools in 1974. In 1962, 1959 60 61 62 63 64 65 66 67 68 69 70 73 74 1959-1974 :Ii: l:l : I I : I I I I ' ' ' I ----L <{ w w w ~ DRESDEN 0 Cl.. ::, - - -l:~ -r r MARSEILLES z • • 8 - "' - - - - - - I- - ---l:~ z > .., STARVED C: ,, ROCK > r - - - - - - - - - -- ::r: ..... l:~ I "' .., 0 ,, PEORIA I I >< I rJl • • • _. C: - - ,, - - ~ l:~ 1"1 >< LA GRANGE I t,:, C: .I r I r • • • • t'1 - --- .., l:~ z ~ ALTON ' w ' c:: ' I- • .. "' .,. T' T • .,. < z I I I I I £. 3: 1959 60 61 62 63 64 65 66 67 68 69 70 73 74 1959-1974 0 Q w I-- Fig. 8 .-The number of largemouth bass taken per 30 minutes of electrofishing in the Illinois River, arranged by pool and year. The average - numbers taken during the years 1959-1974 are shown in the last column. (The following species were also most abundant in collections from Peoria ~ .., and La Grange Pools : gizzard shad, carp, river carpsucker, smallmouth buffalo, bigmouth buffalo, black buffalo, yellow bullhead, green sunfish, blue- :-1" gill, white crappie, black crappie, and freshmater drum.) When electrofishing was conducted, but no fish were taken, a very small bar is shown on 00 the figure. Where no electrofishing was conducted, there is no bar. To determine whether a small number of fish or no fish were taken, refer to the text or the tables. Aug., 1975 SPARKS & STARRETT: ELEcrnOFISHING SURVEY OF ILLINOIS RIVER 331 1964, 1966-1969, and 1974, more black crappie were taken in La Grange Pool than in Alton Pool, perhaps because more backwater and side channel areas with brush piles ( a favorite habitat of crappie) were usually available in La Grange Pool. In 1974 a larger number of small white crappie was taken in La Grange Pool than in Alton Pool but a greater weight of large white crappie was taken in Alton Pool. Both species are popular game fish. Freshwater Drum (Table 27) Freshwater drum ( Aplodinotus grun­ niens) is a commercial species. Most were taken in La Grange Pool. The largest number of individuals and the second greatest weight were taken in 1974, following a high-water period. Species Infrequently Taken The yellow bullhead ( I ctalurus na­ talis) ( Table 18) was uncommon in our collections, and has been taken only from the three lower pools, Alton, La Grange, and Peoria. The shorthead redhorse ( M oxostoma macrolepidotum) ( Table 16) occurred sporadically in our collections through­ out the river. A female spotted gar ( Lepisosteus oculatus) was taken by a commercial fisherman at Havana on 26 February, 1973. Spotted gar are uncommon in the Illinois River. This specimen was the largest that had been taken in Illinois ( 3.41 kg, 83.8 cm in total length) and was fulI of ripe eggs. Mooneye ( H iodon tergisus) ( Table 7) were taken rarely, and only from the Alton Pool until 1974, when one was taken from upper Peoria Pool at mile 215. Goldeye ( H iodon alosoides) ( Table 6) were taken rarely, but ranged farther upstream than their relative, the mooneye. In 1974 only two goldeye were taken, both from one sta­ tion at mile 261 in Marseilles Pool. The American eel ( Anguilla rostrata) was rarely taken. One was taken from Alton Pool at mile 19 and two from Peoria Lake in 1974. The white catfish (lctalurus catus) is a native of brackish to fresh waters along the East Coast from Pennsyl­ vania to Florida. It has been intro­ duced widely in the Midwest, and sev­ eral have been taken from the Illinois River by commercial fishermen at Ha­ vana, including one on 13 May, 1974. White catfish have never been taken in our electrofishing surveys. The few smallmouth bass ( Microp­ terus dolomieui) that were taken were probably introduced from tributary streams that are smaller and colder than the Illinois River. Skipjack herring (Alosa chrysochlor­ is) were taken sporadically throughout the Illinois River. Large numbers ap­ parently moved up the river during the spring flood of 1973, and sport fish­ ermen were catching them on minnows at Havana. One sauger ( Stizostedion canadense) was taken at Big Blue Island Chute (river mile 57.5-58.9) in 1974. This species was common in the river before 1908 ( Forbes & Richardson 1920:275). Orange-spotted sunfish (Lepomis humilis) and pumpkinseeds ( Lepomis gibbosus) were taken sporadically. One species, the longear sunfish ( Lepomis megalotis) , listed as being extirpated from the Illinois River and its bottomland lakes between 1908 and 1970, by W . C. Starrett and P. W. Smith ( Starrett 1972: 163 ), was taken from La Grange Pool, Turkey Island Chute (mile 147.3-148.2) on 5 Sep­ tember, 1973. Three adults, ranging in total length from 10.7 to 15.5 cm were taken. Northern pike ( Esox lucius) were taken by sport fishermen in the river below Marseilles Dam in 1973, and were netted in Lake Chautauqua in 1973 ( river mile 126.0), but were ~ot taken by electrofishing. Northern pike were common in the river before 1908 ( Forbes & Richardson 1920:209). 332 ILLINOIS NATURAL HISTORY SURVEY BULLETIN Vol. 31, Art. 8 Catfishes may be more abundant in the river than our collections indicate. They are bottom-dwelling species and when shocked they do not always come to the surface where they can be seen to be netted. Under nearly ideal con­ ditions for electrofishing, Larimore ( 1961) reported taking only 10 percent of the total population of catfishes in a reach of Jordan Creek, whereas 52 per­ cent of the sunfishes were taken. In the generally turbid waters of the lower Illinois River, a fish must be within 10- 15 cm of the surface to be seen. So our collecting efficiency for catfishes must have been lower than the 10 per­ cent obtained by Larimore in clear water. Since we used a shocker, and 6.35 mm mesh dip nets, minnows and other small fishes were generally not taken. We did obtain emerald shiners (No­ tropis atherinoides) throughout the river in 1974 and in previous years ( Mills, Starrett, & Bellrose 1966: 15). DISCUSSION HISTORICAL CHANGES IN THE FISH POPULATIONS OF THE ILLINOIS RIVER The Illinois-Michigan Canal along the upper Illinois River was completed in 1848, before any biological data were being collected on the Illinois River. Prior to 1871, it is unlikely that this canal had much of an impact on the middle and lower sections of the river, below Hennepin ( river mile 208), which are the sections most productive of fish and wildlife. These are the most productive because the Illinois River below Hennepin follows a large valley developed in the late Pleistocene epoch, and the Illinois has developed lateral levee lakes, side channels, back­ waters, and marshes which fill this an­ cient valley and provide excellent habi­ tat for fish and wildlife. In 1871, the flow of the Chicago River was reversed in order to conduct sanitary wastes from the city of Chi­ cago away from Lake Michigan, which served as the drinking water supply for the city. The polluted waters of the Chicago River were directed through the Illinois-Michigan Canal into the Des Plaines River and thence into the Illinois River. Some of the polluted water apparently backed up into the lower reaches of the Kankakee. The effect of the polluted water on the fishes of the Kankakee and Illinois rivers was dramatic, according to a re­ port by Nelson ( 1878:798): "Previously to the opening of the Chicago River into the canal in 1871, rock-bass, ( Ambloplites rupestris); black-bass, ( Micropterus pallidus) [largemouth bass, Micropterus sal­ moides]; silver bass, ( Roccus chry­ sops) [white bass, Morone chrysops]; wall-eyed . pike, ( Stizostethium vit­ reum) [ walleye, S tizostedion vitreum vitreum]; mud-pike, ( ?) ; pickerel, ( Esoxlucius) [ northern pike, Esox lucius]; mud-eel, (?) [lamprey?]; silver-eel, ( Anguilla rostrata) [Amer­ ican eel]; buffalo fish, ( Bubalichthys bubalus) [buffalo, lctiobus __ ?]; red horse, ( M yxostoma macrolepi­ dota) [shorthead redhorse, M oxosto­ ma macrolepidotum]; suckers, Catos­ tomus __ ?); bull-heads, ( Amiurus catus) [bullhead, Ictalurus __ ?]; spoon-fish, or shovel-bill, ( Polyodon folium) [paddlefish, Polyodon spath­ ula]; sun-fish, ( Pomotis __ ?) [sun­ fishes, Lepomis __ ?]; cat-fish, (Amiurus __ ?) [catfish, Ictalurus __ ?]; dog-fish, (Amia calva) [bowfin]; gar pike, ( Lepidosteus osseus) [longnose gar, Lepisosteus osseus]; perch, ( P erca americana ) [yellow perch, Perea flavescens], were caught in both these rivers, and also in the Du Page River, which flows 6 miles east of Joliet, and emp­ ties into the Desplaines 8 miles south of that town; also in Hickory Creek which rises about 14 miles east of Joliet, and empties into the Des­ plaines just south of the town, and in any of the streams of sufficient size in this vicinity. Aug., 1975 SPARKS & STARRETT: ELECTROFISHING SURVEY OF ILLINOIS RIVER 333 "When the current of Chicago River was first turned through the canal and the rivers, it caused the fish in them to bloat to a large size, and rising to the surface they floated down the stream in large numbers. It was estimated at the time that several tons of dead fish passed through one of the canal locks just after the foul water commenced run­ ning through the canal. "When these bloated fish chanced to float into the clear water at the mouth of some tributary of the river they would revive and swim up the clear stream. Such large numbers of the fish revived in this manner that all the small streams flowing into the Desplaines and Kankaku [sic] rivers were filled with fish in such numbers that many were taken with hook and line, one man taking over 300 in a day in this manner at that time. "When the spring freshets occur the current is so rapid and the amount of pure water in the river is so great, that the foul water does not have much effect upon the fishes, and large numbers of the species mentioned ascend the rivers and are caught with hook and line. Later in the season as the water subsides, and the water from Chicago River pre­ dominates, the fish which came up in the spring die and are floated down the river. In July and August when the water is the worst even the mud turtles leave the river in dis­ gust and seek less odorous homes." Water from the Illinois-Michigan Canal also entered the Illinois River at La Salle ( mile 223), but the wastes were sufficiently decomposed at that point that there was only a slight im­ pact on the ecosystem of the Illinois River below La Salle ( Starrett 1972: 145). The carp was introduced into the Illi­ nois River in 1885, out of a stock brought to the United States a few years earlier from Europe ( Forbes & Richardson 1920: 105). By 1898, the carp catch exceeded the value of all other commercial fishes from the Illinois River ( Thompson 1928: 285). Forbes & Rich­ ardson ( 1920: 108-109) reported fishery statistics which showed that increasing carp populations did not adversely af­ fect the populations of other species, although they did predict that carp might displace the native buffalo fishes, which have the same food preferences as carp. Forbes & Richardson ( 1920: 108-110) did not feel that carp had in­ creased the turbidity of the water in the Illinois River by their rooting habit of bottom feeding. In contrast, Jackson & Starrett ( 1959:163-165) observed lo­ cal areas of heavy turbidity in Lake Chautauqua, a bottomland lake along the middle section of the river, pro­ duced by schools of carp. They felt that some instances of carp activity may have been stimulated by low oxygen levels. The activities of carp may have had a greater effect on turbidity in more recent times because of the pres­ ence of flocculent bottom muds that have been carried into the bottomland lakes by the river ( Starrett & Fritz 1965:88). Forbes ( 1928) does not mention any changes in fish fauna associated with the construction, prior to 1900, of the low navigation dams on the Illinois River at Marseilles, Henry, Copperas Creek, La Grange, and Kampsville. Nelson ( 1878: 798) was of the opinion that a dam at Seneca ( mile 252.5) hindered the upstream movement of fishes. On 1 January, 1900, the Sani­ tary and Ship Canal was opened at Chicago, connecting the Des Plaines and Illinois Rivers with Lake Michi­ gan. The canal was used to flush mu­ nicipal and industrial wastes into the Illinois River system, and away from Chicago's municipal water intakes in Lake Michigan. The quantity and quality of this diverted water had a tremendous impact on the Illinois 334 ILLINOIS NATURAL HISTORY SURVEY BULLETIN Vol. 31, Art. 8 River. There was an average rise in water levels at Havana of 2.8 feet ( .85 m), and during the normal low­ flow period between June and Sep­ tember the rise was 3.6 feet ( 1.10 m) ( Forbes & Richardson 1919: 140- 141). The tree line along the river re­ treated as a result, and the loss of mature pin oak ( Quercus palustris) and pecan ( Carya illinoensis) trees meant a loss of food for mallard ducks ( Anus platyrhynchos) and wood ducks ( Aix sponsa) ( Mills, Starrett, & Bellrose 1966:5). Populations of cavity-nesting tree swallows ( lridoprocne bicolor) and prothonotary warblers ( Protono­ taria citrea) increased, as a result of the increased supply of nest sites in zones of dead trees bordering the river and lakes. Populations of these species declined markedly during the 1940's, as the last of the dead trees finally collapsed ( Dr. Frank C. Bellrose, Waterfowl Biologist, Illinois Natural History Survey, personal communica­ tion). One beneficial effect of the diver­ sion was to increase the surface area of water in lakes and backwaters, which apparently improved the fishery (Forbes & Richardson 1919). It is also likely that the stumps and snags left after the trees had died temporarily provided cover for certain species such as bass, crappie, and other sunfishes. The increased shallow water areas and nutrient loading of the Illinois River and its bottomland lakes initially may have increased the plankton popula­ tions and the biomass of bottom fauna in the middle and lower river ( Forbes & Richardson 1913:494-495). In the river proper, populations of molluscs, especially fingernail clams, probably increased the most, with a beneficial effect on mollusc-consuming species of adult fish such as carp, catfish, buffalo, and drum. After approximately 1910, however, as the pollution load increased, criti­ cally low dissolved oxygen levels oc- curred farther and farther downstream with detrimental effects on food or­ ganisms and fish ( Richardson 1921b: 33). Populations of molluscs, including fingernail clams ( Sphaeriidae), in the middle section of the Illinois River and in several bottomland lakes were quite high in the early 1950's ( Paloumpis & Starrett 1960). In 1938, by order of the Supreme Court of the United States, the amount of water that could be diverted from Lake Michigan at Chicago was limited to a yearly average of 42.48 m3/ sec and minimum gage readings in the middle section of the river at Havana dropped about .61 m as a result ( Star­ rett 1972:146). In spite of an increasing human population in the Illinois basin, the population equivalent of the total combined domestic and industrial waste emptied into the river declined from 6,211,471 in 1922 to 2,417,000 in 1960 ( Mills, Starrett, & Bellrose 1966: 9), because more waste was receiving primary and secondary waste treatment. Populatiori equivalents are based on the average amount of carbonaceous oxygen demand in the waste produced per person, and do not take into ac­ count the oxygen demand of the ni­ trogenous fraction of human waste. The demand placed on the oxygen re­ sources of the river by nitrogenous wastes has actually increased in recent years ( Butts 1975). Minimum dissolved oxygen levels near the surface in the channel of the Illinois River during midsummer in the period 1911-1966 are reported in tables in Mills, Starrett, & Bellrose (1966:9) and Starrett (1971:370-373). In 1966, oxygen levels generally were below saturation throughout the whole length of the river. Levels below 1.0 mg/ I occurred in Dresden, Peoria, and La Grange Pools. The reduction in dissolved oxygen concentration so far downstream of the Chicago and Peoria metropolitan · areas results from the oxygen demand of sediment ( Butts - Aug., 1975 SPARKS & STARRE'IT: ELECTROFISHING SURVEY OF ILLINOIS RIVER 335 1974) and from the oxygen demand as ammonia in municipal waste is con­ verted to nitrate ( Butts 1975). During the winter, bacterial nitrification is slowed, oxygen demand is thereby re­ duced, and higher ammonia concentra­ tions extend farther downstream from Chicago ( Butts 1975). Ammonia places aquatic organisms in double jeopardy; it not only removes oxygen from water, but is also toxic. Only the un-ionized fraction of the total ammonia concentration ( approximately 5 percent of the total ammonia in the Illinois River) is toxic, and the un-ion­ ized ammonia concentrations were gen­ erally well below lethal levels for fish in 1972 and 1973, although concentra­ tions may have been high enough on occasion in the upper river to stress fish (Lubinski et al. 1974). It is not known to what extent the low dissolved oxygen concentrations, perhaps acting in combination with other stresses such as silt and toxic materials, contributed to the die-off of fingernail clams and snails in the mid­ dle section of the river in the mid- 1950' s ( Mills, Starrett, & Bellrose 1966: 12). As late as 1973, fingernail clams had not reappeared in areas of the river where dead shells indicated that they were formerly abundant. The loss of these important food organisms, ac­ cording to the Mills, Starrett, and Bell­ rose report, has resulted in a reduction of the number of diving ducks migrat­ ing along the Illinois River and a de­ cline in the condition factor of the com­ mercially valuable carp. In addition to affecting the food sup­ ply of fish, low oxygen levels have di­ rect effects on fish. Carlson & Siefert ( 1974) have shown that oxygen levels at 35 percent saturation reduced the survival of larval largemouth bass by 13.7 percent, and oxygen levels at 70 percent saturation and below retarded the growth of larval bass. In two areas that provide good physical conditions for largemouth bass, Lower Bath Chute, La Grange Pool ( Fig. 9) and Chilli­ cothe Island Chute, Peoria Pool ( Fig. 10), midsummer oxygen levels were at 35 percent saturation or below for 4--5 years out of the 8-year period 1963-1970. The discharge and water levels were generally high preceding the resurgence in bass populations at Lower Bath Chute ( Fig. 9) . Therefore, it is difficult to separate the beneficial effects of high water levels from the beneficial effects of increased discharge. During high water, flooded areas provide good breeding habitat for many adult fish and good nursery areas for juvenile fish. High discharge results in in­ creased dilution of toxic wastes and oxygen-demanding wastes. At Chilli­ cothe Island Chute ( Fig. 10) the rela­ tive importance of the two effects can be separated, because the water levels in Peoria Pool were maintained within fairly narrow limits by flow regulation at the Peoria Lock and Dam, while the discharge varied considerably. The resurgence in bass populations at Chillicothe Island Chute was as­ sociated with increased discharge. Al­ though we took no oxygen readings in the chute during midsummer 1973 or 197 4, oxygen readings in other parts of the river were generally 80 percent of saturation, and indicate that oxygen­ demanding wastes were being diluted. Toxic wastes probably were diluted during this period also. Lubinski et al. ( 1974) indicated that the combined toxicity of the chemicals routinely monitored by the Illinois En­ vironmental Protection Agency was generally well below levels lethal to fish at 17 locations on the Illinois River during an 18-month period in 1972 and 1973, when discharge was high. Extensive monitoring of toxic materials in the Illinois River has been undertaken only recently, so Lubinski et al. ( 1974) were not able to estimate the combined toxicity of chemicals to fish during low discharge. The real 336 ILLINOIS NATURAL HISTORY SURVEY BULLETIN Vol. 31, Art. 8 test of whether pollution abatement programs in the Illinois Valley have re­ sulted in improvement of water quality for fish will occur during low discharge periods in the years to come. One of the major impacts on the NO, OF LARGEMOUTH BASS TAKEN PER 30 MIN OF ELECTROFISHING 0 0 ...... N I.N C) C) C) ...... Illinois River below Hennepin was the leveeing and draining of bottom­ land areas, primarily in the period 1903-1926. Of 400,000 bottomland acres (161,874 ha) subject to overflow · by the river, approximately 200,000 JULY-AUGUST DISCHARGE AT KINGSTON MINES (M3/sEc) • • ...... N N I.N I.N ... ... u, u, O'> ... u, C) u, C) u, C) u, C) u, 0 C) 0 0 0 0 0 C) C) C) C) 0 lD .,,,..,,.....-0 O'> C) _,,,... O'> _,,,,_,,,... ...... ~1/ O'> N O'> I.N O'> ... O'> r C) u, :::c ,..., ::c O'> to O'> :,,. -I = " O'> = -..J = -I ,..., O'> 00 3 r rn 01 ...... lD C) -..J -..J \ C) -..J \ ,I ...... \ -..J \ 'i---.. N " ) " -..J " I.N '-.... ...... '---. lD -..J ... • 0 N I.N ... O'> 00 .,_.NNNNNI.NI.NI.N\.>J 0 u,c:, C) 0 - . . . - . . . . . 00 0 N ... O'> 00 ON ... O'> JULY-AUG, DISSOLVED OXYGEN LEVELS JULY-AUGUST WATER LEVELS (% SATURATION) AT HAVANA (M) • • [) [) Aug., 1975 SPARKS & STARRETT: ELECTROFISHING SURVEY OF ILLINOIS RIVER 337 acres ( 80,937 ha) are now behind levees ( Mills, Starrett, & Bellrose 1966: 5), with a consequent reduction in wildlife and fish habitat. The back­ waters and bottomland lakes of the Illinois River were, and are, critically important to fish and wildlife produc­ tion. Richardson ( 192la:464) reported that the largest weights of fish per acre were taken in reaches of the river with the largest connecting lake area: "Taking the year 1908 as an illus­ tration, and using the figures for separate shipping points obtained by the Illinois Fish Commission in that year, we find for the 59.3 miles of river and lakes between Copperas Creek dam ( river mile 136.9) and La Grange dam ( river mile 77.6), with about 90% of its acreage con­ sisting of lakes and ponds, an average fish-yield per acre for water levels prevailing half the year, of 178.4 pounds; for the 87 miles from La Salle ( river mile 223.9) to Copperas Creek dam, with about 83% lakes, 130.4 pounds; and for the lower 77 miles, La Grange to Grafton, with around 63% lakes, only 69.8 pounds." Richardson ( 192la:463) indicates that well over 80 percent of the total fish yield in 1908 came from the lakes, with much less than 20 percent coming from the river· itself. The bottomland lakes supported an abundant aquatic weed-inhabiting invertebrate fauna, which supplied food for young fishes of the sunfish, perch, and pike families. In the 1930's high navigation dams were constructed at Dresden Heights ( 6. 71 m high ) , Marseilles ( 7 .32 m ) , Starved Rock ( 5. 79 m), Peoria ( 3.35 m), and La Grange ( 3.05 m) . The navigation dam at Alton on the Missis­ sippi raised water levels in the Illinois as far north as Hardin, at river mile 21.0. Timber and brush were cleared from areas due to be inundated by the new dams. Clearing operations prob­ ably did not markedly reduce the amount of mast available for water­ fowl, according to Dr. Frank C. Bell­ rose, Waterfowl Biologist, Illinois Natu­ ral History Survey. The navigation dams temporarily increase dissolved oxygen levels as the water passes over and through the dams ( Mills, Starrett, & Bellrose 1966:9-10; Forbes & Rich­ ardson 1913:549). Starrett ( 1971:271- 272) indicated that the reduction of diversion from Lake Michigan coupled with the higher dams on the river have resulted in a decrease of average current velocity from about 2.01-4.02 km/ hour prior to 1908 to 0.97 km/hour in 1966. Pools behind navigation dams on the upper river have filled with oxygen-demanding sediment which in places resembles sludge from secondary sewage treatment plants (Butts 1974). Richardson ( 192la:457, 474-475) in­ dicated that abundant populations of fingernail clams in the Illinois River were generally found in areas of re­ duced current and favorable conditions for sedimentation. We ( and others, such as Gale 1969) have found that abundant populations of fingernail clams occur in Pool 19 on the Missis­ sippi River, over soft mud bottoms, and Gale ( 1971) reported that finger­ nail clams will select mud substrates in preference to sandy mud and sand. Fig. 9.-The relationships among mean water levels (open triangles), mean discharge (black triangles), and mean dissolved oxygen levels (black dots) during the months of July and August and the number of largemouth bass taken per 30 minutes of electrofishing (circles) in the fall at Lower Bath Chute (mile 107) in the La Grange Pool. Oxygen levels below 35 percent saturation (heavy line) reduce the survival of larval largemouth bass. Discharge was measured at Kingston Mines (mile 145), water levels at Havana (mile 120), and oxygen levels in the chute. The oxygen reading marked by an asterisk was taken on 12 September, rather than in midsummer. Discharge rates were obtained from Water Resources Data for Illinois, U.S. Dept. of the Interior, Geological Survey. Water levels were obtained from Missouri­ Minissippi River Summary & Forecasts, U.S. Dept. of Commerce, National Oceanic and At­ mospheric Administration, National Weather Service Central Region, Kansas City, Missouri. The other data were obtained by the Illinois Natural History Survey. ...... <.O en N en I..N en Vl en en en 00 en <.O '-I N 338 ILLINOIS NATURAL HISTORY SURVEY BULLETIN Vol. 31, Art. 8 If the high navigation dams constructed in the 1930's did reduce the current and increase sedimentation in parts of the Illinois River, then the habitat suit­ able for fingernail clams may have increased, with a benefit to the mollusc- 0 0 \ NO, OF LARGEMOUTH BASS TAKEN PER 30 MIN OF ELECTROFISHING \ \ \ o~---o ...... 0 \ \ \ N 0 \! N 0 I..N .s::­ Vl D I..N C) en C) JULY-AUG, DISSOLVED OXYGEN LEVELS (% SATURATION) • • eating fish. It is puzzling that condi­ tions have been so dramatically dif­ ferent since 1955, when a die-off of fingernail clams occurred in the middle section of the Illinois River ( Mills, Star­ rett, & Bellrose 1966:12). As late as 00 0 JULY-AUGUST DISCHARGE AT MARSEILLES (M3/sEC) I-' N '-I 0 V, 0 I I • • N N N v, Vl 0 , N I.N I..N '-I D N V1 0 Vl .s::-.s::-v,v,enen OVlOVlOVl JULY-AUGUST WATER LEVELS · AT PEORIA (M) I> I> Aug., 1975 SPARKS & STARRETT: ELECTROFISHING SURVEY OF ILLINOIS R1vER 339 1973, the fingernail clams had not re­ turned to areas of the river where dead shells indicated they had formerly been abundant. Starrett ( 1971 :272) felt that the in­ crease in sluggishness of the river and the increased planting of row crops in the Illinois basin have made siltation in the last 30 years an important factor adversely affecting the survival of mus­ sels and other organisms in the Illinois River and its bottomland lakes. Silt physically removes habitat by filling in areas such as Lake Chautauqua, near Havana (river mile 124-130), which has lost 18.3 percent of its storage capacity in a period of 23.8 years ( Stall & Melsted 1951: 1). Areas in Quiver Lake near Havana where boats could formerly be launched are now only a few centimeters deep in low water stages, and willows are encroaching on the lake. Jackson & Starrett ( 1959: 160) stated: "The sediments in Lake Chautau­ qua are mostly of a fine texture and form a loose, flocculent 'false bottom' ( not similar to the type found in bog lakes ) over the original lake bottom. A slight disturbance of the 'false bottom' causes particles to be­ come resuspended and so increases the turbidity of the water." The same authors found that an in­ crease in wind velocity from light to strong increased the turbidity from 162 to 700 Jackson turbidimeter units (JTU) and that it took a calm period of 7-12 days for much of this sediment to settle from Lake Chautauqua. As a consequence, this lake and other bot­ tomland lakes are highly turbid most of the time. The turbidity levels in bottomland lakes and backwaters along the Illinois River are within the range that reduces fish production. Buck ( 1956) studied fish productioe in farm ponds, hatchery ponds, and reservoirs in Oklahoma which had a wide range of turbidities. The farm ponds were treated with rotenone, then restocked with large­ mouth bass and bluegills or largemouth bass and redear sunfish ( Lepomis microlophus). Twelve farm ponds were divided into three turbidity classes. After two growing seasons, the average total weights of fish were: Clear ponds (less than 25 JTU)-161.5 lb/acre ( 181.0 kg/ha) Intermediate ponds (25-100 JTU)-94.0 lb/acre ( 105.4 kg/ha) Muddy ponds ( >100 JTU)-29.3 lb/acre ( 32.8 kg/ha) The decline in production in turbid ponds resulted from a decline in both reproduction and growth ( Buck 1956). The results from hatchery ponds, where turbidities were artificially con­ trolled, and from the reservoirs which harbored a variety of fishes, generally paralleled the results from the farm ponds, except for two species, channel catfish and flathead catfish. Channel catfish spawn in dark cavi­ ties, such as hollow logs or in holes in banks. Turbid waters are likely to have more suitably dark cavities per surface area or length of shoreline than do clear waters, and thus reproduction of channel catfish was probably greater in the turbid waters. Flathead catfish grow well in turbid waters and appear to be well adapted to turbid conditions. Fig. 10.-The relationships among mean water levels (symbols are the same as in Fig. 9), mean discharge, and mean dissolved oxygen levels during the months of July and August and the number of largemouth bass taken per 30 minutes of electrofishing in the fall at Chillicothe Island Chute (mile 180) on the Illinois River. Oxygen levels below 35 percent saturation (heavy line) reduce the survival of larval largemouth bass. Chillicothe Island Chute is in the Peoria Pool. Discharge was measured at Marseilles (mile 247), water levels at Peoria (mile 163), and oxygen levels in the chute. The oxygen reading marked by an asterisk was taken on 30 September, rather than in midsummer. Data were obtained from the same sources as given for Fig. 9. 340 ILLINOIS NATURAL HISTORY SURVEY BULLETIN Vol. 31, Art. 8 Buck ( 1956:257) concludes that in newly formed reservoirs bass, crappies, and other scaled fish out-produce cat­ fish and then limit them by predation on the young. Turbid waters offer cat­ fish protection from these predators. In addition, sunfishes prefer to con­ struct nests on firm substrates, rather than mud. Their eggs and fry are prob­ ably more susceptible to smothering by sediment than those of catfish and rough fish. The disappearance of the yellow perch ( Perea f/,a,vescens) from the Illi­ nois River and its bottomland lakes is probably also associated with the dis­ appearance of the plant beds and clean sandy or pebbly bottoms the perch uses for spawning. Catfish feed on the types of food organisms which can grow in turbid waters with mud bottoms, such as midges, worms, fingernail clams, and snails. Catfish can use their highly developed sense of smell to locate food, whereas other game fish rely more heavily on sight Food habits studies have shown that young game fish feed first on zooplankton, then on in­ sects such as dragonfly and damseIBy nymphs, then on larger organisms such as fishes and crayfishes. These types of food organisms are associated with weed beds and moderately clear water. The bottomland lakes along the Illinois River have been transformed from the latter type of ecosystem to a turbid type of system, by the influx of sediment from the river. Recently, even the fish and duck food organisms which are adapted to mud bottoms have died out in the channel and lateral areas of the middle section of the Illinois. Fingernail clams in this section died out in 1955, and have not since recolonized the area. It is pos­ sible that some of the heavier benthic animals such as the molluscs find it difficult to remain near the top of the B.occulent bottoms or that the sus­ pended material interferes with their feeding activities. The senior author suspects that the sediments exert an oxygen demand in the lakes, just as they do in the river. In August, 197 4 dissolved oxygen levels in Meredosia Lake ( river mile 72-77) were approxi­ mately 3 mg/ I when a strong wind was blowing that stirred bottom sediments in the shallow lake. A die-off of gizzard shad was occurring, and almost all the fingernail clams maintained in plastic cages on the bottom of the lake had died since they were last checked in mid-July. Oxygen levels may have been lower than 3 mg/ I on previous occa­ sions. Oxygen levels in the river on the same date were approximately 6 mg/I. It is also possible that toxic materials, such as pesticides, that are bound to soil particles, ·were taken up by aquatic organisms such as clams that ingested the soil particles or passed them over their respiratory membranes. In addition, toxicants such as hydrogen sulfide may have been formed and released from bottom muds under anaerobic conditions. The increased barge traffic ( Starrett 1972: 153) associated with the improved navigation channel increases the tur­ bidity of the river. The turbulence produced in midchannel, as well as the washing action along shore, resuspends sediment, thereby increasing the tur­ bidity (Fig. 1 and 2). W. C. Starrett made numerous observations of the effect of barges on turbidity of the river, for example (Starrett 1971:273): "A towboat underway causes a strong current and washing action on the silt bottom ( "false bottom") in­ shore, which resuspends the silt par­ ticles, thereby increasing the tur­ bidity. The increase in turbidity is more noticeable in the lower three pools, particularly in the Alton Pool, than it is upstream because of dif­ ferences in bottom types. . . . The outrush of water from shore toward the· channel caused by a towboat also temporarily exposes the shallow areas. - On November 18, 1964, in the Alton Pool at river mile 65.1, Aug., 1975 SPARKS & STARRETT: ELECTROFISHING SURVEY OF ILLINOIS RIVER 341 the turbidity just prior to the passing of two towboats was 108 units (Jack­ son turbidity units), and within 6 minutes after the tows had passed, the turbidity was 320 units. Sixteen minutes later the turbidity had dropped to 240 units." Some personal observations were made on the effects of towboats during the 197 4 electrofishing investigations. On several occasions, flow reversals in chutes were observed as tows passed first one end, then the other, of a chute. In a narrow part of the river channel above Pekin on 19 September, 197 4, in the midst of electrofishing, our boat was stranded on the mud when the water rushed out from shore as a tow of nine fully loaded coal barges passed upstream. Mussel shells were clearly visible on the bottom for several seconds before the water rushed back again. We had been in approximately 0.5 m of water. Such washing along the shore and flow reversals in side channels may have a detrimental effect on benthic organisms and fishes that make nests in shallow water, such as sunfishes. Low flows from 1962 to 1964, and consequent low oxygen levels and re­ duced dilution of toxic wastes, ap­ parently are responsible for the decline during the same period of game species such as largemouth bass, crappies, and bluegill: Catches of these species showed dramatic recoveries following the high-water period 1971-1973. In 14 years of electrofishing, covering the period 1959-1974, the largest numbers of the following species were obtained in 1974, following the high water pe­ riod: black crappie, white crappie, flathead catfish, white bass, bluegill, bigmouth buffalo, and black buffalo. The maximum weights of the following species were obtained in 1974: white crappie, channel catfish, and bluegill. Fig. 8, 9, and 10 show that bass popula­ tions still had not recovered to the peak levels observed in Peoria and La Grange Pools in the years 1959-1962. High water levels stimulate certain species, such as white bass, to run up tributary streams and spawn. White bass were obtained in the upstream pools, Starved Rock and Marseilles, in fairly substantial numbers in 1973 and 1974, whereas none were obtained in these pools in 1959, 1961, 1963, 1964, 1968, and 1969. High water also in­ creases the space available for spawn­ ing activities of fishes that build nests in shallow water, such as sunfishes, and the amount of protected habitat avail­ able for juvenile fish, in shallow, flooded areas and around brush and tree stumps. As mentioned above, higher oxygen levels have occurred in the Illinois River in association with the high flows, with beneficial effects on fish and fish food organisms. In spite of the improvement in the electrofishing catch in 1973 and 1974, apparently due to high water levels in 1971-1973, the commercial catch of fish in the Illinois River continued its his­ torical decline in the 1970's (Table 28). Depending on whether the Illinois De­ partment of Conservation figures or the National Marine Fisheries Service sta­ tistics are used, the catch dipped under l million pounds ( 454,000 kg) in 1971 or 1972. The decline is not explained by a reduction in the number of com­ mercial fishermen-there were 13 full time and 56 part time Illinois River commercial fishermen in 1973, and 9 full time and 47 part time in 1971. Nor is it explained by a decline in economic value of the catch. The catch from the Mississippi River bordering Illinois has been relatively constant from 1950 through 1973 ( Table 28). A general decline in profits would be reflected in a general decline in fishing effort in both the Illinois and Mississippi Rivers and a corresponding decline in catch. It is possible that because fish­ ermen generally take large adult fish, an increase in the catch of commer­ cially important sizes of fish will not be seen until the fish spawned in 1973 and 1974 reach marketable size. 342 ILLINOIS NATURAL HISTORY SURVEY BULLETIN Vol. 31, Art. 8 FUTURE IMPACTS ON THE FISH POPULATIONS OF THE ILLINOIS RIVER In 1971 the Chicago Metropolitan Sanitary District began a large-scale sludge recycling project near the Illi­ nois River at St. David. In 1974 the District began aerating a sectio~ of the Chicago Sanitary and Ship Canal, and more of the canal will be aerated in succeeding years. In the future, all Chicago storm water probably will be captured and stored in a deep tunnel under Chicago, instead of being dis­ charged into the canal, and will be treated before it is released to the canal. Advanced waste treatment plants should be capable of removing the ammonia that now exerts an oxygen demand so far down river. All of these improvements in waste treatment will have a beneficial impact on the aquatic life in the river, by reducing the oxygen demand on the river and improving oxygen levels during critical low-flow periods. Waste treatment probably will also be improved in the Pekin-Peoria metropolitan area. A proposed increase in the depth of the navigation channel of the Illinois River (from 2.7 to 3.7 m), would be accomplished by a combination of rais­ ing low-flow water levels and dredging. Depending on local topography, the water surface area might be increased. Judging by the increased fishery in the Illinois River following a rise in water levels in 1900, as a result of water di­ version from Lake Michigan, one might expect a beneficial effect. However bottomland lakes that now have ~ chance to clear during periods when they are cut off from the river might then become permanently connected to the river and receive a continuous rather than intermittent, input of oxy: gen-demanding sediment. In 1921, Richardson ( 192la:418) reported that Quiver Lake ( mile 121.0-mile 124.0) and Matanzas Lake (mile 114.5-117.0) received spring water from the sandy bluffs on the east side, and that the waters in these lakes were somewhat clearer than in other bottomland lakes. According to an Illinois Water Survey report ( Singh & Stall 1973: 19), the influx of ground water to the river from Kingston Mines ( mile 145.3) to Mere­ dosia ( mile 71.1 ) amounts to 8. 75 m3 / sec, or about one-twelfth of the total input to this section of the river, during the lowest flow expected for a 7-day period at a recurrence interval of 10 years. According to Matanzas Beach residents, the water and shoreline of Lake Matanzas still are cleared of silt deposited by the river, due to the flush­ ing action of ground water coming through the sandy bottom along the bluff. In contrast, Quiv~r Lake is now filled with silt. The Illinois Department of Conserva­ tion has been able to restore aquatic vegetation to Rice Lake ( mile 133---137) and Stump Lake ( approximately mile 5) by pumping water out of the lakes or allowing them to dry out naturally ( personal communication, Robert L. Glesenkamp, Area Wildlife Manager, Illinois Department of Conservation). Midsummer drying was a natural oc­ currence in this type of shallow lake, during low-flow years, prior to Lake Michigan diversion and construction of navigation dams ( Richardson 1921a: 419). On drying, the bottom muds were compacted, and when the lakes were reflooded, the turbid water generally cleared, and the plants gained root­ hold in the firm bottom. Restoration efforts would be more difficult if sum­ mer water levels were higher. In addi­ tion, private duck clubs and state and federal wildlife refuges along the river would find it difficult to reduce water levels. They attempt to reduce water levels to expose mud flats and encour­ age the growth of moist-soil food plants for waterfowl. Once again, a natural drying cycle has had to be replaced or supplemented by pumping, because water levels do not . attain the low Aug., 1975 SPARKS & STARRETT: ELECTROFISHING SURVEY OF ILLINOIS RIVER 343 levels they once did. Such management techniques require energy, equipment, and manpower. Larger towboats using the improved navigation channel and an increased number of towboats would keep more silt in suspension and increase the washing action along the shore and flow reversals in chutes. Fig. l shows that if towboats pass a point in the river more frequently than once every 21h hours, the resuspended sediment will not have a chance to settle out and the average amount of sediment suspended in the water will increase with a con­ sequent increase in oxygen demand and turbidity. The more silt there is in suspension in the river, the faster bottomland lakes such as Lake Chau­ tauqua ( mile 124-130) will fill with oxygen-demanding sediment, as they are periodically overflowed by the river. The effect of various future channel improvement schemes and various levels of boat traffic on the siltation rate in the critical backwater areas and lakes needs to be predicted. In addi­ tion, the joint effects of man's activities in the river and drainage basin needs to be assessed. For example, it is pos­ sible that the proposed increase in di­ version of Lake Michigan water at Chi­ cago ( discussed in more detail below) may make it ·possible for the present channel to accommodate deeper-draft barges in certain areas, without addi­ tional dredging or higher dams. It would be counter-productive for one arm of government to spend re­ sources in improving and restoring refuge areas if another arm of govern­ ment engages in practices which de­ grade such areas. There will be little benefit to the fisheries of the Illinois River by having the Chicago Metro­ politan Sanitary District and other mu­ nicipalities and industries expend bil­ lions of dollars in improved waste treatment if the river and its bottom­ land lakes are increasingly degraded by silt. Refuges, unpolluted lakes, and unpolluted tributary streams must be maintained if the river is to show the recovery pattern in the future that it exhibited in 1973-1974, following the high-water period and improved oxy­ gen levels from 1971-1973. When for­ merly degraded areas are restored, they can be recolonized rapidly by species that are desirable to man, if reservoirs of such species, and reservoirs of food organisms for desirable species, are available in undegraded pockets in the ecosystem. In a properly functioning system, the refuges maintained by man have precisely this function. The most practicable solution to the silt problem may be to reduce the amount entering -the river in the first place, if predictive studies indicate that a reduction of silt input would actually reduce siltation in the lakes and back­ waters. Once the silt is in the river and lakes, it may be recycled and re­ suspended there, and it is possible that no reduction in turbidity or oxygen demand would be achieved by reduc­ tion of silt input without the use of restoration techniques, such as drying out of lakes. On the other hand, it is possible that reduced silt input may cause the river to flush out backwater areas and lakes during periods of high flow, thus bringing about a natural restoration of these areas. Once the turbidity was reduced, fringing marshes and beds of aquatic plants might ap­ pear again, further accelerating restora­ tion by acting as silt filters and nutrient traps. The silt entering the river could be reduced by wide adoption of soil con­ servation practices in the Illinois basin, including such new practices as no-till farming, where row crops are planted without greatly disturbing the soil. Be­ fore the latter practice is adopted on a wide scale, the total energy require­ ments ( including the energy for the manufacture of agricultural chemicals) of various alternative farming methods need to be determined, and the en- 344 ILLINOIS NATURAL HISTORY SURVEY BULLETIN Vol. 31, Art. 8 vironmental impact of the herbicides that must be µsed with present no-till farming methods needs to be assessed. The City of Chicago and lakefront residents whose property has been dam­ aged as a result of current high water levels in Lake Michigan have requested an increased diversion of Lake Michi­ gan water into the Illinois River. An increased diversion would probably raise water levels, with some of the detrimental effects discussed above. However, Lake Michigan water is good quality water and probably would im­ prove the quality of the upper river by a simple dilution, if diversion oc­ curred during the summer months. On the other hand, if ammonia removal is not achieved by the Chicago Metro­ politan Sanitary District, the effect of increased diversion might be to push this oxygen-demanding waste farther downstream before its oxygen demand could be satisfied. Two introduced species have entered the Illinois River recently and will probably become more abundant, just as the introduced carp, goldfish, and white catfish have. It is difficult to pre­ dict whether the latest arrivals will in­ crease explosively, as carp and goldfish did, or whether they will barely main­ tain themselves, as white catfish have. White catfish are only occasionally taken from the Illinois River and do not seem to reproduce abundantly in the river. The white amur ( Ctenopharyngodon idella ), a plant-eating fish introduced from Asia, is now being taken regularly by commercial fishermen from the Mis­ sissippi River at Crystal City, Missouri and from the Missouri River ( Personal communications, William L. Pflieger, Fishery Biologist, Missouri Department of Conservation, and Peter Paladino District Fishery Biologist, Illinois De~ partment of Conservation), and has probably entered the lower Illinois River. If rooted aquatic vegetation could be restored to the Illinois River and its bottomland lakes by the lake restoration techniques discussed above, or by a reduction of silt loads in the river as a result of improved soil con­ servation practices in the basin, the white amur might have a detrimental impact. On the other hand, white amur from the Mississippi are being mar­ keted in small quantities commercially and their flavor is reported to be ex­ cellent. White amur in the Missis­ sippi grow to a large size- ( 4.5-6.4 kg) in 2 years ( Personal communica­ tions, Pflieger and Paladino). They might become a useful commercial species in the Illinois River. Another exotic species, the Asiatic clam ( C orbicula manilensis) was found at three locations on the Illinois in the course of the 1974 _electrofishing survey: at Kampsville ( river mile 32.0), Bath Chute (mile 106.7), and Turkey Island Chute ( mile 148.4) ( Thompson & Sparks, in press). The Asiatic clam is a serious nuisance, be­ cause it has blocked condenser tubes of power plants in Illinois and else­ where. In addition, it may displace the native fingernail clams. The future of the Illinois River will largely be determined by man's activi­ ties in the river and adjacent Hood­ plain and by his use of the land in the drainage basin. Predictions of the im­ pacts of various activities must be de­ veloped, so a rational management scheme for the Illinois River can be designed and the river can continue to serve a variety of purposes in the fu­ ture. SUMMARY 1. The upper Illinois River is warmer than the lower River, as a re­ sult of warm municipal and industrial effiuents. 2. The upper river is less turbid, be­ cause the bottom is generally rocky, wherea/i Peoria, La Grange, and Alton Pools contain Hocculent muds that have entered the river and are kept in sus­ pension by the river current and by Aug., 1975 SPARKS & STARRETT: ELECTROFISHING SURVEY OF ILLINOIS RIVER 345 wave action resulting from wind, tow­ boats, and pleasurecr~ft. 3. Dissolved oxygen levels at the sur­ face and the bottom of the river were virtually the same in the fall of 1974, and dissolved oxygen levels were 77-97 per­ cent of saturation in Alton Pool, 65-122 percent of saturation in La Grange and Peoria Pools, and 47-104 percent of saturation in the upper Pools of Starved Rock, Marseilles, and Dresden. Local areas of super-saturation occurred where plankton blooms appeared to be in progress. In two areas that provided good physical habitat for largemouth bass, Lower Bath Chute, La Grange Pool ( mile 107) and Chilli­ cothe Island Chute, Peoria Pool ( mile 180), midsummer oxygen levels were at 35 percent saturation or below for 4-5 years out of the 8-year period 1963---1970. Laboratory experiments have shown that oxygen levels below 35 percent saturation reduce the sur­ vival of larval largemouth bass and levels below 70 percent retard their growth. 4. The number of fish species taken by electrofishing in the Dresden Pool, Des Plaines River portion of the Illinois Waterway during the period 1959-1974 was consistently low (Tables 29 and 30). Only carp and goldfish and hy­ brids of thes.e two pollution-tolerant species were commonly taken. 5. The following species showed a trend of increasing abundance in the downstream direction, away from Chi­ cago, with the largest number occur­ ring in Alton Pool: shortnose gar, bowfin, goldeye, mooneye, channel cat­ fish, flathead catfish, and white bass. 6. Goldfish showed a trend of in­ creasing abundance in the upstream direction, toward Chicago. 7. The following species were most abundant in one or both of the two middle pools of the river, La Grange and Peoria Pools, which have the most connecting lake area: gizzard shad, carp, river carpsucker, smallmouth buf- falo, bigmouth buffalo, black buffalo, yellow bullhead, green sunfish, bluegill, largemouth bass, white crappie, black crappie, and freshwater drum. 8. Gizzard shad and carp were gen­ erally abundant throughout the river. 9. Black bullheads were abundant at one atypical station, Ballard Island Chute, Marseilles Pool ( mile 247.8- 248.2), which apparently provides pre­ ferred habitat for this species. 10. Gamefish populations declined during the low water years 1962-1964, and recovered following the high water years 1971- 1973. Largemouth bass populations did not recover to 1959- 1962 levels. The recovery appears at­ tributable to improved oxygen levels in the river, and perhaps to increased dilution of toxic materials, and demon­ strates how rapidly fish populations re­ spond to improved conditions in the river. 11. The commercial and sport fish­ eries in the Illinois River have gen­ erally declined from levels around the turn of the century. The decline is attributable to a loss of habitat and in­ creasing pollution. Habitat was lost due to leveeing and draining of bottom­ land areas in the period 1903---1926 and due to sedimentation in the remaining areas. Sedimentation has resulted in undesirable habitat modification, a'5 well as habitat reduction. 12. Northern pike, yellow perch, and walleye ( Stizostedion vitreum vitreum) were once abundant in the river but are now rare or limited in their distribu­ tion. Yellow perch populations have declined probably as the result of the disappearance of beds of aquatic plants and disappearance of clean sand or pebble substrates perch use for spawn­ ing. 13. In the past the bottomland lakes and backwater areas offered havens for fish and fish food organisms, as the river became increasingly polluted. Now dissolved oxygen levels in the river seem to have improved, while 346 ILLINOIS NATURAL HISTORY SURVEY BULLETIN Vol. 31, Art. 8 the lakes have filled with sediment that apparently exerts an oxygen demand, keeps aquatic plants from growing, and does not support an abundance of food organisms. 14. More and better waste treat­ ment facilities are being constructed by industries and municipalities in the drainage basin of the Illinois River. However, the production of fish and wildlife in the Illinois River and its bottomland lakes is not likely to im­ prove unless sediment pollution is also brought under control. 15. The consequences of future uses of land in the drainage basin and the consequences of future uses of the river must be predicted, so that a wise se­ lection of alternatives can be made. If the river is to be managed in the future for a variety of beneficial uses, then the various state, federal, and pri­ vate agencies charged with managing land and water within the drainage basin must work in a coordinated fashion, rather than at cross purposes. GUIDE FOR USE OF TABLES OF ELECTROFISHING RESULTS (Tables 3-27) SYMBOL 1 2 EXPLANATION Dresden Pool, Des Plaines River-not included in tabu­ lated value for the Illinois River at bottom of each table. Values represent the total number of fish or total weight of fish taken during the desig­ nated year in the Illinois River divided by the number of half­ hour intervals fished. Illinois River pools are Alton, La Grange, Peoria, Starved Rock and Marseilles. The Dresden Pool, Des Plaines River, is ex­ cluded from this tabulation. # Denotes less than 0.01 kilo­ grams or fish per 30 minutes fished. Note: Fish species are listed in phylo­ genetic order. All common and scientific names are taken from A List of Common and Scienti-fic Names of Fishes from the United States and Canada, 3rd edition, 1970, American Fisheries Society Special Publicatio_n No. 6. Spe­ cies that were rarely taken by electrofishing are not shown in the tables, but are discussed in the text. The values in the body of each table are determined by summing the number of fish or weight of fish obtained at all stations in the navigation pool and dividing the sum by the total number of half-hour inter­ vals fished in that pool. Thus the values are average catches per unit effort for each pool. The number of electrofishing sta­ tions in each pool are as follows: Alton Pool ( 4-5), La Grange Pool (6) , Peoria Pool (8), Starved Rock Pool ( 2), Mar­ seilles Pool ( 3), and Dresden Pool ( 1 ). l l Aug., 1975 SPARKS & STARRETT: ELECTROFISHING SURVEY OF ILLINOIS RrVER 347 Table I .-Illinois Natural History Survey electrofishing sites on the Illinois Waterway, Table I .--Continued 1959-1974. Pool Station River Mile• Pool Station River Mile• Alton Mortland Island Chute Below Hardin 18.7-19.4 Diamond Island Chute Above Hardin 24.0-25.6 Hurricane Island Chute Above Hardin 26.0-27.2 Crater Island and Willow Island Chutes Below Kampsville 29.3-30.7 Big Blue Island Chute• Above Florence 67.6-58.9 La Grange Bar Island and Grape Island Chutes Peoria Below Beardstown 86.2-87.1 Sugar Creek Island Chute Below Browning 94.3-96.2 Lower Bath Chute Above Browning 106.8-107.5 Upper Bath Chute Above Bath 112.8-113.3 Turkey Island Chute Above Kingston Mines 147.3-148.2 Illinois River Above Pekin 154.5-156.3 Lower Peoria Lake Near East Peoria 163.0-163.4 Middle Peoria Lake Near Peoria Heights Conservation Landing at Detweiller Park 169.2-171.0 Peoria Starved Rock Chillicothe Island Chute Above Chillicothe 180.1-181.0 Henry Island Chute Below Henry 193.5-194.1 Lower Twin Sisters Island Chute Above Henry 202.2-203.1 Upper Twin Sisters Island Chute Above Henry 203.1-203.5 Hennepin Island Chute At Hennepin 207.0-208.0 Clark Island Chute Below Spring Valley 214.9-216.6 Bulls Island Chute Above Ottawa Bulls Island Bend Section Above Ottawa 240.6-241.1 241.4-241.9 Marseilles Ballard Island Chute Dresden, Des Plaines River Above Marseilles 247.8-248.2 Johnson Island Chute Above Marseilles 249.4-249.9 Sugar Island Chute Below Morris 260.2-261.0 Rapp's Boat Yard and Du Page River Mouth Above Channahon 276.8-277.8 • Stations are located by river miles rather than by kilometers because existing river charts and navigation aids along the river use mileages. • Fished In 197 4 but not In previous year• . Table 2.-Water temperature, dissolved oxygen and Secchi disk (S.D.) visibility values obtained during an eleetrofishing survey of the Illinois ~ Waterway, 1974. Water D.O.• 8.D . Date and Temp. . 91m Bottom Vis. Pool Station River Mile Time (CST) ·c ppm % Sat. ppm cm Mortland Island Chute 18.7-19.4 21 Aug-0930 27.9 6.18 80.5 6.12 18 Diamond Island Chute 24.0-25.5 21 Aug-1520 29.5 7.31 97.3 7.09 18 Alton Hurricane Island Chute 26.0-27.2 22 Aug-0835 27.9 6.18 84.4 6.78 23 Crater and Willow Island Chutes 29.3-30.7 23 Aug-0855 27.4 6.13 77.2 6.10 19 Big Blue Island Chute 57.5-58.9 27 Aug-1430 27.5 6.18 80.5 6.02 19 --------------------------- ------------------------------------------------ Bar and Grape Island Chutes 86.2-87.1 30 Aug-1130 25.8 5.36 67.5 5.21 20 Sugar Creek Island Chute 94.3-95.2 16 Sep-1100 20.9 5.69 64.8 5.42 15 La Grange Lower Bath Chute 106.8-107.5 12 Sep-1000 22.2 7.18 83.7 7.10 20 Upper Bath Chute 112.8-113.3 12 Sep-1430 23.5 7.85 95.2 7.69 20 Turkey Island Chute 147.3-148.2 18 Sep-1100 22.5 7.61 89.4 18 Illinois River Proper 154.5-155.3 19 Sep-1345 21.3 8.21 93.2 8.20 18 ----------------------------------------------------------------------------------------------------- Lower Peoria Lake 163.0-163.4 29 Aug-1915 24.2 10.10 121.7 10.13 18 Middle Peoria Lake 169.2-170.0 10 Oct-1015 13.4 8.61 82.7 8.60 22 Chillicothe Island Chute 180.1-181.0 30 Sep-1415 16.5 6.50 68.4 5.20 17 Peoria Henry Island Chute 193.5-194.1 1 Oct-0940 16.1 5.42 55.7 5.43 16 Lower Twin Sisters 202.2-203.1 2 Oct-0900 16.1 6.31 64.9 6.21 17 Upper Twin Sisters 203.1-203.5 2 Oct Hennepin Island Chute 207.0-208.0 3 Oct-0920 15.5 6.51 67.0 6.49 28 Clark Island Chute 214.9-215.6 18 Oct-0900 15.0 7.83 78.0 7.62 42 --------------------------------------------------------------------------------------------------- Starved Rock Marseilles Dresden Pool, Des Plaines River Bulls Island Chute Bulls Island Bend Ballard Island Chute Johnson Island Chute Sugar Island Chute Du Page River Mouth 240.5-241.1 241.4--241.9 24 7 .8-248.2 249.4-249.9 260.2-261.0 276.8-277.8 17 Oct-0845 17 Oct 16 Oct-1300 16 Oct-0915 15 Oct-1000 14 Oct-1245 • Method: Winkler azlde (21 Aug.-19 Sept.); Oxygen analyzer (30 Sept.-18 Oct.). 17.5 14.5 18.5 19.7 22.0 4.41 10.40 4.51 5.46 5.09 47.3 104.0 48.9 61.1 59.3 4.38 4.44 5.42 36 14 46 41 32 .... ~ ~ Fil z > ~ > t" ::i:: Fil >-l 0 = ~ r,:; C: = tii ~ tJ:l C: ~ z i w !""' ~ 00 - > i:: ~ f--' co -1 Cl{ Vl ~ Table 3.-Shortnose gar (Lepisosteus platostomus) taken by electrofishing in the Illinois Waterway, 1959-1974. ~ Year and Number of Hours Fished "' ~ 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 Vl Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 i Number Per 30 Minutes Dresden1 0.00 0.00 0.00 0.00 ~ Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ~ Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 t"" Peoria 0.25 0.20 0.00 0.15 0.00 0.00 0.00 0.00 0.o7 0.07 0.00 0.00 0.00 0.00 t'1 LaGrange 0.00 0.00 0.08 0.15 0.00 0.31 0.17 0.00 0.00 0.00 0.10 0.00 0.10 ~ Alton 0.00 0.00 0.00 0.27 0.00 0.00 0.00 0.00 0.40 0 "lj ... Ill. R.2 0.10 0.08 0.00 0.07 0.04 0.00 0.15 0.05 0.02 0.02 0.00 # 0.12 "' ~ Kilograms Per 30 Minutes C) Dresden1 0.00 0.00 0.00 0.00 Vl Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 c:: ~ Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 < t'1 Peoria 0.20 0.17 0.00 0.12 0.00 0.00 0.00 0.00 0.02 0.01 0.00 0.00 0.00 0.00 ..,: La Grange 0.00 0.00 0.03 0.13 0.00 0.09 0.04 0.00 0.00 0.00 0.10 0.00 0.09 0 "lj Alton 0.00 0.00 0.00 0.05 0.00 0.00 0.00 0.00 0.07 -Ill. R.2 0.08 0.07 0.00 0.05 0.04 0.00 0.04 0.01 # # 0.00 0.03 0.00 0.04 != z 0 ... "' I ~ co ~ .... t"' Table 4.-Bowfin (Anda catval taken by electrofishing in the Illinois Waterway, 1959-1974. t"' z Year and Number of Hours Fished, 0 .... "' 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 z Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 ~ Number Per 30 Minutes ~ t"' Dresden1 0.00 0.00 0.00 0.00 ::c: Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 .... "' Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 .., 0 Peoria 0.00 0.00 0.o7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ~ LaGrange 0.00 0.00 0.04 0.00 0.00 0.00 0.00 0.00 0.08 0.00 0.10 0.00 0.00 ..,: en Alton 0.00 0.00 0.00 0.00 0.00 0.00 0.13 0.00 0.50 ~ Ill. R.2 0.00 0.00 0.05 0.01 0.00 0.00 0.00 0.00 0.00 0.05 0.00 # 0.00 0.01 ;j ..,: K i lograms Per 30 Minutes b:l Dresden1 0.00 0.00 0.00 0.00 ~ Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ~ Peoria 0.00 0.00 0.12 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 .... z La Grange 0.00 0.00 0.05 0.00 0.00 0.00 0.00 0.00 0.20 0.00 0.39 0.00 0.00 Alton 0.00 0.00 0.00 0.00 0.00 0.00 0.09 0.00 0.39 Ill. R .2 0.00 0.00 0.08 0.01 0.00 0.00 0.00 0.00 0.00 0.07 0.00 0.12 0.00 0.01 < 0 :--' c., _..... > .., !"'" 0:, .,, > ~ T< ...... '° --l Ci{ en 'ti Table 5.--Gizzard shad (Dorosoma cepedianum) taken by electrofishing in the Illinois Waterway, 1959-1974. > ~ Year and Number of Hours Fished "' Re 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 en >-l Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 i Number Per SO Minutes ~ Dresden1 0.00 0.00 3.33 7.30 Marseilles 2.50 4.67 5.50 7.29 14.16 14.00 13.83 20.83 22.17 7.49 20.50 24.70 4.60 13.00 trj Starved Rock 1.50 1.60 4.00 8.60 13.00 24.00 2.75 13.67 13.00 12.00 15.00 0.30 10.67 9.00 t"' Peoria 21.63 45.90 26.00 218.63 59.12 92.31 103.73 81.21 69.20 43.59 74.00 11.40 21.87 16.20 M Q La Grange 137.75 9.00 99.00 62.93 41.23 29.25 23.50 35.25 38.92 22.33 47.60 10.00 9.40 ,, Alton 34.10 25.00 40.88 2.27 14.25 29.50 4:12 6.13 6.60 0 "'1 ... Ill. R.2 37.00 21.76 19.70 103.62 44.71 53.62 41.21 39.51 42.48 28.07 36.25 29.90 14.25 11.26 "' ::i:: Kilograms Per SO Minutes ~ Dresden1 0.00 0.00 0.08 0.05 en Marseilles 0.35 0.64 0.86 0.o7 0.61 0.28 0.02 0.37 0.73 0.29 0.46 0.76 0.18 0.94 C: Starved Rock 0.37 0.32 0.47 0.26 0.68 1.11 0.05 0.05 0.42 0.84 0.35 0.09 0.23 0.33 ~ Peoria 1.02 3.27 1.02 1.08 2.18 0.31 0.63 0.66 0.27 0.26 0.25 0.43 0.49 0.80 o< La Grange 1.44 0.32 0.92 1.59 0.24 1.20 0.90 1.05 1.03 1.22 0.40 0.49 0.69 0 "1 Alton 0.85 0.34 0.44 0.09 0.49 0.33 0.10 # 0.25 -Ill. R.2 0.84 1.54 0.93 0.74 1.37 0.38 0.68 0.61 0.66 0.48 0.50 0.46 0.43 0.62 ~ z 0 !il ~ ~ ~ ...... ~ -t"" Table 6.-Goldeye (Hioclon alosoides) taken by electrofishing in the Illinois Waterway, 1959-1974. t"" z Year and Number of Hours Fished 0 .... C/l 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 z > Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 d Number Per SO Minutes ~ t"" Dresden' 0.00 0.00 0.00 ::r: Marseilles 0.00 0.00 0.00 0.07 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.40 .... C/l Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 .., 0 Peoria 0.00 0.10 0.00 0.00 0.00 0.00 0.13 0.00 0.00 0.07 0.00 0.00 0.00 0.00 ::i:I LaGrange 0.00 0.00 0.04 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.10 0.08 0.00 >< Alton 0.00 0.13 1.13 0.64 0.00 1.50 0.00 0.25 0.00 CJ') c:: ::i:I 111. R.2 0.00 0.04 0.00 0.02 0.02 0.19 0.17 0.00 0.27 0.02 0.05 # 0.03 0.05 < M >< Kilograms Per 30 Minutes IJ:i Dresden1 0.00 0.00 0.00 ? Marseilles 0.00 0.00 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.05 t"" Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 M .., Peoria 0.00 0.01 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.01 0.00 0.00 0.00 0.00 ... z La Grange 0.00 0.00 # 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.02 0.00 Alton 0.00 # 0.05 0.07 0.00 O.G7 0.00 0.01 0.00 111. R.2 0.00 # 0.00 # # 0.01 0.02 0.00 0.01 # # # 0.01 # < ~ w !'"' > ;:t. 00 > C: ~ ,.... '° -1 en er, 'ti Table 7.-Mooneye (Hiodon tergisus) taken by electrofishing in the Illinois Waterway, 1959-1974. > ,, ~ Year and Number of Hours Fished "' R'> 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 er, >-l Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 > :,, :,, Number Per 30 Minutes ~ Dresden1 0.00 0.00 0.00 0.00 Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 . 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 t%:I Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 r Peoria 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.10 tTl LaGrange 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ~ Alton 0.00 0.12 0.00 0.36 0.00 0.00 0.00 0.00 0.00 0 .,, .... Ill. R.2 0.00 0.00 0.00 0.00 0.02 0.00 0.08 0.00 0.00 0.00 0.00 0.00 0.00 0.02 "' ::i: Kilograms Per 30 Minutes z C"l Dresden1 0.00 0.00 0.00 0.00 er, Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 C: ,, Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ~ Peoria 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 # >< La Grange 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 .,, Alton 0.00 0.05 0.00 0.03 0.00 0.00 0.00 0.00 0.00 -Ill. R.2 0.00 0.00 0.00 0.00 0.01 0.00 # 0.00 0.00 0.00 0.00 0.00 0.00 # r r z 0 !il ~ ~ ~ w ~ - Table 8.----Goldfish (Carassius auratus) taken by electrofishing in the Illinois Waterway, 1959-1974. != z Year and Num ber of Hours Fished 0 ... rn 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 z Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 ~ Number Per S{) Minutes ~ Dresdenl 16.50 101.25 34.67 18.60 :z:: Marseilles 18.00 34.33 :S3.75 12.64 19.50 7.00 9.50 6.66 7.16 3.83 6.33 6.50 0.40 2.70 ~ Starved Rock 2.50 24.40 64.50 30.50 17.75 16.75 32.75 6.33 6.33 10.67 7.00 15.40 3.33 0.00 0 Peoria 0.37 0.60 3.07 0.15 0.00 2.56 1.07 0.50 0.33 0.13 1.07 0.20 0.13 0.10 ,, >< La Grange 0.00 0.14 0.42 1.16 0.62 1.81 0.25 0.08 0.00 0.17 0.10 0.00 0.00 Cl) Alton 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 i Ill. R.2 4.25 9.28 15.35 " 5.84 4.32 3.36 4.48 1.61 1.55 1.30 1.76 3.30 0.39 0.14 >< K i lograms Per SO M i nutes t:,::I Dre_sdent 2.37 4.53 2.27 ~ Marseilles 3.21 6.09 5.72 2.48 3.51 1.17 1.59 1.14 1.51 0.24 1.16 1.32 0.10 0.20 Starved Rock 0.34 2.76 6.71 4.50 2.88 1.99 4.18 1.07 1.18 2.09 1.40 3.28 0.89 0.00 Peoria 0.06 O.Q7 0.16 0.01 0.00 O.Q7 0.06 0.03 0.01 0.01 0.06 0.02 0.01 0.10 z LaGrange 0.00 0.02 0.03 0.05 0.10 0.25 0.06 # 0.00 0.01 0.02 0.00 0.00 Alton 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Ill. R.2 0.73 1.32 1.92 0.95 0.71 0.37 0.60 0.26 0.29 0.18 0.27 0.68 0.10 0.06 < ~ c.:> .!'""' > .., "" 00 > i:: ~ ..... co -l C/l r:r, '1:1 Table 9.---Carp x Goldfish (Cyprinus c:arpio x Carassius auratus) taken by electrofishing in the Illinois Waterway, 1959-1974. > ,:I Year and Number of Hours Fished ~ R" 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 r:r, .., Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 i Number Per 30 Minutes M Dresden1 2.50 1.00 0.00 0.70 ~ Marseilles 2.50 0.67 0.75 2.79 1.00 0.83 0.83 0.50 0.16 0.33 0.33 0.50 o.'oo 0.00 ~ Starved Rock 0.75 4.00 0.50 3.50 3.25 1.25 4.75 1.67 3.33 1.67 1.00 1.30 0.67 0.70 t"' Peoria 0.00 0.40 0.71 0.81 0.81 1.12 1.53 2.71 2.27 1.60 1.67 2.60 1.60 1.60 M LaGrange 0.25 0.00 0.04 0.15 0.62 0.25 0.34 0.25 0.00 0.17 0.00 0.00 0.30 ~ Alton 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.10 0 "1 .... Ill. R.2 0.70 1.04 0.70 1.14 0.73 0.77 0.98 1.16 1.09 0.70 0.73 1.20 0.72 0.64 VJ :i: Kilograms Per 30 Minutes z G'l Dresden1 0.78 0.00 0.26 r:r, Marseilles 1.30 0.19 0.27 1.75 0.82 0.99 0.54 0.25 0.05 0.86 0.21 0.17 0.00 0.00 g Starved Rock 0.73 4.05 0.57 2.05 1.75 0.82 3.11 0.80 2.20 1.12 0.63 0.69 0.36 0.40 < M Peoria 0.00 0.18 0.18 0.29 0.20 0.27 0.43 0.78 0.63 0.42 0.46 0.80 0.39 0.33 ~ La Grange 0.13 0.00 # # 0.12 0,07 0.08 0.08 0.00 0.05 0.00 0.00 0.05 0 "1 Alton 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.04 ..... Ill. R.2 0.44 0.91 0.24 0.62 0.32 0.32 0.45 0.37 0.40 0.34 0.24 0.41 0.19 0.15 t"' t"' z 0 .... VJ !'X' ~ ~ C/l Table 10.---Carp (Cyprinus carpio) taken by electrofishing in the Illinois Waterway, 1959-1974. Year and Number of Hours Fished 1959 1960 1961 1962 1963 1964 1965 1966 1967 Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 Number Per 30 Minutes Dresden1 8.00 18.25 Marseilles 10.00 5.33 20.25 9.07 19.33 15.17 21.00 12.00 19.50 Starved Rock 3.00 28.60 53.00 25.00 26.75 11.00 31.50 19.67 15.33 Peoria 13.25 11.20 36.00 17.70 17.56 18.81 14.53 19.72 18.13 LaGrange 15.00 20.71 28.42 51.69 77.39 14.63 61.75 37.59 Alton 10.70 24.50 36.63 12.55 21.87 20.88 Ill. R.2 10.90 16.64 34.55 19.34 29.19 36.92 16.19 30.77 23.93 Kilograms Per 30 Minutes Dresden1 6.36 Marseilles 7.53 4.45 12.40 6.67 13.34 12.53 16.70 11.55 16.51 Starved Rock 2.09 17.25 12.99 20.12 17.71 4.70 11.84 6.10 9.24 Peoria 6.81 6.70 10.26 8.18 8.00 5.79 5.72 6.90 7.78 LaGrange 7.72 14.73 18.63 29.46 37.51 7.73 23.60 15.62 Alton 9.82 26.90 41.87 11.19 20.73 18.19 Ill. R.2 6.19 10.79 10.96 12.48 18.66 21.47 9.23 14.73 12.98 1968 1969 1970 22.0 22.0 13.5 13.17 10.00 16.70 9.00 9.67 18.00 17.73 20.60 18.20 38.91 27.58 21.60 16.00 19.50 21.98 20.11 18.90 9.91 7.91 14.91 5.98 5.67 7.70 7.22 10.17 14.13 15.83 12.34 12.91 12.90 16.18 10.89 11.24 13.23 1973 1974 19.5 21.8 6.00 16.00 14.80 13.80 4.00 10.30 10.60 27.40 25.23 30.50 15.70 15.92 22.74 4.06 7.05 8.66 8.76 3.15 4.90 4.84 9.78 14.91 15.23 13.28 8.87 11.58 w c.n 0, ..... I:"' I:"' z 0 ... r:r, z > ~ ~ I:"' ::i:: til >-l 0 :,:: -< r,; C: :,:: < t"1 -< tc C: I:"' I:"' t"1 >-l ... z <: ~ w ..... > '"I ~ 00 > :: T' ~ .;o -l Cll rJ) "Ii Table 11.-River carpsucker (Carpiocles carpio) taken by electrofishing in the Illinois Waterway, 1959-1974. > = ~ Year and Number of Hours Fished rJ, R- 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 rJ) .., Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 > Number Per 30 Minutes ~ Dresden1 0.00 0.00 0.00 0.00 ::l Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.17 0.00 0.00 0.00 0.00 0.40 tzj Starved Rock 0.00 0.60 0.00 0.10 0.00 0.00 0.00 0.33 0.00 0.33 0.00 0.00 1.00 2.40 t:-< Peoria 0.12 0.70 1.71 0.19 0.00 0.00 0.07 0.o7 0.67 0.40 0.13 0.10 0.73 1.30 ~ La Grange 0.75 0.43 0.08 0.15 0.15 0.81 ·o.oo 1.17 1.08 0.09 0.00 0.31 0.10 Alton 0.30 0.25 0.00 0.64 0.62 0.12 0.50 0.00 0.00 0 ;l Ill. R.2 0.20 0.52 1.20 0.13 0.09 0.04 0.40 0.16 0.59 0.55 0.07 0.01 0.50 0.67 rJ, :i: Kilograms Per .10 Minutes z C"l Dresden1 0.00 0.00 0.00 0.00 rJ) Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.05 0.00 0.00 0.00 0.00 0.24 c::: = Starved Rock 0.00 0.17 0.00 0.05 0.00 0.00 0.00 0.18 0.00 0.22 0.00 0.00 0.43 0.88 < t,j Peoria 0.05 0.15 0.14 0.05 0.00 0.00 0.01 # 0.21 0.14 0.10 0.06 0.21 0.31 ~ La Grange 0.43 0.03 0.02 0.09 0.04 0.23 0.00 0.22 0.25 0.05 0.00 0.15 0.02 0 .., Alton O.Q7 0.10 0.00 0.21 0.27 0.02 0.19 0.00 0.00 -IU.R.2 0.11 0.10 0.10 0.04 0.04 0.01 0.12 0.06 0.15 0.16 0.05 0.02 0.18 0.20 ~ .... z 0 .... rJ, ~ < t,j = ~ -l ~ .... t"' Table 12.---Quillback carpsucker (Carpiodes cyprinus) taken by electrofishing in the Illinois Waterway, 1959-1974. t"' z 0 Year and Number of Hours Fished .... "' 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 z > Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 ~ ::c Number Per 30 Minutes > t"' Dresden1 0.00 0.00 0.00 0.00 ::r: Marseilles 0.00 0.00 0.25 0.00 0.17 1.33 0.00 0.50 2.00 1.33 1.17 1.50 1.00 0.70 ~ Starved Rock 0.00 -0.40 0.00 0.60 1.75 2.75 3.00 2.00 1.67 2.67 1.00 1.40 0.67 1.40 0 Peoria 0.00 0.30 0.36 0.22 1.13 0.88 0.33 0.79 0.60 1.33 1.13 0.10 0.13 0.00 ::c o< La Grange 0.00 0.00 0.08 0.54 0.23 0.19 0.25 0.00 0.33 0.34 0.00 0.15 0.00 r,i Alton 0.00 0.25 0.00 0.09 0.00 0.00 0.13 0.38 0.10 C: ::c Ill. R.2 0.00 0.20 0.30 0.16 0.75 0.77 0.40 0.54 0.59 0.93 0.77 0.50 0.31 0.19 ~ o< Kilograms Per 30 Minutes t:,:, Dresden1 0.00 0.00 0.00 0.00 ~ Marseilles 0.00 0.00 0.04 0.00 0.07 0.59 0.00 0.20 0.34 0.29 0.38 0.32 0.36 0.27 Starved Rock 0.00 0.12 0.00 0.23 0.64 0.98 0.95 0.65 0.65 0.82 0.36 0.70 0.38 0.53 !:l Peoria 0.00 0.04 0.04 0.07 0.34 0.09 0.09 0.20 0.13 0.40 0.44 0.03 0.06 0.00 .... z La Grange 0.00 0.00 0.04 0.05 0.03 0.06 0.06 0.00 0.05 0.08 0.00 0.03 0.00 Alton 0.00 0.08 0.00 0.01 0.00 0.00 0.03 0.12 Ill. R.2 0.00 0.04 0.04 0.06 0.20 0.20 0.12 0.16 0.14 0.25 0.27 0.16 0.12 0.07 < ?-- w j-' > ... r"" 0:, > i:: qq . ..... co -l CJ1. er, "C Table 13.-Smallmouth buffalo ( lctiobus buba'lus) ..taken by electrofishing in the Illinois Waterway, 1959-1974. > :0 :,,,: Year and Number of Hours Fished en i:l" 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 rJJ .., Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 ~ Number Per 30 Minutes 1;l Dresden1 0.00 0.00 0.00 0.00 ~ Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.17 0.00 0.00 0.10 0.20 0.00 ~ Starved Rock 0.00 0.60 0.00 0.00 0.00 0.00 0.00 0.00 0.33 0.00 0.00 0.30 0.33 2.00 r< Peoria 0.13 0.20 0.36 0.56 0.75 1.87 0.13 0.79 1.47 1.20 0.60 0.20 0.40 0.70 t'l Q La Grange 5.25 0.00 1.54 2.31 0.62 0.25 0.25 0.83 0.17 1.34 0.60 0.08 0.30 :0 Alton 0.60 0.13 0.00 0.00 0.00 0.12 0.00 0.12 0.00 0 ..., Ill. R.2 1.10 0.20 0.25 0.68 0.91 0.81 0.12 0.33 0.80 0.45 0.59 0.30 0.25 0.45 i;; ::i: Kilograms Per ,30 Minutes z Cl Dresden1 0.00 0.00 0.00 0.00 rJJ Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.02 0.00 C: Starved Rock 0.00 0.64 0.00 0.00 0.00 0.00 0.00 0.00 0.09 0.00 0.00 0.14 0.42 1.10 ~ Peoria 0.10 0.04 0.29 0.34 0.52 1.03 0.14 0.35 0.54 0.45 0.31 0.10 0.21 0.33 >< LaGrange 1.66 0.00 0.73 2.20 0.38 0.18 0.09 0.21 0.05 0.57 0.38 0.02 0.24 0 Alton 0.13 0.03 0.00 0.00 0.00 0.04 0.00 0.10 0.00 ..., ..... III. R.2 0.37 0.15 0.20 0.33 0.79 0.45 0.10 0.14 0.26 0.17 0.28 0.16 0.13 0.25 r< r< z 0 ... en ~ ... < t'l :0 ~ co ~ .... t"' Table 14,-Bigmouth buffalo ( lctiobus cyprinellus) taken by electrofishing in the Illinois Waterway, 1959-1974. t"' .... z Year and Number of Hours Fished 0 .... "' 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 z > Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 ~ ,, Number Per 30 Minutes > t"' Dresden1 0.00 0.00 0.00 0.00 ::i::: Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.20 .... "' Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.33 0.00 0.00 0.00 0.00 0.00 0.30 .., 0 Peoria 2.25 0.70 2.57 3.89 4.56 5.12 5.00 9.22 12.20 6.87 6.20 0.90 4.33 17.20 ,, La Grange 9.75 3.29 5.21 9.54 8.92 1.44 3.33 5.25 1.33 0.83 0.40 1.92 3.50 ..,: r:r., Alton 0.60 0.50 0.62 0.00 0.37 0.63 0.13 0.12 0.00 C: ,, Ill. R.2 2.85 1.20 1.80 2.78 4.28 4.32 1.88 4.03 5.70 2.73 2.36 0.50 2.50 6.48 c:: (!Q -~ ~ CJ1. V) Table 15.-Black buffalo ( lctiobus niger) taken by electrofishing in the Illinois Waterway, 1959-1974. "ti > ::ii Year and Number of Hours Fished ~ CJ) I<" 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 V) Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 .., > Number Per 30 Minutes sl Dresden1 0.00 0.00 0.00 0.00 9 Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.30 t-rl t"' Peoria 0.00 0.10 0.50 0.52 0.06 O.o7 0.00 0.22 0.00 0.33 0.40 0.40 0.00 0.00 t,j La Grange 0.50 0.00 0.33 1.08 0.46 0.06 0.08 0.33 0.08 0.00 0.00 0.15 0.00 ~ Alton 0.00 0.00 0.12 0.00 0.12 0.00 0.13 0.00 0.00 0 >rj Ill. R.2 0.10 0.04 0.35 0.26 0.32 0.17 0.02 0.12 0.09 0.16 0.14 0.20 0.06 0.01 ... CJ) Kilograms Per 30 Minutes ~ Dresden1 0.00 0.00 0.00 0.00 C) V) Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ~ Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.22 Peoria 0.00 # 0.58 0.68 0.12 0.11 0.00 0.12 0.00 0.32 0.42 0.46 0.00 0.00 t,j -< La Grange 0.31 0.00 0.32 1.19 0.62 0.02 0.06 0.41 0.14 0.00 0.00 0.16 0.00 0 Alton 0.00 0.00 0.22 0.00 0.21 0.00 0.11 0.00 0.00 >rj -Ill. R.2 0.06 0.00 0.40 0.31 0.37 0.25 # 0.10 0.11 0.17 0.15 0.17 0.06 # t"' t"' z 0 ~ :,:, ~ ::ii 85 - w l?J .... t" Table 16.-Shorthead redhorse (Moxostoma macrolepidotum) taken by electrofishing in the Illinois Waterway, 1959-1974. t" z Year and Number of Hours Fished 0 .... V, 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 z > Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 ~ Number Per 30 Minutes > t" Dresden1 0.00 0.33 0.70 ::i:: Marseilles 0.00 0.00 0.00 0.07 0.17 0.00 0.16 0.17 0.17 0.00 0.00 0.00 0.00 0.00 .... Starved Rock 0.00 · 0.80 0.00 0.20 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.30 0.67 0.00 ~ Peoria 0.13 0.10 O.Q7 0.11 0.06 0.13 0.07 0.00 0.00 0.00 0.o7 0.10 0.33 0.10 g LaGrange 0.75 0.29 0.04 0.00 0.08 0.44 0.17 0.00 0.08 0.08 0.40 0.15 0.30 ~ en Alton 0.00 0.00 0.00 0.00 0.00 0.00 0.13 0.00 0.60 C: !::l Ill. R.2 0.20 0.28 0.05 0.08 O.o4 0.o7 0.17 0.07 0.02 0.04 0.05 0.20 0.25 0.26 ;J ~ Kilograms Per SO Minutes t::CI Dresden1 0.06 0.00 0.05 0.15 ~ Marseilles 0.00 0.00 0.00 0.01 0.01 0.00 0.04 # 0.04 0.00 0.00 0.00 0.00 0.00 Starved Rock 0.00 0.16 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.10 0.23 0.00 l:'l .., Peoria 0.10 0.02 0.03 0.03 # 0.02 0.01 0.00 0.00 0.00 # # 0.06 0.03 z LaGrange 0.06 0.01 0.00 0.00 # 0.06 0.03 0.00 # o.oi 0.02 0.06 0.05 Alton 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0,00 0.23 Ill. R.2 0.05 0.04 0.02 0.01 # 0.01 0.02 0.01 # # # 0.02 0.06 0.08 i w r > .., :-'" 00 > C (!Q -(0 -:t "" CF) "' Table 17.-Black bullhead ( lctalurus melas) taken by electrofishing in the Illinois Waterway, 1959----1974. > ~ ;,:: Year and Number of Hours Fished rn R" 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 CF) .., Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 ~ ~ Number Per 30 Minutes M Dresden1 0.00 0.00 0.00 0.00 ~ Marseilles 0.50 2.00 2.00 1.36 2.17 2.17 4.67 4.33 3.50 6.50 2.50 3.50 6.60 19.60 l:%j Starved Rock 0.00 0.60 2.00 0.20 0.00 0.00 2.25 0.00 0.33 0.00 0.00 0.00 0.00 0.00 t"' Peoria 0.13 1.00 1.21 1.00 0.56 0.12 0.13 0.22 0.13 0.00 0.06 0.10 0.07 0.10 M LaGrange 0.00 0.00 0.00 0.08 0.00 0.19 0.75 0.42 0.08 0.08 0.00 0.00 0.00 ~ Alton 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 "l ... Ill. R.2 0.15 0.76 1.45 0.56 0.49 0.32 0.81 0.88 0.66 0.91 . 0.39 0.80 0.94 2.12 rn :i:: ... Kilograms Per 30 Minutes z C) Dresden1 0.00 0.00 0.00 0.00 CF) Marseilles 0.14 0.31 0.29 0.12 0.15 0.06 0.24 0.18 0.16 0.35 0.20 0.37 0.35 0.53 C: ~ Starved Rock 0.00 0.11 0.14 0.03 0.00 0.00 0.22 0.00 0.05 0.00 0.00 0.00 0.00 0.00 ;i Peoria 0.04 0.15 0.21 0.12 0.05 # # 0.03 # 0.00 0.01 0.02 0.01 0.01 >< La Grange 0.00 0.00 0.00 # 0.00 0.01 0.01 0.04 # # 0.00 0.00 0.00 0 Alton 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 "l -lll.R.2 0.04 0.12 0.22 0.06 0.04 0.01 0.05 0.04 0.04 0.05 0.03 0.09 0.06 0.06 t"' t"' z 0 ... rn ~ ... < M ~ ~ w ~ ..... t"< Table 18.-Yellow bullhead ( lctalurus natalis) taken by electrofishing in the Illinois Waterway, 1959-1974. t"< .... z Year and Number of Hours Fished 9 "' 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 z > Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 a Number Per 30 Minutes ~ t"< Dresdenl 0.00 0.00 0.00 0.00 :::i:: Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 '"' Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ~ 0 Peoria 0.00 0.00 0.00 0.15 0.06 0.06 0.o7 0.21 0.Q7 0.07 0.13 0.00 0.07 0.10 :x, -< La Grange 0.00 0.72 0.04 0.08 0.15 0.00 0.08 0.08 0.00 0.08 0.00 0.00 0.10 V") Alton 0.00 0.00 0.12 0.00 0.00 0.00 0.00 0.00 0.00 c:: :x, Ill. R.2 0.00 0.20 0.00 0.06 0.04 0.08 0.02 0.09 0.05 0.02 0.Q7 0.00 0.03 0.o7 <: t,j -< Kilograms Per 30 Minutes t:c Dresden1 0.00 0.00 0.00 0.00 c:: Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 t:: Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 t,j .., Peoria 0.00 0.00 0.00 0.02 0.01 0.01 0.02 0.07 # 0.01 0.01 0.00 0.02 0.03 '"' z LaGrange 0.00 0.09 0.01 0.01 0.03 0.00 # 0.02 0.00 0.ol 0.00 0.00 0.03 Alton 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 Ill. R.2 0.00 0.02 0.00 0.ol # 0.01 # 0.02 # # 0.01 0.00 0.01 0.02 < ~ w r > ... :-'" 00 > i:: (!Cl f--' '° -l Cll v:, 'tl Table 19.--Channel catfish (lctaluru1 punctatusl taken by electrofishing in the Illinois Waterway, 1959-1974. > ,:, ~ Year and Number of Hours Fished "' I<" 1969 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 v:, .., Pooz 12.0 12.5 10.0 44 .6 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.6 19.5 21.8 ~ ,:, Number Per SO Minutes t'l Dresden! 0.00 0.00 0.00 0.00 ::l Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.20 t'1 Starved Rock 0.00 0.20 0.00 0.70 0.00 0.00 1.25 0.33 0.00 0.00 0.00 0.30 2.00 0.00 I:"' Peoria 0.00 0.20 0.14 0.19 0.00 0.00 0.13 0.07 0.13 0.20 0.47 0.00 0.40 0.40 t'l LaGrange 0.00 4.00 1.46 2.69 0.31 0.25 2.67 2.42 2.51 1.42 1.10 0.62 1.30 ~ Alton 3.50 8.50 2.37 2.00 3.00 1.63 4.75 2.75 6.30 0 "l ... Ill. R.2 0.00 1.24 0.10 0.96 2.19 0.51 0.64 1.36 1.00 1.62 1.06 0.40 0.66 1.74 "' :i: Kilograms Per SO Minutes z C'l Dresden1 0.00 0.00 0.00 0.00 v:, Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.19 C: ::z:, Starved Rock 0.00 0.05 0.00 0.34 0.00 0.00 0.17 0.00 0.00 0.00 0.00 0.02 0.66 0.00 < t'l Peoria 0.00 0.03 0.02 0.07 0.00 0.00 0.01 0.01 0.04 0.06 0.31 0.00 0.21 0.19 -< La Grange 0.00 0.57 0.35 0.79 0.12 0.07 0.28 0.42 0.45 0.25 0.44 0.46 0.44 0 "l Alton 0.88 2.13 1.01 0.25 1.47 0.68 0.84 0.90 1.91 -Ill. R.2 0.00 0.18 0.01 0.26 0.68 0.20 0.09 0.35 0.24 0.29 0.34 0.13 0.31 0.65 I:"' I:"' z 0 .... "' I ::z:, w ffi 8i .... t"' Table 20.-Flathead catfish (Pylodictis olivaris) taken by electrofishing in the Illinois Waterway, 1959-1974. t"' .... z Year and Number of Hours Fished 8 V, 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 z > Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 j Number Per 30 Minutes t"' Dresden1 0.00 0.00 0.00 0.00 ::r: Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Jooo< V, Starved Rock 0.00 0,00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 --l 0 Peoria 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 !:zj i< LaGrange 0.00 0.00 0.00 0.15 0.00 0.00 0.00 0.00 0.00 0.00 0.40 0.08 0.60 en Alton 0.30 0.13 0.00 0.00 0.00 0.25 0.25 0.25 0.50 C: !:zj 111. R.2 0.00 0.00 0.00 0.04 0.06 0.00 0.00 0.00 0.05 0.05 0.05 0.10 0.03 0.29 < l:'1 i< Kilograms Per 30 Minutes to Dresden' 0.00 0.00 0.00 0.00 C: Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 t"' t"' Starved Rock 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 (l.00 0.00 ~ Peoria 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 z La Grange 0.00 0.00 0.00 0.21 0.00 0.00 0.00 0.00 0.00 0.00 1.42 0.05 1.08 Alton 0.04 0.01 0.00 0.00 0.00 0.01 0.06 0.02 0.10 Ill. R.2 0.00 0.00 0.00 # 0.06 0.00 0.00 0.00 # 0.01 # 0.42 0.02 0.31 < ~ w .:-' > ..... ~ 00 > C: qq ...... '° -1 Cll ,;;:, Table 21.-White bass ( Morone chrysops) taken by electrofishing in the Illinois Waterway, 1959-1974. 'O > ::,:, ~ Year and Number of Hours Fished rn R" 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 ,;;:, .., Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 > sl Number Per 30 Minutes t'1 Dresdenl 0.00 0.00 0.00 0.00 ~ Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.17 0.00 0.00 0.00 0.00 0.20 0.20 0.40 tzj Starved Rock 0.00 0.20 0.00 0.20 0.00 0.00 0.75 1.00 0.33 0.00 0.00 1.70 1.33 0.60 r Peoria 0.00 0.10 0.00 0.44 0.00 0.25 1.26 0.93 0.66 0.40 0.47 1.30 0.93 2.20 t'1 Q La Grange 0.00 0.29 0.33 0.46 0.15 0.94 0.75 0.58 0.25 0.00 0.80 0.08 0.80 ::,:, Alton 0.00 4.40 2.62 1.62 1.27 1.00 2.00 3.49 5.75 1.70 0 ::l Ill. R.2 0.00 0.16 0.00 0.78 0.58 0.40 1.00 0.77 0.77 0.84 1.20 0.60 0.56 1.41 rn ::i: Kilograms Per 30 Minutes z C'l Dresden1 0.00 0.00 0.00 0.00 ,;;:, Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 # 0.00 0.00 0.00 0.00 # 0.01 0.09 g Starved Rock 0.00 # 0.00 0.06 0.00 0.00 0.07 0.21 0.10 0.00 0.00 0.07 0.06 0.08 ~ Peoria 0.00 0.02 0.00 0.10 0.00 0.07 0.15 0.26 0.27 0.19 0.12 0.16 0.05 0.21 >< LaGrange 0.00 0.13 0.09 0.06 0.00 0.15 0.20 0.20 0.10 0.00 0.27 # 0.12 0 "'l Alton 0.00 1.03 0.80 0.26 0.25 0.14 0.62 1.28 1.14 0.50 -Ill. R.2 0.00 0.05 0.00 0.25 0.15 0.04 0.23 r 0.18 0.15 0.07 0.15 0.18 0.27 0.32 r z 0 vl !:J:j .. < gi ~ ~ w ~ -r" Table 22.---Green sunfish (Lepomis cyanellus) taken by electrofishing in the Illinois Waterway, 1959-1974. r' .... z 0 Year and Number of Hours Fished .... "' 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 z > Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 ~ ~ Number Per 30 Minutes > t"" Dresden1 0.25 0.00 0.67 0.00 :::c: Marseilles 0.25 0.33 0.25 O.o7 0.00 0.00 0.00 0.17 0.33 0.33 0.67 2.00 1.80 8.00 .... Starved Rock 0.00 · 0.00 0.00 0.20 0.25 0.00 0.00 0.33 0.33 1.66 1.33 0.00 3.33 1.70 ~ 0 Peoria 1.00 0.00 1.36 0.74 3.50 1.56 0.27 5.00 2.27 4.80 7.20 1.50 7.20 4.30 ~ --< LaGrange 0.00 2.72 1.00 0.77 1.15 0.19 0.33 0.58 2.25 7.50 2.00 3.54 1.00 Cl:) Alton 0.10 0.25 1.12 0.00 0.63 0.12 0.00 1.50 1.00 C: ~ Ill. R.2 0.45 0.80 1.00 0.56 1.47 1.04 0.13 1.88 1.02 2.41 4.95 1.60 4.81 2.83 -< 1:11 --< Kilograms Per 30 Minutes t:cl Dresden1 # 0.00 # 0.00 C: Marseilles # # 0.03 # 0.00 0.00 0.00 # 0.02 0.01 # 0.05 0.05 0.09 t"" Starved Rock 0.00 0.00 0.00 # # 0.00 0.00 0.01 0.01 0.08 0.05 0.00 0.11 0.05 6 Peoria 0.04 0.00 0.03 0.03 0.03 # # 0.09 0.06 0.10 0.14 0.05 0.18 0.10 .... z LaGrange 0.00 0.03 0.01 0.01 # 0.01 0.01 0.07 0.20 0.05 0.10 0.51 Alton # # 0.-00 0.01 # 0.00 0.02 0.04 Ill.R.2 0.01 0.08 0.03 0.02 0.01 # # 0.04 0.03 0.06 0.11 0.05 0.13 0.06 < ~ w J-' > ... r'" 00 > C ~ ..... co -..J CJl r;r., Table 23.-Bluegill (Lepomis macrochirus) taken by electrofishing in the Illinois Waterway, 1959-1974. 'O ~ :,:: Year and Number of Hours Fished V, R" 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 r;r., Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 .., > ,, ,, Number Per SO Minutes t'1 Dresden1 0.00 0.00 0.00 0.00 ::l Marseilles 0.25 1.00 0.00 0.14 0.17 0.00 0.00 0.00 0.00 0.17 0.00 2.00 0:00 0.90 trl Starved Rock 0.00 0.20 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.67 0.00 0.00 0.00 r' Peoria 1.75 0.20 3.93 3.07 7.31 5.06 0.20 3.14 1.80 1.80 1.80 1.90 2.20 9.30 t'1 ~ La Grange 0.25 24.71 11.13 7.54 6.92 0.06 3.34 3.08 5.09 3.08 7.90 4.92 14.60 ,, Alton 4.30 3.50 5.13 0.00 4.38 3.12 3.75 7.25 12.70 0 "lj .... 111. R.2 0.80 7.16 2.75 4.65 5.19 4.51 0.08 2.77 2.02 2.70 2.82 3.50 2.69 9.93 V, :i:: .... Kilograms Per SO Minutes z C"l Dresdenl 0.00 0.00 0.00 0.00 r;r., Marseilles # 0.04 0.00 # # 0.00 0.00 0.00 0.00 # 0.00 0.03 0.00 0.04 C: ,, Starved Rock 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.00 0.00 ~ Peoria 0.08 # 0.23 0.11 0.05 0.03 # 0.02 0.01 # 0.03 0.05 0.04 0.18 -< LaGrange # 0.89 0.30 0.06 0.04 # 0.10 0.07 0.18 0.07 0.20 0.12 0.51 ~ Alton 0.12 0.01 0.01 # 0.05 0.12 0.16 0.37 0.50 -Ill.R.2 0.04 0.26 0.16 0.13 0.04 0.02 # 0.05 0.05 0.08 0.10 0.09 0.06 0.31 r' r' z 0 .... V, ~ ~ ,, C,;) O:> co ~ -t"' Table 24.-Largemouth bass (Micropterus salmoidesl taken by electrofishing in the lllir.ois Waterway, 1959-1974. t"' z Year and Number of Hours Fished 8 "' 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 z > Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 .., ~ Number Per SO Minutes ~ Dresden1 0.00 0.00 0.00 0.00 ::i::: Marseilles 0.00 0.67 0.50 O.o7 0.00 0.17 0.00 0.17 0.00 0.17 0.50 0.10 2.40 1.78 ... "' Starved Rock 0.00 0.60 0.00 0.00 0.00 0.00 0.25 0.00 0.00 0.00 0.00 0.00 1.00 0.00 .., 0 Peoria 2.13 3.20 10.36 4.85 2.69 1.13 0.27 0.21 0.87 0.67 0.27 0.80 6.20 5.78 ,, LaGrange 8.00 20.71 8.71 2.15 2.15 0.06 0.92 1.17 1.42 1.25 2.50 3.38 2.55 ~ Alton 3.70 0.62 0.63 0.00 1.13 2.50 0.63 1.75 4.30 r;,i c:: Ill . R,2 2.45 7.28 7.35 4.45 1.62 1.11 0.12 ,, 0.56 1.07 0.75 0.82 1.10 4.19 3.74 ;i ~ Kilograms Per SO Minutes t:o Dresden1 0.00 0.00 0,00 0.00 I Marseilles 0.00 0.04 0.01 # 0.00 0.01 0.00 0.01 0.00 0.00 0.08 # 0.76 0.15 Starved Rock 0.00 0.23 0.00 0.00 0.00 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.21 0.00 Peoria 0.80 0.98 2.32 1.83 0.90 0.36 0.16 0.07 0.15 0.14 0.04 0.22 1.41 1.57 La Grange 2.06 5.11 2.74 0.73 0.64 0.01 0.27 0.33 0.37 0.14 0.31 0.72 0.92 Alton 1.11 0.29 0.12 0.00 0.22 0.64 0.10 0.53 0.94 Ill. R.2 0.73 1.87 1.63 1.49 0.56 0.32 0.05 0.14 0.25 0.ltr 0.16 0.18 0.97 0.99 ~ i- w .:-' > .., ::-,- 00 > C: q:. ..... co --:i Cll r:r, Table 25.-White crappie (Pomoxis annularis) taken by electrofishing in the Illinois Waterway, 1959-1974. >o ;J>, ;!j ~ Year and Number of Hours Fished "' f<" 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 r:r, Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 .., ~ ;!j Number Per 30 Minutes t'1 Dresdenl 0.00 0.00 0.00 0.00 ::J Marseilles 0.00 1.67 0.00 0.00 0.00 0.00 0.00 0.33 0.00 0.00 0.00 0.50 0.00 2.00 tr1 Starved Rock 0.00 0.40 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.30 t"' Peoria 0.25 0.00 1.36 1.41 1.31 0.63 0.20 2.64 1.80 0.33 0.47 1.30 3.33 5.50 t'1 La Grange 0.00 4.29 3.63 0.62 1.00 0.13 2.08 3.17 3.08 1.25 1.50 0.46 1.50 ~ Alton 0.50 0.88 0.88 0.64 1.00 1.37 1.99 1.63 0.70 0 "1 Ill. R.2 0.10 1.48 0.95 1.53 0.77 0.64 0.23 1.68 1.73 1.32 0.80 1.00 1.56 2.57 .... "' ::i: .... Kilograms Per 30 Minutes z C'l Dresden1 0.00 0.00 0.00 0.00 r:r, Marseilles 0.00 0.14 0.00 0.00 0.00 0.00 0.00 0.06 0.00 0.00 0.00 0.06 0.00 0.20 C: Starved Rock 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.07 ;!j 0.00 ~ Peoria 0.01 0.00 0.15 0.17 0.18 0.11 0.00 0.39 0.28 0.08 0.o7 0.21 0.50 1.02 -< La Grange 0.00 0.33 0.31 0.09 0.15 0.03 0.20 0.42 0.47 0.13 0.23 0.05 0.13 0 Alton 0.10 0.10 0.13 0.08 0.27 0.25 0.34 0.22 0.19 "1 -Ill. R.2 # 0.11 0.11 0.15 0.10 0.10 0.03 0.24 0.25 0.22 0.10 0.16 0.23 0.44 t"' t"' z 0 ... "' !::c < gJ w --:i ..... ~ to ..... Table 26.-Black crappie (P-xis nigromaculatus) taken by electrofishing in the Illinois Waterway, 1959-1974. != z 0 Year ana Number of Hours Fishea ,.. Cl) 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 z > Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.5 21.8 ~ Number Per 30 Minutes ~ Dresdenl 0.00 0.00 0.00 0.00 ::t Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.17 0.10 0.00 0.40 I Starved Rock 0.00 0.00 0.00 0.10 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.00 1.40 Peoria 0.00 0.00 2.36 7.56 1.75 0.56 0.00 1.64 2.33 1.34 1.53 2.60 4.47 8.00 ~ La Grange 0.75 8.71 5.67 1.15 1.85 0.44 5.00 8.00 11.50 8.42 6.90 4.23 9.50 r:J") Alton 0.00 2.50 1.50 0.45 1.75 ~.63 6.88 8.38 1.80 c= Ill. R .2 0.20 2.44 1.65 4.30 1.34 0.96 0.23 2.26 3.64 4.85 4.36 3.00 3.47 5.62 ~ ~ Kilograms Per 30 Minutes tXl Dresdenl 0.00 0.00 0.00 0.00 ~ Marseilles 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.00 0.05 Starved Rock 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.12 0.33 ~ Peoria 0.00 0.00 0.30 1.58 0.29 0.10 0.00 0.24 0.53 0.25 0.31 0.48 0.52 1.37 z LaGrange 0.08 1.16 1.08 0.12 0.09 om 0.50 0.97 1.38 0.82 0.91 0.56 0.74 Alton 0.34 0.25 0.25 0.03 0.24 0.26 0.90 1.48 0.23 Ill. R.2 0.01 0.33 0.21 0.85 0.17 0.10 0.03 0.26 0.49 0.63 0.60 0.44 0.43 0.72 < ~ c.., !""' ~ r'" 00 > C: ~ ...... '° --'.I Cll en "C Table 27.-Freshwater drum (Aploclinotus grunniens) taken by electrofishing in the Illinois Waterway, 1959-1974. ~ :,,: Year and, Number of Hours Fished Vl ~ 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1973 1974 en "".l Pool 12.0 12.5 10.0 44.5 23.5 23.5 26.0 21.5 22.0 22.0 22.0 13.5 19.6 21.8 § Number Per 30 Minutes Dresden1 0.00 0.00 0.00 0.00 Marseilles 0.00 0.00 0.00 0,07 0.00 0.00 0.00 0.00 0.00 0.60 0.33 0.70 0.00 0.40 M Starved Rock 0.00 0.00 0.00 0.10 0.00 0.00 0.00 0.00 0.00 0.00 0.33 0.00 0.00 0.00 t"' Peoria 0.38 0.10 0.79 0.40 0.06 0.31 0.07 0.00 0.13 0.20 0.53 0.50 0.73 0.60 ; LaGrange 3.26 2.00 0.92 0.69 0.54 1.56 1.33 3.50 2.75 3.92 2.30 4.62 5.00 Alton 0.30 0.87 0.00 3.55 0.38 0.38 1.12 1.12 6.70 .., ... Ill. R.2 0.80 0.60 0.55 0.45 0.36 0.26 1.25 0.44 1.07 1.09 1.52 1.00 1.97 2.90 = Kilograms Per 30 Minutes ~ Dresden1 0.00 0.00 0.00 0.00 en Marseilles 0.00 0.00 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 # 0.00 # g Starved Rock 0.00 0.00 0.00 0.05 0.00 0.00 0.00 0.00 0.00 0.00 0.10 0.00 0.00 0.00 < C2l Peoria 0.03 # 0.09 0.06 0.03 0.15 # 0.00 # 0.06 0.18 0.10 0.01 0.03 -< LaGrange 0.33 0.38 0.10 0.11 0.05 0.24 0.14 0.25 0.24 0.62 0.29 0.62 0.46 0 Alton 0.01 0.09 0.00 0.20 0.06 0.02 0.11 0.12 0.49 .., -Ill.R.2 0.08 0.11 0.06 0.06 0.06 0.06 0.12 0.05 0.07 0.10 0.26 0.12 0.19 0.24 !'.= z 0 !il 2? ~ w -l w Table 28.-Summary of the commercial catch of fish from the Illinois Waterway and the Mississippi River bordering Illinois, 1950-1973.• Species 1950 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 197119721973 Thousand Kilograms Bowfin 5 2 1 1 1 3 3 1 3 3 b 1 b b b b 1 b b b b Buffalo 622 567 469 365 464 400 486 378 418 344 447 298 279 327 428 385 378 241 209 118 54 Carp 1833 808 1074 851 626 723 596 524 486 537 486 337 330 354 355 246 397 188 342 142 97 Catfish & bullheads 88 85 136 141 106 94 72 74 62 74 60 59 37 40 45 44 67 43 30 28 28 Garfish b 1 b b 3 1 1 2 b b Paddle fish 12 1 4 3 b 2 b b b b 4 1 b 3 3 2 b Quillback 2 78 1 3 3 1 1 b 1 3 b Sheepshead (shovelnose) 52 90 44 82 56 63 24 31 21 27 18 18 10 10 17 9 20 12 20 8 3 Sturgeon b 1 b b b Suckers 1 b 1 b 1 b b Yellow bass Crappie 11 16 12 15 13 11 14 15 2 Carpsucker 1 b Yenow perch b 1 b White bass Total fish, 111. River 2613 1556 1816 1460 1266 1302 1197 1025 1005 1000 1016 717 657 737 848 690 866 487 602 297 182 -------------------------------------~----------------------------------------------------------------· No. of Ill. River fishermen Full time 106 69 22 9 13 13 Part time 169 73 46 47 42 56 --------------------------------------------------------------------------------------------------------- Total fish, Miss. R. borGering Ill. 1326 1236 1766 1501 1462 1909 1973 1916 1440 1571 1664 1469 1574 1567 1317 1211 1310 1442 1379 1473 1637 • Most of the statistics were obtained from statistical digests published by the U.S. Dept. of Commerce. The 1972 and 1973 data and the number of full time and part time commercial fishermen on the IllinoiE River were provided by Mr. Larry Dunham, Fisheries Biologist, Illinois Department of Conservation. h Less than 1000 kg. w -l ~ -t" t" .... z 0 .... "' z > .., C: ~ > t" ::i::: .... ~ 0 ~ -< r:r.i C: ~ < l:'l -< ~ C: ~ l:'l .., .... z i w J-' > .., :"'" (¥) Aug., 1975 SPARJs:S & STARRETT: ELECTROFISHING SURVEY OF ILLINOIS RIVER 375 Table 29.-Average number of kilograms of fish taken per 30 minutes of electrofishing in each navigation pool of the Illinois Waterway during the period 1959-1974. Pools Ref. Downstream Upstream Table La Starved Mar- Dres- No. Species Alton Grange Peoria Rock seilles den 3 Shortnose gar 0.01 0.04· 0.04• 0.00 0.00 0.00 4 Bowfin 0.05· 0.05 0.01 0.00 0.00 0.00 5 Gizzard shad 0.36 0.88 0.90• 0.40 0.47 0:03 6 Goldeye 0.02• # # 0.00 # 0.00 7 Mooneye 0.01• 0.00 # 0.00 0.00 0.00 8 Goldfish 0.00 0.04 0.05 2.38 2.10 3.05" 9 Carp x goldfish # 0.05 0.38 1.37• 0.53 0.35 10 Carp 19.01 • 17.40 8.02 9.24 10.85 5.82 11 River carpsucker 0.10 0.12 0.10 0.14• 0.02 0.00 12 Quillback carpsucker 0.03 0.03 0.14 0.50· 0.20 0.00 13 Smallmouth buffalo 0.03 0.52" 0.34 0.17 # 0.00 14 Bigmouth buffalo 0.48 4.21 5.70• -0.02 # 0.00 15 Black buffalo 0.06 0.25• 0.20 0.01 0.00 0.00 16 Shorthead redhorse 0.03 0.02 0.02 0.04 0.01 0.06· 17 Black bullhead 0.00 # 0.05 0.04 0.24• 0.00 18 Yellow bullhead # 0.01• 0.01• 0.00 0.00 0.00 19 Channel catfish 1.12• 0.36 0.o7 0.09 0.01 0.00 20 Flathead catfish 0.03 0.21" 0.00 0.00 0.00 0.00 21 White bass 0.67" 0.10 0.11 0.05 0.01 0.00 22 Green sunfish 0.01 0.09• 0.06 0.02 0.02 # 23 Bluegill 0.15 0.20• 0.06 # 0.01 0.00 24 Largemouth bass 0.44 1.11• 0.78 0.04 0.08 0.00 25 White crappie 0.19 0.20 0.23· 0.01 0.03 0.00 26 Black crappie 0.44 0.65· 0.43 0.03 # 0.00 27 Freshwater drum 0.12 0.29• 0.05 0.01 # 0.00 • Indicates the pool or pools where the maximum number of kilograms of each species was taken in the period 1959-1974. # Less than 0.01 kilogram taken. 376 ILLINOIS NATURAL HISTORY SURVEY BULLETIN Vol. 31, Art. 8 Table 30.-Average number of fish taken per 30 minutes of electroflshlng in each naviga- tion pool of the Illinois Waterway during the period 1959-1974. Pools Ref. Downstream Upst,-eam Table La Starved Mar- Dres• No. Species Alton Grange Peoria Rock seilles den 3 Shortnose gar 0.Q7• 0.07· 0.05 0.00 0.00 0.00 4 Bowfln 0.07· 0.02 0.01 0.00 0.00 0.00 5 Gizzard shad 18.09 43.55 63.20• 9.22 12.52 2.66 6 Goldeye 0.41· 0.02 0.02 0.00 0.03 0.00 7 Mooneye 0.05• 0.00 0.01 0.00 0.00 0.00 8 Goldfish 0.00 0.37 0.73 17.02 12.02 42.76· 9 Carp x goldfish 0.Ql 0.18 1.39 2.02• 0.80 1.05 10 Carp 19.81 34.69· 18.67 18.92 14.29 12.06 11 River carpBUcker 0.27 0.39 0.44• 0.34 0.04 0.00 12 Quillback carpsucker 0.11 0.16 0.52 1.38· 0.71 0.00 13 Smallmouth buffalo 0.11 1.04· 0.67 0.25 0.03 0.00 14 Bigmouth buffalo 0.33 4.21 5.79· 0.05 0.Ql 0.00 15 Black buffalo 0.04 0.24· 0.19 0.02 0.00 0.00 16 Shorthead redhorse 0.08 0.21 0.09 0.02 0.00 0.00 17 Black bullhead 0.00 0.12 0.35 0.38 4.39· 0.00 18 Yellow bullhead 0.Ql 0.10• 0.07 0.00 0.00 0.00 19 Channel catfish 3.76· 1.60 0.17 0.34 0.01 0.00 20 Flathead catfish 0.19· 0.09 0.00 0.00 0.00 0.00 21 White b!W!s 2.65· 0.42 0.64 0.44 0.07 0.00 22 Green sunfish 0.52 1.77 2.91" 0.65 1.01 0.23 23 Bluegill 4.90 7.12• 3.10 0.06 0.33 0.00 24 Largemouth bass 1.70 4.23· 2.82 0.13 0.47 0.00 25 White crappie 1.07 1.75• 1.47 0.05 0.32 0.00 26 Bi!lck crappie 2.99 5.55· 2.44 0.18 0.04 0.00 27 Freshwater drum 1.49 2.49· 0.34 0.03 0.14 0.00 • Indicates the pool or pools where the maximum number of Individuals of each species was taken lil the period 1959-1974. LITERATURE CITED BUCK, D. H. 1956. Effects of turbidity on fish and fishing. Twenty-First North American Wildlife Conference Transac­ tions: 249-261. Burrs, T. A. 1974. Measurements of sedi­ ment oxygen demand characteristics of the upper Illinois Waterway. Report of Investigation 76. Illinois State Water Survey. 32 p. --- . 1975. Nitrification effects on the dissolved oxygen resources of the Illinois Waterway. In: Water-1974: II. Mu­ nicipal Wastewater Treatment. American Institute of Chemical Engineers Sympo­ sium Serles 71 ( 145) : 38-43. CARLSON, A. R., and R. E . SIEFERT. 1974. Effects of reduced oxygen on the embryos and larvae of lake trout (Salvelinus namaycush) and largemouth bass (Mi­ cropterus salmoides). Journal of the Fisheries Research Board of Canada 31(8) :1393-1396. FORBES, S. A. 1928. Foreword, p. 387-'388. In: R. E. Richardson. The bottom fauna of the Middle Illinois River, 1913-1915. IllinoLs Natural History Survey Bulletin 17 ( 12): 387-476. ---, and R. E. RICHARDSON. 1913. Stud­ ies on the biology of the upper Illinois River. Illinois State Laboratory of Nat­ ural History Bulletin 9(10) :481-674, 21 plates. ---, and ---. 1919. Some recent changes in Illinois River biology. Illinois Natural History Survey Bulletin 13 ( 6) : 139-156. ---, and ---. 1920. The fishes of Illi­ nois. Second ed. Illinois Natural History Survey. cxxxvl + 367 p. GALE, W. F. 1969, Bottom fauna of Pool 19, Mississippi River, with emphasis on the life history of the fingernail clam, Sphaer­ ium transversum. PhD dissertation. Iowa State University. Ames, Iowa. 234 p. ---. 1971. An experiment to determine substrate preference of the fingernail clam, Sphaerium transversum (Say). Ecology 52(2) :367-370. JACKSON, H . 0., and w. C. STARRETT. 1969. Turbidity and sedimentation at Lake Chautauqua, Illlnoi•s. Journal of Wild­ life Management 23(2) :157-168. LARIMORE, R. w. 1961. Fish population and electrofishing success in a warm-water stream. Journal of Wildlife Management 25(1) :1-12. LU13INSKI, K. S., R. E. SPARKS, and L. A. JAHN. 1974. The development of tox­ icity indices for assessing the quality ot the Illinois River. Research Report No. 96. Water Resources Center, University of Illinois at Urbana-Champaign. 46 p. MILLS, H. B., W. C. STARRETT, and F . C. BEI,LROSE. 1966. Man's effect on the fish and wildlife of the Illinois River. Illinois Natural History Survey Biological Notes No. 67. 24 p. NELSON, E. w. 1878. Fisheries of Chicago and vicinity. In: Report of the U.S. Commissioner of Fish and Fislleries for 1876-1876, Part 4, Appendix B, p. 783-800. O'DONNELL, J. D. 1935. Annotated list of the fishes of Illinois. Illinois Natural History Survey Bulletin 20(5) :473-600. PALOUMPIS, A. A., and w. C. STARRETI. 1960. An ecological study of benthlc or­ ganisms In three Illinois River flood plain lakes. American Midland Naturalist 64 ( 2) : 406-435. RICHARDSON, R. E. 1921a. The small bottom and shore fauna of the Middle and Lower Illinois River and its connecting lakes, Chillicothe to Grafton: its valuation; its sources of food supply; and its rela­ tion to the fishery. Illinois Natural His­ tory Survey Bulletin 13 (15) : 363-522. ---. 1921b. Changes in the bottom and shore fauna of the middle Illinois River and Its connecting lakes since 1913-1915 as a result of the increase, southward, of sewage pollution. Illinois Natural His­ tory Survey Bulletin 14 ( 4) : 33-75. ---. 1928. The bottom fauna of the mid­ dle Illinois River, 1913-1925, its distribu­ tion, abundance, valuation, and Index value in the study of stream pollution. Illinois Natural History Survey Bulletin 17 ( 12) : 387-476. SINGH, K. P., and J. B. STALL. 1973. The 7-day, 10-year low flows of Illinois Streams. Illinois State Water Survey Bulletin 57. STALL, J. B., and s. w. MELSTED, 1951. The silting of Lake Chautauqua, Havana, Illi­ nois. Illinois State Water Survey, in co­ operation with Illinois Agricultural Ex­ periment Station, Report of Investigation 8. 15 p. STARRETT, W. C. 1971. A survey of the mussels ( Unionacea) of the Illinois Riv­ er : a polluted stream. Illinois Natural History Survey Bulletin 30(5): 267-403. 377 378 ILLINOIS NATURAL HISTORY SURVEY BULLETIN Vol. 31, Art. 8 1972. Man and the Illinois River, p. 131-169. In: R. T. Oglesby, C. A. Carl­ son, and J. A. McCann (eds.). River ecology and man. Proceedings of an In­ ternational Symposium on River Ecology and the Impact of Man, held at the Uni­ versity of Massachusetts, Amherst, Mas­ sachusetts, June 20-23, 1971. Academic Press. New York. 465 p. - - -, and A. w. FRITZ. 1965. A bl-O!ogical Investigation of the fishes of Lake Chau- tauqua, Illinois. Illinois Natural History Survey Bulletin 29(1) :1-104. THOMPSON, D. H. 1928. The "Knothead" carp of the Illinois River. Illinois Nat­ ural History Survey Bulletin 17(8): 285- 320. U. S. ARMY ENGINEER DISTRICT, CHICAGO. 1970. Charts of the Illinois Waterway from Mississippi River at Grafton Illi­ nois to Lake Michigan at Chicag~ and Calumet Harbors. 77 p. INDEX A Alosa chrysochloris, 331 Alton, 337 Alton Dam, 318 Alton Pool, 319, 322, 326, 329, 331, 340, 344, 345 Ambloplites rupestria, 332 American eel (see Anguilla rostrata) Amia calva, 322, 332, 345, 350 Ammonia, 334, 335, 342, 344 Anguilla rostrata, 331, 332 Aplodinotus grunniens, 322, 331, 334, 345, 373 Asiatic clam (see Corbicula manilensis) B Ballard Island Chute, 319, 326, 345 Barges (see navigation) Bath Chute, 335, 344 Big Blue Island Chute, 318, 331 Bigmouth buffalo (see lctiobus cyprinellus) Black buffalo (see Ictiobus niger) Black bullhead (see Jctalurus melas) Black crappie (see Pomoxis nigromaculatus) Bluegill (see Lepomis macrochirus) Boat traffic (see navigation) Bottomland lakes, 317, 336, 337, 339, 340, 342, 345 Bowfln (see Amia calva) Brown bullhead (see Jctalurus nebulosus) Bullheads (see lctalurus) C Carassius auratus, 322, 323, 324, 344, 34·5, 354, 355 Carp ( see Cyprinus oarpio) Carp x goldfish hybrids (see Carassius auratus) Carpiodes carpio, 322, 326, 345, 357 cyprinus, 326, 358 Catfishes (see also Jctalurus), 332, 339, 340 Catostomus, 332 Channel catfish ( see I ctalurus punctatus) Chicago, 317, 332, 335, 342 Chicago Metropolitan Sanitary District, 342, 343 Chicago River, 332, 333 Chicago Sanitary and Ship Canal, 318, 333, 30 . Chillicothe Island Chute, 335, 345 Clams ( see also Sphaerium) Commercial fish (es), 321, 322, 326, 329, 331, 333, 341, 344, 345, 374 Commercial fishermen, 321, 322, 326, 331, 341, 344 Commercial fishery, 317, 326, 329, 345 Commercial river traffic (see navigation) Copperas Creek, 333 Copperas Creek Dam, 337 Corbicula manilensis, 344 Crappie (see Pomoxis) Ctenopharyngodon idella, 344 Current, 337, 338, 344 Cyprinus carpio, 322, 325, 326, 333-335, 344, 345, 355, 356 D Des Plaines River, 318, 322, 329, 345 Detweiller Park, 318 Discharge ( river flow), 335 Dorosoma cepedianum, 322, 326, 345, 3.51 Dresden Dam, 318 Dresden Heights, 337 Dresden Pool, 318, 319, 321, 326, 345 Drought effects, 329, 341 Ducks, 334, 335, 342 Du Page River, 318, 332 E Electrofishing, 317, 321, 322, 332, 347, 375, 376 Eel (see Anguilla rostrata} Emerald shiner (see Notropis atherinoides) Esox lucius, 331, 332, 345 Exotic species (see introduced species) F Fingernail clams (see Sphaeriidae) Fish (see names of species, commercial fish, sport fish, etc.) Fisherman's Special (train between Springfield and Havana), 317 Flathead catfish (see Pylodictis olivaris) Aug., 1975 SPARKS & STARRETT: ELECTROFISHING SURVEY OF ILLINOIS RIVER 379 Food organisms ( see also Sphaeriidae), 340, 341, 345, 346 Freshwater drum (see Aplodinotus grunniens) G Game fish (see sport fish) Gar ( see Lepisosteus platostomus) Gizzard shao ( see Dorosoma cepedianum} Godar Landing, 326 Goldeye ( see H iodon alosoides) Goldfish ( see Carassius auratus) Goldfish x carp hybrids (see Carassius auratus) Grafton, 318, 337 Green sunfish (see Lepomis cyanellus) H Habitat, 318, 332, 335, 344, 345 brush piles, 318, 331 degradation by pollution, 335, 339, 340-345 increase due to high water, 334, 335 loss by leveeing, 335, 337, 345 sampling, 318 Hardin, 337 Havana, 317, 331, 339 Hennepin, 319, 332 Henry, 333 Herbicides, 344 Hickory Creek, 332 Hiodon alosoides, 331, 345, 352 Hiodon tergisus, 331, 345, 353 Historical background of Illinois River, 317, 332-341 Hoop nets, 317 Hybrids ( see Carassius auratus) Hybrid vigor, 322 Ictalurus, 334 catus, 331, 344 melas, 326, 327, 345, 363 natalis, 331, 345, 364 punctatus, 326, 328, 329, 339, 341, 345, 365 Ictiobus, 332, 334, 345 bubalus, 326,345,359 cyprinellus, 326, 341, 345, 360 nige~ 326,341, 34t 361 Illinois-Michigan Canal, 332, 333 Illinois River description, 318 historical background, 317, 332-341 lower section, 318, 319, 329, 331, 334, 344 middle section, 319, 334, 338 navigation pools, 318 upper section, 319, 321, 322, 332, 344 valley, 317 Introduced species (see Carassius auratus, Corbicula manilensis, Ctenopharyngodon idella, Cyprinus carpio, Ictalurus catus) K Kampsvllle, 333, 344 Kampsv!lle Landing, 326 Kankakee River, 318 Kingston Mines, 342 L LaGrange, 333, 337 LaGrange Dam, 318, 337 LaGrange Pool, 318, 319, 322, 326, 329, 331, 335, 344, 345 Lake Chautauqua, 331, 339 Lake Michigan, 333, 334, 337, 342, 343 Lake restoration, 342, 344 Lamprey, 332 Largemouth bass (see Micropterus salmoides) LaSalle, 333 Lepisosteus oculatus, 331 osseus, 332 platostomus, 321, 322, 345, 349 Lepomis, 334 cyanellus, 329, 345, 368 gibbosus, 331 humilis, 331 macrochirus, 329, 339, 341, 345, 369 megalotis, 331 microlophus, 339 Longnose gar ( see Lepisosteus osseus) Longear sunfish (see Lepomis megalotis) M Marquette, 317 Marsellles, 333, 337 Marseilles Dam, 318, 331 Marseilles Pool, 318, 319, 321, 326, 329, 331, 341, 345 Matanzas Beach, 342 Matanzas Lake, 342 Meredosia, 317, 342 Micropterus, 334 dolomieui, 331 salmoides, 322, 329, 330, 332, 335, 339, 344, 345, 370 Minnows (see also Notropis), 331, 332 Minnow seines, 317 Mississippi River, 318, 341, 344 Molluscs (see also Sphaeriidae), 322, 334, 340 Moone ye ( see Hiodon tergisus) Morone chrysops, 329, 332, 341, 367 Mortland Island Chute, 318 Moxostoma macrolepidotum, 331, 332, 362 N Navigation, 342-344 effects on aquatic life, 341 effects on dissolved oxygen, 320, 321, 343 effects on turbidity, 319, 320, 340-344 channel, 318, 342 channel dredging, 342, 343 380 ILLINOIS NATURAL HISTORY SURVEY Buu.ETIN Vol. 31, Art. 8 dams, 318, 333, 337, 342, 343 pools, 318, 337 Northern pike (see Esox ·lucius) Notropis atherinoides, 332 0 Orangespotted sunfish (see Lepomis humilis) Oxygen dissolved, 319-321; 333-339, 341- 345, 348 demand, 320, 321, 334, 337, 3~2-345 p Pekin ( see also Peoria-Pekin), 318, 341 Peoria, 337 Peoria Dam, 318 Peoria Lake, 318, 319, 331 Peoria-Pekin metropolitan area, 342 Peoria Pool, 318, 319, 321, 322, 326, 329, 331, 335, 344, 345 Perea flavescens, 340, 345 Perches ( see also Perea, Stizostedion), 337 Pesticides, 34.0 Pikes (see also Esox), 337 Plankton, 319, 334, 346 Plants (aquatic). 340, 342, 343, 344, 345, 346 Pollution (see also ammonia, oxygen, pesticides, sediment, toxic chemicals, turbidity), 345 agricultural, 339, 340, 343, 344 industrial, 333, 335, 344 municipal (sewage), 332-335, 337-341, 344 Pomoxis, 322, 334, 340, 341 annularis, 329, 331, 341, 345, 371 nigromaculatus, 329, 331, 341, 346, 372 Pumpklnseed (see Lepo1nis gibbosus) Pylodictis olivaris, 329, 339, 341, 366 Q Quillback (see Carpiodes cypri nus) Quiver Lake, 339, 342 R Recovery from pollution (see also lake . restoration), 343, 346 Redear sunfish (see Lepomis microlophus) Refuges, 343 Restoration, 342, 343, 346 Rice Lake, 342 River (see Illinois River, Kankakee River, etc.) River carpsucker ( see Carpiodes carpio) River redhorse (see Moxostoma carinatum) Rock bass (see Ambloplites rupestris) s Sampling method, 318, 319 Sauger (see Stizostedion canadense) Sediment, 319- 321, 333, 337, 340, 342, 343 , 345 . Seneca, 333 Shortnose gar (s ee L episostus platostomus) Shorthead redhorse (see Moxostoma macrolepidotum) Siltation (s ee sediment) Skipjack herring (see Alosa chrysochloris) Smallmouth bass (see Micropterus dolomieui) Smallmouth. buft'alo (see lctiobus bubalus) Soil conservation, 343 Sphaeriidae, 334,336,340 Sport fish(es), 317,329, 33L 339- 341, 345 Sport fishermen, 331 Spotted gar (see Lepisosteus oculatus) Starved Rock, 337 Starved Rock Dam, 318 Starved Rock Pool, 318,319,321,326,329, 341, 346 St. David, 342 Stizostedion canadense, 331 vitreum vitreum, 332, 345 Stump Lake, 342 Suckers (see Catostomus, Moxostoma) Sunfishes (see also Lepomis, Micropterus, Pomoxis), 332, 334,. 337 T Temperature, 321, 348 Towboats (see navigation) Toxic chemicals, 335, 340, 341 Trawling, 326, 329 Turbidity, 319, 320, 333, 339, 340, 342 Turkey Island Chute, 331, 344 u U.S. Government Corps of Engineers, 318 fisheries station, 317 w Walleye (see Stizostedion vitreum Vitreuni) Water levels effects on fishes and other organisms, 329, 331, 334, 335-339, 341, 343 effects on sampling, 319 White amur (see Ctenopharyngodon idella) White bass (see Morone chrysops) White catfish (see Jctalurus catus) White crappie (see Pomoxis annularis) y Yellow bullhead (see lctalurus natalis) Yellow perch ( see Perea flavescens l