1 82 



Imcrtibralcs — Our Z.;r//;i; Rcsiuiives 



¥i^. 4. Percentage of live and 

 dead native mussels collected at an 

 nidex station in western Lake Erie 

 of the Lake Huron-Lake Erie cor- 

 ridor of the Great Lakes, 1989-91 . 



For further int'urmation: 



Don W. Schloesser 



National Biological Service 



Great Lakes Science Center 



Ann Arbor. MI 48105 



biological pollution. Exotic species such as 

 zebiu mussels are being recognized as new and 

 wide.spread threats to ecosystem stability 

 throughout North America (Office of 

 Technology Assessment 1993). 



References 



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 159. 



Bums. N.M. 1985. Erie: the lake that survived. Rowman and 

 Allanheld. Totowa. NJ. .320 pp. 



Clarke. AH. 1981. The freshwater molluscs of Canada. 

 National Museum of Natural Sciences, Ottawa. 446 pp. 



Clarke. A.M., and D.H. Stansbery. 1988. Are some Lake Erie 

 mollusks products of post-Pleistocene evolution? Pages 

 S5-92 ill J.F. Downhower, ed. The biogeography of the 

 island region of western Lake Erie. Ohio State University 

 Press, Columbus. 208 pp. 



Farara. D.G., and A.J. Burt. 1993. Environmental assessment 

 of western Lake Erie sediments and benthic communi- 

 ties — 1991. Ontario Ministry of Environment and Energy, 

 Water Resources Branch, Great Lakes Section by Beak 

 Consultants Limited, Brampton, Ontario. 193 pp. 



Goodnch, C, and H. van der Schalie. 1932. The naiad 

 species of the Great Lakes. Occasional Papers of the 

 Museum of Zoology University of Michigan 238:8-14. 



Herdendort\ C.E.. C.N. Raphael, and E. Jaworski. 1986. The 

 ecology of Lake St. Clair wetlands: a community profile. 



U.S. Fish and Wildlife Service Biological Rep. 85(7.7). 

 187 pp. 



Mackie, G.L., D.S. White, and TW. Zdeba. 1980. A guide to 

 freshwater mollusks of the Laurentian Great Lakes with 

 special emphasis of the genus Pisidium. U.S. 

 Environmental Protection Agency EPA-600/3-80-068. 

 Duluth, MN. 144 pp. 



Nalepa. T.F, and D.W. Schloesser, eds. 1992. Zebra mussels; 

 biology, impacts, and control. CRC Press, Inc., Boca 

 Ratoii. FL. 810 pp. 



National Academy of Sciences. 1970. Eutrophication: caus- 

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Office of Technology Assessment (U.S. Congress). 1993. 

 Harmful non-indigenous species in the LInited States. 

 OTA-F-565. U.S. Government Printing Office, 

 Washington. DC. 390 pp. 



Schloesser, D.W., and W.P Kovalak. 1991. Infestation of 

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 and Canada: mollusks. American Fisheries Society 

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 Fisheries 18(9):6-22. 



Aquatic 

 Insects As 

 Indicators of 

 Environmental 

 Quality 



by 

 William T. Mason, Jr. 



National Biological Senice 



Calvin R. Fremling 



Winona State University 



Alan V. Nebeker 



U.S. Environmental 



Protection Agency 



Aquatic insects are among the most prolific 

 animals on earth, but are highly specialized 

 and lepresent less than 1% of the total animal 

 diversity (Pennak 1978). Most people know the 

 12 orders and about 11.000 species of North 

 American aquatic insects (Merritt and 

 Cummins 1984) only by the large adults that tly 

 around or near wetlands. 



Aquatic insects are excellent overall indica- 

 tors of both recent and long-term environmental 

 conditions (Patrick and Palavage 1994). The 

 immature stages of aquatic insects have short life 

 cycles, often several generations a year, and 

 remain in the general area of propagation. Thus, 

 when environmental changes occur, the species 

 must endure the disturbance, adapt quickly, or 

 die and be replaced by more tolerant species. 

 These changes often result in an overabundance 

 of a few tolerant species, and the communities 

 become destabilized or "unbalanced." 



Members of the order Diptera. or true tlies. 

 are especially good "bioindicators" of aquatic 

 environmental conditions because, in addition 

 to the attributes of other aquatic insects, they 

 occupy the full spectrum of habitats and condi- 

 tions (Paine and Gaufm 1956: Roback 1957; 

 Mason 1975; Hudson et al. 1990). 



Although considerable information on 

 aquatic insects and other macroinvertebrates 

 has been collected since the 1950's. most stud- 

 ies have been abbreviated surveys. There are 

 few good examples of long-temi biomonitoring 

 of aquatic insects in the United States because 



of the discontinuance of most routine biomoni- 

 toring in the 1980's, We present ongoing and 

 past examples of surveillance monitoring of 

 aquatic insects of the Ohio and Mississippi 

 rivers. Our interest here centers on the immature 

 stages of aquatic insects that, although usually 

 unnoticed, are part of the framework of natural 

 ecosystems (Fig. 1 ). 



Ohio River Aquatic Insects 



During 1963-67. aquatic insects (primarily 

 midges [Diptera]. caddisflies [Trichoptera]. 

 mayflies [Ephemeroptera]. and stoneflies 

 [Plecoptera]) and other benthic invertebrates 

 were monitored at 80-161 km (50-100 mi) 

 increments along the 1.582 km (963 mi) of the 

 mainstem Ohio River from Pittsburgh. 

 Pennsylvania, to Cairo, Illinois (Mason et al. 

 1971 ). Rock-filled basket samplers were a pre- 

 liminary collection device in addition to Ponar 

 substrate grab collections. 



In the upper Ohio River from river mile to 

 260 (418 km) at Addison, Ohio, during 1965- 

 67. the aquatic insect diversity (Fig. la) and 

 individuals (Fig. lb) in rock-filled basket sam- 

 plers were low compared with collections from 

 downriver sites. The macroinvertehrate fauna 

 consisted mostly of pollution-tolerant midge 

 larvae and worms, indicating poor to fair water 

 quality. In the lower reach from Louisville to 

 Evansville (distance of about 200 river miles or 

 322 km) the fauna was double to triple that of 



