244 



Aquatic Ecosystems — Our Living /iesmiives 



3.0- 



— DDT 



Fig. 6. Contaminant results from 

 Lake Eiie walleye. 1977-90. 



Fig. 7. Lip tumor and stubbed bar- 

 bels on a brown bullhead. 



For further information: 



Robert J. Hesselberg 



National Biological Service 



Great Lakes Science Center 



1451 Green Road 



.^nn Arbor. Ml 48105 



presence of PAH.s in the sediment (Bauniann et 

 al. 1991: Smith et al. 1994: Fig. 7). Tumors and 

 other deformities have been detected in 15 loca- 

 tions (Hartig and Mikol 1992; Fig. 1 ). 



Conclusions 



The monitoiing program for contaminants in 

 Great Lakes fish has documented successful 

 reduction of contaminants in response to usage 

 bans for DDT and PCBs. Trends in dieldrin are 

 less clear and concentrations of this pesticide 

 remain especially high in Lake Michigan in 

 comparison to the other Great Lakes. Fish com- 

 munities are rebounding in some Great Lakes 

 iiarbors. tributaries, embayments, and connect- 

 ing channels that formerly were so contaminat- 

 ed that only the most pollution-tolerant organ- 

 isms could survive. More reductions in contam- 

 inants are required, however. Monitoring results 

 clearly indicate that the downward trend in con- 

 taminants leveled off in the mid-i980's, and 

 resource-management agencies and research 

 institutions are investigating the potential to fur- 

 ther reduce sources of contamination in Great 

 Lakes fish. 



Reproductive problems, tumors, and other 

 deformities are still being detected in certain 

 fish and wildlife populations in most of the 

 Great Lakes. Similarly, consumption advisories 

 recommending restrictions on eating certain 

 species and sizes of Great Lakes fish still 

 remain. The United States and Canada have 

 agreed upon a virtual elimination policy for 



toxic contaminants under the auspices of the 

 Great Lakes Water Quality Agreement. 

 Remedial action plans are being developed by 

 federal and state agencies in cooperation with 

 local municipalities and local citizens to elimi- 

 nate beneficial use impairments in the most 

 contaminated rivers, harbors, and bays in the 

 Great Lakes. Continued long-term monitoring 

 of contamination in fish is required to determine 

 the success of these programs and to guide 

 where further corrective actions may be neces- 

 sary. 



References 



Baumann, P.C. M.J. Mac, S.B. Smith, and H.C. 

 Harshbarger. 1991. Tumor frequencies in walleye 

 {Stirnstediim vitreum) and brown bullhead ilclaluius 

 nchiilosus) and sediment contaminants in tributaries of 

 the Laurentian Great Lakes. Canadian Journal of 

 Fisheries and Aquatic Sciences 48: 1 804- 1810. 



Baumann, RC. and D.M. Whittle. 1988. The status of 

 selected organics in the Laurentian Great Lakes: an 

 overview of DDT. PCBs. dioxins. furans. and aromatic 

 hydrocarbons. Aquatic To.xicology ! I ;241-257. 



De Vault. D.S.. and R.J. Hesselberg. 1995. Contaminant 

 trends in lake trout and walleye from the Laurentian 

 Great Lakes. Journal of Great Lakes Res. 2 1 . In press. 



DeVault. D.S.. W.A. Willford. R.J. Hesselberg. 1985. 

 Contaminant trends in lake trout iSulvelinus namuycush) 

 from the upper Great Lakes. U.S. Environmental 

 Protection Agency, Great Lakes National Program 

 Office, Chicago. 11^. EPA 905/3-85-001 . 22 pp. 



Giesy. J. P. J.P Ludwig, and D.E. Tillitt. 1994. Deformities 

 in birds of the Great Lakes region: assigning causality. 

 Environmental Science and Technology 28:128A-135A. 



Hartig. J., and G. Mikol. 1992. "How clean is clean?" An 

 operational definition for degraded areas in the Great 

 Lakes. Journal of Environmental Engineering and 

 Management 2:15-23. 



Hesselberg, R.J.. J.P Hickey, D.A. Nortrup. and W.A. 

 Willford. 1990. Contaminant residues in the bloater 

 iCmegonus hoyi) of Lake Michigan, 1969-1986. Journal 

 of Great Lakes Research 1 6: 1 2 1 - 1 29. 



Mac. M.J., and C.C. Edsall. 1991. Environmental contami- 

 nants and the reproductive success of lake trout in the 

 Great Lakes: an epidemiological approach. Journal of 

 To.xicology and Environmental Health 33:375-394. 



Mac. M.J.. T.R. Schwartz, C.C. Edsall, and A.M. Frank. 

 1993. PCBs in Great Lakes lake trout and their eggs: 

 relations to survival and congener composition 1979- 

 1988. Journal of Great Lakes Research 19:752-765. 



Smith. S.B.. M.A. Blouin. and M.J. Mac. 1994. Ecological 

 comparisons of Lake Erie tributaries with elevated inci- 

 dence of fish tumors. Journal of Great Lakes Res. 

 20:701-716. 



Lake Trout in 

 the Great 

 Lakes 



by 



Michael J. Hansen 



National Biological Service 



James W. Peck 



Michigan Departtnent of 



Natural Resources 



Lake trout (Salvelinus mmuiyciish) popula- 

 tions in the Great Lakes collapsed cata- 

 strophically during the 1940"s and 1950"s 

 because of excessive predation by the sea lam- 

 prey {Petromyzon marimis) and exploitation by 

 fisheries. The lake trout was the top-level preda- 

 tor in most of the Great Lakes as well as an 

 important species harvested by commercial 

 fisheries. Interagency efforts to restore lake 

 trout into the Great Lakes included comprehen- 

 sive control of sea lamprey populations (Smith 

 1971 ), regulation of commercial and recreation- 



al fisheries, and stocking (Eschmeyer 1968). It 

 was hoped that without sea lamprey predation 

 and fishery exploitation, stocked lake trout 

 could reproduce and eventually restore wild 

 lake trout populations in each of the Great 

 Lakes. Lake trout restoration began during the 

 I950's in Lake Superior (Hansen et al. 1995), 

 the I960"s in Lake Michigan (Holey et al. 

 1995), the 1970's in Lake Huron (Eshenroder et 

 al. 1995) and Lake Ontario (EIrod et al. 1995), 

 and the 1980's in Lake Erie (Cornelius et al. 

 1995). 



