Biota of Lake St. Clair: habitat evaluation and environmental assessment

Abstract

As a shallow, productive lake in the drainage system between Lake Huron and Lake Erie, Lake St . Clair provides habitat for a diverse biota including significant populations of fish and wildlife that are of use to man . Of the more than 70 species of native and migrant fishes, 43 use the lake for spawning . Peak numbers of waterfowl utilizing the lake and adjoining wetlands have been estimated at 60 000 in spring and 150000 in autumn. In addition to recreational fishing and hunting, the lake is also used for swimming, boating and as a source of municipal water . It is located downstream from an industrial centre and adjacent to a population estimated at about four million . Mercury contamination closed the fisheries in 1970 and concentrations of the metal persist above consumption guidelines in some species . Almost all of the Michigan shoreline is urbanized and much of it altered through dyking and bulkheading . Coastal wetlands of the lake have declined 41 percent in the past century and only about one-half of the remaining area is open to the lake .Despite impacts from the large urban population and users, ecosystem quality remains reasonably good . The flushing action of relatively clean water from Lake Huron has slowed the eutrophication process . Major habitat problems are toxic substances from industries located on the St . Clair River and the continued loss of shoreline and wetlands to urbanization and agriculture . Further research and monitoring of sources, fates and impacts of toxic substances in sediments and biota are required . In addition, there is a need for environmental and economic evaluations of shorelines and wetlands to prevent further losses of these important habitats .

Lake St. Clair Zooplankton: Evidence for Post-DreissenaChanges

“…Ecologically, Lake St. Clair is part of the St. Clair-Detroit upper connecting channels system and supports diverse habitats and a productive biological community (Edsall et al 1988, Leach 1991. Over 70 species of fishes are found in the lake, and 43 of those use the lake for spawning (Leach 1991).…”

Impact of zebra mussel (Dreissena polymorpha) on phosphorus cycling and chlorophyll in lakes

“…The three lakes are well mixed (Mills et al 1978;Schertzer et al 198'7;Leach 1991), but differ in their hydrology, morphology, and water chemistry budgets: this allowed us to examine the effects of zebra mussel on P dynamics over a range of conditions. For each lake, we developed simple P mass balance models to predict how much of a reduction in P levels would be expected because of zebra mussel growth, and compared our predictions with data from the literature.…”

Daphnia lumholtzi Sars a new alien species in Lake St. Clair

“…This 3.5-m deep station is along a seawall at the mouth of the Thames River in the southeast corner of Lake St. Clair. This area is influenced by warm, turbid, nutrientenriched water from the Thames (Leach, 1991). Water temperature was 24°C and Secchi depth was 0.5 m. D. lumholtzi density (117 individuals/m 3 ) was higher than the average (30 individuals/m 3 ) calculated for the same species in Lake Erie in August 1999 (Muzinic, 2000).…”