IMPINGEMENT LOSSES AT THE D. C. COOK NUCLEAR PLANT DURING 1975-1979 WITH A DISCUSSION OF FACTORS RESPONSIBLE AND RELATIONSHIPS TO FIELD CATCHES by Nancy Thurber and David Jude Special Report No, 104 of the Great Lakes Research Division The University of Michigan Ann Arbor, Michigan August 1984 Introduction • 1 Methods • • • 2 Results and Discussion. . . • • • . • 4 Species Composition • .> « 4 Seasonal Abundance • 12 Impinged Fish Compared with Field-Caught Fish • 17 Plant Effects « • 21 Literature Cited « 23 Appendixes 1-75 • » <> • • .A-l iii LIST OF FIGURES Fig. 1. Ntimber of alewives impinged and caught annually during field sampling at the Cook Plant, southeastern Lake Michigan, 1975-1979. ... 19 Fig. 2. Seasonal abundance of impinged and field-caught alewives at the Cook Plant, southeastern Lake Michigan, 1975-1979 20 LIST OF TABLES Table 1. Common and scientific names of field-caught and impinged fish species collected during 1975 at the Cook Plant, southeastern Lake Michigan 5 Table 2. Number of fish impinged on Cook Plant traveling screens during 1975 6 Table 3. Estimated number of fish impinged on Cook Plant traveling screens during 1976 7 Table 4. Estimated number of fish impinged on Cook Plant traveling screens during 1977 8 Table 5. Estimated number of fish impinged on Cook Plant traveling screens during 1 978 9 Table 6. Estimated number of fish impinged on Cook Plant traveling screens during 1979 10 Table 7. Monthly water volume pumped through the condenser circulating water system of the Cook Plant, southeastern Lake Michigan, from 1975 to 1979 12 Table 8. Frequency of occurrence by year of fish species impinged at the Cook Plant, southeastern Lake Michigan, 1975-1979 13 Table 9. Percent change in mean number of fish impinged and field-caught during two-unit operation (1978, 1979) over mean number impinged and field-caught during one-unit operation (1975, 1976) 22 iv INTRODUCTION The Donald C. Cook Nuclear Plant is a 2,200 MW utility on the southeastern shore of Lake Michigan near Bridgman, Michigan. Unit 1 (1,100 MW) , which began operation in 1975, requires 2.7 x 10^ liters/min cooling water, while Unit 2, also 1,100 MW, uses 3.6 x 10" liters/min. Though Unit 2 began operation in 1978, sustained pumping for a month or longer at full capacity did not occur until 1979. Cooling water enters through three intake cribs located 686 m offshore in 7.3 m of water, and heated water (with a calculated maximum AT of 21*^0) is discharged through two slot- jet discharge structures located 366 m offshore in 5.5 m of water. With two units operating, water velocity at the intake crib is 0.4 m/s. Maximum water velocity is 1.8 m/s within the intake pipe. To prevent erosion and scour, a riprap bed (approximately 6 ha) of crushed limestone 0.1-1.0 m in diameter was deposited around the intake and discharge structures during plant construction. Within the screenhouse, trash bars 6.6 cm apart prevent large debris from entering the forebay. Within the forebay, vertical traveling screens impinge trash and fish too large to pass through the 9.5-mm-mesh screens. Smaller or- ganisms (mostly fish fry, larvae and eggs, and zooplankton) are entrained with the cooling water and pass through the condensers. In addition to the terms "impingement" and "entrainment ," "entrapment" in this report refers to fish entering the forebay through the intakes. Impingement is distinguished from entrapment because of the possibility that not all fish which enter the forebay are eventually impinged. This report contains annual estimates of impingement losses for the Cook Plant and species composition of impinged fish and compares them with compo- sition of field-caught fish for 1975-1979. Also discussed are seasonal and yearly trends in fish abundance, environmental and plant operation effects on rates of fish impingement, and possible effects of high impingement rates on local abundance of certain fish species. METHODS Fish and debris collected from the traveling screens were separated by Cook Plant personnel. All fish were bagged, labeled with date and time, and then frozen. University of Michigan personnel collected and weighed all frozen fish; a 24-h sample was saved every fourth day and sorted by species and size. When many fish of the same size were collected in fourth-day samples, a subsample of up to 30 fish was randomly selected and the remaining fish were weighed and discarded. All saved fish were measured to the nearest mm (total length), weighed to the nearest g, sexed, and examined for presence of food, condition of gonads, presence of disease, or physical damage. Both fourth-day samples (number and weight of fish) and weight of fish impinged on interim days were used to estimate total monthly impingement by species. Percent species composition by weight of fourth-day samples was used to partition the actual monthly weight of fish impinged into weight estimates by species, according to the formula: ^w "" (S^/^w)'^w where : E^ = Estimated monthly weight of fish impinged for a given species; S^ = Monthly weight of fourth-day impingement samples, for a given species; P^ = Monthly weight of fourth-day impingement samples, all fish combined; T^ = Total monthly weight of all fish impinged (includes fourth-day and interim samples). Number of fish impinged per month was then estimated using: En " E„/r where: E^ = Estimated total number of fish impinged each month for a given species; W = Mean weight per fish of a given species, calculated for each species from number and weight of fish of each species impinged in fourth-day samples for a given month. Offshore standard-series field samples were collected by gill net and bottom trawl from four stations: 6- and 9-m stations at the Cook Plant and 6- and 9-m stations at Warren Dunes State Park, about 11 km south of the Cook Plant. Fish were seined from the beach zone at two stations north and south of the Cook Plant, and one station at Warren Dunes State Park. Gill nets 160 x 1.8 m were set at offshore stations once per month for approximately 12 h during daylight and 12 h during the night. Catch was ad- justed to catch per 12 h to standardize data. Nets were composed of 12 panels of netting as follows: 7.6-m sections of each of the following mesh sizes (bar measure) - 1.3 cm, 1.9 cm, and 2.5 cm; 15.2-m sections of mesh sizes 3.2-7.6 cm by 0.6- cm intervals; and a final 15.2-m section of 10-cm mesh. All gill nets were set parallel to shore on the bottom. Duplicate, 10-min bottom tows were taken monthly both day and night at off- shore stations, using a semi-balloon, nylon trawl having a 4. 9-m headrope and a 5.8-m footrope. The body and cod end were composed respectively of 1.9-cm and 1,6-cm bar mesh, while the cod end interliner was 0.7-cin bar mesh. All trawl hauls were made at an average speed of 5 km/h, i.e., at a fixed rpm using the University of Michigan's R/V MYSIS. The trawl was towed parallel to shore following the 6- and 9-m depth contours; one replicate was taken north to south and the other south to north. Beach seining was usually conducted during periods of reduced wave height using a nylon seine 38 x 1.8 m with a 1.8 x 1.8 x 1.8-m bag; the entire seine had 0.64-cm bar mesh. The seine was first stretched perpendicular to the shoreline and then pulled parallel to shore a distance of 61 m. Duplicate, non- overlapping samples were taken in this manner both day and night once each month at beach stations. The seine was pulled against the current or southerly when no current was detectable. When the current was too strong to seine against, seining was done with the current. Field-caught fish were processed in the same manner as impinged fish. For a more detailed discussion of field-sampling methods, see Jude et al. (1979). Common and scientific names of fish discussed in this paper are presented in Table 1. RESULTS AND DISCUSSION Species Composition The number of fish impinged annually at the Cook Plant ranged from 64,279 fish in 1977 to 615,397 fish in 1978 (Tables 2-6). 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C »- ^ JC ^ C 9 £ 3 ♦- — C 3 E (0 c n 9 ♦^ N a 3 C 9 C C O C £ « TJ ♦* — o J£ 9 U 3 «« 9 © . L. jC ■« N C £ 6 t- ^ « — « « C 9 9 9 0-^90-^ 9 ^ ao « t. £ 3 o «£ - t.£- 0£ 9 9 E- 9- J- £ c < (/) > a H* I/ICDO QSZ -t 31 O -I O 00 1/1 Z "3 U o oe -i ^ O (J (/> l/> 01 QC -i CO OO 3 Ik 10 of the total for any 1 yr (Tables 2-6). Except for alewife, which was always the most abundant species, ranks of the other species varied from year to year. In making comparisons among years, note that both units were operating during 1978 and 1979, so these years should be considered separately from 1975-1977. Compared to other years, fish impingement was exceptionally low during 1977 for the five most abundant species, but most dramatically for alewives. Alewives showed a marked decrease in number of adults impinged in June-August, a pattern which was also true for rainbow smelt but was not as clear for spot- tail shiner, trout-perch, or yellow perch. It is not at all clear why 1977 was such an exceptional year. Number of fish impinged in 1977 did not correlate with abundance in field catches, which were relatively high (Appendixes 1-5); the plant was operating at full capacity during the months when fish were most abundant inshore (Table 7); and inshore water temperatures and patterns of upwelling were not unusual during 1977 (Appendixes 6-10). Slimy sculpin was most abundant in impingement samples in 1975 and 1976. Because sculpin colonize the riprap in preference to nearby sand (Dorr and Jude 1980), high impingement rates during 1975 and 1976 may have resulted from rapid colonization during these years. Stabilization of the sculpin population after 1976 may have resulted in fewer sculpin being impinged. Few bloaters were impinged in 1975 (49 fish) and 1976 (63 fish), while over 500 were impinged in 1977 and over 23,000 in 1978. Increased impingement of this species apparently reflected an increase in the lake-wide bloater popula- tion, as was indicated by our field catches and those of others (Crowder et al. 1981). 11 Table 7. Monthly water volume (in millions of cubic meters) pumped through the conaenser circulating water system of the Cook Plant, southeastern Lake Michigan from 1975 to 1979. Unit 1 was operational since January 1975, Unit 2 since February 1978. Month 1975 1976 1977 1978 1979 January 64.9 85.7 24.9 1 14.4 273.2 February 75.6 88,5 54.5 121. S 275.2 March 117.7 103.6 118.7 207. 1 281 .9 Apr i 1 121 .0 76.2 114.5 115.9 173.7 May 125.8 86.0 97.4 90.4 100.5 June 122,8 122.7 93.5 194.4 33.3 July 81 .7 120.5 103.6 224.5 227.7 August 128.7 130.5 123.3 249.6 324.6 September 125.2 109.0 97.7 277.6 314,3 October 132.2 137.9 112.4 298.8 245.9 November 90.6 126.2 76.3 202.8 107.3 December 111.6 105. 1 120.9 272.5 118.0 Annual total 1298. 1292. 1138. 2370. 2476. During 1975-1979, 53 species were impinged. Twenty species were impinged every year for all 5 yr of the study (Table 8), while 17 species were impinged 2 years or less and were considered rare. Seasonal Abundance Number of fish impinged per month at the Cook Plant varied seasonally (Tables 2-6). Most fish were impinged April through October; few were impinged during winter. Each year (1975-1979) was characterized by a month of peak im- pingement during June or July; often a secondary peak in October; and in 1975 and 1979, a secondary peak in April. In 1975, fish impinged in April were 89% alewives and 5% slimy sculpins by number; in 1979 fish impinged in April were 57% spottail shiners, 21% rainbow smelt, and 11% slimy sculpin. Warming of inshore water during April of both 1975 and 1979 was characterized by a narrow band of warmer water within 2 km of shore, which was separate and distinct from colder, offshore water. Fish seek- ing warm water may have congregated within this narrow band. High fish im- 12 Table 8. Frequency of occurence by year of fish species impinged at the Cook Plant, southeastern Lake Michigan, 1975-1979. 5 years 4 years 3 years 2 years 1 year Al ewi f e Black bul 1 head Black crappie Bloater Burbot Channel catf ish Coho salmon Gizzard shad Johnny darter Lake trout Longnose sucker Ni nespine st ickl eback Rainbow smelt Rock bass SI imy sculpin Smal 1 mouth bass Spottai 1 shiner Trout-perch White sucker Yel low perch Bluegi 1 1 Brown trout Common carp Chinook salmon Green sunfish Largemouth bass Longnose dace Pumpkinseed Rainbow trout Central mudmi nnow Lake chub Mottled sculpin Northern pike Shorthead redhorse White crappie Yel low bul 1 head Brown bul 1 head Chestnut lamprey Deepwater sculpin Emerald shiner Freshwater drum Goldf i sh Lake chubsucker Lake whi tef ish Si 1 ver redhorse Golden shiner Grass pickerel Logperch Pirate perch Oui 1 Iback Sea lamprey Spotted sucker Tadpole madtom pingememt rates during this time may have resulted from increased activity and movement of fish, and higher densities of fish inshore. Over 80% of the fish impinged during June and July 1975-1977, and 1979 were adult alewives (Tables 2-6). During these months, alewives move inshore to spawn, and as in April, the increase in activity and density of fish apparently resulted in increased impingement of this species. July 1978 was an exception to this pattern, as the species composition of impinged fish was very different (Table 5). Over 455,000 fish were impinged, the most fish impinged during any 1 mo of the 5-yr study period. However, only 34% of the fish impinged during July 1978 were alewives. From the large number of fish impinged, it is clear that the unusual species composition was not due to a scarcity of alewives, but rather the extraordinary abundance of several other species. Spottail shiners were nearly as abundant (33%) as alewives. 13 Other abundant species were trout-perch (17%), rainbow smelt (6%), bloater (5%), and yellow perch (5%). In July 1978, three upwellings occurred which were exceptional in their intensity (Appendix 9). On each occasion, water tenr- peratures dropped 5-12*^0 and upwelling persisted 3 or 4 days. Upwelling increases fish activity and causes many fish to move shoreward seeking preferred warmer temperature (Wells 1968, Emery 1970, Jude et al. 1979). Rainbow smelt and bloater, which prefer cold water (Wells 1968, Jude et al. 1979), may accompany cold, upwelled water inshore. Species composition of fish impinged during October was variable, but spot- tail shiner, trout-perch, and YOY (young-of-the-year) alewives, yellow perch, and smelt, were usually abundant. In 1976 there was no increase in number of fish impinged in October, nor was there as sharp a decrease in impingement rates during August and September as occurred in the other 2 yr of one unit operation (Tables 2-4). In 1976, August water temperatures were extraordinarily high (Appendix 7), and there was no upwelling during August to October. Instead, water temperatures declined gradually during September and October. The homo- geneity and gradual change in water temperature may have led to a gradual change in species composition, with no abrupt shifts of fish abundance in the inshore area, or abrupt increase in fish activity. As indicated by seine data (Appendixes 11-15), strong alewife year classes were produced in 1976 and 1979. This may indicate good survival and growth, as alewives attained a size (50 mm) at which they were retained by traveling screens as early as August in 1976 and 1979 (Appendixes 17, 20), whereas YOY were first impinged in September in other years (histograms for alewives, spot- tail shiners, trout-perch, yellow perch, and rainbow smelt impinged during 1975 through 1979 appear in Appendixes 16-40). Large YOY year classes contributed to 14 the relatively large number of fish impinged in August and September 1976 and in September 1979 (Appendixes 17, 20). The biology of individual species is an important factor determining seasonal patterns in impingement rates. Alewives may be entrapped by plant intakes in large numbers just as inshore waters begin to warm in April. Alewife movement and density inshore may be determined by the differential rate of warming of inshore and offshore waters. Peak impingement of alewives during 1975-1979 usually occurred during June or July, when alewives moved inshore to spawn. In late summer or autumn there was an increase in impingement of YOY alewives, which by this time were large enough (>^ 50 mm) to be retained by the traveling screens (Appendixes 16-20 )• Spottail shiners prefer shallow depths and warm water (Jude et al. 1979, Wells 1968), and these preferences affected spottail shiner impingement rates. Imping€iment of spottail shiners increased in March and April as spottails moved shoreward seeking warmer, inshore water. In May and June, impingement of spottail shiners was low; field data indicated spottail shiners were mostly inshore of the intake depth (9 m) . Peak spawning for spottail shiners occurs in July (Jude et al. 1979), and they also begin their post-spawning migration from the area this month. Large late summer impingement of spottail shiners in 1978 and 1979 was probably due to increased activity and offshore movement of spottail shiners during these months. Impingement of spottail shiners in October was usually due to offshore migration of adults and, in 1975-1977, of YOY (Appendixes 21-23), which by this time were large enough to be retained on the traveling screens. A few spottails remained inshore all winter. Winter impingement rates seemed dependent on water temperature, increasing when temperature in the area rose to 3 "^C or above, but there were exceptions. 15 Besides water temperature, winter impingement of spot tail shiners was probably affected by attraction to the plxjme, winter storms, and ice cover • Numbers of trout-perch impinged began to increase in April but did not become high until July. At this time, trout-perch move inshore for spawning, which continues throughout summer. Impingement of trout-perch during summer was spotty rather than continuous, and appeared to coincide with upwelling or storms. In 1978 and 1979, trout-perch impingement rates remained high through October; in 1975-1977, impingement losses tapered off during late summer and rose again in September or October as trout-perch migrated offshore. A few trout-perch were impinged during winter. Impingement of yellow perch increased slightly in March and April, as in- shore water temperatures warmed in the spring. Except for 1975, peak impinge- ment of yellow perch occurred during July through September. Because this was past the spawning season for yellow perch, their mid-to-late summer abundance evidently reflected post-spawning migration into the Cook area after spawning in other areas of the lake (Jude et al. 1979, Dorr 1982). There is some evidence that impingement of yellow perch during summer increased sharply after storms. YOY yellow perch were first impinged in September and continued to be impinged during fall and winter, apparently remaining inshore, (Appendixes 31-35). During 1975-1979, peak impingement of rainbow smelt occurred in spring, mostly during April and May. During these months, rainbow smelt migrate through the area as they move inshore to spawn (Jude et al. 1979). Because adult rain- bow smelt prefer cold water (Jude et al. 1979, Wells 1968), they move offshore during months of warm water temperature. Impingement of rainbow smelt during the summer usually occurred when cold, upwelled water allowed smelt to move 16 shoreward. In 1978 and 1979 large numbers of rainbow smelt were impinged during summer. YOY smelt were impinged in September and October (Appendixes 36-40). Impinged Fish Compared with Field-Caught Fish In general, the most abundantly impinged species were also most abundant in field catches (Appendixes 1-5). Exceptions were bloater and sculpin, which were impinged in much higher numbers than would be predicted from field catches. Bloater field abundance increased dramatically during the last 2 yr of the study. Sculpins preferentially inhabited the riprap around the intake struc- ture; preference for hiding in dark places and nocturnal activity patterns probably increased their susceptibility to entrapment. Alewives and spottail shiners proportionally comprised a somewhat higher percentage in field catches than in impingement (70% and 20%, respectively, of all fish caught in standard series fishing 1975-1979). For alewives, the difference in proportion was primarily due to large numbers of seined YOY (Appendixes 41-45). Young-of-the-year alewives apparently were most abundant inshore of the intakes, and during most of the season they were too small (< 50 mm) to be impinged on the traveling screens (histograms for alewives, spottail shiners, trout-perch, and yellow perch caught in standard-series field sampling during 1975 through 1979 appear in Appendixes 41-65). Trout-perch, yellow perch, and rainbow smelt each constituted 3% or less of the total field catch. These species often were most abundant in the area during upwelling, storms, or other conditions of weather and water temperature which not only increased fish density but also activity, and thus the chance that these fish would be entrapped (Lifton and Storr 1977). Though in the most broad terms, over-all species composition of impinged fish was determined by local abundance of each species, there were exceptions. 17 and fluctuations in impingement rates seasonally or among years often showed little correlation with changes in field abundances of that species. As an example, yearly abundance of impinged and field-caught alewives (Fig. 1) were uncorrelated, and seasonal patterns of alewife impingement were not always predictable from seasonal alewife field abundance (Fig. 2). The lack of cor- relation portrayed for alewives was true of other species as well. The dif- ferences may be partially explained by limitations of field sampling, because each gear type only samples one 24-h period each month, but this explanation alone is inadequate. Young- of- the-y ear fish were often more abundant in field catches than they were in impingement samples, because they were most likely to be inshore of the intakes and because they were too small to be impinged. Disproportionally high entrapment may occur when fish are attracted to the riprap or the intake structure; or when weather or water temperature changes increase horizontal or vertical movement of fish, or decrease fish avoidance of the intake structure or current. Sculpin spp. and yellow perch are examples of fish which are attracted to the riprap and apparently prefer that substrate over the flat sand bottom which characterizes field sampling stations. Sculpins, in particular, as confirmed by project divers (Dorr and Jude 1980), reside on the riprap almost exclusively. Divers also observed aggregations of yellow perch around the intakes (Dorr and Jude 1980), and yellow perch, sculpins, johnny darter, spottail shiners, and ninespine stickleback may use the riprap as a spawning substrate (Dorr 1982). Trout-perch and rainbow smelt, however, are examples of fish which are not normally attracted to the intakes or riprap. Even when present inshore, they may not be impinged in large numbers unless weather or water temperature changes occur. Entrapment of all fish, even those which normally are attracted to the 18 350 U- O 300 O O 5 250 CO LL. 200 g 150 CD 3 100 50 IMPINGED FISH n FIELD-CAUGHT FISH 1975 1976 1977 1978 YEAR 1979 Figure 1 . Number of alewives impinged and caught annually during field sampling at the Cook Plant, southeastern Lake Michigan, 1975-1979. 19 o o o X w UJ e> 80 - 60 40 20 O q: UJ CD Z 1975 1977 1976 156016 1978 IMPINGED FIELD- CAUGHT 154201 108157. i 1979 8 O O O X en Li. O < O I O AMJJASON AMJJASON AMJJASON MONTH Figure 2. Seasonal abundance of impinged and field-caught alewives at the Cook Plant, southeastern Lake Michigan, 1975-1979. 20 intakes, increases when fish activity increases. Spawning, spring warming of inshore water, fall turn-over, upwelling, and storms are all conditions which increase fish movement through the area of the intakes . Upwelling can force fish to move upward in the water column (Emery 1970), increasing their chances of entrapment. Fish not only are more active during storms, but may shelter in the lee of an intake structure (Lifton and Storr 1977). Turbidity and turbu- lence associated with storms may also reduce fish awareness and avoidance of the intake structure and current. Plant Effects Two-unit operation increased cooling water flow rate from 2.7 x 10^ liters/min to 6.1 x 10^ liters/min (Table 7), and increased fish impingement during certain times of the year substantially over impingement during one-unit operation. In making comparisons of impingement rates, 1977 was not considered because so few fish were impinged compared with the preceding 2 years. Because 1977 was a year of one-unit operation, its exclusion should contribute to a more conservative estimate of the differences between one-unit and two-unit operation. For the five most abundant species , percent increase in mean numbers impinged during two-unit operation (1978, 1979) compared with one-unit operation (1975, 1976) (Table 9) was far in excess of the 87% increase in cooling water volume (Table 7). Whether a relationship existed between increased impingement losses during the last 2 years of the study and changes in field abundance during these years is inconclusive. In general, there appeared to be little relationship. However, in the case of rainbow smelt, high field abundance may have contributed to impingement losses. Monthly impingement of each species (Tables 5, 6) indicated that extremely large numbers of fish were impinged 21 Table 9. Percent change In mean number of fish impinged and field-caught during two-unit operation (1978, 1979) over mean number impinged and field-caught during one-unit operation (1975, 1976). Percent change Percent change Species Impingement Field Catch Alewife 96 1 Spottail shiner 577 90 Trout-perch 303 69 Yel low perch 1 14 -9 Rainbow smelt 1226 232 during only a few months, (July, August, and September) which typically were months of high abundance of fish locally. The plant was not operating at full two-unit capacity during much of April and May in either 1978 or 1979, thus data examined to date do not indicate the potential maximum impingement due to two-unit operation as fish move inshore during spring warming. Preliminary 1980 data, however, indicate that impinge- ment of extremely large numbers of fish (> 1 million fish) is possible during this season. Zion Station in Illinois (Lake Michigan) experienced a similar influx of alewives during May 1975 (Kitchel 1975). Such heavy impingement losses may possibly affect local abundance of affected species, especially in combination with total impingement losses within the southern basin of Lake Michigan. Jensen et al. (1982) estimated that water withdrawal through all intakes on Lake Michigan reduced alewife biomass by nearly 3%, based on 1975 data. Many fish impinged at the Cook Plant during peak periods in 1978 and 1979 were YOY or yearlings which had not spawned (Appendixes 66, 68, 70, 72, 74) (composite yearly histograms for major species collected in standard-series field sampling during 1975 through 1979 appear in Appendixes 67, 69, 71, 73, 75). Losses among this age-group might be particularly detrimental. Because it appears that total impingement losses during 1980-1982 were quite high, analysis of impingement losses and field abundance during these years may be enlightening. 22 LITERATURE CITED Crowder, L. B., J. J. Magnuson, and S. B. Brandt. 1981. Complementarity in the use of food and thermal habitat b^^ Lake Michigan fishes. Can. J. Fish. Aquat. Sci. 38:662-668. Dorr, J. A. 1982. Substrate and other environmental factors in reproduction of the yellow perch ( Perca flavescens ). Ph.D. thesis. Univ. Mich., Ann Arbor, Mich. Dorr, vl. A., and D. J. Jude. 1980. SCUBA assessment of abundance, spawning, and behavior of fishes in southeastern Lake Michigan near the Donald C. Cook Nuclear Plant, 1975-1978. Michigan Academician 12:345-364. Emery, A. R. 1970. Fish and crayfish mortalities due to an internal seiche in Georgian Bay, Lake Huron. J. Fish. Res. Board Can. 27:1165-1168. Jensen, A. L., S. A. Spigarelli, and M. M. Thommes. 1982. Use of conventional fishery models to assess entrainment and impingement of three Lake Michigan fish species. Trans. Amer. Fish. Soc. 111:21-34. Jude, D. J., F. J. Tesar, J. C. Tomlinson, T. J. Miller, N. J. Thurber, G. G. Godun, and J. A. Dorr III. 1979. Inshore Lake Michigan fish populations near the D. C. Cook Nuclear Power Plant during preoperational years - 1973, 1974. Spec. Rep. No. 71, Great Lakes Res. Div., Univ. Mich., Ann Arbor, Mich. 529 pp. Kitchel, M. 1975. Screen monitoring study. Pages 237-260 in Operational environmental monitoring in Lake Michigan near Zion Station, July 1974 through June 1975. Vol. IV. Annual Report to Commonwealth Edison Co., Nalco Environmental Science, Northbrook, 111. 23 Lifton, W. S., and J. F. Storr. 1977. The effect of environmental variables on fish impingement. Pages 299-311 in L. D. Jensen, Ed., Proceedings of the Fourth National Workshop on Entrainment and Impingement. Ecological Analysts, Inc., Melville, New York. Robins, C. R. , R. M. Bailey, C. E. Bond, J. R. Brooker, E. A. Lachner, R. N. Lea, and W. B. Scott. 1980. A list of common and scientific names of fishes from the United States and Canada. 4th ed. Spec. Pub. No. 12, Amer. Fish. Soc. 174 pp. Wells, L. 1968. Seasonal depth distribution of fish in southeastern Lake Michigan. 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U (Q £ '- K 03 U^ -t 3 M c « 3 « U O (OS &. JC to O C 4^ O £0 o c3< W W, W "^ « « L _ T9 (. n > t. C • C c « o ^ • C N > fl -0 r N - o - o - ^ - o -3 O m BD O So. C S3 U CD O Jt. C (J • — 10 «• ai3 o OS — c 9—01 c ^ c - 3 O Z 0-! — n > C il E O — A-12 en u 'HO 3 i:ih ,^ o o u M c •H c •H OJ W CO (D •H J-i (D CO « d 'U 4J M cd cd x) -o d o cd P ■P CO li g -u rC • bC r^ ;3 r^ ':t3 C7^ O r- 4 r-C CO r* •H a M-l cd 60 M-l •H O rd o l-i •H (D S J2 g OJ ;3 ^ IS2; cd hJ • c 0-) M t-H 0) 4-) ^< CO •H . cd T3 OJ a rC cu ■P a D f^ O * «B « - t. • CM £ u « « 3S-3S U • £ • - a • - • 3 O t. -^ • n M - a c c i: •£ CD c c n n r c ^ -S i « fi - 9 ID ^ — — « c ■- — -- 3 :< C IQ 3 — O a o c • H- ae O -i 31 U U OQ ui wo a o A-13 CO 0) u 4-i 0] P rH P-. o O W} c •H C •H OJ CO CO Q) •H J^ O CO • CT3 TJ 4-J J-) CO CO Ti T3 O cd C 4J CO II >. P rO ;z: 4-J ri: • W) 00 p r-s CU o> o r-^ rT: CO #s •H c M-4 03 f>D m •H o ri: o u •H CD S rn B Q) :3 ^ ;2: 03 hJ .- C Cu :3 a o <: CO ^ vvvvvvvvvvv O m 09 CI eo o( o « « — «o ct O oOO'-ci CO'-OW'^ cnoOOO O-^OOO OOOO** iiiis iiiii iii3§ s§iii i§i§§ i§ i§iss iiiss i§ii§ i§§i3 §§§§3 §ssis ii3§i §§ §§§§§ i§i§3 §§§§i ii u J (. u ? £ C -0 J< 9 c s. « » - u C ♦* • IJ • • s- - — JC M — "0 C - - £ 6 U t. C « £ <*. U I- v £ « U C ^ £ ^ « • Q. --> C • V 3 « • « C IB E (. M « e gliS'tS I. r s. ;.♦-£- (0 n > £ - ■M c 10 « « 3 « £ C - 2 10 S - a- (.0 9 3 - T3 00 W — (D - C ■^(9 3 « -M ajt n « 3 £ "O t c C £ — w « — "0 T3 (0 <*. 3 « C ^ c • 3 3 C OI** IB - • > C •^ - c u « ^u23§ t. « ^ 6 • ♦* "0 C C ^ WO 10 « •H 3 C ^ c a £ N £ 0) r - c - ;Si2€ E ^ — « (Q C C C N -»- a— (c 0) t. {- r r «j a - £ C - 3 - (Q (/) < oe > (J DQ >- u -i a a (/) ui CO ~3 u -1 (/> 00 U -t OQ Z 00 C3 u. A-14 CO cd cu u cd P^ ^0 ;3 u CO +J c Cd r-H P-4 r^ o O ^; a •H C>0 c: •H a •H 0) 00 00 CJ •H V.4 OJ OO • T3 cd J.-I 4J 03 Cd T3 nj c: 03 O 4.J C C/D II J^^ rCi P J2: ■l-J x: bS) • z^ a^ a3 r^ a a^ T-H rC 0) #v •H CJ M-4 cd bO «^^ •H o ^ u a) =d ^i e 0) ;:3 .iij iz: Cd hJ .. c iTi 5-1 r— ( CD 4-J IxJ CO •H Cd t:) 0) a rC ai 4-) Cu ^3 Cu O C>ci '-OOOq OOOOO OOOOO OOOOO OOOOO O io-^ 6 66 66 666 66666 666 66 6 6 666 66666 6 • "^ vvvvvvvvvvvvvv •-mjof**© eoooBfl'T ••wf**^ ooo<0«i>n nwcici"^ i^.-.-*-.*.^ «- w p> ^ O p> in ^ — in « « in fio «- S33SS Sis§i Siifs iiiss sisss iisss s S3SSS sssss SSiSS SSiSS SSSSi SiSSS s MnOiOi^ 0'"'-00 *nOOO OciWOO -"^WOOO OOOOO O n OS d d <0 •■ ^^ ^ la^i^dCT OdOr«0 OOOOO O'-^'-O OOctOO OOOOO O ^ naon O^mOO OOOOO O'-OOc* ciOO'-O OOOOO O '- CO (P d 0) « — in -•-000(0 r^viPOtO O'TdO'- O'-O'-O OOOO*" O'-OOO O Sisss §i§§s iSiii §§§§>§ i§§is i§§i§ § i SS.fSS §§SS§ i§§§3 §S§i!3 i§3S§ SSSSS 3 S 33333 3S333 33333 333SS 33333 33333 3 3 « - O ' ^ a • «- ( < (/I > CO < « U J£ « u u ^^- I ^^ « C 3 *- ^ o - £ t. £ O I- 3 ll ll -3 O C U t. - O — u iA CO « • « u c?2 « « E N U 6 N • O ^ B U O UJ 3 U CI O « 21 • 1. T3 ■• « o c 8*".,, «•! crt-TJO -MOOCi-H — WOiOC • COICJ-Q ♦'■O^-jCC (oaoci3 amota- -iOE-j.ioo (/}«/>zu.ca « Jt C V 01 o u o c « v C (Q O ^ 3 ■^ — t. r m *- Z CD O t/f -i CO A-15 CO 4000 4000 4000 16000 12000 8000 4000 8000 4000 28000 'ill Q_ 24000 O Cc: 20000 LU ^ 16000 ID ^ 12000 8000 4000 4000 4000 4000 4000 4000 4000 jnN I I r I T I I I I I t > I t II T f II FEB I I 11 I I I I I T I I t f f I t I I I Jtf yVfc J^ Alayiii^ MflR I I I I ■C^ZlZ^SEBa flUG f I I SEP JJSJsSSfZL OCT NOV DEC i I I I I I I 50 100 150 200 TOTAL LENGTH (MM) 250 Appendix 16. Length-frequency histograms of alewives impinged during 1975 at the Cook Plant, southeastern Lake Michigan. A-16 31 CO q: LU CD 2400 h 1200 100 150 200 TOTAL LENGTH (MM) 250 Appendix 17. Length-frequency histograms of alewives impinged during 1976 at the Cook Plant, southeastern Lake Michigan. A-17 CO M LL o en UJ CD 400 400 400 400 800 400 4400 4000 3600 3200 2800 2400 2000 1600 1200 800 400 400 h 400 " 400 - 3600 3200 2800 2400 2000 1600 1200 800 400 JflN r I I I 1 I I 1 I I I I I I I I -1 1 I I III I I I I I I FEB I I I I I I r I I I I AUG I I I I I I I I I I I iiMi'iF" I I I I I I I' I ■ i . I II F ■ II ^ 1 JT^ '^' F SEP yv i iJ^ivi , , 1 rprt9p9Clyy a^ , , , , , , , r- 400 400 f"— T— I I I I I 'I !--•*—¥* iii^il7>*aTnpT>-pi NOV I II I I 1 I I 1 I DEC I I I 50 100 150 200 TOTAL LENGTH (MM) 250 Appendix 18. Length-frequency histograms of alewives impinged during 1977 at the Cook Plant, southeastern Lake Michigan. A-18 4000 4000 4000 4000 _ I I I I I t r I I t I I' I I J, I f ' r t I » II t I I I i r I I I I t 12000 8000 4000 CO 36000 ^ 32000 O 28000 g 24000 CD n 20000 ^ 16000 12000 8000 4000 4000 4000 4000 4000 4000 JflN -I 1 I I I 1 1 I I 11 r FEB r III I I I I r I I I I' I I I I I MflR I IT' RPR I I I I I I I I -r I t I I I I I nflY =^1 AUG I I I = — I I 1 I I I ■! ■ i f>9» i» j I f s^a. I I r " SEP gry??! , Kyanprwyr T "^ 11 ^ m II I , OCT I II NOV I t I I I N" ■ I DEC 50 100 150 200 TOTAL LENGTH (MM) 250 Appendix 19. Length-frequency histograms of alewives impinged during 1978 at the Cook Plant, southeastern Lake Michigan. A-19 n: CO LL. o cr LU CD 8000 8000 8000 8000 8000 8000 40000 32000 24000 16000 8000 16000 8000 80000 72000 64000 56000 48000 40000 32000 24000 16000 8000 8000 8000 8000 I t I r 1 I I » I t r I I I II I I I I JflN FEB I I I r nflR I I I I II I I I 1 t I I I I I I' 11 » » » I I ' I'll I I" I I I I I I I I I I I ' "I I I — 1— — T— — T— I II I I I APR nflY JUN SEP I « I I I f I I I I » OCT I I I I -^Mye— p I I I I I ' NOV r I' I I I I I ' I f I I I I ' I I I I I II I I DEC 11 t ■ I I I I I I — n**— l—^T" i I I 50 100 150 200 TOTAL LENGTH (MM) 250 Appendix 20. Length-frequency histograms of alewives impinged during 1979 at the Cook Plant, southeastern Lake Michigan. A-20 r I fr7y;rm. hi, i 80 130 TOTfiL LENGTH (fin) Appendix 21. Length-frequency histograms of spottail shiners impinged during 1975 at the Cook Plant, southeastern Lake Michigan . A-21 400 400 2400 2000 1600 1200 800 400 CO 800 400 - 400 = O q: LU g 400 ID «f77?wariTry-rTflnngnnd l^^^EZ^SSzss^zszsa 'vwywi r- nflY 400 = •- 400 "^ JSg^gg^^gsgzac JUN JUL r f ^W'^tx;u^AA^vi»^>^?<» ^K»$^^ 80 130 TOTRL LENGTH (MM) nuG Appendix 22. Length-frequency histograms of spottail shiners impinged during 1976 at the Cook Plant, southeastern Lake Michigan. A-22 CO LU QQ 30 ., , [TTYTTX^^^^y^^l^gg^g^gZggas^^^ 80 130 TOTAL LENGTH (MM) Appendix 23. Length-frequency histograms of spottail shiners impinged during 1977 at the Cook Plant, southeastern Lake Michigan . A-23 8000 4000 8000 4000 8000 4000 8000 4000 8000 4000 8000 4000 48000 44000 40000 36000 32000 28000 24000 20000 16000 12000 8000 4000 8000 4000 h 'Z2?ZZtiszsz^zsszh JflN FEB HflR flPR MRY JUN O cr CD 8000 4000 8000 4000 8000 4000 8000 4000 30 ^ rTTTTTfgg^?gggTv.rnrv^^ , AUG n — ggggpngw^r^ -, — wvvyvvrkV >< y^MAAVvvwvvyvs zb I ' r SEP OCT NOV 80 130 TOTAL LENGTH (m) DEC Appendix 24. Length-frequency histograms of spottail shiners impinged during 1978 at the Cook Plant, southeastern Lake Michigan. A-24 CO o q: Ui CD TZ ID 80 130 TOTAL LENGTH (m) Appendix 25. Length-frequency histograms of spottail shiners impinged during 1979 at the Cook Plant, southeastern Lake Michigan . A-25 200 200 200 200 200 200 200 200 200 I I I I i I I t I ' f .., KOBafszxaa^zJSh frpc7^^x;^xxA^VA1Av^<^fcgygte ' I ' T' ■ ,■ ■ i««^«a — f r^^7-^^^^^^^teg?g^is^^ iV V V V tf I gya JflN FEB T " nflR I flPR mv JUN JUL RUG SEP 60 110 TOTAL LENGTH iW) Appendix 26. Length-frequency histograms of trout-perch impinged during 1975 at the Cook Plant, southeastern Lake Michigan. A-26 TOTAL LENGTH {m) Appendix 27. Length-frequency histograms of trout-perch impinged during 1976 at the Cook Plant, southeastern Lake Michigan. A-27 240 120 240 120 240 120 240 120 240 120 240 120 360 240 120 ^ 240- M ^ 120 - O 240 F cr 120 LU CD 2Z 1560 Z 1440 1320 1200 1080 960 840 720 600 480 360 240 120 240 120 240 120 I I » It f I 1 1 t __Jg^?^ ' ^ ■ *M' I f t' ' " I -I I I 1 m^aa^BBOmmm^ I I \ I JESS^S^taqa JflN FEB nflR APR nfiY JUN AUG 't ' ' 't SEP NOV DEC 60 110 TOTAL LENGTH iW) 160 Appendix 28. Length-frequency histograms of trout-perch impinged during 1977 at the Cook Plant, southeastern Lake Michigan. A-28 60 110 TOTAL LENGTH (Mri) 160 Appendix 29. Length-frequency histograms of trout-perch impinged during 1978 at the Cook Plant, southeastern Lake Michigan. A-29 CO M Ll. zz ID 60 110 TOTAL LENGTH (m) 160 Appendix 30. Length-frequency histograms of trout-perch impinged during 1979 at the Cook Plant, southeastern Lake Michigan. A-30 180 230 280 TOTAL LENGTH (m) Appendix 31. Length-frequency histograms of yellow perch impinged during 1975 at the Cook Plant, southeastern Lake Michigan. A-31 600 400 200 200 200 JflN FEB HflR 200 - APR 200 200 200 - 400 200 ^ 2000 [^ 1800 L^ 1600 O 1400 p^. 1200 Ll! CD 1000 § 800 ^ 600 400 200 1800 1600 1400 1200 1000 800 600 400 200 200 200 P?^??k7-i MAY JUN ^ Z^LUL^LO!^ SEP T 1 I I , , , 1 y ■ y KyiyJyK^fry lX,^U,iii.f-i» OCT III! I I I I I I NOV -1 1 1 I i" I I I I T— T-^tF"^ I 1 I I I I I I I I DEC 30 80 130 180 230 280 TOTAL LENGTH (MH) 330 380 Appendix 32. Length-frequency histograms of yellow perch impinged during 1976 at the Cook Plant, southeastern Lake Michigan. A-32 120 120 480 360 240 120 120 120 120 X CO M Ll. 720 LL. O 600 UJ QQ IZ 480 360 240 120 120 120 360 240 120 I , , , . gpg^^TTP^W' . ^ i ^^^^^S^^sgoinn^^ ■ I II 1 1 1 I [ I I 1 p— I i--'T^=^"F"^HF*5?EL-, ,, 11 ^ lll j ll | i , lli ; il , i iy i PfTH , , | i I , , , , r— T I I 1 " ' I I t ' I I I I I II II % I I I I I I " I " I 1 ' "I I I "i|iM I I JFIN ■I I' r FEB ■f ill MflR I I' I I I '> " ' I I r I " APR I' I II r It I 1 MRY r '>' " '!' I I' r ' "f I I ' " I "' I " ' r "I I ' I " " t I " 1' ■ n n I ". |ii ii|ii i f JUN ■ T 'I 1 ' 'I " I qpcjE ■flryl?j?^ffTrfc JUL * ' ^" ' I I 'I 'I ' M yi^^-T r" r I I 'I " ' r r AUG " I ' '■ ¥ ' " I ' " 'I ' '1' " I ' I T-T" SEP I I I' ' i j '¥ 120 120 B y Ey Pi^i , Mfyi OCT iyfa«|»f— pB»ypi.aifi-i , iii. . ,1 11,1 , .1 WTTl I t rrn^ NOV 1^ I DEC 30 80 130 I 'T' I i 11 180 230 280 330 380 TOTAL LENGTH (nh) Appendix 33. Length-frequency histograms of yellow perch impinged during 1977 at the Cook Plant, southeastern Lake Michigan. A-33 400 400 400 400 400 JflN -T— I t i l l I I I I I I FEB -I r— I 1 I I I I I I I i I I I I I I I I I I I I I I I t I I i I I I — I I I t -"¥— ^n I I I I I I I I I I I I i I 'll I I I MflR I I I I I I I I I APR I I I ■ ^ ■ M I I t f I ! i I I I I > I ' I I I I I I I I' r I I I I I I nflY I I I I I I I I I I I I' I I I I i I i I I I I I I I I I I I I I I I I CO M Ll. O cr LU CD ^fl^^gyl■^■ilill?i?^!ill^^ , I ffTH )l■jll?9^^^>tj^l;^^n^f ■! I I i SEP I I I I 400 800 400 400 OCT H , H f B f K^ncy^^^ ^ w^ i I , , , I — til l — r— I — I I I — I— r* NOV I I I I I I I I i I i I I I »» I ^ I I "V DEC 1 — III' I' I ' I I" I I i I I I I I I I I I I I I I I i I I" 30 80 130 180 230 280 330 380 TOTAL LENGTH (MH) Appendix 34. Length-frequency histograms of yellow perch impinged during 1978 at the Cook Plant, southeastern Lake Michigan. A-34 800 400 800 400 800 400 800 400 800 400 800 400 800 400 800 400 4800 4400 4000 3600 3200 2800 2400 2000 1600 1200 800 400 800 400 - 800 400 - 800 400 - 30 — I I 1 JS^I^a^y IX^ D<^ff?VT*«F T " I I > I JflN » » t 1 I 1 1 1- FEB t I 1 1 — " I - ' r nflR ' "I ' " I V I I RPR '" I I I t I I I t MAY -r I I I I I \ 1 I r JUN I I I I I I JZ CO M Ll. CD -T 1 1 I I '"l"' I a^zh^JS:^ JUL I I I T ' r ^ ^ iv,Hiu^iR7a 8?3gynL,^JDpa_, — , — ^ OCT ' 11 » 11 1 I I r I I I T NOV t 'I " I ' !' " r I I I I DEC 80 I I I I I I I ■ I I I 130 180 230 280 330 380 TOTAL LENGTH (HM) Appendix 35. Length-frequency histograms of yellow perch impinged during 1979 at the Cook Plant, southeastern Lake Michigan. A-35 31 CO o LU m n 80 80 80 160 80 240 160 80 80 80 80 JRN I I' " " I I ' ' I " t I I I I I ' f ' I ' ' I I I ' I P" I II I I I -BBPE^SSPL. FEB nflR I I I I I , , III, ig^y7K?$iXiK?ySL. ■?y^fsinpTii 1 1 ■,^ii JUN 'I ' 'I ' ' I I ' " » I I I *yi I JUL i I I I y "" I ' ' 'I ' I' " r I I I I AUG I I I I 80 - I I |i 'I' |l N l I I I " i I SEP -I 1 1 ■■ S" I I I <"iy^pM I I 110 160 210 TOTAL LENGTH (MM) Appendix 36. Length-frequency histograms of rainbow smelt impinged during 1975 at the Cook Plant, southeastern Lake Michigan. A-36 CO O q: UJ en z: ZD 2: 60 110 160 TOTAL LENGTH (Mn) 210 260 Appendix 37. Length-frequency histograms of rainbow smelt impinged during 1976 at the Cook Plant, southeastern Lake Michigan, A-37 X CO o cr. LU 03 n 110 160 210 TOTAL LENGTH (MM) Appendix 38. Length-frequency histograms of rainbow smelt impinged during 1977 at the Cook Plant, southeastern Lake Michigan. A-38 CO 800 800 800 800 800 800 8000 7200 6400 5600 4800 - LL. 4000 Uu. 3200 O 2400 q: LU 1600 § 800 5600 4800 4000 3200 2400 1600 800 800 - 800 800 800 I " I' t I I i IT' I ' 1 I I I I ' I I I I I I g l U I I I I ' I V II I I ■g^?^M P " js;z£^ I I I '" V " I I 't I' " " I' ' f ' T ' 'T T I I I I I JflN FEB nflR APR nflY JUN " I " ' ' I I > t I ' I I I SEP OCT NOV I I t " I DEC I I I 60 I I I t" t I I 110 160 210 TOTAL LENGTH (fin) 260 Appendix 39. Length-frequency histograms of rainbow smelt impinged during 1978 at the Cook Plant, southeastern Lake Michigan. A-39 800 800 800 800 -I 1 1 r I "M JFIN FEB I' f I r I I I I 'I 'I' I I ' "" ^ " nnR flPR III I I I I I nnv I I I ' f ' I I' 'I " ' r 11 III t I I I 800 - I % ' I ' ' ' I JUN I I ' r ' ' I " ' i I I' ' I ' I "■ I' " ' 1 f " I I ' 1 CO LU 2400 1600 800 1600 - 800 - 5600 h 4800 4000 3200 2400 1600 800 800 800 I I I I I I I niii|iini OCT I I I I I NOV I I I I II I I 11 I I I 11 I 800 - DEC I I 1 11 10 60 t I II I 110 160 210 TOTAL LENGTH (HM) 260 Appendix 40. Length-frequency histograms of rainbow smelt impinged during 1979 at the Cook Plant, southeastern Lake Michigan. A-40 CO en UJ CD 10 60 110 160 TOTAL LENGTH mm 210 Appendix 41, Length-frequency histograms of alewives caught during 1975 field sampling at'the Cook Plant, southeastern Lake Michigan, A-41 110 160 TOTAL LENGTH im) Appendix 42. Length-frequency histograms of alewives caught during 1976 field sampling at the Cook Plant, southeastern Lake Michigan. A-42 CO UJ m 110 160 TOTAL LENGTH (fin) Appendix 43. Length-frequency histograms of alewives caught during 1977 field sampling at the Cook Plant, southeastern Lake Michigan. A-43 240Q 1200 2400 1200 2400 1200 2400 1200 2400 1200 2400 1200 -1978 ,, I ! f f I I I I I I I r I APR r r 1 I t " t r i i I I 1 I ' t ' ' f I ' ' 1 T ■' t I t ' " ' f ' r ' I 'I I I I 'i.i y I I . I , I I I ^ip— ^ I yi I nflY JUN Zi "T" '' ' » '» " > ' I I I t f I 'M"' I I JUL AUG CO o UJ CD 19200 =" 18000 - 16800 15600 - 14400 13200 12000 10800 - 9600 - 8400 7200 6000 - 4800 3600 2400 1200 - I I I I I I SEP i I I OCT I I I I I 1 r" » 2400 1200 - 10 , wrpggX?3L NOV I ' ' t ' ' t ' " 1 " 1 "" I "" f t I I I II I I I I 60 110 160 TOTAL LENGTH mri) 210 Appendix 44. Length-frequency histograms of alewives caught during 1978 field sampling at the Cook Plant, southeastern Lake Michigan. A-44 60 110 160 TOTAL LENGTH (Hn) 210 Appendix 45. Length-frequency histograms of alewives caught during 1979 field sampling at the Cook Plant, southeastern Lake Michigan. A-45 200 200 - 1975 1400 1200 1000 800 600 CO M 400 200 Ll. O cn LU CD n 600 400 I ' r i I RPR I » nflY JUN 200- JUL 400 200 400 200 400 200 200 RUG SEP 10 OCT NOV 60 110 TOTAL LENGTH (nn) 160 Appendix 46. Length-frequency histograms of spottail shiners caught during 1975 field sampling at the Cook Plant, southeastern Lake Michigan. A-46 CO UL o on 60 110 TOTAL LENGTH (Mn) Appendix 47. Length-frequency histograms of spottail shiners caught during 1976 field sampling at the Cook Plant, southeastern Lake Michigan. A-47 60 no TOTAL LENGTH (HM) Appendix 48. Length-frequency histograms of spottail shiners caught during 1977 field sampling at the Cook Plant, southeastern Lake Michigan. A-48 'wO LU CD TOTAL LENGTH (MM) Appendix 49. Length-frequency histograms of spottail shiners caught during 1978 field sampling at the Cook Plant, southeastern Lake Michigan. A-49 en Li_ o cr uu CD n 10 60 no TOTAL LENGTH (riM) Appendix 50. Length-frequency histograms of spottail shiners caught during 1979 field sampling at the Cook Plant, southeastern Lake Michigan. A-50 80 80 320 240 160 80 800 720 640 560 480 400 320 240 160 80 80 80- - 1975 I I I I I I I I APR < I r r I I If I'l l I » I 1 flflY t I — I I I r I 1 r I > I t " CO cr LU en zz I 1 ^ J^??tqnrTT>T»,, P^fe??tr?^^ SEP 1111 80 I I I I I I I I f , l ip l n'^?^il?nrFfl?ff{^ ^ I I fTJTL ^ OCT I I I I r 80 - 10 60 I 1 ^ 1 I I WTT^MMf ' M' ' Kf^^m^ 1— r- NOV 110 160 210 260 310 360 TOTAL LENGTH (fin) I I I I Appendix 51. Length-frequency histograms of yellow perch caught during 1975 field sampling at the Cook Plant, southeastern Lake Michigan. A~5l 32 16 32 16 CO O cr LU CD 1976 -1 1 I 1 I r-^ f-" \ "^ I 1 '■ r» ' I APR t ' " 'T " 1 » I' I 'I " ' 1 j ' I ' ' I' 't' " ■ 1 • r r " MflY f » I 1 r— p fuyMfmftmTi i , , , r I II > r r ' I 1 ' ' I ' f 'I ' r r NOV I I r I I " < I 1 — r I 1 II I I *f " I 1 I » I ■ »■ I 10 60 110 160 210 260 TOTAL LENGTH (m) 310 360 Appendix 52. Length-frequency histograms of yellow perch caught during 1976 field sampling at the Cook Plant, southeastern Lake Michigan. A-52 40 40 - 40 - 440 400 360 320 280 240 200 X CO M 160 120 Ll. O 80 UJ QQ 40 120 80 40 120 80 40 40 160 120 80 40 16Q 210 260 310 360 TOTAL LENGTH (Mfl) Appendix 53. Length-frequency histograms of yellow perch caught during 1977 field sampling at the Cook Plant, southeastern Lake Michigan. A-53 - 1978 -1 r' I I '* r i' f II I 1 r--? rfipriya , nrpn ^ tw^nm ^ P{>f>9sKfti«-p-i -^ ■^ APR ' N ' "Y ■ J I f i 1 1 p— T I 1 I II I * * i*' 1 —I- nflY I I — I — I I 1 I I "1" I I I I t "V^'i" . 1 1 "i" I 1 1 1 r- -T 1 II I I I ' » I r T " 10 160 210 260 TOTAL LENGTH (riM) Appendix 54. Length-frequency histograms of yellow perch caught during 1978 field sampling at the Cook Plant, southeastern Lake Michigan. A-54 CO o cr LlI QQ z: 80 80 - 80 h 160 80 160 80 800 720 640 560 480 400 320 240 160 80 80 80 I f I I * ^ PyvtTn , , , , , , , I I I I 10 60 110 1 ' ' t T ' r » " % I » t » t I I t T I r 1 I I I 1 I 1 160 210 260 310 360 TOTAL LENGTH (ntl) Appendix 55. Length-frequency histograms of yellow perch caught during 1979 field sampling at the Cook Plant, southeastern Lake Michigan. A-55 M Ll. Ul O q: UJ 100 150 200 TOTAL LENGTH mn) Appendix 56. Length-frequency histograms of rainbow smelt caught during 1975 field sampling at the Cook Plant, southeastern Lake Michigan. A-56 96 80 64 48 32 16 32 16 48 32 16 192 176 160 144 128 112 96 80 64 48 32 16 32 16 32 16 32 16 48 32 16 T^^r^ f f my ' " f r " I " JUN » r T T I ! r t I r > * CO M Ll. Ll O CC UJ cn I " I " > >' ! " ' r " I JUL AUG r ' r " ' ' » " ' > "T I " f 'I " > ' f r I , M l , i „ i ^ M , , 1, 1 , , , 1 I I I , tyYvffgpSL SEP 11 I I t "1 ' ■ I I r- " > ' t , i M , . , I , 1 ( OCT • • — T- r I t 1 1 "" ' . " . ' » ' " ' f " 1 T' NOV 1 I ' f ' ■ 100 150 200 TOTRL LENGTH (nn) 250 Appendix 57. Length-frequency histograms of rainbow smelt caught during 1976 field sampling at the Cook Plant, southeastern Lake Michigan . A-57 100 150 200 TOTAL LENGTH (m) Appendix 58. Length-frequency histograms of rainbow smelt caught during 1977 field sampling at the Cook Plant, southeastern Lake Michigan. A-58 CO M cr Ld CD 2Z ID TOTAL LENGTH (nri) Appendix 59. Length-frequency histograms of rainbow smelt caught during 1978 field sampling at the Cook Plant, southeastern Lake Michigan. A-59 CO LlJ en 100 150 200 TOTAL LENGTH (Mil) Appendix 60. Length-frequency histograms of rainbow smelt caught during 1979 field sampling at the Cook Plant, southeastern Lake Michigan, A-60 100 TOTAL LENGTH (m) Appendix 61. Length-frequency histograms of trout-perch caught during 1975 field sampling at the Cook Plant, southeastern Lake Michigan. A-61 80 40 80 40 80 40 520 480 440 400 360 320 280 240 200 160 120 80 40 80 40 80 40 80 40 80 40 - 1976 flPR rf7::^X?J^?gg9Sk777p?7ff7777'^^ ' ." ^ " .* ' MAY " »' ' T" CO o tr LlJ en n 2: rpri , fgg?M ^^g^^»^ 46666 I t ' r K>C>QO S m 1Q"7Q 5WX^»66il!*J '"-' '" 3600 2400 ^ M XxSoQ >— ^ssssi ^'^l^ 1200 '— p fW^ 2SSSS fVXWI , , , , 1 10 60 110 TOTAL LENGTH (Mm 160 Appendix 72. Length-frequency histograms of trout-perch impinged from 1975 through 1979 at the Cook Plant, southeastern Lake Michigan. A-72 CO o en LU CD 100 TOTRL LENGTH (flM) 150 200 Appendix 73. Length-frequency histograms of trout-perch caught during field-sampling from 1975-1979 at the Cook Plant, southeastern Lake Michigan. A-73 X CO M cr LU QQ 110 160 TOTAL LENGTH (MM) Appendix 74. Length-frequency histograms of rainbow smelt impinged from 1975 through 1979 at the Cook Plant, southeastern Lake Michigan. A-74 CO M U- U- O CC LU CD 100 150 200 250 300 TOTAL LENGTH (MM) Appendix 75. Length-frequency histograms of rainbow smelt caught during field-sampling from 1975-1979 at the Cook Plant, southeastern Lake Michigan. A-75