Drift of Zooplankton, Benthos, and Larval Fish and Distribution of Macrophytes and Larval Fish during Winter and Summer, 1985

摘要

The St Marys River, the connecting channel between Lake Superior and Lakes Huron and Michigan, is part of the vast surface waters of the Great Lakes and therefore bears a considerable amount of recreational boat and commercial ship traffic. Several questions have been raised regarding the impact of large ship passage on the indigenous fish and wildlife. Extended winter operation of the lock complex at Sault Ste. Marie, Michigan has been proposed to 31 January + or - 2 wk. This contract was prepared to obtain data to allow predictions regarding the impact of winter shipping to as late as 15 February on the St. Marys River. Because of the surge and currents that ships can generate, they may have substantial effects on the spawning grounds of such important fish as lake whitefish (Coregonus clupeaformis), lake herring (C. artedii), and other recreationally important species. There is also concern about the effects of ship passage on benthic invertebrate communities, and how sediment resuspension, possibly caused by ship traffic, may impact the primary producers in the system, especially the aquatic macrophytes. The fauna of the St. Marys River is a combination of animals drifting or moving in from Lakes Superior, Huron, and Michigan and those produced within the system. The river includes backwater; connecting channels, embayments, and Lakes; scattered wetlands; and other estuarine habitat. To examine some of the impacts of winter and summer navigation on the indigenous fauna and flora, we studied three components of the St. Marys River ecosystem; the macrophyte community, the drifting benthos and zooplankton community, and the larval fish community.