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H ILLIN I S UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
PRODUCTION NOTE
University of Illinois at Urbana-Champaign Library Large-scale Digitization Project, 2007.
Natural History Survey C/1/^ 19E AFiS- - Library ILLINOIS
NATURAL HISTORY N SURVEY
The Long-Term Illinois River Fish Population Monitoring Program
SProject F-101-R
Center for Aquatic Ecology
Thomas V. Lerczak, Richard E. Sparks, and K. Douglas Blodgett
Illinois Natural History Survey River Research Laboratory Forbes Biological Station P.O. Box 590 Havana, IL 62644
Juno 1994
I NN..N. Aquatic Ecology Technical Report 94/5
The Long-Term Illinois River Fish Population Monitoring Program
F-101-R Final Report
Thomas V. Lerczak, Richard E. Sparks, and K. Douglas Blodgett
Illinois Natural History Survey River Research Laboratory of the Forbes Biological Station Post Office Box 590 Havana, Illinois 62644
June 1994
Dr. R.E. Sparks, Principw1 Investigator K.D. Blodgett, Co-Investigator Center for Aquatic Ecology Center for Aquatic Ecology Illinois Natural History Survey Illinois Natural History Survey
T.V. Lerczak, Project Manager Dr. Robert . Herendeen, Acting Director Center for Aquatic Ecology Center for Aquatic Ecology Illinois Natural History Survey Illinois Natural History Survey DISCLAIMER The findings, conclusions, and views expressed herein are those of the researchers and should not be considered as the official position of the United States Fish and Wildlife Service or the Illinois Department of Conservation.
ACKNOWLEDGMENT OF SUPPORT The Long-Term Illinois River Fish Population Monitoring Program (F-101-R) is supported by the Federal Aid in Sport Fish Restoration Act (P.L. 81-681, Dingell-Johnson/Wallop-Breaux).
ii EXECUTIVE SUMMARY
The Long-Term Illinois River Fish Population Monitoring Program has been conducted at selected stations along the Illinois River, mostly in side channels, 29 out of 37 years during late summer and early autumn since 1957. Objectives of the project were to: 1) determine trends in fish populations by examining trends in catch rates, 2) make inferences on the environmental state of the river as reflected in upstream-to- downstream and year-to-year changes in catch rates and fish condition, 3) develop a database which could be used to evaluate resource management strategies, and 4) provide information needed to manage the Illinois River fishery.
Three segments of the Illinois River were defined based on the amount of non-channel aquatic habitat available per unit length of river: the lower river, from the Illinois River's confluence with the Mississippi (river mile [RM] 0.0) to La Grange Dam (RM 80); the middle river, RM 80 to Starved Rock Dam (RM 231); and the upper river, above RM 231. Middle river reaches have the most habitat per unit length of river; while lower and upper river reaches have much less, but similar amounts. Most of the lower river floodplain is separated from the river proper by levees. The upper river has been impacted the most by industrial and municipal pollution. Siltation and
subsequent loss of volume in backwaters is most severe along the middle river.
iii Fish populations were sampled by electrofishing for
approximately 1 hour or less at each of 27 stations. Fish were stunned in an electric field, gathered with a net, and
temporarily stored in a livewell before being identified to species, measured, checked for externally visible abnormalities
(sores, eroded fins, etc.), and returned to the water. The same methods and similar equipment have been used for all years of the
survey.
To characterize recent fish communities, data collected over
the last five years were analyzed in detail. Gizzard shad, carp,
emerald shiner, and bluegill were the 'most abundant and widespread. Largemouth bass was an important piscivore in all
reaches, on average ranking as the seventh most abundant species by individuals collected and fourth by weight. In most cases, carp dominated catches by weight. Bigmouth buffalo also made important contributions to weight, but only in lower and middle river catches. Catches of minnow and shiner species made minor
contributions to weight, and were highest in relative abundance
on the upper river. Other upstream-to-downstream differences
were apparent, and seemed to resemble species range distributions
that were documented before major system modifications (pre- 1900). Catch rates (fish collected per hour) of pollution indicator fishes were analyzed for the presence of long-term trends. The
hypothesis was that a highly degraded system would be dominated by pollution-tolerant, habitat-generalist species such as carp or
iv goldfish while supporting only small numbers of less pollution- tolerant, less habitat-generalist fishes such as most members of the family Centrarchidae; a less degraded system would harbor more centrarchids and less carp or goldfish. The green sunfish was not included with other centrarchids in this analysis because of its known tolerance of degraded conditions. From 1962 to 1992, long-term downward trends were evident in catches of carp in all three river segments. Over the same time period, catch rates for centrarchids (minus green sunfish) showed increasing trends on the lower and, especially, upper river, where catches ranged from 0 per hr in 1965 to an average of 15 per hr over the last five years. From 1962 to 1992, goldfish and carp x goldfish were mostly absent in catches from the lower river, collected in varying small numbers from the middle river, and decreased significantly in catches from the upper river, from 78 per hr in 1963 to an average of 2 per hr over the last five years. Improved water quality over the last thirty years may explain the increase in centrarchids. Since many centrarchids are at least partially piscivorous, a higher predation rate on young fish could be one of the reasons for carp and goldfish declines. Over the last three decades, fishes that frequently contact bottom sediments (e.g., carp) had higher incidences
of external abnormalities than pelagic fishes (e.g., bluegill) in the lower and middle river for most years, and
for all years in the upper river. In addition, the
v percentages of sediment-contact fishes with abnormalities increased in the upstream direction toward the Chicago metropolitan area. Other investigators reported higher concentrations of toxicants in sediments in the upper river than in other reaches, which suggests a cause for the fish abnormalities might be in the sediments. Percentages of pelagic fishes with abnormalities showed long-term decreasing trends in all three river segments, possibly as a result of better water quality throughout the river. Pathological analyses should be conducted to explicitly determine the cause or causes for the fish abnormalities.t Excessive sedimentation continues to be a significant environmental problem. Perhaps centrarchids (other than green sunfish) would have had increasing populations in the middle river, in response to better water quality, had it not been for deterioration of spawning habitats from siltation. System-wide declines in carp may also be related to siltation of spawning habitats. Improving water quality is important to maintaining a sustainable fishery in the Illinois River, as the increase in centrarchids in the upper river has shown, but it is not enough. Since backwaters have continued to lose capacity, decreasing fish populations should be an expected result. Increased attention should be given to solving the sedimentation problem.
vi TABLE OF CONTENTS
Title and Signature Page......
DISCLAIMER...... ii
ACKNOWLEDGMENT OF SUPPORT...... ii
EXECUTIVE SUMMARY...... LL
TABLE OF CONTENTS...... vi
LIST OF TABLES.....*...... ix
LIST OF FIGURES...... xii Index to Job Accomplishments...... xv
ACKNOWLEDGMENTS...... L...... )CIXV·
STUDY AREA...... 3
MATERIALS AND METHODS...... 10
Criteria for Sampling......
Seasonal Criterion...... 12
Water Level Criteria,...... 12 Temperature Criterion...... 13 Data Analysis......
RESULTS...... ·...... ·...... ····....17 I. PROJECT F-10-1- FIELD SAMPLING, 1989-1993...... 17 Electrofishing Stations...... 1
1989...... 17
1990...... 23
1991...... 23
1992...... 23
1993...... ·...... 2 vii Catch Rates in Number of Individuals...... 25
Catch Rates in Weight...... 37 Mississippi River Station...... 48 Fish Community Classification...... 52
II. LONG-TERM TRENDS--POLLUTION INDICATORS, 1959 -1993...... 56
Catch Rates in Number of Individuals, 1962-1993...... 56
Incidence of External Abnormalities, 1959-1993...... 66
DISCUSSION.....*...... a...... 71
Long-Term trends...... 71
Recent Fish Population Data, 1989-1993...... 77
Conclusions...... 79
LITERATURE CITED...... 00 00...... 85
APPENDIX Ao.....a...... 91
APPENDIX B...... 97
APPENDIX C...... 101
viii LIST OF TABLES
Table 1. Off channel aquatic habitat per length of river (Gilbertson and Kelly 1981)...... 5 Table 2. Fixed sampling stations of the long-term electrofishing survey (LTEF) of the Illinois Waterway...... 9
Table 3. Station information and characteristics during sampling for 1989 ...... 18 Table 4. Station information and characteristics during sampling for 1969...... 19 Table 5. Station information and characteristics during sampling for 1991 ...... 20 Table 6. Station information and characteristics during sampling for 1992...... 21 Table 7. Station information and characteristics during sampling for 1993 ...... 22 Table 8. Number of individuals of each fish species collected per hour of electrofishing in 1989 arranged by waterway reach...... 26 Table 9. Species ranked by relative abundance (number of fish collected per hr) for 1989...... 27
Table 10. Number of individuals of each fish species collected per hour of electrofishing in 1990 arranged by waterway reach...... 28
Table 11. Species ranked by relative abundance (number of fish collected per hr) for 1990...... 29 Table 12. Number of individuals of each fish species collected per hour of electrofishing in 1991 arranged by waterway reach...... 30 Table 13. Species ranked by relative abundance (number of fish collected per hr) for 1991...... 31 Table 14. Number of individuals of each fish species collected per hour of electrofishing in 1992 arranged by waterway reach...... 32 Table 15. Species ranked by relative abundance (number of fish collected per hr) for 1992...... 33 ix Table 16. Number of individuals of each fish species collected per hour of electrofishing in 1993 arranged by waterway reach...... 34
Table 17. Species ranked by relative abundance (number of fish collected per hr) for 1993...... 35
Table 18. Pounds of each fish species collected per hour of electrofishing in 1989 arranged by waterway reach...... 38
Table 19. Species ranked by relative abundance (pounds per hr) for 1989...... 39
Table 20. Pounds of each fish species collected per hour of electrofishing in 1990 arranged by waterway reach...... 40
Table 21. Species ranked by relative abundance (pounds per hr) for 19 09...... 41
Table 22. Pounds of each fish species collected per hour of electrofishing in 1991 arranged by waterway reach...... 42
Table 23. Species ranked by relative abundance (pounds per hr) for 1991 ...... 43 Table 24. Pounds of each fish species collected per hour of electrofishing in 1992 arranged by waterway reach...... 44
Table 25. Species ranked by relative abundance (pounds per hr) for 1992...... 45
Table 26. Pounds of each fish species collected per hour of electrofishing in 1993 arranged by waterway reach...... 46
Table 27. Species ranked by relative abundance (pounds per hr) for 1993...... 47
Table 28. Catch per unit effort in terms of number of individuals (CPUEn ) and weight (CPUEw) collected per hour of electrofishing for 1989 through 1992 for the Brickhouse Slough station on the Mississippi River...... 49
X Table 29. Percentage of total catch per hour of electrofishing for selected pollution indicator fishes in the lower Illinois River (RM 0-80), 1962-1992...... 59
Table 30. Percentage of total catch per hour of electrofishing for selected pollution indicator fishes in the middle Illinois River (RM 80-231), 1962-1992 ...... 63
Table 31. Percentage of total catch per hour of electrofishing for selected pollution indicator fishes in the upper Illinois Waterway (RM 231-280), 1962-1993...... 67
Table 32. Sedimentation in backwater lakes in the Illinois River valley (adapted from Demmisie et al. 1992)...... 75
xi LIST OF FIGURES
Figure 1. Outline of Illinois showing some of the major rivers......
Figure 2. Stream gradient of the Illinois River and the effects of navigation locks and dams (adapted from Starrett 1972:138)......
Figure 3. Mean daily river stage above sea level for the lower, middle, and upper Illinois River, 1991......
Figure 4. Electrode pole configuration at the bow of the electrofishing boat (top view)...... 11
Figure 5. Cluster analysis (flexible strategy, Beta = -0.25) of electrofishing stations (sampling units) based on the number of fish collected per hour at bach station in 1991...... 53
Figure 6. Cluster analysis (flexible strategy, Beta = -0.25) of electrofishing stations (sampling units) based on the number of fish collected per hour at each station in 1992...... S . . . 54 Figure 7.. Number of individuals collected per hour of electrofishing from the lower Illinois River from 1962 to 1992 for fish species identified as pollution indicat'ors...... 58
Figure 8. Number of individuals collected per hour of electrofishing from the middle Illinois River from 1962 to 1992 for fish species identified as pollution indicators...... 62
Figure 9. Number of individuals collected per hour of electrofishing from the upper Illinois River from 1962 to 1993 for fish species identified as pollution indicators...... 65
Figure 10. Incidence of externally-visible abnormalities (sores, eroded fins, lumps) on fish collected from the upper (top figures), middle (middle figures), and lower Illinois Waterway (bottom figures) from 1959 to 1993...... 68
Figure 11. Yearly departures in discharge of the Illinois River at Valley City (RM 62) from the 54-year mean discharge of 22,110 cubic feet per second.....73
xii Page 13 missing from the bound original Index to Job Accomplishments
Job Number8 Job Title Page Number
1 Prepare electrofishing equipment...... 17 2 Train Staff...... 17 3 Electrofish 26 stations along the Illinois River...... 17
4 Database design...... 17
5 Data entry and verification...... 17,56
6 Data analysis...... 17-84
7 Data archiving...... 17 8 Presentation of results...... 101
9 Report preparation...... All aJob numbers and titles refer to project F-101-R Application for Federal Assistance dated 3 March 1989.
xiv ACKNOWLEDGMENTS
Project F-101-R is supported by Federal Aid in Sport Fish Restoration Act (P.L. 81-681, Dingell-Johnson/Wallop-Breaux), with funds administered by the U.S. Fish and Wildlife Service and the Illinois Department of Conservation (IDOC). Mr. Larry Dunham (IDOC), Mr. Bill Bertrand (IDOC), Mr. Michael Sweet (IDOC), Dr. Lorin Nevling, Chief of the Illinois Natural History Survey (INHS), and Dr. David Philipp, Director of the Center for Aquatic Ecology (INHS), provided administrative support. Long Term Rpsource Monitoring Program (LTRMP) staff at Havana, Mr. Steve Stenzel, Mr. Paul Raibley, Mr. Kevin Irons, Mr. Matt O'Hara, Mr. Rick Wright, Mr. Thad Cook, Mr. Barry Newman, Ms. Stephanie Wickman, and Ms. Cammy Smith of the INHS River Research Laboratory (RRL) at Havana, provided technical or secretarial support. Ms. Cammy Smith also completed the vast majority of data verification and correction. Dr. Sharook Madon (RRL) and Dr. Jeffrey D. Brawn of the Center for Wildlife Ecology (INHS) provided statistical advice. Mr. Robert Illyes (INHS) contributed to the computerization of the long-term electrofishing database.
This survey was originally conceived of and initiated by the late Dr. William C. Starrett in 1957.
XV INTRODUCTION
The Long-Term Illinois River Fish Population Monitoring Program, begun in 1957, was designed to collect a yearly representative sample of the Illinois River fish community in order to: 1) determine trends in fish populations by examining trends in catch rates, 2) make inferences on the environmental state of the river as reflected in upstream-to-downstream and year-to-year changes in catch rates and fish condition, 3) develop a database which could be used to evaluate resource management strategies, Iand 4) provide information needed to manage the Illinois River fishery.
By the time this sampling program was initiated, though, the
Illinois River had long been degraded to varying degrees and at different periods of time by system modifications (e.g., conversion of bottomlands to drainage and levee districts) and by pollution (e.g., industrial, municipal, and non-point), the details of which have been well documented and will not be repeated here (see, for example, Kofoid 1903, Forbes and
Richardson 1919, Thompson 1928, Mills et al. 1966, Starrett 1971,
Starrett 1972, Bellrose et al. 1979, Sparks 1984, and Sparks and
Lerczak 1993). Butts (1987), however, reported that water quality of the Illinois River has improved since the early 1960s. On the other hand, Essig (1991) and the Illinois Environmental Protection Agency (IEPA) (1992) indicated that sediments of the
Illinois River contain elevated levels of contaminants (e.g., mercury, lead, PCBs), especially in the upper river reaches near 1 the Chicago metropolitan area. Un-ionized ammonia is also known to contribute to sediment toxicity (Sparks et al. 1992). In addition, Demissie et al. (1992) showed that important fish spawning habitats in contiguous backwaters of the Illinois River have been gradually losing volume due to excessive sedimentation, with an average loss of 72% since 1903. There have, therefore, been both positive and negative environmental factors which must have simultaneously affected fish populations over the course of the last few decades.
The objectives of this report are to: 1) provide a summary document of Illinois River fish population data collected from
1989 to 1993 during federal aid project F-101-R; 2) relate this recently collected data to long-term trends in Illinois River fish populations; 3) identify possible factors responsible for long-term trends in Illinois River fish populations; 4) determine data gaps and problem areas in need of additional research or management attention.
2 STUDY AREA
The Illinois River is formed by the confluence of the Des Plaines and Kankakee rivers approximately 50 mi (80 km) southwest of Chicago, and then flows 273 river miles (RM) (439 km) to join with the Mississippi River approximately 30 mi (50 km) northwest of St. Louis, Missouri (Figure 1). The Illinois Waterway includes the entire Illinois River and extends through part of the Des Plaines River, the Chicago Sanitary and Ship Canal, and part of the Chicago River to Lake Michigan. The Illinois Waterway is divided into reaches defined by navigation dams. Lock and Dam 26 on the Mississippi River, near Alton, Illinois, maintains water depths for the lower 80 miles of the Illinois Waterway (named the Alton reach); other navigation dams (whose names also refer to their respective waterway reaches) in upstream order are: La Grange (RM 80), Peoria (RM 158), Starved Rock (RM 231), Marseilles (RM 247), Dresden
(271.5), and Brandon Roads (RM 286) (Figure 1). To simplify comparisons among sections of the waterway, the reaches were grouped according to the amount of aquatic habitat
(side channels, backwaters, and floodplain lakes) available per unit length of river (Table 1). Three groups of reaches resulted from this classification: the lower river (RM 0 to RM 80), the middle river (RM 80 to RM 231), and the upper river (above RM 231) (Figure 1 and Table 1).
The upper river flows through a narrower valley than the other two segments and has the least amount of aquatic habitat, 3 Figure 1. Outline of Illinois showing some of the major rivers. Distance on the Illinois River (in bold) is measured in river miles, where river mile 0 is at the confluence of the Illinois and Mississippi rivers. Long-term electrofishing stations are numbered from 1 through 26 consecutively in the upstream direction. Station 27 is on the Mississippi River.
4 E U) LA -3 ,- )4-#1 L V-LA
Cr C- C0% %0 0, U '-@2N LA OCL c *00 ·.ca0 0C cc V-l~ V) M- LA 0.. -tc N LU N- NI 0 n to 0 QU) NU '- rVn0% C 0 %-000 LA co cu, CLL m Ln LA Ct LOUJn ccwu h N N· v\s 0% N C C u N-LA 0 NI N- (U %0 u) (-I 1. 0 0 L CU L 4) IxL 0, L 0W 0 4- a 0 0C (1)mC 0 (U LU4- L C) 0 0) -r L L LU U OL 0. QM *( 0. -J 0 LU N0 LU D 0 0. 0 :3 5 mostly due to a different geologic history than the rest of the river (Willman 1973). The upper river can also be differentiated from the lower/middle river by longitudinal gradient, which is 17 in per mi (27 cm per km), compared with 1.3 in per mi (2.1 cm per km) for the lower/middle river (Willman 1973) (Figure 2). The middle river has the most aquatic habitat (Table 1). Because contiguous backwaters can store flood waters, the middle river has a greater buffering capacity against rapid changes in water levels than the upper river. Figure 3 illustrates the difference between the flashy hydrograph which is characteristic of a mid- reach location on the upper river compared with the more gradual water level fluctuations which occur on the lower/middle river. The lower river has had most of its floodplain separated from the river by levees and is now more similar to the upper river in terms of available aquatic habitat (Table 1). Twenty-six fixed sampling stations were located along the Illinois Waterway, with one additional station located on the Mississippi River to serve as a reference (Figure 1 and Table 2). Seventeen stations were exclusively in side channel habitats; the rest of the stations were in a combination of habitats, including three boat harbors (Table 2). Kilometers from the Mississippi River 30 60 90 120 150 180 210 240 270 300 330 360 390 420 25 20 V) a) 15 j tLL 10 5 0 25 20 , a, 0) a U- 150 10 0 20 40 60 80 100 120 140 160 180 200 220 240 260 Miles from the Mississippi River Figure 2. Stream gradient of the Illinois River and the effects of navigation locks and dams (adapted from Starrett 1972:138). At low river stages, the dams maintain a 9 ft navigation channel, and are also responsible for slowing the river's current velocity. At high river stages, the dams have little effect (note the 1943 high water line on the lower figure). 7 504 - 500 Upper River at Morris (RM 263) 496 - - 492 488 484 480 S Jan FI 1Ma J Jl IAg epI Ot SJan 'Feb' Mar' Apr' May Jun Jul ' Aug ' Sep Oct ' Nov 'Dec 0) 446 Middle River at Havana (RM 119) (D 442 co0 438 .Q 434 0) 430 ------U) 426 L_ 422 cCD 418 03 414 446 442 438 _ Lower River at Valley City (RM 62) 434 430 426 422 418 414 SJan ' Feb MarL Apr IMay' Jun Jul ' A.g 'Sep ' Oct 'Nov 'Dec Figure 3. Mean daily river stage above sea level for the lower, middle, and upper Illinois River, 1991. Dashed lines represent flat pool, ie., the minimum level maintained by the U.S. Army Corps of Engineers for navigation. Table 2. Fixed sampling stations of the long-term electrofishing survey (LTEF) of the Illinois Waterway. River Mile a Station Station Habitat . Lower Upper River Reach number name characterization 279.5 280.0 Des Plaines Dresden 26 Treats Island Side channel 276.8 277.8 Des Plaines Dresden 25 Mouth of Du Page River Boat harbor, main channel border 260.2 261.1 Illinois Marseilles 24 Waupecan Island Side channel 249.7 249.8 Illinois Marseilles 23 Johnson Island Side channel, main channel border 247.7 248.2 Illinois Marseilles 22 Ballards Island Side channel, main channel border 241.1 241.6 Illinois Starved Rock 21 Bulls Island Bend Side channel 240.3 241.0 Illinois Starved Rock 20 Bulls Island Side channel 214.9 215.6 Illinois Peoria 19 Clark Island Side channel 207.6 208.1 Illinois Peoria 18 Hennepin'Island Side channel, main channel border 203.0 203.5 Illinois Peoria 17 Upper Twin Sisters Side channel 202.6 203.2 Illinois Peoria 16 Lower Twin Sisters Side channel 193.5 194.5 Illinois Peoria 15 Henry Island Side channel 180.6 181.1 Illinois Peoria 14 Chillicothe Side channel, main channel border 170.8 170.9 Illinois Peoria 13 Upper Peoria Lake c d Boat harbor 170.6 170.8 Illinois Peoria 13 Lambies Boat Harbor Boat harbor 163.4 163.5 Illinois Peoria 12 Peoria Lake Boat harbor, main channel border 154.5 155.3 Illinois La Grange 11 Pekin Boat dock, main channel border 148.0 148.4 Illinois La Grange 10 Turkey Island Side channel, main channel border 112.8 113.2 Illinois La Grange 9 Upper Bath Chute Side channel 106.9 107.3 Illinois La Grange 8 Lower Bath Chute Side channel 95.5 96.3 Illinois La Grange 7 Sugar Creek Island Side channel 85.7 87.0 Illinois La Grange 6 Grape-Bar Islands Side channel 57.5 59.0 Illinois Alton 5 Big Blue Island Side channel 29.2 30.8 Illinois Alton 4 Crater-Willow Islands Side channel 27.0 27.9 Illinois Alton 3 Hurricane Island Chute Side channel 23.8 25.5 Illinois Alton 2 Dark Chute Side channel 18.1 19.5 Illinois Alton 1 Mortland Island Side channel 205.1 205.3 Mississippi Pool 26 27A Lower Brickhouse Slough Side channel, main channel border 204.9 205.0 Mississippi Pool 26 27B Below Brickhouse Slough Inlet to backwater lake aActual river miles sampled varied slightly from year-to-year depending upon the amount of structure available for fish habitat and, therefore, the time needed to cover a specific area. Habitat names are from Sternberg (1971) as cited in Gilbertson and Kelly (1981). coriginal upper Peoria Lake station at Detweiller Park, which was used until 1990. When depths decreased due to siltation, this station was made inaccessible to the electrofishing boat. Substituted for the Detweiller Park station in 1991 and 1992. MATERIALS AND METHODS Fish populations were sampled by electrofishing from a 16-ft (5-m) aluminum boat using a Homelite 3000-Watt three-phase AC electric generator. Figure 4 shows a top view drawing of the electrode pole configuration at the bow of the electroshocking boat. Metal electrodes, connected to the electric generator, extended from the ends of the poles to approximately 20 in (0.5 m) below the water line, thereby creating the electroshocking field. The same generator and electrode configuration have been used since 1957. Before starting fish sampling, physico-chemical parameters (e.g., dissolved oxygen [DO] concentration, surface water velocity) were measured at the beginning of each station. The goal then was to sample each station for one hour, but electrofishing ceased if all obvious structures (woody debris, rip rap) were sampled in less than one hour. Stunned fish were gathered with a net, and stored in a livewell until sampling was completed. They were then identified to species, measured, checked for externally-visible abnormalities (sores, eroded fins, etc.), and returned to the water. A more detailed description of the electrofishing method is presented in Appendix A. Criteria for Sampling. The following criteria for sampling were developed to increase the probability that differences in catch rates among years will reflect fish population changes and not changes in 10 -- 200 cm Figure 4. Electrode pole configuration at the bow of the electrofishing boat (top view). Metal droppers, connected to a 3000-Watt three-phase AC generator, extended from the ends of the poles to approximately 20 in (0.5 m) below the water line. 11 electrofishing efficiency or fish distributions. Sampling was usually suspended until all criteria were met. 1. Seasonal Criterion. To increase the chance that young- of-the-year fish would be large enough to be collected with a 1/4-in dip net, sampling was usually not initiated until the last week of August. 2. Water Level Criteria. During high water, fish are able to disperse into the expanded habitat (Pierce et al. 1985); while during low water, various species tend to concentrate at the few solid structures, such as fallen trees and rip rap, still remaining submersed. Because turbidity increases with rising water levels (Stenzel and Blodgett 1992), due to increased runoff and subsequent erosion, catch efficiency decreases (i.e., fish are less likely to be seen by the netter). Fish may also be carried away in higher currents before they are netted. Indeed, Pierce et al. (1985) noted a decrease in electrofishing catch in numbers of fish and species obtained during high water, due to a decreased ability to net fish. For these reasons, electrofishing on our survey was usually discontinued if water levels were more than 1.5 ft above flat pool at stations on the lower and middle river or more than 2.5 ft above flat pool at stations on the upper river, and rising more than 0.5 ft during the previous 24 hr. Gammon (1994) followed a similar criterion during an electrofishing survey of the Wabash River, where hydrographic conditions resemble that which occurs on the Illinois River. Up- to-date water level data were obtained from the U.S. Army Corps 12 of Engineers, who maintain 27 river gages spread along the entire length of the Illinois Waterway. 3. Temperature Criterion. Breder and Nigrelli (1935) showed that redbreast sunfish (Lepomis auritus) form aggregations when the water temperature is below 50 OF (10 oC), and begin dispersing at higher temperatures, becoming completely dispersed at 64 OF (18 OC). Stauffer et al. (1976) reported that fish temperature preferences influence local distributions. In fact, many river fishes overwinter in deep-pooled backwaters (Sheehan et al. 1990, Bodensteiner and Lewis 1992, Pitlo 1992), which were not sampled on this project. This evidence makes it seem likely that falling water temperature may be an important stimulus initiating movement of some fishes toward overwintering areas. But it is probably unlikely that a single temperature is the one important behavioral stimulus; rather, there might be a range of temperatures where migratory behavior begins, perhaps in concert with other stimuli, such as normal rising autumn water levels, which would allow access to backwaters. It was, therefore, important to complete fish sampling before migratory movements began; otherwise, a decline in catch rates resulting from fish migration to overwintering areas could not be differentiated from population changes. For this reason, we usually did not sample if the water temperature was below 58.0 OF (14.4 OC), which is not reached on the normal autumn water temperaturc decline in the Illinois River until about mid-October (Kofoid 1903, Stenzel and Blodgett 1992). 13 Data Analysis. Fish catch rates were expressed as number of individuals collected per hour of electrofishing (number catch rates) and as weight in pounds collected per hour of electrofishing (weight catch rates). For 1989 to 1993 catch rate data from each station were grouped by navigation reach. The species composition and relative abundances of catches can be highly variable among nearby stations in a single year and among several successive years at a single station. For example, catches of schooling species such as gizzard shad and various minnows can vary widely depending upon'whether or not a school happens to be in the path of the electroshocking field. Also, a high percentage of species which occur in small numbers can make the list of species collected in any one year unique. To minimize these influences from obscuring an overall characterization of fish communities, species were ranked by relative abundance (i.e., percent of total catch) by waterway reach and by year. Separate tables were constructed listing only those species that accounted for at least 95% of total catch rates. This percentage was arbitrarily chosen as being a convenient cut-off point for determining which species were rare enough (the last 5% of the catch) to be considered minimally important for analyzing fish community composition. Cluster analyses (Ludwig and Reynolds 1988) of number catch rates for 1991 and 1992 for each species by station were used to determine if the stations would fall into three groups 14 corresponding to their river mile location within one of the three river segments (see STUDY AREA). This was done to determine whether classifying the river into three segments has a biological as well as geomorphological basis. Number catch rates for fish species thought to be reliable pollution indicators were examined for the presence of long-term trends. Fishes of the family Centrarchidae were treated as a group to simplify data analysis because they have very similar habitat requirements, and most species are generally considered to be intolerant of pollution. The green sunfish (Lepomis cyanellus) was treated separately because it is known to be more tolerant of pollution than other centrarchids, and may be considered indicative of a stressed environment (Karr et al. 1986). Also, because many of these fishes are at least partially piscivorous, their presence or absence will have a direct impact on overall fish community structure. Catches of common carp (Cyprinus carpio) and goldfish (Carassius auratus), both non- natives to North America, and their hybrid were analyzed because they are omnivorous habitat generalists that are tolerant of polluted waters. Data are presented as total catch rates against years for each of the three river segments. Data collected before 1962 were not used because sampling was done in early summer or late spring. Toxic substances in sediments are thought to contribute to the incidence of abnormalities on fishes that forage in those sediments, while minimally affecting fishes that forage in the 15 water column. To test this hypothesis, all fishes were assigned to one of two groups: benthic species that frequently forage in bottom sediments (e.g., carp) and pelagic species that usually inhabit the water column (e.g., bluegill) (see Appendix B). Data are presented as the percentage of fish with external abnormalities against years for each of the three river segments. Long-term trends in catch per hour and the percentage of fish with external abnormalities were tested for statistical significance against a null hypothesis of no trend using nonparametric rank trend analysis, which makes use of a test statistic, D (Lehmann and D'Abrera 1975:291). Statistical significance was assumed when the P-value of a one-tailed test was less than 0.05. 16 RESULTS (Job 6) I. PROJECT F-101-R FIELD SAMPLING, 1989-1993 All equipment was tested and repaired as necessary before each sampling season (Job 1). Also, staff were given a review in safety procedures and electrofishing methods (Job 2). Robert Illyes helped design a database (Job 4) using Rbase computer software. Data collected during F-101-R were entered directly into this database, and verified against the original data sheets until no errors were detected (Job 5). The original field data sheets were stored in the fireproof vault at the Forbes Biological Station at Havana, Illinois (Job 7). Electrofishing Stations. Tables 3 through 7 show which stations were sampled for each year from 1989 to 1993, respectively. Water quality parameters at the time of sampling are also listed. (Job 3) 1989. All stations were successfully sampled between 29 August and 04 October, taking 26.03 hr , with sampling times ranging from 0.25 to 1.03 hr (Table 3). Sampling was conducted in full daylight between the hours of 8:35 AM and 6:10 PM. The ranges for physical measurements were as follows: air temperature, 44.6-82.4 OF (7.0-28.0 OC); water temperature, 60.8- 81.5 OF (16.0-27.5 °C); dissolved oxygen concentration, 5.5-15.1 ppm; Secchi disk transparency, 7.1-25.8 in (18-66 cm); conductivity, 380-650 umhos; surface velocity, 0.0-2.1 ft/s (0.0- 0.64 m/s) ; water depth, 0.3-10.0 ft (0.1-3.1 m). 17 000000000 00000000 00o 0 O E (A I- c Ol E Lr%rolLnMLri a in L CD CDCD %%0LA LnLn 0 i 140L C C 3 C;:C; C C; CC V: 1W: 3; C CC C V- (( C M0 %0u0~0000 M 0- 00 .- '0060000 .- 0000000 CI N0 U C JV-- 0 0% 0O00 00 in 003C2 %000 ' rIONr( 0m 00%'0% . 0 Y D 00 '-000.-.- 00 C; C; (cC .- OC; Ci C 4) paC00 cc00000000000000000000D a a p D D 0a 3 00o 0 0".ON % '0a %00- "'4 U' U'" U' V - - ('4 '- N* -00 00% 0D0% *-7W-WU' U' on00 )< . r U' ' U' U U' U' U' U' U' UA UA U' UA 'Lx'W'VI U' U' -o I %r UN % %0 Ln %0 - 0a-0 r U) wo i 00 0 CDU' -00- 00 '00 C M Iý-. 0Ma - m WU fI CD0 U'%00 tn I 0000o Go VU U U 0 '0 0 0%a a '0 f 0 U I")a '.7 '.7 0% N. 000 0 0. 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The ranges for physical measurements were as follows: air temperature (not measured after 11 September), 70.7-96.8 OF (21.5-36.0 oC); water temperature, 65.3-85.1 OF (18.5-29.5 OC); dissolved oxygen concentration, 5.4-19.9 ppm; Secchi disk transparency, 7.1-25.2 OF (18-23 cm); conductivity, 375-700 umhos; surface velocity, 0.0-2.2 ft/s (0.0-0.7 m/s). Water depths were not recorded for this year. 1991. All stations were successfully sampled between 04 September and 30 September, taking 20.59 hr with sampling times ranging from 0.36 to 1.09 hr (Table 5). Sampling was conducted in full daylight between the hours of 8:50 AM and 6:50 PM. The ranges for physical measurements were as follows: air temperature, 44.1-89.6 OF (6.7-32.0 OC); water temperature, 52.5- 82.4 OF (11.4-28.0 OC); dissolved oxygen concentration, 5.6-11.1 ppm; Secchi disk transparency, 3.9-31.9 in (10-81 cm); conductivity, 452-700 umhos; surface velocity, 0.0-1.1 ft/s (0.0- 0.3 m/s); water depth, 0.5-4.0 ft (0.2-1.2 m). 1992. All stations were successfully sampled between 25 August and 30 September, taking 24.17 hr with sampling times ranging from 0.45 to 1.07 hr (Table 6). Sampliny was conducted in full daylight between the hours of 9:10 AM and 5:45 PM. The 23 ' ranges for physical measurements were as follows: air temperature, 52.0-91.4 OF (11.1-33.0 OC); water temperature, 59.0-81.5 OF (15.0-27.5 OC); dissolved oxygen concentration, 5.4- 12.4 ppm; Secchi disk transparency, 3.9-21.7 in (10-55 cm); conductivity, 400-750 umhos; surface velocity, 0.0-1.9 ft/s (0.0- 0.6 m/s); water depth, 0.7-8.3 ft (0.2-2.5 m) . 1993. Sampling was canceled at the middle and lower river stations due to persistently high water. All stations on the upper waterway, however, were successfully sampled between 05 October and 07 October, taking 6.44 hr with sampling times ranging from 0.44 to 1.00 hr (Table 7). Sampling was conducted in full daylight between the hours of 8:35 AM and 5:40 PM. The ranges for physical measurements were as follows: air temperature, 58.1-71.6 OF (14.5-22.0 oC); water temperature, 59.2-74.5 OF (15.1-23.6 OC); dissolved oxygen concentration, 8.3- 12.8 ppm; Secchi disk transparency, 13.8-21.7 in (35-55 cm); conductivity, 500-800 umhos; surface velocity, 0.7-1.3 ft/s (0.2- 0.4 m/s); water depth, 0.7-4.9 ft (0.2-1.5 m). Although measured physical parameters exhibited upstream-to- downstream as well as year-to-year variations among stations, there were no values which strongly deviated from expectations or could be expected to affect catch rates in an unusual way (e.g., a dissolved oxygen concentration less than 5 ppm). A consideration of how upstream-to-downstream differences in water transparency at the time of sampling might affect fish catch rates is presented in the DISCUSSION. 24 In 1991, three stations were sampled when water temperatures were below our 58 OF criterion: Lambies Boat Harbor (20 September), 52.5 oF; Pekin (26 September), 57.7 oF; lower Peoria Lake (26 September), 55.4 OF. There was an unusual cold period between 17 and 27 September which lowered water temperatures considerably. Had it been several weeks earlier, we would have waited for water temperatures to rise above 58 OF; however, as October was approaching, it seemed unlikely sufficient warm weather would return for the time required to raise water temperatures. Therefore, sampling was completed before water temperatures dropped even further. Catch Rates in Number of Individuals. We collected 60 species of fishes representing 12 families from the Illinois Waterway from 1989 to 1993 (Appendix B). Common names are used throughout the text of this report, with scientific names listed in Appendix B. Tables 8 through 17 summarize number catch rates and species rankings by waterway reach and year. For all stations combined, the most species were collected in 1990 (43) and the least in 1993 (29), when only the upper waterway was sampled (Tables 10 and 16, respectively). The number of species collected from upper waterway reaches ranged from 12 for Starved Rock in 1990 (Table 10) to 25 for Marseilles in 1989 (Table 8). In contrast, the number of species collected from other reaches ranged from 18 from La Grange to 30 from 25 Table 8. Number of individuals of each fish species collected per hour of electrofishing in 1989 arranged by waterway reach. Reach and Number of Hours Fished Starved ALL Alton La Grange a Peoria Rock Marseilles Dresden Reaches Species 5.44 5.49 6.67 2.01 2.89 2.00 24.50 Longnose Gar 0.18 0.04 Shortnose Gar 0.18 0.04 Gizzard Shad 16.91 37.89 27.14 18.41 23.53 5.00 24.33 Skipjack Herring 5.33 1.46 3.30 0.35 2.45 Goldeye 0.50 0.04 Grass Pickerel 0.35 0.04 Bigmouth Shiner 0.37 0.08 Bluntnose Minnow 0.60 10.45 2.42 26.50 3.47 Carp 6.80 23.32 17.39 3.48 8.30 9.00 13.47 Carp x Goldfish 0.18 1.50 0.69 1.50 0.65 Central Stoneroller 0.15 0.04 Emerald Shiner 114.89 5.83 14.09 410.80 48.44 171.50 31.51 Golden Shiner 0.35 0.04 Goldfish 3.10 1.65 4.84 20.00 3.35 Red Shiner 0.18 0.04 Sand Shiner 1.'00 0.35 0.12 Spottail Shiner 1.80 8.46 3.81 3.50 1.92 Bigmouth Buffalo 2.02 3.83 0.60 1.47 Golden Redhorse 0.30 1.00 0.16 River Carpsucker 1.10 0.18 1.20 1.00 5.19 0.50 1.35 Shorthead Redhorse 1.47 0.55 0.15 1.00 0.57 Smallmouth Buffalo 0.92 0.36 1.50 0.50 0.73 Quiltback 0.55 0.60 0.50 1.38 0.49 Black Bullhead 0.18 0.15 1.04 0.20 Channel Catfish 6.25 1.28 2.70 4.48 2.08 0.50 3.06 Flathead Catfish 1.10 0.18 0.15 0.33 Yellow Bullhead 0.45 1.38 0.29 Striped x White Bass 0.18 0.04 White Bass 5.88 5.28 2.55 1.49 0.69 3.39 Yellow Bass 2.08 0.24 Black Crappie 6.25 0.36 3.11 1.00 1.92 Bluegill 28.49 4.74 4.80 14.93 10.03 3.50 11.39 Green Sunfish 1.10 8.74 24.74 13.43 19.72 3.50 12.65 Largemouth Bass 4.23 1.46 2.25 7.46 8.30 2.50 3.67 Orangespotted Sunfish 0.18 0.18 0.30 2.77 2.00 0.65 Rock Bass 0.50 0.04 Smallmouth Bass. 1.35 2.49 3.11 1.00 1.02 Spotted Sunfish 3.00 0.24 Warmouth 0.18 0.18 0.08 White Crappie 0.18 0.18 0.08 Sauger 0.15 0.04 Walleye 0.35 0.04 Freshwater Drum 31.99 24.04 16.34 1.00 8.30 18.00 Total 136.95 123.50 127.89 130.85 162.98 256.50 143.80 Number of species 24 21 26 18 25 17 41 aData from Turkey Island were not included in the calculations because smapling was done during high watcr, which may hnve binsed catch rntrs. State Threatened species. Preserved specimens are in the Illinois Natural History Survey collection at Havana. 26 Table 9. Species ranked by relative abundance (number of fish collected per hr) for 1989. Species were added to the list by reach until 95% of the total catch rate for that reach was obtained. Rankings by Reach Starved All Species Alton La Grange Peoria Rock Marseilles Dresden Reaches Gizzard Shad 3 1 1 2 2 5 2 Skipjack Herring 8 7 12 Bluntnose Minnow 5 11 2 8 Carp 5 3 3 9 5 4 4 Carp x Goldfish 13 Emerald Shiner 4 5 5 .1 1 1 1 Goldfish 9 12 7 3 10 Spottait Shiner 11 6 8 6 13 Bigmouth Buffalo 10 8 14 River Carpsucker 6 15 Shorthead Redhorse 11 Smatlmouth Buffalo 13 Channel Catfish 6 8 8 12 11 White Bass 7 6 9 9 Yellow Bass 12 Black Crappie 6 9 13 Bluegill 2 7 6 3 4 6 6 Green Sunfish 4 2 4 3 6 5 Largemouth Bass 9 10 10" 7 5 7 Orangespotted Sunfish 10 Smallmouth Bass 10 9 Spotted Sunfish 7 Freshwater Drum 1 2 4 5 3 Number of fishes accounting for 95% 12 10 14 10 16 9 16 27 Table 10. Number of individuals of each fish species collected per hour of electrofishing in 1990 arranged by waterway reach. Reach and Number of Hours Fished Starved All Alton La Grange Peoria Rock Marseilles Dresden Reaches Species 4.38 3.53 3.94 0.99 2.02 2.00 16.86 Longnose Gar 0.28 0.06 Shortnose Gar 0.23 0.06 Gizzard Shad 20.78 34.84 56.09 38.38 13.37 44.00 34.88 Threadfin Shad 2.28 9.35 1.02 2.02 2.91 Skipjack Herring 7.08 2.79 2.02 2.25 Mooneye 0.46 0.12 Bluntnose Minnow 4.46 9.50 1.66 Bullhead Minnow 0.76 0.18 Carp 15.53 11.61 12.18 1.01 9.90 6.00 11.27 Carp x Goldfish 6.00 0.71 Emerald Shiner 1.60 4.82 0.25 6.06 22.77 5.50 5.22 Golden Shiner 1.50 0.18 Goldfish 2.50 0.30 River Shiner 0.50 0.50 0.12 Silver Chub 0.23 0.06 Spottail Shiner 0.25 0.50 0.12 Bigmouth Buffalo 2.74 3.40 2.79 2.08 Black Buffalo 0.57 0.25 0.18 Golden Redhorse 1.52 0.36 Highfin Carpsucker 1.01 0.06 River Carpsucker 1.13 3.55 4.04 1.49 1.48 Shorthead Redhorse 0.46 0.28 0.18 Smallmouth Buffalo 1.42 9.14 7.07 0.99 2.97 Quillback 0.46 0.57 0.99 0.50 0.42 Channel Catfish 12.33 3.97 1.52 4.04 1.98 1.50 5.04 Flathead Catfish 0.91 0.85 0.25 0.47 Striped x White Bass 1.52 0.36 White Bass 5.71 16.43 9.90 0.99 7.35 Yellow Bass 0.23 0.06 Black Crappie 3.88 5.38 0.76 1.98 2.55 Bluegill 10.96 11.33 16.50 1.01 10.89 4.00 10.91 Green Sunfish 0.23 5.38 5.58 1.01 5.45 8.00 4.15 Largemouth Bass 5.02 4.25 4.82 3.96 4.00 4.27 Longear Sunfish 1.00 0.12 Orangespotted Sunfish 0.68 0.28 0.24 Pumpkinseed 0.50 0.06 Redear Sunfish 0.50 0.06 Rock Bass 2.00 0.24 Smaltmouth Bass 0.23 1.01 0.50 2.00 0.42 Warmouth 0.25 0.06 White Crappie 0.46 0.57 3.30 1.01 Logperch 0.28 0.06 Sauger 0.23 0.51 0.18 Yellow Perch 0.99 0.12 Freshwater Drum 4.79 3.40 8.12 0.50 3.91 Total number per hr 90.41 127.48 143.65 68.69 82.18 99.50 109.43 Number of species 23 23 23 12 18 17 43 28 Table 11. Species ranked by relative abundance (number of fish collected per hr) for 1990. Species were added to the list by reach until 95% of the total catch rate for that reach was obtained. Rankings by Reach Starved All Species Alton La Grange Peoria Rock Marseilles Dresden Reaches Gizzard Shad 1 1 1 1 2 1 1 Skipjack Herring 6 11 5 13 Threadfin Shad 10 5 5 11 Bluntnose Minnow 6 2 15 Carp 2 3 3 6 4 4 2 Carp x Golfish 4 18 Emerald Shiner 11 8 .3 1 5 5 Golden Shiner 9 Goldfish 7 Bigmouth Buffalo 9 11 11 14 Golden Redhorse 12 Highfin Carpsucker 6 River Carpsucker 9 4 9 16 Smallmouth Buffalo 5 2 10 Quillback 10 Channel Catfish 3 10 12 4 8 6 Flathead Catfish 12 White Bass 5 2 4 4 Black Crappie 8 7 8 12 Bluegill 4 4 2 3 6 3 Green Sunfish 7 7 5 3 8 Largemouth Bass 6 9 8 7 6 7 Rock Bass 8 Smallmouth Bass 8 White Crappie 10 17 Yellow Perch 10 Freshwater Drum 7 11 6 9 Number of fishes accounting for 95% 12 13 14 9 12 12 18 29 Table 12. Number of individuals of each fish species collected per hour of electrofishing in 1991 arranged by water reach. Reach and Number of Hours Fished Starved All Alton La Grange Peoria Rock Marseilles Dresden Reaches Species 4.77 4.46 5.22 1.43 1.92 1.79 19.59 Shortnose Gar 0.42 0.22 0.15 Gizzard Shad 29.56 20.18 40.23 9.79 22.40 16.20 31.19 Skipjack Herring 1.47 0.45 0.77 0.56 0.71 Threadfin Shad 4.82 5.60 1.92 0.52 5.59 3.83 Bluntnose Minnow 2.10 3.12 15.64 1.89 Bullhead Minnow 2.80 12.00 1.63 Carp 6.50 5.38 9.00 2.80 3.12 5.59 6.53 Carp x Goldfish 0.21 0.38 0.52 1.68 0.36 Emerald Shiner 0.63 0.45 1.72 26.57 9.90 14.52 5.10 Goldfish 0.42 0.19 0.15 Golden Shiner 0.52 0.56 0.10 Red Shiner 16.08 16.15 2.76 Silver Chub 0.42 0.10 Spottail Shiner 0.38 0.15 Bigmouth Buffalo 0.63 3.36 4.79 2.25 Black Buffalo 0.21 0.05 Golden Redhorse 0.52 0.56 0.10 River Carpsucker 0.63 0.67 S4.98 1.63 Shorthead Redhorse 0.42 0.45 0.77 0.52 0.46 Smallmouth Buffalo 2.31 1.57 3.64 1.40 2.35 Quillback 0.38 0.52 0.15 White Sucker 0.57 0.56 0.20 Black Bullhead 0.52 0.05 Channel Catfish 6.30 1.34 1.34 1.40 0.52 1.12 2.50 Flathead Catfish 0.63 0.22 0.20 Yellow Bullhead 0.38 0.10 White Bass 1.89 6.73 4.60 3.68 White Perch 0.19 0.05 Yellow Bass 0.77 0.70 0.26 Black Crappie 5.87 13.45 4.02 1.40 2.08 1.12 6.18 Bluegill 58.91 58.74 35.06 3.50 7.29 7.26 41.81 Bluegill x Green Sunfish 0.45 0.77 0.31 Green Sunfish 2.31 4.48 19.54 4.89 8.33 12.85 9.14 Largemouth Bass 13.63 9.19 6.32 2.10 2.60 6.14 8.17 Longear Sunfish 0.56 0.05 Orangespotted Sunfish 0.38 0.15 Redear Sunfish 0.19 0.56 0.15 Rock Bass 2.23 0.20 Smaltmouth Bass 0.70 0.52 0.10 Sunfish (unid.) 0.63 0.19 0.31 Warmouth 0.42 0.67 0.26 White Crappie 0.42 1.79 0.38 0.87 Sauger 0.21 0.19 0.10 Freshwater Drum 7.55 12.56 8.24 8.47 Total number per hr 147.38 147.98 152.30 76.22 91.67 93.30 144.97 Number of species 24 20 27 14 18 17 41 30 Table 13. Species ranked by relative abundance (number of fish collected per hr) for 1991. Species were added to the list by reach until 95% of the total catch rate for that reach was obtained. Rankings by Reach Starved All Species Alton La Grange Peoria Rock Marseilles Dresden Reaches Gizzard Shad 2 2 1 3 1 1 2 Skipjack Herring 11 Threadfin Shad 8 7 12 7 9 Bluntnose Minnow 7 7 2 15 Bullhead Minnow 6 3 16 Carp 5 8 4 6 7 7 6 Carp x Goldfish 9 Emerald Shiner 13 1 4 3 8 Red Shiner 2 2 11 Bigmouth Buffalo 10 8 14 River Carpsucker 7 16 Smallmouth Buffalo 9 11 13 Quitlback 10 Channel Catfish 6 14 8 10 12 White Bass 10 6 9 10 Black Crappie 7 3 10 8 9 7 Bluegill 1 1 2 5 6 5 1 Green Sunfish 9 9 3' 4 5 4 3 Largemouth Bass 3 5 6 7 8 6 5 Rock Bass 8 White Crappie 11 Freshwater Drum 4 4 5 4 Number of fishes accounting for 95% 12 11 14 11 11 11 17 31 Table 14. Number of individuals of each species collected per hour of electrofishing in 1992 arranged by waterway reach. Reach and Number of Hours Fished Starved Alton La Grange Peoria Rock Marseilles Dresden All Species 5.17 5.00 6.73 1.89 2.45 1.93 23.17 Spotted Gar 0.19 0.04 Gizzard Shad 11.03 5.80 24.37 7.41 6.12 23.32 13.98 _Skipjack Herring 0.19 0.20 0.59 0.26 Threadfin Shad 0.39 0.15 0.13 Bluntnose Minnow 15.34 18.37 23.32 5.14 Bullhead Minnow 0.40 0.74 1.59 17.96 0.52 2.37 Carp 7.16 14.80 15.45 4.76 8.98 5.70 11.09 Carp x Goldfish 0.30 1.55 0.22 Emerald Shiner 5.22 8.60 13.52 41.8 42.86 5.70 15.36 Golden Shiner 0.15 0.04 Goldfish 0.59 2.07 0.35 Minnow (unid.) S0.15 0.04 Red Shiner 0.40 0.15- 2.12 0.30 Sand Shiner 18.52 20.00 3.63 Silver Chub 0.15 0.53 0.09 Spottail Shiner 0.20 . 0.89 1.59 3.63 0.73 Bigmouth Buffalo 4.45 5.20 1.78 0.41 2.68 Black Buffalo 0.19 0.04 Golden Redhorse 0.45 0.13 Highfin Carpsucker 1.06 0.09 River Carpsucker 0.19 0.20 6.54 0.53 0.41 2.07 Shorthead Redhorse 0.19 0.20 0.30 0.82 0.26 Smallmouth Buffalo 3.29 3.00 2.82 2.12 0.41 2.42 Quillback 0.59 0.53 0.41 0.26 Black Bullhead 0.15 0.04 Brown Bullhead 0.15 0.04 Channel Catfish 5.61 3.60 2.53 6.35 0.82 1.55 3.50 Flathead Catfish 0.19 0.15 0.09 Blackstripe Topminnow 1.04 0.09 White Bass 0.97 1.80 3.27 0.53 1.60 Black Crappie 4.84 3.20 3.12 0.82 2.76 Bluegill 18.96 13.80 35.96 5.82 7.76 3.63 19.25 Bluegill x Green Sunfish 0.74 0.22 Green Sunfish 1.16 18.28 8.47 16.73 13.47 9.15 Largemouth Bass 6.77 2.60 6.09 4.76 5.31 1.04 4.88 Longear Sunfish 0.53 0.04 Orangespotted Sunfish 0.15 0.04 Rock Bass 0.53 2.07 0.22 Smallmouth Bass 0.30 2.65 1.22 7.77 1.08 Sunfish (unid.) 1.22 0.13 Warmouth 0.19 0.04 White Crappie 0.19 0.60 0.89 0.43 Sauger 0.19 0.04 Freshwater Drum 3.48 8.60 6.09 0.82 4.49 Total number per hr 75.05 73.20 147.55 127.51 151.43 96.37 109.84 Number of species 22 18 30 21 18 14 40 32 Table 15. Species ranked by relative abundance (number of fish collected per hr) for 1992. Species were added to the List by reach until 95% of the total catch rate for that reach was obtained. Rankings by Reach Starved All Species Alton La Grange Peoria Rock Marseilles Dresden Reaches Gizzard Shad 2 4 2 5 8 1 3 Bluntnose Minnow 3 3 1 6 Bullhead Minnow 11 4 14 Carp 3 C 1 4 8 6 4 4 Carp x Golfish 7 Emerald Shiner 6 3 5 1 1 4 2 Goldfish 6 Red Shiner 10 Sand Shiner 2 2 9 Spottail Shiner 5 Bigmouth Buffalo 8 5 12 12 River Carpsucker 6 10 15 Smattmouth Buffalo 10 8 10 13 Channel Catfish 5 6 11 6 10 White Bass 10 8 16 Black Crappie 7 7 9 11 Bluegill 1 2 1 7 7 5 1 Green Sunfish 11 3 4 5 2 5 Largemouth Bass 4 9 7 8 9 7 .Rock Bass 6 Smallmouth Bass 9 3 White Crappie 13 Freshwater Drum 9 3 7 8 Number of fishes accounting for 95% 11 11 14 13 9 11 16 33 Table 16. Number of individuals of each species collected per hour of electrofishing in 1993 arranged by waterway reach. Reach and Number of Hours Fished ALl Alton La Grange Peoria Starved Rock Marseilles Dresden Reaches Species 2.00 2.44 2.00 6.44 Gizzard Shad 0.50 25.41 47.50 24.53 BLuntnose Minnow 4.50 2.05 38.00 13.98 Bullhead Minnow 1.50 5.33 1.50 2.95 Carp 9.00 5.33 6.00 6.68 Carp x Goldfish 1.00 0.31 Emerald Shiner 29.50 22.54 49.50 33.07 Fathead Minnow 1.50 0.82 0.78 Golden Shiner 1.00 0.31 Goldfish 4.50 1.40 Red Shiner 6.50 13.11 1.50 7.45 Sand Shiner 2.46 0.93 Spottail Shiner 0.41 8.00 2.64 Golden Redhorse 1.00 0.50 0.47 Highfin Carpsucker 0.50 0.16 River Carpsucker 1.00 0.82 0.50 0.78 Smallmouth Buffalo 5.00 1.23 2.02 Quillback 1.00 1.23 0.78 Channel Catfish 1.00 0.82 0.50 0.78 Yellow Bullhead 1.64 0.62 White Bass 1.00 0.82 0.62 Black Crappie 1.50 0.41 1.00 0.93 Bluegill x Green Sunfish 0.50 0.16 Bluegill 1.50 3.28 6.50 3.73 Green Sunfish 2.50 6.56 42.50 16.46 Largemouth Bass 1.50 4.51 4.50 3.57 Longear Sunfish 2.50 0.78 Orangespotted Sunfish 0.41 0.50 0.31 Rock Bass 0.50 0.16 Smallmouth Bass 1.00 2.05 3.00 2.02 Logperch 0.50 0.16 Freshwater Drum 1.00 3.28 1.55 Total number per hr 73.00 104.51 221.50 131.06 Number of species 21 22 20 29 34 Table 17. Species ranked by relative abundance (number of fish collected per hr) for 1993. Species were added to the list by reach until 95% of the total catch rate for that reach was obtained. Rankings by Reach Starved ALL Species Alton La Grange Peoria Rock Marseilles Dresden Reaches Gizzard Shad 1 2 2 Bluntnose Minnow 5 9 4 4 Bullhead Minnow 7 5 9 Carp -2 5 7 6 Emerald Shiner 1 2 1 1 Fathead Minnow 7 Goldfish 8 13 Red Shiner 3 3 5 Sand Shiner 8 14 Spottail Shiner 5 10 Golden Redhorse 8 Quillback 11 River Carpsucker 8 15 Smallmouth Buffalo 4 11 11 Yellow Bullhead 10 White Bass 8 Black Crappie 7 14 Bluegill . 7 7 6 7 Green Sunfish 6 4 3 3 Largemouth Bass 7 6 8 8 Longear Sunfish 10 Smallmouth Bass 8 9 9 11 Freshwater Drum 8 7 12 Number of fishes accounting for 95% 16 15 11 17 35 Peoria, both in 1992 (Table 14). This seems to indicate the upper reaches yielded fewer species than other reaches. After eliminating most rare species from consideration and ranking species by relative abundance, it became apparent that the Illinois Waterway's fish communities can be characterized by a small number of species which were consistently collected in substantive relative abundances from year to year (Tables 9, 11, 13, 15, and 17). Gizzard shad stands out as the most obvious, ranking high on the list in most reaches and years, the exception being 0.50 gizzard shad per hour from Starved Rock in 1993 (Tables 16 and 17). Carp was the only species that ranked high in all reaches and years. Bluegill .and emerald shiner also ranked high in most reaches for all years (Tables 8 through 17). Differences among the reaches become more apparent as rankings of particular fishes are examined (Tables 8 through 17). For example, white crappie ranked low in all years and reaches and did not.appear in catches from the upper waterway. Bigmouth buffalo were collected in small numbers (0.41 fish per hr) in upper waterway catches only in 1992 (Table 14). On the other hand, smallmouth bass and rock bass ranked high only on upper waterway reaches, with the latter being collected exclusively from the upper waterway. Shiners and small minnow species (e.g., sand and spottail shiner, bullhead and bluntnose minnow) ranked higher in upper waterway reaches. The emerald shiner also consistently ranked higher in upper waterway reaches: rankings ranged from first to fifth on upper waterway reaches compared 36 with least to third most abundant on the lower and middle river reaches. Finally, white bass and freshwater drum were collected in greater numbers from the lower and middle river reaches in all years and were absent from Dresden reach catches (Tables 8, 10, 12, 14, 16). Catch rates in weight. A different pattern emerged when catch rates in weight (Ib) were examined. Tables 18 through 27 present these data and species rankings by waterway reach and year. For most reaches,la smaller 'number of species accounted for 95% of total weight catch rates.(5 to 13) than for 95% of total number catch rates (9 to 18). Minnow and shiner species contributed minimally to catch rates in weight, and gizzard shad were reduced in importance in comparison to their dominance in number catch rates. Not surprisingly, weight catch rates were dominated by fishes which tend to be massive, but may not necessarily be collected in large numbers: examples are the buffalofishes, carpsuckers, channel catfish, and largemouth bass. Common carp had the highest weight catch rates most often for separate reaches and for the waterway as a whole, exceptions being from: Starved Rock in 1990, where smallmouth buffalo was first (Table 21); and from La Grange in 1991, where largemouth bass was first (Table 23). In most cases, however, weight catch rates of carp accounted for much greater percentages of total weight catch rates than the next ranked species, which resulted in a median percentage of 45.4 (N = 32), a mean of 46.0%, and a 37 Table 18. Pounds of each fish species collected per hour of electrofishing in 1989 arranged by waterway reach. Blanks indicate weight data were not available or the species was not taken (see Table 8). Pounds per hour less than 0.01 are indicated by 0.00. Reach and Number of Hours Fished Starved ALL Alton La Grange Peoria Rock Marseilles Dresden Reaches Species 5.44 5.49 6.67 2.01 2.89 2.00 24.50 Longnose Gar 0.03 0.01 - Shortnose Gar 0.13 0.03 Gizzard Shad 1.91 1.75 0.50 3.17 2.15 0.88 1.54 Skipjack Herring 0.08 0.04 0.10 0.04 0.06 Goldeye 0.66 0.05 Grass Pickerel 0.02 0.00 Bigmouth Shiner 0.00 0.00 Bluntnose Minnow 0.00 0.01 0.01 0.06 0.01 Carp 112.42 27.72 24.48 13.03 15.31 18.25 20.00 Carp x Goldfish 0.01 1.02 00.37 1.41 0.44 Central Stoneroller 0.00 0.00 Emerald Shiner 0.03 0.02 0.05 0.11 0.19 0.33 0.08 Golden Shiner 0.01 0.00 Goldfish 0.14 0.06 0.95 2.59 0.37 Red Shiner Sand Shiner Spottail Shiner 0.01 0.03 0.02 0.04 0.01 Bigmouth Buffalo 7.78 10.82 1.67 4.61 Golden Redhorse 0.11 0.11 0.04 River Carpsucker 0.71 0.02 1.96 0.91 4.06 0.55 1.29 Shorthead Redhorse 0.96 0.19 0.04 0.07 0.27 Smallmouth Buffalo 1.07 0.30 1.88 0.47 0.85 Quillback 0.12 0.01 0.04 0.17 0.05 Black Bullhead 0.02 0.04 0.23 0.04 Channel Catfish 4.45 1.23 3.03 5.82 2.83 1.04 2.98 Flathead Catfish 0.65 2.46 0.00 0.70 Yellow Bullhead 0.13 0.25 0.07 Striped x White Bass 0.16 0.03 White Bass 3.37 1.61 0.78 2.15 0.48 1.55 Yellow Bass 0.22 0.03 Black Crappie 2.84 0.11 1.84 0.46 0.91 Bluegill 0.95 0.14 0.71 1.05 0.65 0.18 0.61 Green Sunfish 0.01 0.16 1.81 0.88 0.57 0.08 0.67 Largemouth Bass 3.79 1.19 2.29 1.48 2.98 1.06 2.29 Orangespotted Sunfish 0.03 0.04 0.01 Rock Bass 0.06 0.00 Smallmouth Bass 0.47 0.71 0.58 0.27 0.28 Spotted Sunfish 0.08 0.01 Warmouth 0.01 0.07 0.02 White Crappie 0.12 0.03 Sauger 0.03 0.01 Walteye 0.00 0.00 Freshwater Drum 1.05 0.83 2.77 0.35 0.72 0.00 1.29 Total 42.49 48.95 43.94 30.93 34.69 27.47 41.24 aData from Turkey Island were not included in the calculations bacause sampling was done during high water, which may have biased catch rates. 38 Table 19. Species ranked by relative abundance (pounds per hr) for 1989. Species were added to the list by reach until 95% of the total catch rate for that reach was obtained. Rankings by Reach Starved All Species Alton La Grange Peoria Rock Marseilles Dresden Reaches Gizzard Shad 7 4 3 5 6 6 Goldeye 10 Carp 1 1 / 1 1 1 1 Carp x Goldfish 9 3 Goldfish 7 2 Bigmouth Buffalo 2 2 8 2 River Carpsucker 5 7 2 7 8 Shorthead Redhorse 10 Smallmouth Buffalo 8 6 10 Channel Catfish 3 6 2 2 4 5 3 Flathead Catfish 3 11 White Bass 5 5 10 4 12 5 Black Crappie 6 6 8 9 Bluegill 11 11 6 9 13 Green Sunfish 7 8 11 12 Largemouth Bass 4 7 4 5 3 4 4 Smallmouth Bass V 9 10 Freshwater drum 9 3 8 7 Number of fishes accounting for 95% 11 7 11 10 12 8 13 39 Table 20. Pounds of each fish species collected per hour of clectrofishing in 1990 arranged by waterway reach. Blanks indicate weight data were not available or the species was not taken (see Table 10). Pounds per hour less than 0.01 are indicated by 0.00. Reach and Numnbcr of Hours Fished Starved ALL Alton La Grange Peoria Rock Marseilles Dresden Reaches Species 4.38 3.53 3.94 0.99 2.02 2.00 16.86 Longnose Gar 0.12 0.03 Shortnose Gar 0.84 0.22 Gizzard Shad 0.68 0.80 2.69 7.06 2.03 7.79 2.56 Threadfin Shad 0.03 0.10 0.02 0.05 0.04 Skipjack Herring 0.20 0.03 0.03 0.05 Mooneye 0.22 0.06 Bluntnose Minnow 0.04 0.01 Bulthead Minnow Carp 38.31 18.47 19.21 0.81 22.67 11.62 22.45 Carp x Goldfish 4.54 0.54 Emerald Shiner 0.00 .0.03 0.11 0.03 0.02 Golden Shiner 0.03 0.00 Goldfish 0.62 0.07 River Shiner 0.02 0.00 Silver Chub 0.00 0.00 Spottail Shiner Bigmouth Buffalo 7.47 9.10 8.63 5.86 Black Buffalo 0.79 0.04 0.17 Golden Redhorse 0.98 0.23 IHighfin Carpsucker 0.81 0.05 River Carpsuckcr 0.80 3.32 3.47 1.58 1.34 Shorthead Redhorse 0.32 0.27 0.14 Smallmouth Buffalo 0.86 9.52 11.12 0.88 3.16 Quill1back 0.25 0.10 0.64 0.45 0.22 Channet Catfish 111.82 6.21 1.09 5.30 2.71 1.40 5.43 FLathcad Catfish 2.45 3.88 0.48 1.56 Striped x White Bass 0.69 0.16 White Bass 4.04 2.72 4.23 0.56 2.67 Yellow Bass 0.05 0.01 Black Crappie 1.29 1.76 0.26 0.30 0.80 BluegiLL 0.68 0.64 1.06 0.13 0.63 0.43 0.69 Green Sunfish 0.04 0.12 0.23 0.01 0.23 0.36 0.16 Largemouth Bass 6.55 3.72 3.39 1.30 1.33 3.59 Longear Sunfish 0.03 0.00 Orangcspotted Sunfish 0.02 0.00 Pumpkinseed 0.05 0.01 Redear Sunfish 0.02 0.00 Rock Bass 0.28 0.03 Smallmouth Bass 0.30 0.35 0.15 0.16 0.14 Warmouth White Crappie 0.20 0.18 1.05 0.34 Log Perch Sauger 2.01 0.03 0.53 Yellow Perch 0.05 0.01 Freshwater Drum 0.87 2.11 1.68 0.04 1.07 I- Total 78.46 52.96 58.63 29.18 33.91 29.14 54.40 40 Table 21. Species ranked by relative abundance (pounds per hr) for 1990. Species were added to the list by reach until 95% of the total catch rate for that reach was obtained. Rankings by Reach Starved All Species Alton La Grange Peoria Rock Marseilles Dresden Reaches Gizzard Shad 10 7 2 3 2 7 Carp 1 1 1 5 1 1 1 Carp x Goldfish t 3 13 Goldfish 6 Bigmouth Buffalo 3 2 3 2 Quillback 7 7 River Carpsucker 10 6 4 4 9 Smallmouth Buffalo 9 2 1 6 5 Channel Catfish 2 3 9 3 2 4 3 Flathead Catfish 6 4 8 White Bass 5 6 4 6 Black Crappie 8 8 11 Bluegill 10 8 12 Largemouth Bass 4 5 5 5 5 4 White Crappie 11 Sauger 7 Freshwater Drum 9 7 8' 10 Number of fishes accounting for 95% 9 11 11 5 8 7 13 41 Table 22. Pounds of each fish species collected per hour of electrofishing in 1991 arranged by waterway reach. Blanks indicate weight data were not available or the species was not taken (see Table 12). Pounds per hour less than 0.01 are indicated by 0.00. Reach and Number of Hours Fished Starved All Alton La Grange Peoria Rock Marseilles Dresden Reaches Species 4.77 4.46 5.22 1.43 1.92 1.79 19.59 Shortnose Gar 0.21 0.24 0.11 Gizzard Shad 1.12 1.01 1.82 0.84 1.66 1.63 1.36 Skipjack Herring 0.03 0.00 0.12 0.06 0.04 Threadfin Shad 0.06 0.12 0.01 0.01 0.10 0.05 Bluntnose Minnow 0.00 0.02 0.07 0.01 Bullhead Minnow 0.00 0.03 0.00 Carp 13.43 6.33 13.97 9.56 9.98 12.61 11.26 Carp x Goldfish 0.10 0.08 0.57 3.83 0.45 Emerald Shiner 0.00 0.01 t 0.11 0.06 0.08 0.02 Goldfish 0.18 0.03 0.05 Golden Shiner 0.01 0.01 0.00 Red Shiner 0.04 0.06 0.01 Silver Chub 0.00 0.00 Spottail Shiner 0.00 0.00 Bigmouth Buffalo 3.58 7.31 11.19 5.52 Black Buffalo 0.25 0.06 Golden Redhorse 0.52 0.05 River Carpsucker 0.67i 0.81 3.35 1.24 Shorthead Redhorse 0.22 0.28 0.75 0.51 0.37 Smallmouth Buffalo 1.63 0.80 3.24 1.77 1.57 Quillback 0.01 0.00 White Sucker 0.37 0.21 0.12 Black Bullhead 0.03 0.00 Channel Catfish 4.92 3.62 1.48 1.29 0.11 1.56 2.67 Flathead Catfish 0.28 0.06 0.08 Yellow Bullhead 0.24 0.07 White Bass 0.61 3.33 2.23 1.50 White Perch 0.00 0.00 Yellow Bass 0.29 0.12 0.09 Black Crappie 0.91 3.35 0.63 0.57 0.64 0.58 1.31 Bluegill 3.34 4.39 1.90 0.01 0.20 0.72 2.41 Bluegill x Green Sunfish 0.03 0.07 0.03 Green Sunfish 0.10 0.22 1.12 0.14 0.32 0.37 0.45 Largemouth Bass 5.92 8.22 4.92 0.18 0.25 5.04 5.12 Longear Sunfish 0.02 0.00 Orangespotted Sunfish 0.03 0.01 Redear Sunfish 0.00 0.01 0.00 Rock Bass 0.60 0.05 Smallmouth Bass 0.05 0.29 0.03 Sunfish (unid.) 0.00 0.02 0.01 Warmouth 0.03 0.12 0.03 White Crappie 0.06 0.61 0.10 0.18 Sauger 0.02 0.34 0.09 Freshwater Drum 0.43 1.40 1.55 0.84 Total 38.12 42.25 49.91 14.70 15.28 27.51 37.29 42 Table 23. Species ranked by relative abundance (pounds per hr) for 1991. Species were added to the list by reach until 95% of the total catch rate for that reach was obtained. Rankings by Reach Starved ALL Species Alton La Grange Peoria Rock Marseilles Dresden Reaches Gizzard Shad 7 9 8 .4 2 4 8 Carp 1 t3 1 1 11 1 Carp x Goldfish 4 3 12 Bigmouth Buffalo 4 2 2 2 Golden Redhorse 5 River Carpsucker 9 10 4 10 Shorthead Redhorse 12 6 Smallmouth Buffalo 6 11 5 2 6 Channel Catfish 3 5 10 3 5 4 White Bass 10 7 6 7 Black Crappie 8 6 5 3 8 9 Bluegill 5 4 7 6 5 Green Sunfish 11 7 12 Largemouth Bass 2 1 3 9 2 3 Rock Bass 7 Smallmouth Bass 8 Freshwater Drum 11 8 9 11 Number of fishes accounting for 95% 11 11 12 5 9 8 13 43 Table 24. Pounds of each fish species collected per hour of electrofishing for 1992 arranged by waterway reach. Blanks indicate weight data were not available or the species was not taken (see Table 14). Pounds per hour less than 0.01 are indicated by 0.00. Reach and Number of Hours Fished Starved ALL Alton La Grange Peoria Rock Marseilles Dresden Reaches Species 5.17 5.00 6.73 1.89 2.45 1.93 23.17 Spotted Gar 0.15 0.03 Gizzard Shad 0.76 1.24 1.69 1.95 0.92 2.00 1.35 Skipjack Herring 0.04 0.03 0.00 0.02 Threadfin Shad Bluntnose Minnow 0.04 0.05 0.09 0.02 Bullhead Minnow 0.00 0.04 0.00 Carp 16.20 22.80 24.16 15.57 11.97 9.81 18.91 Carp x Goldfish 0.13 2.31 0.23 Emerald Shiner 0.01 0.02 0.03 0.12 0.10 0.06 0.04 Golden Shiner 0.00 0.00 Goldfish 0.08, 0.28 0.05 Minnow (unid.) 0.00 0.00 Red Shiner 0.00 0.00 0.00 0.00 Sand Shiner 0.05 0.05 0.01 Silver Chub 0.01 0.03 0.00 Spottail Shiner S0.00 0.01 0.03 0.00 Bigmouth Buffalo 10.69 12.29 3.00 0.12 5.92 Black Buffalo 0.34 0.08 Golden Redhorse 0.32 0.09 Highfin Carpsucker 0.73 0.06 River Carpsucker 0.01 0.02 7.01 0.30 0.42 2.11 Shorthead Redhorse 0.20 0.28 0.05 0.01 0.12 Smallmouth Buffalo 3.29 1.80 1.74 2.13 0.40 1.84 Quillback 0.56 0.22 0.04 0.18 Black Bullhead 0.03 0.01 Brown BuLLhead 0.02 0.01 Channel Catfish 7.52 6.12 3.76 7.70 0.84 3.17 5.07 Flathead Catfish 0.03 0.04 0.02 Blackstripe Topminnow White Bass 0.55 0.53 1.12 0.15 0.58 Black Crappie 1.34 0.63 0.64 0.30 0.65 Bluegill 1.91 1.44 3.49 0.50 0.39 0.03 1.84 BluegiLL x Green Sunfish 0.11 0.03 Green Sunfish 0.01 1.51 0.47 0.39 0.79 0.59 Largemouth Bass 3.72 2.11 2.72 0.90 3.22 0.65 2.55 Longear Sunfish 0.06 0.00 Orangespotted Sunfish 0.00 0.00 Rock Bass 0.04 0.83 0.07 Smallmouth Bass 0.16 0.00 0.72 0.07 Sunfish (unid.) 0.01 0.00 Warmouth 0.02 0.00 White Crappie 0.10 0.42 0.15 Sauger 0.01 0.00 Freshwater Drum 0.47 1.31 1.18 0.26 0.76 - - Total 47.28 50.73 53.86 31.13 19.55 20.78 43.48 -- 44 Table 25. Species ranked by relative abundance (pounds per hr) for 1992. Species were added to the list by reach until 95% of the total catch rate for that reach was obtained. Rankings by Reach Starved All Species Alton La Grange Peoria Rock Marseilles Dresden Reaches Gizzard Shad 8 4 3 41 Carp 1' 1 1 1 Carp x Goldfish 3 Bigmouth Buffalo 2 2 5 Golden Redhorse Highfin Carpsucker River Carpsucker 2 5 Smallmouth Buffalo 5 7 6 Channel Catfish 3 3 2 3 White Bass 11 Black Crappie 9 Bluegill 4 6 Green Sunfish 9 6 10 Largemouth Bass 6 8 4 Rock Bass Smallmouth Bass Freshwater Drum 7 10 Number of fishes accounting for 95% 8 8 11 8 9 8 11 45 Table 26. Pounds of each fish species collected per hour of electrofishing in 1993 arranged by waterway reach. Blanks indicate weight data were not available or the species was not taken (see Table 17). Pounds per hour less than 0.01 are indicated by 0.00. Reach and Number of Hours Fished Starved ALL Alton La Grange Peoria Rock Marseilles Dresden Reaches Species 2.00 2.44 2.00 6.44 Gizzard Shad 0.02 1.31 5.07 2.08 Bluntnose Minnow 0.01 0.01 0.14 0.05 Bullhead Minnow 0.01 0.01 0.01 Carp , 32.52 15.37 16.14 20.93 Carp x Goldfish 2.41 0.75 Emerald Shiner 0.22 0.16 0.36 0.24 Fathead Minnow 0.01 Golden Shiner 0.01 Goldfish 1.34 0.41 Red Shiner 0.02 0.05 0.02 Sand Shiner Spottail Shiner 0.05 0.02 Golden Redhorse 0.05 0.03 0.02 Highfin Carpsucker 0.26 0.08 River Carpsucker 0.67 0.84 0.49 0.68 Smallmouth Buffalo 6.96 0.57 2.38 Quillback 0.75 0.84 0.55 Channel Catfish 0.35 1.29 1.27 0.99 Yellow Bullhead 0.41 0.16 White Bass 0.03 0.03 0.02 Black Crappie 0.12 0.14 0.69 0.30 Bluegill x Green Sunfish 0.02 0.01 Bluegill 0.01 0.01 0.22 0.07 Green Sunfish 0.08 0.18 0.81 0.35 Largemouth Bass 0.71 2.51 0.51 1.33 Longear Sunfish 0.10 0.03 Orangespotted Sunfish 0.01 0.01 0.01 Rock Bass 0.20 0.06 Smallmouth Bass 0.08 0.37 0.94 0.45 Logperch 0.01 Freshwater Drum 0.55 0.98 0.54 Total 43.38 25.12 30.78 32.55 46 Table 27. Species ranked by relative abundance (pounds per hr) for 1993. Species were added to the list by reach until 95% of the total catch rate for that reach was obtained. Rankings by Reach Starved All Species Alton La Grange Peoria Rock Marseilles Dresden Reaches Gizzard Shad 3 2 3 Carp 1 1 1 1 Carp x Goldfish 3 6 Goldfish 4 11 Quillback 3 6 8 River Carpsucker 5 6 10 7 Smallmouth Buffalo 2 7 2 Channel Catfish 4 5 5 Yellow Bullhead 8 Black Crappie 8 Green Sunfish 7 Largemouth Bass 4 2 9 4 Smallmouth Bass 6 10 Freshwater Drum 5 9 Number of fishes accounting for 95% 5 9 10 11 47 range from 2.8% from Starved Rock in 1990 (Table 20) to 75.0% from Starved Rock in 1993 (Table 26). Species that made significant contributions to weight catch rates in all reaches together for one or more years in addition to carp were gizzard shad in 1991 (Table 23) and 1992 (Table 25); river carpsucker in 1993 (Table 27); channel catfish in 1989 (Table 19), 1990 (Table 21), and 1992 (Table 25); and largemouth bass in 1989 (Table 19), 1992 (Table 25), and 1993 (Table 27). Upstream-to-downstream patterns in weight catch rates were evident for several species. Goldfish made significant contributions to weight catch rates only on the upper waterway in 1989 (Table 19), 1990 (Table 21), and 1993 (Table 27). Carp x goldfish hybrid ranked third in contribution to weight catch rates in the Dresden reach every year, ninth in Peoria reach in 1989 (Table 19), fourth in Marseilles reach in 1991 (Table 23), and was of minor importance or absent elsewhere. Freshwater drum made significant contributions to weight catch rates more often on the lower and middle river reaches than on the upper waterway except for the Marseilles reach in 1989 (Table 19) and 1993 (Table 27). White bass showed a similar trend, making a minor contribution to weight catch rates in the Marseilles reach only in 1989 at 1.4% of the total reach's weight catch rate (Tables 18 and 19). Msissijinni River Station. Data collected from Brickhouse Slough are presented in Table 28. For 1989 and 1990, collections were made from river miles 48 Table 28. Catch per unit effort in terms of number of individuals (CPUE ) and weight (Ib) (CPUE ) collected per hour of electrofishing for 1989 through 1992 for the BrickRouse Slough station on the Mississippi River. Electrofishing was not conducted at Brickhouse Slough during 1993. Numbers followed by an asterisk indicate those species which together accounted for at least for 95% of total catch per effort for that year. CPUEn, Year and hr Fished CPUE b Year and hr Fished 1989 1990 1991 1992 1989 1990 1991 1992 Species 0.75 1.00 1.00 1.00 0.75 1.00 1.00 1.00 Gizzard Shad 202.67* 408.00* 84.00* 37.00* 16.13* 8.32* 7.45* 0.82 Threadfin Shad 6.00* 0.05 Bluntnose Minnow 1.33 Bullhead Minnow 5.00* 0.01 Carp 2.67* 11.00* 6.00* 10.00* 6.13* 24.98* 14.67* 21.52* Emerald Shiner 3.00* 1.00 Silver Chub 2.00* 0.01 Spottail Shiner 1.00 1.00 Bigmouth Buffalo 1.00 1.97* Golden Redhorse 1.33 1.33* River Carpsucker 1.33 2.00 0.27 0.08 Shorthead Redhorse 1.00 0.02 Smallmouth Buffalo 2.67 7.00* 32.00* 1.73* 4.23* 3.51* Quillback 2.00 1.00 0.96 0.07 Channel Catfish 8.00* 1.00 5.77* 0 .00c Flathead Catfish 1.33 6.53* Brook Silversidea 2.67* Striped x White Bass 1.33 0.13 White Bass 2.00 9.00* 4.00* 0.23 0.23 0.03 Yellow Bass 1.33 0.12 Black Crappie 4.00* 6.00 4.00* 5.00* 0.53 3.42* 0.64 2.12* Bluegill 60.00* 61.00* 30.00* 2.03* 1.96* 1.81* Largemouth Bass 14.67* 6.00 2.00 2.00* 13.33* 5.61* 0.23 2.71* Orangespotted Sunfish 1.33 0.69 1.00 Redear Sunfish 1.00' 0.01 Sunfish (unid.) 2.00 0.02 Warmouth 5.33* 0.53 White Crappie 1.33 11.00* 5.00* 3.00* 0.93 8.34* 3.69* 1.04* Sauger 1.00 0.07 Freshwater Drum 1.33 2.00 31.00* 28.00* 0.13 3.06* 0.80* 0.59 Total Catch per hour 306.67 457.00 230.00 159.00 49.88 60.69 35.97 34.36 Number of species 16 11 17 15 Number of species accounting for 95% 7 4 11 10 7 7 7 6 aThis species was last collected from the Illinois River on the Long-Term Illinois River Fish Population Monitoring Program in 1969. It has, however, been routinely collected in small numbers from the La Grange reach by Long Term Resource Monitoring Program (LTRMP) personnel, based in Havana, every year since 1989, the first year of that particular sampling project. LTRMP uses a wide variety of sampling gears, including .electrofishing, and samples other habitats in addition to side channels. bennk sp'ces for a sp'cir" vWhich £hou a valt'rfor nymrrer cntCh rhtoe (CPtIc ) indicnte weight data are not available. CLess than 0.01 lb per hour of electrofishing. 49 207.4 to 209.0. After 1990, a Habitat Rehabilitation and Enhancement Project (HREP) (funded by the U.S. Army Corps of Engineers and the U.S. Fish and Wildlife Service) closed the upstream end of the slough with a levee, which made our sampling station inaccessible. In 1991 and 1992, therefore, electrofishing was conducted at the downstream end of the slough, from river miles 204.9 to 205.3. Sampling was canceled in 1993 due to high water. We collected twenty-nine species representing nine families from Brickhouse Slough from 1989 to 1992. The number of species collected ranged from 11 in 1990 to 17 in 1992. All species, with the exception of the brook silverside, were also collected from the Illinois River. This species, though, has been regularly collected from the La Grange reach from 1989 to the present by researchers of the Long Term Resource Monitoring Program stationed at Havana (Raibley, P.T., Illinois Natural History-Survey fisheries biologist, personal communication). Number catch rates were dominated by gizzard shad in 1989 (66.1% of total number catch rate) and 1990 (89.3%), but less so in 1991 and 1992 (36.5% and 23.3%, respectively) when bluegill (26.5% in 1991, 18.9% in 1992) and freshwater drum (13.5% in 1991, 17.6% in 1992) were more numerous (Table 28). In addition, the smallmouth buffalo was collected in larger numbers in 1992 compared with the previous three years, representing 20.1% of the total number catch rate. Total number catch rates for 1989 (306.67) and 1990 (457.00) were much higher than total number 50 catch rates for 1991 (230.00) or 1992 (159.00). On the other hand, more species made up the 95% list in 1991 (11) and 1992 (10) than in 1989 (7) or 1990 (4). In terms of weight catch rates, seven species made up the 95% list in 1989, 1990, and 1991; while in 1992, there were 6 species (Table 28). In 1989, weight catch rates were dominated by gizzard shad (32.2% of total weight catch rate) and largemouth bass (26.7% of total weight catch rate). Carp dominated weight catch rates in 1990 (41.2%), 1991 (40.8%), and 1992 (62.6%). Total weight catch rates for 1989 (49.88) and 1990 (60.69) were much higher than total weight catch rates for 1991 (35.97) or 1992 (34.36). Interpretation of data collected at Brickhouse Slough is confounded by several factors: 1) variability of catches from year-to-year is probably higher for single stations than for groups of stations combined, although this idea has not been sufficiently tested; 2) fish habitats at the river miles sampled in 1989 and 1990 may not be equivalent to those sampled in 1991 and 1992; 3) habitat changes due to the HREP project may have resulted in fish community changes. The several possible alternative explanations for changes in catch rates at Brickhouse Slough make using this station as a reference, with which to compare Illinois River data, problematical. The effects of the flood of 1993 and cancellation of sampling during that year have added other factors which will need to be considered when examining data collected in the future. 51 Fish Community Classification. Cluster analysis is an agglomerative method of organizing sampling units (SUs), corresponding to electrofishing stations in the following analyses, into pairs and groups of pairs based on their similarity in terms of some quantitative measure. The pairs are organized into dendrograms, where paired SUs or groups of SUs are considered more similar to each other than to other SUs. Of the many clustering techniques available, Ludwig and Reynolds (1988) recommended using the flexible strategy together with chord distance as a measure a similarity between SUs. Figure 5 and 6 show the results 6f clustering electrofishing stations by number catch rates for 1991 and 1992, respectively. In each case, the dashed line on the figure was drawn subjectively at chord distance 1.65, where three groupings were discernable. To help determine whether the clusters in Figures 5 and 6 correspond to the three river segments defined in Table 1, the letters U for upper, M for middle, and L for lower river were placed above the station numbers (see Table 2 and Figure 1). For 1991, five of the seven upper river stations were in the same cluster (III) (Figure 5). Upper river stations 22 and 23 were grouped with middle river stations (cluster II). Because of similarities in catches on the lower and middle river, it seems reasonable that those stations would be clustered together in a large group; even so, with the exception of station 2, all lower river stations were grouped together (sub-group in Cluster I). The Brickhouse Slough stations (27A and 27B) were separated in 52 Sampling units LMM L LL MM MMMMUU LMMMUUUU MUMM 3 9 14 4 1 5 6 8 27B 7 16 17 11 22 23 27A 2 15 18 19 20 21 24 25 13 26 10 12 0.1 0.2 0.3 0.4 0.5 0.6 0.7 (10 0.8 0.9 o 1.0 o0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 Figure 5. Cluster analysis (flexible strategy, Beta = -0.25) of electrofishing stations (sampling units) based on the number of fish collected per hour at each station in 1991. Sampling unit numbers correspond to station numbers in Table 2 and Figure 1. Letters above the sampling unit numbers are defined as follows: L = lower, M = middle, U = upper. 53 Sampling units L M 0.1 0.2 0.3 0.4 0.5 0.6 0.7 o 0.8 4-' 0.9 UO 1.0 0 -0 1.1 .r 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 Figure 6. Cluster analysis (flexible strategy, Beta = -0.25) of electrofishing stations (sampling units) based on the number of fish collected per hour at each station in 1992. Sampling unit numbers correspond to station numbers in Table 2 and Figure 1. Letters above the sampling unit numbers are defined as follows: L = lower, M = middle, U = upper. 54 amongst the lower and middle river stations. Analysis of 1992 data yielded a similar dendrogram as the 1991 data in that five of the seven upper river stations were again grouped in the same cluster (III) (Figure 6). Upper river stations 25 and 26, however, were paired with a sub-cluster containing the Brickhouse Slough stations (27A and 27B), which were paired together. Catch variability at a single station is illustrated by the fact that the two Lambies Boat Harbor samplings (25 August [13A in Figure 6] and 30 September [13B in Figure 6]) were grouped in two different of the largest three clusters. In 1991 Lambies Boat Harbor was paired with Treats Island (26 in Figure 5) and clustered with upper river stations. Interpretation of these results should be done with caution, however, since dendrograms constructed from large, complex data sets can'sometimes vary substantially depending on the clustering strategy used (Ludwig and Reynolds 1988). Even though considerable overlap in species composition and relative abundance among all the sampling stations definitely existed, upstream-to-downstream differences apparent in the data presented in Tables 8 through 25 together with the dendrograms of Figures 5 and 6 appear to support the notion of viewing the upper Illinois River as a sub-system of the entire river-floodplain complex, simply based on its fish community. The difference between lower and middle river segments was less apparent, and may require a different type of analysis, such as principle components analysis or correspondence analysis with environmental factors in addition 55 to the clustering technique, to be discernable. More work is being planned in this direction. II. LONG-TERM TRENDS--POLLUTION INDICATORS, 1959-1993. Before the long-term electrofishing data set could be examined for trends, the data had to be entered into the computer and checked for errors introduced during entry (Job 5). All original data sheets for all years when the survey was conducted from 1957 to 1993 were compared line by line with computer printouts until no further errors were found. This process, completed during segment 5 of project.F-101-R, has given us confidence in the correctness of the computerized data set. Catch Rates in Number of Individuals, 1962-1993. On the lower Illinois River from 1962 to 1992 there was a slight upward trend in catches of centrarchids (minus green sunfish) (N = 22, D = 1026, P < 0.05) and a steady downward trend in catches of carp (N = 22, D = 404, P < 0.05) (Figure 7). Goldfish and carp x goldfish were mostly absent, except for very small numbers collected in 1974 and 1991, where they made up less than 1% of the catch (Figure 7 and Table 29). As a percentage of total catch per effort, centrarchids (minus green sunfish) ranged from 4.29% in 1965 to 57.93% in 1984, and carp ranged from 4.41% in 1991 to 46.43% in 1965 (Table 29). Green sunfish were small percentages of the total catch (maximum of 2.23% in 1969) in all years where they were collected (Table 29). 56 Figure 7. Number of individuals collected per hour of electrofishing from the lower Illinois River from 1962 to 1992 for fish species identified as pollution indicators. Dashed lines connect data points for years between which electrofishing was not conducted. From 1962 to 1992, there was a slight upward trend in catches of centrarchids (minus green sunfish) and a steady downward trend in catches of carp. Goldfish and carp x goldfish were mostly absent. Note the change in scale for goldfish and carp x goldfish. 57 Lower Illinois River (RM 0-80) 12U 100 80 60 40 20 0 I 1965 1970 1975 1980 1985 1990 120 S10oo Carp S 80- O0 - 4- S 60-6 0 - cD 40 - 0 O - Su - I I I I I I. . o 1965 1970 1975 1980 1985 1990 jC I Z 4- Goldfish -C 0 * 2- 0 -5 1 - * l ,!-n., o- - i -- -- - .------= --- r = I ------9c-- A 1965 1970 1975 1980 1985 1990 5 4- Carp x Goldfish 3- 2- S1 1 1965 1970 1975 1980 1985 1990 58 Table 29. Percentage of total catch per hour of electrofishing for selected pollution indicator fishes in the lower Illinois River (RM 0-80), 1962-1992. Selected Pollution Indicator Fishes (% of total number per hour) ALL Fishes Sampling Total Centrarchids Carp x Time Number (minus Green Goldfish Yeara (hr) Per hr Green Sunfish) Sunfish Carp Goldfish Hybrid 1962 5.00 152.00 15.79 0.13 14.08 0.00 0.00 1963 3.00 170.67 12.70 0.39 33.79 0.00 0.00 1964 4.00 198.75 9.31 1.13 36.98 0.00 0.00 1965 4.50 62.22 4.29 0.00 46.43 0.00 0.00 1966 4.00 105.50 j7.54 1.18 ' 41.47 0.00 0.00 1967 4.00 142.25 15.47 0.18 29.35 0.00 0.00 1968 4.00 95.75 27.68 0.00 33.42 0.00 0.00 1969 4.50 119.56 30.86 2.23 29.00 0.00 0.00 1970 1971 1972 1973 1974 5.00 118.00 34.92 1.69 26.61 0.00 0.17 1975 4.75 91.16 30.72 0.00 24.25 0.00 0.00 1976 5.00 91.20 28.29 0.88 36.62 0.00 0.00 1977 4.50 73.33 17.88 0.61 26.36 0.00 0.00 1978 5.00 49.60 13.71 0.00 34.27 0.00. 0.00 1979 4.50 83.33 26.67 1.07 30.93 0.00 0.00 1980 1981 1982 3.00 67.33. 7.43 0.00 28.71 0.00 0.00 1983 3.75 159.73 51.75 1.34 12.02 0.00 0.00 1984 2.75 190.18 57.93 0.96 20.27 0.00 0.00 1985 3.75 67.20 40.87 0.00 18.65 0.00 0.00 1986 1987 1988 1989 5.44 136.95 28.86 0.81 4.97 0.00 0.00 1990 4.38 89.73 23.66 0.25 17.30 0.00 0.00 1991 4.77 147.38 54.20 1.56 4.41 0.28 0.14 1992 5.17 75.05 41.24 1.55 9.54 0.00 0.00 aBlank rows indicate years when electrofishing was not conducted. 59 On the middle Illinois River there was no long-term trend evident in catches of centrarchids (minus green sunfish) (N = 24, D = 1968, P > 0.05) or goldfish (N = 24, D = 1594, P > 0.05), but downward trends from 1962 to 1992 were evident in catches of carp (N = 24, D = 1060, P < 0.05) and carp x goldfish (N = 24, D = 1243, P < 0.05) (Figure 8). Goldfish and carp x goldfish occurred in much smaller numbers than carp or centrarchids with a maximum goldfish catch of 3.45 per hr in 1964 and a maximum carp x goldfish catch of 3.87 per hr in 1976. In contrast, the maximum centrarchid catch (minus green sunfish) was 64.36 per hr in 1991, while the maximumt carp catch,was 92.29 per hr in 1979. As a percentage of total catch per effort, centrarchids (minus green sunfish) ranged from 0.56% in 1965 to 42.82% in 1991; green sunfish ranged from 0.00% in 1977 to 13.91% in 1989 (Table 30); carp ranged from 4.88% in 1991 to 56.07% in 1977; goldfish ranged from 0.00% in 1962, 1977, 1985, and 1990 to 1.83% in 1989; and carp x goldfish ranged from 0.00% in 1977, 1983, and 1990 to 1.66% in 1978 (Table 30). On the upper Illinois Waterway there was a very evident upward trend in catches of centrarchids (minus green sunfish) from 1962 to 1993 (N = 24, D = 376, P < 0.05) and downward trends in catches of carp (N = 24, D = 744, P < 0.05), goldfish (N = 24, D = 235, P < 0.05), and carp x goldfish (N = 24, D = 653, P < 0.05) (Figure 9). As a percentage of total catch per effort, centrarchids (minus green sunfish) ranged from 0.00% in 1965 to 16.05% in 1983; green sunfish ranged from 0.00% in 1964 and 1965 60 L Figure 8. Number of individuals collected per hour of electrofishing from the middle Illinois River from 1962 to 1992 for fish species identified as pollution indicators. Dashed lines connect data points for years between which electrofishing was not conducted. There was no long-term trend evident in catches of centrarchids (minus green sunfish) or goldfish, but downward trends from 1962 to 1992 were evident in catches of carp and carp x goldfish Note the change in scale for goldfish and carp x goldfish. 61 Middle Illinois River (RM 80-231) 100 --___II __ - Centrarchids 80- (minus green sunfish) 60- 40 20 F~c~t~l c S%/* -ýP -*-". ) 0 I i I I I . 1980 I 1965 1970 1975 1980 1985 1990 100 80 cl) 60 -a3 40 '4- 20 0 0 1965 1970 1975 1980 1985 1990 CD 5- 4- Goldfish 3- 9. 2- O 1- 0 -- 4-o 0 I -WF -W 7%. i 1-- - I I I - I - - I 1965 1970 1975 1980 1985 1990 5 4 Carp x Goldfish 3 2 ' , -- %%"A 1 ._/____Vv%% ~-- \^4 0 1975 19651965 19701970 1975 1980 1985 1990 62 Table 30. Percentage of total catch per hour of electrofishing for selected pollution indicator fishes in the middle Illinois River (RM 80- 231), 1962-1992. Selected Pollution Indicator Fishes (% of total number per hour) All Fishes Sampling Total Centrarchids Carp x Time Number (minus Green Goldfish Yeara (hr) Per hr Green Sunfish) Sunfish Carp Goldfish Hybrid 1962 11.50 700.43 7.25 0.26 9.17 0.00 0.02 1963 14.50 298.34 8.95 1.53 , 22.03 0.35 0.35 1964 14.50 292.76, 17.40 0.94 30.27 1.18 0.61 1965 9.00 177.33 0.56 0.19 14.04 1.07 1.25 1966 13.00 288.85 7.67 1.97 27.08 0.24 1.15 1967 13.50 260.74 8.75 1.16 20.54 0.17 1.05 1968 14.00 232.93 10.92 3.04 22.48 0.06 0.74 1969 13.50 438.00 5.02 3.35 9.86 0.30 0.46 1970 9.00 191.89 13.20 1.80 20.56 0.17 1.51 1971 1972 1973 14.00 146.36 21.18 7.52 23.77 0.10 1.17 1974 13.25 173.13 30.86 2.96 30.86 0.09 1.05 1975 13.00 149.23 17.16 2.37 22.5B 0.36 1.44 1976 7.50 238.53 18.17 4.36 29.29 0.11 1.62 1977 2.25 106.22 9.21 P.00 56.07 0.00 0.00 1978 11.25 171.64 9.89 4.76 22.94 0.67 1.66 1979 7.00 254.71 11.44 7.23 36.23 0.45 1.01 1980 1981 1982 9.62 110.71 11.08 3.29 35.12 0.19 0.66 1983 7.93 209.46 15.95 8.37 21.85 0.18 0.00 1984 8.50 216.82 13.40 6.24 27.94 0.05 0.22 1985 9.33 162.17 14.54 10.18 25.91 0.00 0.26 1986 1987 1988 1989 12.16 125.90 6.34 13.91 14.63 1.83 0.72 1990 7.47 136.01 17.52 4.04 8.76 0.00 0.00 1991 9.68 150.31 42.82 8.38 4.88 0.07 0.14 1992 11.73 115.86 30.83 9.05 13.10 0.29 0.15 aBlank rows indicate years when electrofishing was not conducted. 63 Figure 9. Number of individuals collected per hour of electrofishing from the upper Illinois River from 1962 to 1993 for fish species identified as pollution indicators. Dashed lines connect data points for years between which electrofishing was not conducted. From 1962 to 1993, there was an upward trend in catches of centrarchids (minus green sunfish) and downward trends in catches of carp, goldfish, and carp x goldfish. Note the change in scale for carp x goldfish. 64 Upper Illinois Waterway (RM 231-280) 80 I_ Centrarchids 60 (minus green sunfish) 40- 20- c_ - P...- ..Aso U 7 I _,1 _1 _ -1 I I I I I 19 1 1965 1970 1975 1980 1985 1990 0) IcCl) 60 - Carp 0 40 - ftN ·r co 20 - __ 0- 1 I 1 1 I I 1965 1970 1975 1980 1985 1990 80 60 0 4-__ 40 20 Hc 0 1965 1970 1975 1980 1985 1990 5- 4- Carp x Goldfish 3- 2- 1- .A, 4z r 5 .. p\ . . . 0 - I I I I ----Iblmd - Imr ý op 1965 1970 1975 1980 1985 1990 65 to 13.26% in 1976; carp ranged from 2.83% in 1985 to 38.27% in 1979; goldfish ranged from 0.00% in 1991 to 38.40% in 1964; and carp x goldfish ranged from 0.00% in 1985 to 2.77% in 1990 (Table 31). Incidence of External Abnormalities, 1959-1993. -Percentages of fish with external abnormalities were greater for sediment-contact fishes than for water-column fishes for all years and river segments except for the lower river in 1976 (5.99% for sediment-contact, 6.35% for water-column) and 1991 (1.60% sediment-contact, 2.77% water-column) and the middle river in 1977 (13.27% sediment-contact, 19.05% water-column). Percentages of sediment-contact fishes with external abnormalities generally increased for specific years in the upstream direction, while this trend was not apparent for water- column fishes (Figure 10). For all river segments, percentages of water-column fishes with external abnormalities showed-decreasing trends with increasing years (lower river, N = 20, D = 2069, P < 0.05; middle river, N = 24, D = 3654, P < 0.05; upper waterway, N = 19, D = 3156, P < 0.05) (Figure 10). Percentages of sediment-contact fishes with external abnormalities showed a decreasing trend on the middle river with increasing years (N = 24, D = 1228, P < 0.05), but no trend on the lower river (N = 20, D = 1032, P > 0.05) or upper waterway (N = 19, D = 2062, P > 0.05) (Figure 10). For sediment-contact fishes there is the suggestion of a slight periodicity in the percentages which appears to occur at a 66 Table 31. Percentage of total catch per hour of electrofishing for selected pollution indicator fishes in the upper Illinois Waterway (RM 231- 280), 1962-1993. Selected Pollution Indicator Fishes (% of total number per hour) All Fishes Sampling Total Centrarchids Carp x Time Number (minus Green Goldfish Yeara (hr) Per hr Green Sunfish) Sunfish Carp Goldfish Hybrid 1962 7.00 232.71 0.31 0.06 11.60 30.14 1.47 1963 7.00 242.29 9.06 0.061, 28.66 32.02 1.95 1964 6.00 127.17 6.13 0.00 20.71 38.40 1.57 1965 4.50 299.11 0.00 0.00 17.09. 12.70 1.49 1966 4.50 130.00 0.68 0.34 22.39 10.09 1.37 1967 4.50 194.00 0.57 0.34 18.67 7.10 1.26 1968 4.50 97.33 2.74 1.60 24.20 12.56 1.60 1969 4.50 96.44 1.38 1.84 20.51 13.59 1.38 1970 4.50 232.44 2.68 1.15 14.72 8.13 0.67 1971 1972 1973 5.50 93.82 4.65 3.88 20.35 22.48 0.39 1974 4.50 109.33 6.71 8.13 23.98 6.50 0.61 1975 4.25 127.76 7.37 4.24 23.57 2.21 1.29 1976 4.75 128.63 12.11 13.26 19.97 4.91 0.65 1977 1978 5.70 154.04 5.47 7.86 27.45 5.58 0.80 1979 6.50 92.46 2.83 2.00 38.27 7.32 0.83 1980 1981 1982 5.00 80.00 5.00 7.00 24.00 1.50 0.25 1983 4.50 185.56 16.05 12.10 14.13 0.60 0.00 1984 4.00 378.50 7.99 4.95 8.12 1.12 0.13 1985 4.35 431.03 3.25 3.68 2.83 0.32 0.00 1986 1987 1988 1989 6.90 180.72 12.51 7.30 3.93 4:33 0.40 1990 5.01 86.43 15.01 6.47 7.62 1.15 2.77 1991 5.14 87.94 14.82 10.18 4.42 0.00 0.88 1992 6.27 127.27 11.90 10.40 5.26 0.50 0.38 1993 6.44 131.06 8.65 12.56 5.09 1.07 0.24 aBlank rows indicate years when electrofishing was not conducted. 67 Water-Column Fishes Sediment-Contact Fishes Upper (RM 231-280) 100 80 60- 40- 20- 0 J -~LCLC~·'A -ICC ' --~CYI - - Y- Middle (RM 80-231) ci.9 100 E 80- 60- -Q 40- A U. 20- L.< 0- -M.,s -o- - nekL -0-crl Lower (RM 0-80) 100 80- 60- 40- 20- 0- --·~--~----- ~r I 7[ I T-I 1 I 1960 1970 1980 1990 1960 1970 1980 1990 Figure 10. Incidence of externally-visible abnormalities (sores, eroded fins, lumps) on fish collected from the upper (top figures), middle (middle figures), and lower Illinois Waterway (bottom figures) from 1959 to 1993. Left figures are for fishes which mainly inhabit the water column. Right figures are for fishes which are more likely to come into frequent contact with bottom sediments (see Appendix B). 68 15-year interval. If this is true, the state of health of sediment-contact fish populations in the early 1990s apparently appeared much as they did in the mid-1970s and early 1960s. The cause for such a cycle, if indeed there is one, is unknown. 69 Page 70 missing from the bound original DISCUSSION Long-Term Trends. The more obvious long-term trends in fish habitats of the Illinois River system during the past three decades have been: 1) measurable improvements in water quality, largely due to better municipal and industrial waste treatment (Butts 1987, Patterson et al. 1992); and 2) loss or degradation of habitats due to excessive sedimentation (Bellrose et al. 1983, Demissie et al. 1992). High sedimentation rates have been a larger problem on the lower and middle river reaches than on the upper waterway (Demissie et al. 1992), while the converse has been mostly the case for industrial and municipal pollutants (Essig 1991), although the Peoria metropolitan area has long been recognized as a significant pollution source (Kofoid 1903). The connection among these factors and trends in our electrofishing catch rates seems obvious, although lack of the experimental method, inherent in a long-term monitoring survey on the scale of an entire river, invites alternative explanations (Hairston 1989). The apparent response of fish populations to improvements in water quality was most evident on the upper waterway. In 1963, almost two-thirds of total number catch rates consisted of pollution-tolerant carp (28.7%) and goldfish (32.0%) (Figure 9 and Table 31). Conditions must have been so degraded that even the green su;ifish was collected only in small numbcrs or not at all (Table 31). As water quality improved following the early 1960s, centrarchids, less tolerant of polluted waters than carp 71 or goldfish, began to increase, from being absent in catches in 1965 to an average of 13% (minus green sunfish) of number catch rates in the most recent five years (Table 31). During the same period, carp, goldfish, and carp x goldfish decreased, perhaps resulting, in part, from predation by piscivorous centrarchids (Figure 9). On the lower and middle river, centrarchids (minus green sunfish) were present in varying relative abundances in all years (Figure 8 and Figure 7), which suggests that industrial and municipal pollutants were of less influence on those reaches. The general lack of goldfish and carp'x goldfish in lower river catches (Figure 7), their consistently low relative abundances on the middle river (Figure 8), and the small percentage of total catch that consisted of green sunfish on the lower river (Table 29) support.this hypothesis. Access to backwaters for spawning (Richardson 1913) and overwintering (Sheehan et al. 1990) has probably been the limiting factor influencing some fish populations in the lower and middle river reaches. Yearly discharges at river mile 62 were higher than the 54- year mean for twelve of the most recent 20 years (or 60%), while from 1959 to 1972 there were five years (or 36%) higher than the 54-year mean (Figure 11). High water years may have been beneficial to spawning fishes if the water was high at the proper time and remained so long enough for breeding cycles to be completed. The upward trend in catches of centrarchids on the lower river (Figure 7) may reflect the recent two decades of 72 J-%01 2U 18 2c 16 -. 14 "O.D 12 c 10 d 8 Es 6 0E= o 4 2 (D C. = 0 i -2 a, -4 -6 -8 -10 -12 1960 1965 1970 1975 1980 1985 1990 Figure 11. Yearly departures in discharge of the Illinois River at Valley City (RM 62) from the 54-year mean discharge of 22,110 cubic feet per second. 73 mostly high water years. At the same time, reasons for the decline of carp throughout the river and the lack of trend in catches of centrarchids on the middle river are less easily explained. But it may be that effects from years of excessive sedimentation are beginning to be noticeable in fish catch rates. By 1985, sedimentation rates (inches per year) in backwaters ranged from 0.08 in Pekin Lake (RM 153) to 3.12 in Muscooten Bay (RM 89) with capacity losses since 1903 ranging from 22% in Lake Chautauqua (RM 125) to 100% in Muscooten Bay (Table 32). These losses represent, among other things, less fish spawning habitat, which will eventually result in population declines of certain species. Pitlo (1992) noted that decreases in centrarchids should be expected with increased siltation of backwaters. Although carp can be considered habitat generalists, their use of backwaters for spawning has long been acknowledged (Richardson 1913). Hughes and Gammon (1987) reported an increase in the incidence of abnormalities on fishes of the Willamette River in Oregon, with increasing pollution. Tyler and Everett (1993) reported that bottom-dwelling barbel (Barbus barbus) collected in England from polluted rivers had a higher incidence of abnormalities than those collected from a clean river. Lindesjoo and Thulin (1987) associated fin erosion of perch (Perca fluviatilis) with chlorinated pulp mill effluents. Because the relationship between an incidence of abnormalities on fish and 74 Table 32. Sedimentation in backwater takes in the Illinois River valley (adapted from Demissie et at. 1992). Sedimentation Capacity Rate Loss Reach Lake Name iRiver Mile (in/yr) (%) Alton Swan Lake 5 0.18 51 Lake Meredosia 72 0.43 56 La Grange Muscooten Bay 89 3.12 100 Patterson Bay 107 0.31 47 Lake Chautauqua 125 0.33 22 Rice Lake 133 0.32 77 Pekin Lake 153 0.08 36 Peoria Peoria Lake 162 0.79 76 Babb's Slough 185 0.14 66 Weis Lake 191 0.15 91 Sawmill Lake 197 0.47 99 Lake Senechwine 199 0.30 86 Lake DePue 203 0.59 88 Huse Slough 221 0.96 96 Marseilles Ballards Slougha 248 0.91 90 a Electrofishing station #22 (see Table 2). 75 polluted waters seems well established, we infer that long-term downward trends in the percentages of water-column fishes with abnormalities collected from the Illinois River (Figure 10) are related to known trends of improvements in water quality, which occurred over the same time period (Butts 1987). Sediment-contact fishes, with few exceptions, had higher incidences of external abnormalities than water-column fishes (Figure 10), which suggests sediments may contain significant amounts of contaminants. Brown et al. (1973) reported, however, that benthic fishes had a higher frequency of tumors than pelagic fishes (1.7% and 1.0%, respectively) 'even when collected from a relatively unpolluted Canadian watershed. Both groups of fishes, though, had higher rates of tumors in the polluted Fox River of northeastern Illinois (sediment-contact fishes, 7.0%; water- column fishes, 3.0%) than in the Canadian system (Brown et al. 1973). At any rate, the IEPA (1992) identified several locations near our electrofishing stations on the upper Illinois and Des Plaines rivers as having sediments that contained elevated levels of toxicants, including mercury, lead, and PCBs; and Essig (1991) reported that concentrations of mercury, zinc, and PCBs in sediments of the Illinois River increase in the upstream direction, a trend similar to that shown in Figure 10 for the percentages of sediment-contact fishes with external abnormalities. A connection between these trends, however, remains inferential. 76 The lack of long-term downward trends in percentages of upper and lower river sediment-contact fishes with abnormalities (Figure 10) perhaps reflects the persistent nature of whatever factor caused the abnormalities, or a continuing source of the factor. It is unclear why percentages of sediment-contact fishes with abnormalities collected from the middle river showed a long- term decreasing trend. Recent Fish Population Data, 1989-1993. Long-term trends become most apparent when many years or even decades of data are examined. The last five years of carp catch rates (Figures 7 though 9), for example, indicate the population is somewhat stable, especially on the upper waterway (Figure 9). When examined in perspective over thirty years, though, the downward trends in catch rates become obvious, even as catch rates varied quite.a bit from year to year. Metaphorically speaking, the last five years of electrofishing data provide us with a detailed snapshot of Illinois River fish populations, which should not be taken out of the long-term context. Even though the system is dynamic, there are consistencies in the data which may allow some generalizations to be made concerning fish community composition. Carp, bluegill, gizzard shad, and emerald shiner seemed to be the more consistently widespread and abundant species. The piscivoirous largemouth bas was important in all reaches, on average ranking as the seventh most abundant species by individuals collected and fourth by 77 weight (Tables 8 through 17). In terms of weight, carp were overwhelmingly dominant, except for certain instances which may have been the result of catch variability (Table 22 and Table 23). In the Dresden reach, small numbers of large goldfish and carp x goldfish may still be collected, but this may not be the case in the next few years as larger, older individuals die, while young-of-the-year may be subjected to higher rates of predation. Previously noted upstream-to-downstream differences in fish distributions (Tables 8 through 17) show some consistency with distributions reported by Fqrbes and Richardson (1920), who based their work on studies begun by Forbes in 1876. Bigmouth buffalo were mostly absent from the upper waterway on our survey and were reported by Forbes and Richardson (1920) as occurring only as far upstream as Henry (RM 196). We found white bass to be less abundant in the upper waterway than in the lower and middle river, and white crappie to be absent. Forbes and Richardson (1920) noted that white bass were less common in the northern part of the state than elsewhere, and black crappie apparently were more abundant than white crappie in the northeastern region of the state. Freshwater drum were more abundant in lower and middle river catches than on upper waterway catches on our survey and when Forbes and Richardson made collections. Rock bass apparently were always more common in the northern half of Illinois (Forbes and Richardson 1920), a situation consistent with our electrofishing survey, where this species was collected 78 only on the upper waterway (Tables 8 through 17). Catch rates of most minnows and shiners were higher from the upper waterway than from the lower or middle river (Tables 8 through 17). A representative species is the bluntnose minnow, which Smith (1979) indicated to be widely distributed and abundant throughout Illinois, including the entire Illinois River system. However, the bluntnose minnow was absent from Alton and La Grange reach catches, but was very abundant in upper waterway catches (Tables 8 through 17). When minnows are stunned, they tend to remain motionless and suspended in the water column, rather than jerking to the water's surface as a largemouth bass might (T.V. Lerczak, personal observation). Water transparency tended to be much higher in the upper waterway than the lower or middle river. Secchi disk transparencies for the three waterway segments from 1989 to 1993 were as follows: upper, 5.9 to 31.9 in (median = 19.7 in, mean = 19.7 in, N = 35); middle, 3.9 to 16.9 in (median = 9.8 in. mean = 10.3 in, N = 58) ; lower, 6.3 to 13.7 in (median = 8.9 in, mean = 9.3 in, N = 21) (Tables 3 through 7). Perhaps minnows and shiners in the lower and middle river were carried away by currents before they could float to the surface to be seen by the netter. If so, this apparent sampling bias should be taken into consideration when making conclusions about fish community composition. Conclusions. Improvements in water quality of the Illinois River over the last three decades have apparently contributed to fish population 79 changes. These changes were most evident on the upper Illinois Waterway, where centrarchids (minus green sunfish) increased in catches from a low of 0 fish per hour in 1965 to an average of 15 per hr over the last five years. But excessive sedimentation rates may eventually result in fish population declines, especially on the lower and middle river. Perhaps centrarchids may have had increasing populations in the middle river as a response to better water quality had it not been for deterioration of spawning habitats from siltation. The downward trend in carp catch rates over the long-term for all waterway segments may be partly the result of spawning habitat losses. The higher incidence of abnormalities on sediment-contact fishes compared with water-column species suggests a causal factor for the abnormalities is associated with known sediment contaminants.. Pathological analyses are needed to identify the cause or causes for the abnormalities, which apparently increase in the upstream direction toward the Chicago area. Improvements in water quality seemed to have resulted in the healthier appearance of water-column fishes throughout the waterway. Some upstream-to-downstream trends in fish relative abundances appear to be consistent with that which existed even when the earliest fish surveys were conducted by Forbes and Richardson. This indicates at least some semblance of fish communities to a "normal" state, however that may be defined, despite decades of system modifications and degradation from pollution. In fact, environmental factors which stimulate yearly 80 biological cycles (hydrologic and temperature changes) still appear very much as they did when the earliest data were collected by Charles A. Kofoid in the 1890s (Figure 12), at least on the lower and middle river. This suggests that ecological restoration of the Illinois River system might have a high probability of success, provided the sedimentation problem is solved, with a minimum of management "tinkering." Figure 12 is a representation.of what is known about the system dynamics as they relate to fish populations, where key biological events (e.g., spawning) probably occur over a range of parameter values. On Ithe average,, river fish experience an expanded habitat during the regular spring flood pulse (Junk et al. 1989). When water levels are high, fish are allowed access to backwaters (Guillory 1979, Kwak 1988) as temperature increases stimulate spawning '(Richardson 1913, Cramer and Marzolf 1970). Kofoid (1903) documented recurring pulses of plankton in the river and, especially, in the backwaters throughout six years of intensive study (1894-1899) near Havana (RM 121), with the largest pulse usually occurring in late April and early May. A large plankton pulse at the proper time would provide a needed food resource for young fish (Forbes 1880, Kofoid 1903). Decoupling of the system dynamics (i.e., critical temperature and water levels not occurring together) would probably result in decreased fish production (Sparks et al. 1990). 81 00r- 0 a) 4 0 CO a) I-7 Cd 4-J (1) r ý4 ( (dcd r-i U) 00 d 04.. H0Q:4j 13 t (), 4- f)ý d (1) 0C-H(1) r-i1C4iy0m 4-)Q$4 CM J-44-i 4-JCI pHH 44(dl~ci W0 a C Q)) 1) I -- ) 0 o~ Cd E3 -H tPCdO 0 (1)rM140H % 0dFUtU~+14rIQ 34 ~ 0 00 4J-i -H4-) CAIQ(1d (d asCd zCd )4-)4-) f-i 0 4-) 4J -H-HQ) CdWH> d a) 100 U) W,4 'O 4) r. o44 i 0 d0 F~ a) ~ )H- (1d-H 0 F4 M'4a) -H( ~ k a) - 04a-) 0CdCc( a ) p) U0U)TI ) Q) Cd ý4-3 4-4 :1X 0 to S ,o) > -l a rdM ( 41 O)4r-4 (IJ -- '>11 CdZ.0 :ýý-4 m rLolc Cdf (U(a) Cd 0 Cd1 C4a) Cd ' (1)4-Ht()I0N~- Cd Cd- 1)4-).U)l(' ( 0 a) C( :) ý_ ·c'i4-cOa)rd) 4 -HUr.0() :1U)4-)rC- i 02 ý454 - -H 4) U4d(C) r-iP Q)-HP 0 ::f·r Q) .44o r-I-H IT rc; >,Fu -a) >o 1:U4PH Cd E-i C CO S::(1)Ctý 4 >1I *H Ul*~Ha)oJm campy,3 (1)a))0 - i 00)C,> 044-m ~k Oai ~jE a) ~co a) >>104 mCI (15* U) (0Cl, -H r: H9~ %4 -H t %D S ~-Cd C 0a)) m MC0% 0Cd~0 4-) P 0 X4 Cd(- -H C r-iH0 -HHr-i 4 P4 > 0 ý-4 24 >i 4-) 04 (d0d 0 4- 0-kO)-> cx1 C 0)U)H 0'U '01-4 0 Zn 04 -i > (a)00 40 4-4 -4 H -4 -vI Hfi0 Crod 0 1- mU)C$-r-0 0Or-404- 0 4-) -4 r, PIH Cd-4 $:rWd U) t>U) Cdi) L4f Cd't ,~ a)>-ia 00 0 ý4 -H 0 0 > r-. a) Cd :IHU) (1)0 cU) a1) 0 ~124 r-q4 co r-q 1) U) u)% ~4-J :ý4-) 00() > -I 4 ri 0> -H 134 4 - HC4J (C U)r -4 ý r r tIV 1 A) AaII 0\ r1 82 laeal Pas DAoqe aa_ a) CC) Ct to) CY) C\I 11CY) CY) CY)Cf) Cf) C) CO) ICfCY) 0 G) o 1 0) C C) co 0)0)0)o 0) 0)0)0) o ocQ 1r 1 U. 0.. + 0:-- O <1 X XF aa 03 4oa $n 0)*C: CL- (1) 0 ./ ILO cr' + + ± 0V 0 LL Ct3 -- I I I-· I I I ------'A- ,Q (\I C) C) mC) K N CD mo mO Q- C co Co I4- (Nj co m ) co 04 4 4 (N V- It- V- 7 ainVeiodwaj_ 83 The Illinois River system appears to be at a critical point in its history, where benefits from pollution control are being realized just as the system seems about to be literally smothered by siltation. Even though recommendations for solving the environmental problems of the Illinois River system have been made many times for many years (Havera 1994), perhaps continued vigilance toward water quality improvements, solving the sedimentation problem, and recognizing and working with the natural dynamics of the system, to which the biota are especially adapted, will allow for an optimistic future. 84 LITERATURE CITED Bellrose, F.C., F.L. Paveglio, Jr., and D.W. Steffeck. 1979. Waterfowl and the changing environment of the Illinois River valley. Illinois Natural History Survey Bulletin 32(1):1- 54. Bellrose, F.C., S.P. Havera, F.L. Paveglio, Jr., and D.W. Steffeck. 1983. The fate of lakes in the Illinois River valley. Illinois Natural History Survey Biological Notes No. 119. 27 pp. Bodensteiner, L.R., and W.M. Lewis. 1992. Role of temperature, dissolved oxygen, and backwaters in the winter survival of freshwater drum (Aplodinotus grunniens) in the Mississippi River. Canadian Journal of Fisheries and Aquatic Sciences 49:173-184. Breder, C.M., Jr., andR.F. Nigrelli. 1935. The influence of temperature and other factors on the winter aggregations of the sunfish, Lepomis auritus, with critical remarks on the social behavior of fishes. Ecology 16:33-47. Brown, E.R., J.J. Hazdra, L. Keith, I. Greenspan, and J.B.G. Kwapinski. 1973. Frequency of fish tumors found in a polluted watershed as compared to nonpolluted Canadian waters. Cancer Research 33:189-197. Butts, T.A. 1987. Illinois River water quality. Past, present, future. Pages 195-209 in H. Korab, ed. Proceedings Governor's Conference on the Management of the Illinois River System: the 1990's and beyond. Special Report No. 16. Water Resources Center, University of Illinois, Urbana. Cramer, J.D., and G.R Marzolf. 1970. Selective predation on zooplankton by gizzard shad. Transactions of the American Fisheries Society 99:320-332. Demissie, M., L. Keefer, and R. Xia. 1992. Erosion and sedimentation in the Illinois River basin. Report No. ILENR-RE-WR-92/04 prepared for Illinois Department of Energy and Natural Resources. Illinois State Water Survey, Champaign. 112 pp. Essig, H.W. 1991. Chemical and biological monitoring of the upper Illinois River. Pages 68-77 in H. Korab, c-d. Proceedings 1991 Governor's Conference on the MaLnagement of the Illinois River System. Water Resources Center, University of Illinois, Urbana. 85 Pflieger, W.L. 1975. The fishes of Missouri. Missouri Department of Conservation. 343 pp. Forbes, S.A. 1880. The food of fishes. Bulletin of the Illinois State Laboratory of Natural History 1(3):18-65. Forbes, S.A., and R.E. Richardson. 1919. Some recent changes in Illinois River biology. Illinois State Natural History Survey Bulletin 13(6):139-156. Forbes, S.A., and R.E. Richardson. 1920. The fishes of Illinois. 2nd ed. Illinois Natural History Survey. cxxxvi + 357 pp. Gammon, J.R. 1994. The Wabash River ecosystem, A report for PSI-Energy, Plainfield, Indiana, and Eli Lily and Company, Indianapolis, Indiana. 213 pp. Gilbertson, D.E., and T.J. Kelly. 1981. Summary resource description Upper Mississippi River System. Unpublished report. 102 pp. Guillory, V. 1979. Utilization of an inundated floodplain by Mississippi River fishes., Florida Scientist 42:222-228. Hairson, N.G., Sr. 1989. Ecological experiments: purpose, design, and execution. Cambridge University Press, Cambridge. 370 pp. Havera, S.P. 1994. A historical perspective on wetlands and waterfowl populations and their importance in the Illinois River valley. Pages 101-111 in H. Korab, ed. Proceedings 1993 Governor's Conference on the Management of the Illinois River System. Special Report No. 20. Water Resources Center, University of Illinois, Urbana. 195 pp. Hughes, R.M., and J.R. Gammon. 1987. Longitudinal changes in fish assemblages and water quality in the Willamette River, Oregon. Transactions of the American Fisheries Society 116:196-209. Illinois Environmental Protection Agency. 1992. Illinois water quality report, 1990-1991. Illinois Environmental Protection Agency, Springfield. Junk, J.W., P.B. Bayley, and R.E. Sparks. 1989. The flood pulse concept in river-floodplain systems. Pages 110-127 in D.P. Dodge, ed. Proceedings of the International Large River Symposium. Canadian Special Publication of Fisheries and Aquatic Sciences 106. 86 Karr, J.R., K.D. Fausch, P.L. Angermeier, P.R. Yant, and I.J. Schlosser. 1986. Assessing biological integrity in running waters: a method and its rationale. Illinois Natural History Survey Special Publication 5, Champaign. Kofoid, C.A. 1903. Plankton studies. IV. The plankton of the Illinois River, 1894-1899, with introductory notes upon the hydrography of the Illinois River and its basin. Part I. Quantitative investigations and general results. Illinois State Laboratory of Natural History Bulletin 6(2):95-635. Kwak, T.J. 1988. Lateral movement and use of floodplain habitat by fishes of the Kankakee River, Illinois. The American Midland Naturalist 120:241-249. Lehmann, E.L., and H.J.M. D'Abrera. 1975. Nonparametrics. Holden-Day, Inc, San Francisco. 457 pp. Lindesjoo, E., and J.tThulin. 1987. Fin erosion of perch (Perca fluviatilis) in a pulp mill effluent. Bulletin of the European Association of Fish Pathologists 7:11-14. Ludwig, J.A., and J.F. Reynolds. 1988. Statistical ecology. John Wiley and Sons, New York. 377 pp. Mills, H.B., W.C. Starrett, and F.C. Bellrose. 1966. Man's effect on the fish and wildlife of the Illinois River. Illinois Natural History Survey Biological Notes No. 57. 24 pp. Page, L.M., and B.M. Burr. 1991. A field guide to freshwater fishes. Houghton Mifflin Company, Boston. 432 pp. Patterson, J.W., S.J Sedita, B. Sawyer, D.R. Zenz, and C. Lue- Hing. 1992. Report No. 92-25. Comprehensive water quality evaluation summary report for the period of 1989 through 1991. Metropolitan Water Reclamation District of Greater Chicago, Chicago. Pierce, R.B., D.W. Coble, and S.D. Corley. 1985. Influence of river stage on shoreline electrofishing catches in the Upper Mississippi River. Transactions of the American Fisheries Society 114:857-860. Pitlo, J.P., Jr., 1992. Federal aid to fish restoration completion report, Mississippi River investigations, Project No. F-109-R. Report to Fish and Wildlife Division, Iowa Department of Natural Resources. 128 pp. 87 Richardson, R.E. 1913. Observations on the breeding habits of fishes at Havana, Illinois, 1910 and 1911. Bulletin of the Illinois State Laboratory of Natural History 9:405-416. Sheehan, R.J., W.M. Lewis, and L.R. Bodensteiner. 1990. Winter habitat requirements and overwintering of riverine fishes. Project Completion Report (F-79-R). Fisheries Research Laboratory, Southern Illinois University, Carbondale. 86 pp. Smith, P.W. 1979. The fishes of Illinois. University of Illinois Press, Urbana, Illinois. 314 pp. Sparks, R.E. 1984. The role of contaminants in the decline of the Illinois River: implications for the Upper Mississippi. Pages 25-66 in J.G. Wiener, R.V. Anderson, and D.R. McConville, eds. Contaminants in the Upper Mississippi River. Butterworth Publishers, Boston. 368 pp. Sparks, R.E., P.B. Bayley, S.L. Kohler, and L.L. Osborne. 1990. Disturbance and recovery of large floodplain rivers. Environmental Management 14:699-709. Sparks, R.E., and T.V. Lerczak. .1993. Recent trends in the Illinois River indicated by fish populations. Aquatic Ecology Technical Report 93/16. Illinois Natural History Survey, Champaign. 34 pp. Sparks, R.E., P.E. Ross, and F.S. Dillon. 1992. Identification of toxic substances in the upper Illinois River. Report No. ILENR/RE-WR-92/07 prepared for Illinois Department of Energy and Natural Resources. Illinois Natural History Survey, Champaign. 59 pp. Starrett, W.C. 1971. A survey of the mussels (Unionacea) of the Illinois River: a polluted stream. Illinois Natural History Survey Bulletin 30(5):267-403. Starrett, W.C. 1972. Man and the Illinois River. Pages 131- 169 in R.T. Oglesby, C.A. Carlson, and J.A.:McCann, eds. River ecology and man. Academic Press, New York. 465 pp. Stauffer, J.R., Jr., K.L. Dickson, J. Cairns, Jr., and D.S. Cherry. 1976. The potential and realized influences of temperature on the distribution of fishes in the New River, Glen Lyn, Virginia. Wildlife Monographs 40:1-40. 88 Stenzel, S.W., and K.D. Blodgett. 1992. Water quality parameters from selected habitats on La Grange Pool, Illinois River, January-December 1990. Annual Report to the U.S. Fish and Wildlife Service Environmental Management Technical Center, Onalaska, Wisconsin. Aquatic Ecology Technical Report 91/21. Illinois Natural History Survey, Champaign. 34 pp. Sternberg, R.B. 1971. Upper Mississippi River Habitat Classification Survey. Upper Mississippi River Conservation Committee, Rock Island, Illinois. Thompson, D.H. 1928. The "knothead" carp of the Illinois River. Illinois Natural History Survey Bulletin 17(8):285- 320. Tyler, C.R., and S. Everett. 1993. Incidences of gross morphological disorders in barbel (Barbus barbus) in three rivers in southern England. Journal of Fish Biology 43:739- 748. Willman, H.B. 1973. Geology along the Illinois Waterway--a basis for environmental planning. Illinois State Geological Survey Circular 478. 48 pp. 89 Page 90 missing from the bound original Appendix A. Long-Term Electrofishir. Survey of the Illinois River Field Methods. Prepared by Richard E. Sparks 6 September 1989 Revised: 29 May 1990 1. Goals. The goals of the long-term electrofishing survey (LTEF) are to detect upstream-downstream and year-to-year trends in fish populations of the Illinois River and to relate these trends to changes in water and habitat quality. 2. General approach. The objective is to sample the same stations using the same methods every year, so that results will be comparable across years and differences in catch per unit effort will reflect real changes in fish populations, rather than differences in sampling technique. The task then is to duplicate the field methods used by Starrett, Sparks, and Lubinski. The stations are all in areas permanently connected to the main channel of the Illinois River, even during low river stages. No isolated backwaters are sampled because water quality conditions and fish populations can diverge markedly from conditions in the flowing channels and mainstem lakes. Sampling is conducted in a 6-week "window" extending from the last week in August to the end of the first week in October. The actual sampling requires 4 5-day weeks, but allowances have to be made for weather, water levels, and equipment breakdowns. Sampling is initiated late in the summer, so that young-of-the-year (yoy) of species such as largemouth bass have grown large enough to be taken in the 1/4-inch mesh dip nets. Sampling does not extend beyond the first week of October because the distribution of fish within the river changes markedly when the water temperature drops below 58.0 OF (14.4 OC), usually during the second or third week of October. Sampling effort is based on equal time (normally 60 minutes of electrofishing) rather than equal distance at each sampling station. Most stations encompass an area larger than can be sampled in 60 minutes at the standard rate of movement, so subareas are selected within the station (see details on how to select subareas behlow). Starrett used a stratified sampling design, concentrating on the best fish habitat available within each station. "Best" means habitat likely to produce the 91 greatest diversity of species, including sport fish (crappies, sunfishes, and bass), more specifically, habitat with structure such as brush piles, stumps, undercut banks, riprap, pilings, and even boat docks at two locations (Rapp's Boat Yard and Detweiler Park). There are a few stations (e.g. Pekin) along the main channel where there is little or no structure, and Starrett also intentionally sampled unstructured habitat as he moved from one structure to another with the generator on (they could not shut off the field independently of the generator). The next items give particulars about the field methods, and are listed in the order in which they should be read. Item 3, water levels, is first among these because it is the basis for a "go" or "no go" decision. 3. Water levels. Fish are concentrated in permanent channels -and backwaters during low river stages and disperse widely during high stages. Starrett fished only when water levels were low and stable so results were obtained under consistent water level conditions. There are gaps in the data during years when water levels rose and electrofishing was discontinued. Gaps are preferable to introducing other .source of variation in catch per-unit effort. Check water levels by calling the NWS and COE or listening to the weather radio'before you electrofish. If the river is no more than 2.5 ft. above flat pool at stations above Starved Rock dam or 1.5 feet above flat pool at stations below Starved Rock and rising less than 6 inches in 24 hours at the station to be sampled that day, fish; otherwise, cease and desist (better luck next year). Another indication of low, stable water levels is when the wickets are up on the Peoria and La Grange dams and the Corps of Engineers refers to the river as being "in pool" or at "pool stage". 4. Survey the site. Look over the entire sampling site. If you cannot see the entire site when you first approach it, drive through the entire area before planning your sampling runs. 5. Plan the sampling runs. The netter and driver agree on a sampling plan that optimizes these objectives: (1) 15-min. or 30-min. sampling runs should cover entire site (i.e., if the site is over a mile long and has similar habitat throughout its length, don't concentrate all the sampling runs in the upstream end only), (2) concentrate on structure, but fish unstructured areas as you move from structure to structure (e.g., from one brushpile to another), and (3) plan a crossing at higher speed with the electric field on (crossing from one side to another), except in wide areas, such as Peoria Lake. Optimization means that you don't fulfill one objective to the exclusion oi the others. For example, if you have a long side channel with only 1 brushpile, you should fish that brushpile as long as you would in another area with multiple brushpiles, then go on to the unstructured habitat--don't spend 92 more time there because you are trying to fulfill objective (2), concentrating on structure. 6. Water quality measurements. Driver fills in the station description sheet, dipper makes the measurements within the area which will be covered by the first run. It's best to anchor the boat instead of trying to hold position with the outboard because the propeller and wave wash disturbs the water column and the sediments and may alter water quality. If an instrument does not work, spend no more than 15 minutes trying to fix it, then do the remaining water quality measurements and begin electrofishing. Turbidity has the lowest priority because it is redundant: it correlates well with Secchi disk visibility, and the Secchi always works! 7. Electrofishing. Remember that you are trying to duplicate what your predecessors did. Starrett and Sparks used the Queen Merrie with one dipper on the bow platform and 1 driver. The only kill switch was operated by the driver and it shut off the gasoline motor of the generator. When that happened, the dipper had to climb down, go to the back of the boat and restart the engine. The driver started the timing watch when the motor started and stopped it whenever the motor stopped. Because it was a nuisance to restart the generator motor, Sparks and Starrett left it on for the entire 15-minute or 30-minute run and when they made a rapid crossing from one side to another (crossings usually take much less than a minute, if you don't stun any fish). The .other reason the generator was, and still is left on, is that crossings sometimes shock fish that are not commonly taken otherwise, such as bi'gmouth buffalo, and for this reason the dipper looks backward and stays ready during the crossing. If a school of fish is shocked during a crossing, the boat circles back to pick them up, and the generator is left on to hold them. The entire process usually takes less than 5 minutes. Dipper starts the generator and steps on the mat (driver makes sure generator switch is up or generator won't start). Driver switches on field and records the starting electrode voltages, then switches off the field and moves the boat to the first site. Driver makes sure the dipper is ready, then switches on the field and makes the approach to the brushpile or shoreline. This approach procedure duplicates what Sparks and Starrett did when they fished without a field switch. Do not dip fish when you are checking the electrode voltage. In general, the dipper should stay on the mat and the driver should leave the field switch on during the entire run, to duplicate the Sparks-Starrett technique. Do not "sneak up" on brushpiles or switch the field on and off. Remember that the dipper had to start the generator (watch went on at the same time), run to the bow, climb up on the S93 platform and pick up his net,.,and then the driver would move into the brushpile or other structure. Fish from upstream to downstream at a pace so the fish are coming up around you instead of drifting rapidly downstream away from you. An exception is made when you approach a large brushpile in moderate to fast current. If you approach from the upstream side, fish are carried into the brushpile and downstream away from you before you can maneuver the boat around the brushpile to the downstream side. In this case, fish on the downstream side of the brushpile, rather than on the upstream side.. Ideal depth is less than 3 feet. Fish all around a structure until fish stop coming up, then move on. Back up and circle to pick up fish, if doing so will yield more fish or more different kinds of fish than you are getting right in front .of you. Dipper uses hand signals to show driver where the dipper wants to go. Go for the unusual specimen, even if it means you miss a few gizzard shad or carp. Remember that the addition of one new species to the sample provides more information than the addition of a few more individuals of the more abundant species. The driver should help the dipper flip the net to dump the fish. Wear gloves to prevent injury from spines. Break or clip spines to remove fish, if necessary. If the driver cannot free fish quickly from the net, the dipper should grab the second net and continue dipping. The driver's primary responsibilities are to maneuver the boat and assist the dipper, but he can also dip any fish he can reach. The long-handled dip nets should be used. Dipper inspects them frequently for tears in the mesh which would bias the sample against small fish. The driver should expect to be steering and shifting constantly, to maintain optimum speed and position for the dipper. Even at idle, the boat will move too fast for the dipper to recover fish efficiently. Shift in and out of nuutral for more precise speed control. Warn the dipper of overhanging branches and any fish he does not see. If the boat is parallel and close to shore or some obstruction, back the stern away from shore before going forward. If you try to turn and go forward, the stern will swing into shore 94 and strand the prop. Use the current to "ferry" the boat in the direction you want to go; i.e., you angle the bow slightly to the left into the current to cause the current to move you left--the greater the angle, the greater the pushing effect of the current. In electrofishing, you often end up pointing the bow in some direction other than your intended direction of travel. In some side channels, particularly in the upper river, the current moves you at about the right speed, so the driver keeps the bow pointed toward shore and the electrodes in 3 feet of water or less while the current carries the boat downstream. Occasionally, you will become hopelessly entangled or stranded. Shut everything off (including the timer), and Sextricate yourself by poling, with the dipper's assistance. The dipper is an active participant in maneuvering the boat and warding off obstacles, with the aid of his dip net. The dip net is also used as a depth gage for the driver's benefit--the dipper is often aware that the boat is in danger of being stranded before the driver is. Although the electrofishinc time at each station is 60 minutes it is possible to cover some of the smaller stations thoroughly in 45 minutes. Just record the actual time spent (it should be in blocks of 15 minutes). Do not go back over an area which has already been fished. Record electrode voltages and end time. The goal is for the dipper, driver, and equipment to function together like a maximally efficient predator, spending just the right time to capture fish from brush piles, but moving on when the catch rate drops, and moving at just the right speed to maximize shocking and capture in unstructured areas. 8. Safety. Both dipper and driver wear hearing protection, life jackets, and rubber boots. -Dipper also wears rubber gloves. Use standard hand signals for directions and for engine kill. Dipping large numbers of fish is exhausting, so driver and dipper should trade places at the end of 15 or 30 minutes. In addition to safety considerations, capture efficiency of a tired dipper is reduced. All participants in electrofishing must first read and sign the form which acknowledges their comprehension of the dangers involved. 9. Work up fish. One person handles the fish, the recorder keeps his hands and the data sheets clean. Although Starrett recorded body depths of carp and took scales from largemouth bass, we will not be doing either this year. Enter date and river mile on every sheet--sheets sometimes get separated. Note on the data sheet in the comment column which fish are archived or unidentified and preserved in forimilin. Unidentified fish should be identified as soon as possible and the correct name entered in the data sheet. New location records should be noted (check dot maps in Fishes of Illinois) and the specimen archived for the Survey 95 ichthyological collection. Work up any rare or endangered species or game fish in distress first, photograph the rare species, and return them to the water as quickly as possible. Until the codes are familiar, write out common names of fishes and common descriptions of lesions. However, do use standard terminology for lesions, and double check terminology in the evening on the houseboat. When doing groups of similar-sized fish, record the length of the largest and smallest member of the group, the number of individuals in the group, and the group weight. Wet the balance pan and check the zero adjustment before weighing the first fish. Empty water and slime out of the balance pan frequently, to avoid errors. Interpolate weights of small fish to the nearest 0.025 lb., i.e., a fish between 0.2 and 0.3 lbs. might be 0.220, 0.225, 0.250, 0.275, or 0.300. For fish above 1 lb., round off to the nearest 0.1 lb. 10. Complete the data sheets. Number the fish data sheets, make sure each sheet has date and location at the top. Draw the sampling runs on the ýxerox copy'of the site, taken from navigation charts or USGS maps. Also note number of brushpiles and crossings. Use the standard symbols shown in the example on back of the. site description sheet. For each run, the electrode time should be recorded. Remember that the electrode timer reads in 100ths of an hour, not in minutes. Fifteen minutes is 0.25 on the clock and half an hour is 0.50. The clock runs when someone is on the mat and the electrode switch is up, even if the generator is turned off! Hence you inadvertently run the clock if the dipper stays on the mat as you run from one substation to another. To prevent this, the driver should switch off the field switch whenever he switches off the generator. Place field data sheet on top, site map next, then the fish data sheets in order by page number. Staple package together and place in field data box. 11. Specimens. Place any unidentified or archival fish in formalin. The specimens from each site should go into their own jar, with a label written in no. 2.5 pencil on Rite-in-the-Rain paper giving the date, location, and collector. The label goes in the jar with the fish. Concentrated formaldehyde should be diluted 1:4 with river water. Remember that the disposition of the fish (preserved, buried) should be written on the fish data sheets in the comments column, for the annual report on collecting activities which we submit to the DOC. Al:o note which fish you took pictures of. 12. Dead fish. Use the shovel to bury dead fish, and note disposition on fish data sheet for the DOC report, as mentioned in item 11. 96 Appendix B. Fish species collected during the Long-Term ELectrofishing Survey of the Illinois Waterway, 1957-1993 . Commron names preceded by an asterisk indicate species that were colLected from 1989 through 1993 during federal aid project F-1O1-R. Habitat Association b Family Name Commnon Name Scientific Name (B = bottom. blank = pelagic) Lepisosteidae *Longnose Car Leoisosteus osseus *Shortnose Gar Lepisosteus platostormus *SPotted Car Lepisosteus oculatus Ami idae Bowf in Amia colva Angui IIidae American Eel Anguitta rostrata Ctupeidae *Gizzard Shad Dorosoma cepedianum *Skiplack Herring ALosa chrysochloris *Threadf in Shad Dorosorna petenense Hiodontidae *Goldeye Hiodon atosoides *Mooneye Hiodon tergisus Salmonidae Rainbow Trout Cncorhynchus yis Esocidae *Grass Pickerel !Esox americanus Northern Pike Esox Lucius Cyprinidae *Bigmouth shiner Hybopsis dorsafis *Bluntnose Minnow PimephaLes notatus B *Bullhead Minnow Pimephates viix *Carp Cyprinus cari *Carp x Goldfish B Cypri nus carpio X B Carassius auratus *Central Stoneroller Campostoma anomalum B Commron Shiner Luxiti us cornutus' Creek Chub Semotilus atromaculatus *Emerald Shiner Notropsatherinoides *Fathead Minnow Pi-mephales pr'orelas Ghost Shiner Notropsbuchanani *Golden Shiner Notemionscrysoteucas *Goldfish. Carassius auratus B Hornyhead Chub Nocomis biguttatus Pugnose Minnow Qpsopoeodus emiliae *Red Shiner Cyprinella lutrensis Redfin Shiner Lythrurus umbratilis Ribbon Shiner Lythrurus fumeus *River Shiner Notropsblennius *Sand Shiner Notropsludibundus Spotf in Shiner Cyprinella spiloptera *Silver Chub Macrhybopsis storeriana B Silverband Shiner Notr shumardi Silverjaw Minnow Ericvmba buccata Silvery Minnow B Hybognathus nuchalis B *Spottail Shiner Notropshudsonius Steelcolor Shiner Cyprinetla whippLeif Striped Shiner LuxiLus chrysocephalus Suckermouth Minnow Phenacobius mirabilis B catostomidneIctichus rvnrinet[us Black Redhorse Moxostoma duouesnei 97 Continued. Habitat Associationb Family Name Conrnon Name Scientific Name (B = bottom, blank = Pelagic) Catostomidac *Golden Redhorse Moxostoma erythrurum B *Hjghfin Carpsucker Caroiodes velifer B *QuiLlback Caroiodes, cyprinus B *River Carpsucker Carpiodes carpioo B *River Redhorse Moxostoma carinatum B *Shorthead Redhorse Moxos tomna macrotepidoturn B Silver Redhorse Moxostoma anisurum B *Smaltmouth Buffalo Ictiobus bubalus B *White Sucker Catostomnus comnersoni B Ictaluridae *Black BulLhead Ameiurus melas B Blue Catfish Ictalurus furcatus B *Brown Bullhead Ameiurus nebulosus B *Channel Catfish Ictaturus punctatus B *Flathead Catfish Pylodictis otivaris B Freckled Madtom Noturus nocturnus B Tadpole Madtom Noturus gyrinus '. B White Catfish Ameiurus catus B *Yellow Bullhead Ameiurus natalisB Percops idac Trout-~Perch Percor isomiscomaycus B Fundul idac *Bl[ackstripe.Topminnow Fundutus notatus PoeciIi idac Mosqui tof ish Gombusia affinis Ather inidac *Brook Silverside Labidcsthes siccutus Moron idac *Striped Bass x Morone saxatilis x White Bass M. chrysocs Striped Bass Morone saxatilis *White Bass Morone chrysops *Yellow Bass Morone mississippiensis *White Perch Morone americana Cent rarch idae *Black Crappie Pomoxis nigrornaculatus *BluegiLl LeEoomis macrochirus *Green Sunfish Lepomis cyanellus *Green Sunfish x Lepomis cyanellus x Bluegill L. macrochirus Green x Lepomis cyanellus x Orangespotted Sunfish L. humilis *Largemouth Bass Micropterus salmoides *Longear Sunfish Lepomis, Otis *Orangespot ted Sunfish Lepomis humitis Orangespotted Sunfish Lepomis humiIi s x x Bluegill L. macrochirus Green Sunfish x Lepomis cvyanellus x Pumnpk inseed L. gibbosus *Pumpk inseed Leom isAgi bbosus *Redear Sunfish Lepornis microlophus *Rock Bass Amblop ites rupestris *Smatlmouth Bass M!ic~ropterus dotomieu *Spottedi Sunfish *Warmouth Lepomis gutosus *White Crappie Pomoxis annularis 98 Continued. Habitat Associationb Family Name Common Name Scientific Name (B = bottom, blank pelagic) Pcrcidae Bluntnose Darter Etheostoma chlorosomum B Johnny Darter Etheostoma nigrum B *Log perch Percina caprodes B *Sauger Stizostedion canadense *Walleye Stizostedion vitreun *Yellow Perch Perca flavescens -Sciaenidae *Freshwater Drum Aplodinotus grunniens B -a- -aScientific names are from Page and Burr (1991). Based on behavioral descriptions from Pflieger (1975) and cormunications with INHS fisheries biologists. 99 Appendix C. Publications, reports, and presentations which (Job 8) resulted, wholly or in part, from research conducted on The Long-Term Illinois River Fish Population Monitoring Program (funded under Federal Aid in Sport Fish Restoration Act, P.L. 81-681, Dingell-Johnson-Wallop-Breaux), project F-101-R, from 1989 to 1993. I. Publications. Lerczak, T.V. 1992. A long-term electrofishing survey of the Illinois River documents change. The Newsletter of the Illinois Chapter of the American Fisheries Society 6:11-12. Lerczak, T.V., K.D. Blodgett, and R.E. Sparks. In Preparation. Voltage measurements of a fish electroshocking field in three dimensions. Illinois Natural History Survey Aquatic Ecology Technical Report. , Lerczak, T.V., R.E. Sparks, and K.D. Blodgett. 1992. A long-term electrofishing survey shows evidence for improved conditions on the Upper Illinois Waterway. Abstract. Transactions of the Illinois State Academy of Science 85(Supplement):55. Lerczak, T.V., R.E. Sparks, and K.D. Blodgett. 1992. The long-term Illinois River fish population monitoring program. Illinois Natural History Survey Aquatic Ecology Technical Report 92/9. 51 PP. Lerczak, T.V., R.E. Sparks, and X.D. Blodgett. 1993. The long-term Illinois River fish population monitoring Program annual report. Illinois Natural History Survey Aquatic Ecology Technical Report 93/3. 76 pp. Lerczak, T.V., R.E. Sparks, and K.D. Blodgett. 1993. A long-term electrofishing survey shows evidence for improved conditions on the Upper Illinois Waterway. Abstract. Page 5 in American Fisheries Society Abstracts from the Joint 31st Annual Meeting of the Illinois Chapter and the 25th Annual Meeting of the Iowa Chapter. 41 pp. Lerczak, T.V., R.E. Sparks, and K.D. Blodgett. 193. A long-term electrofishing survey shows evidence for improved conditions on the Upper Illinois Waterway. Abstract. River Almanac, February issue, p. 1. 101 Raibley, P.T., K.D. Blodgett, K.S. Irons, T.M. O'Hara, and R.E. Sparks. 1993. A study of Illinois River largemouth bass. Abstract. Page 8 in American Fisheries Society Abstracts from the Joint 31st Annual Meeting of the Illinois Chapter and the 25th Annual Meeting of the Iowa Chapter. 41 pp. Raibley, P.T., K.D. Blodgett, and R.E. Sparks. 1993. The importance of side channels as fish habitat in La Grange Pool, Illinois River. Abstract. Page 3 in American Fisheries Society Abstracts from the Joint 31st Annual Meeting of the Illinois Chapter and the 25th Annual Meeting of the Iowa Chapter. 41 pp. Raibley, P.T., K.D. Blodgett, K.S. Irons, T.M. O'Hara, and R.E. Sparks. 1993. Abstract. A study of Illinois River largemouth bass. River Almanac, February issue, p. 1,3. Sparks, R.E. 1994. IMaking predictions that change the future: forecasts and alternative visions for the Illinois River. Pages 80-100 in H. Korab, ed. Proceedings 1993 Governor's Conference on the Management of the Illinois River System. Special Report No. 20. Water Resources Center, University of Illinois, Urbana. 195 pp. Sparks, R.E., and K.D. Blodgett. 1991. Long-term Illinois River fish population monitoring program. Illinois Natural History Survey Aquatic Ecology Technical Report 91/10. 97 pp. Sparks, R.E., K.D. Blodgett, F.S. Dillon, and T.V. Lerczak. 1992. Does ammonia limit recovery of the Illinois river? Abstract. Illinois Water Pollution Control Association, Thirteenth Annual Conference. Sparks, R.E., K.D. Blodgett, and T.V. Lerczak. 1992. The relationship between long-term monitoring and short-term problem assessment techniques in management of large river-floodplain ecosystems. Pages 9-35 in North American Benthological Society, 5th Annual Technical Information Workshop: Biological Assessments in Large Rivers. 102 Sparks, R.E., and T.V. Lerczak. 1993. Recent trends in the Illinois River indicated by fish populations. Submitted as part of the Flowing Water Ecosystems Section in the Critical Trends Assessment Project CTA1. Illinois Natural History Survey Center for Aquatic Ecology Technical Report 93/16. 34 pp. II. Unpublished Reports. Irons, K, and K.D. Blodgett. 1993. Annual report for bioresponse monitoring of habitat rehabilitation and enhancement projects for Peoria Lake and Lake Chautauqua (May 1993). Prepared for U.S. Corps of Engineers, Rock Island District. Illinois Natural History Survey, Long Term Resource Monitoring Program Field Station, Havana, IL. Raibley, P.T., J.R. Haryey, and K.D. Blodgett. LTRMP fisheries parameters for La Grange Pool, Illinois River, 1990. Annual report submitted to the U.S. Fish and Wildlife Service Environmental Management Technical Center, Onalaska, WI. 48 pp. Sparks, R.E., and K.D. Blodgett. 1990. Electrofishing survey on the Illinois River. Annual report to the Illinois Department of Conservation (F-101-R-1). Illinois Natural History Survey, Havana, IL. III. Technical Papers (presenter underlined). Lerczak, T.V., R.E. Sparks, and K.D. Blodgett. A long- term electrofishing survey shows evidence for improved conditions on the Upper Illinois Waterway. American Fisheries Society Abstracts from the Joint 31st Annual Meeting of the Illinois Chapter and the 25th Annual Meeting of the Iowa Chapter, Bettendorf, IA, 16-18 February 1993. Lerczak, T.V., R.E. Sparks, and K.D. Blodgett. A long- term electrofishing survey shows evidence for improved conditions on the Upper Illinois Waterway. Contributed paper presented at the Illinois State Academy of Science Annual Meeting, Springfield IL, 16 October 1992. 103 Raibley, P.T., K.D. Blodgett, K.S. Irons, T.M. O'Hara, and R.E. Sparks. A study of Illinois River largemouth bass. American Fisheries Society the 25th Annual Meeting of the Iowa Chapter, Bettendorf, IA, 16-18 February 1993. Sparks, R.E., K.D. Blodgett, F.S. Dillon, and T.V. Lerczak. Does ammonia limit recovery of the Illinois River? Illinois Water Pollution Control Association, Thirteenth Annual Conference, Bloomingdale, IL, 10-12 March 1992. IV. Poster Presentations. Sparks, R.E., and K.D. Blodgett. Long-term electrofishing program on the Illinois River. 22nd Annual Meeting of the Mississippi River Research Consortium, La Crosse, WI, 19-20 April 1990. Sparks, R.E., and K.D. Blodgett. "Long-term electrofishing program on the Illinois River. Midwest Fish and Wildlife Conference, Springfield, IL, 3-6, December 1989. V. Popular Presentations. Blodgett, K.D. The biology of the Illinois River - yesterday, today, and tomorrow. Forest Park Nature Center, Peoria, IL, 21 March 1989. Raibley, P.T. The Long Term Resource Monitoring Program and Illinois River fisheries. Havana Optimist's Club, 27 March 1991. Lerczak, T.V. Illinois River Issues. Presentation to Mid- County Jr.-Sr. High School Students aboard "Spirit of Peoria" River Boat, 23 October 1992. Lerczak, T.V. Seminar on Illinois River environmental issues. Conducted for Biology 140 (Human Ecology) at Spoon River College, Havana, 24 February 1993. 104 VI. Workshop Organization/Participation. Sparks, R.E., T.V. Lerczak, and K.D. Blodgett. The relationship between long-term monitoring and short-term problem assessment techniques inmanagement of large river-floodplain ecosystems. Technical Information Workshop Notebook: Biological Assessment in Large Rivers. North American Benthological Society Annual Meeting, Louisville, KY, 26-29 May 1992. VII. Contributions to Media Publications. Blodgett, K.D. Interviewed by Beth Walsh about floods' impacts on river biota for article in the Peoria Journal Star on 6 August 1993. Blodgett, K.D. "Exotic Finds Concern Scientists", The Fulton Democrat, 7 July 1993., Blodgett, K.D. Interviewed by Tamara Aldus for feature article on the Illinois river in the Pekin Daily Times on 22 December 1992. Blodgett, K.D. Provided information to and interviewed by Ms. Marnie Oberle for a series entitled "A Way of Life - the Illinois River," Peoria Journal Star, Peoria, IL, 18 August 1992. Blodgett, K.D. Interviewed for 'feature article on the Illinois River by Ms. Tamara Aldus, Pekin Daily Times, Pekin, IL, 15 June 1992. 105