Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U. S. Environmental Protection Agency, 6201 Congdon Boulevard, Duluth, Minnesota 55804 USA

Summary

         We conducted an extensive survey of the nearshore waters in western Lake Superior along a continuous segment (537 km) from Grand Marais, Minnesota to near Eagle Harbor, Michigan on the Keweenaw Peninsula. A depth contour of 20 m was targeted using a towed CTD, fluorometer, transmissometer, and laser optical plankton counter (LOPC) to gather data on temperature, conductivity, fluorescence, light transmittance, and zooplankton size and abundance. The continuous electronic data stream provided a high resolution image of spatial variability both vertically and horizontally for each parameter. We describe the character of local, regional, and complete transect with goals of revealing spatial patterns not easily detected by other technologies, and briefly compare patterns to published historical trends. Preliminary relationships are presented among water quality and plankton measures. Regional patterns within the lake were related to gradients in landscape character along this stretch of coastline. Strong correlations to landscape characteristics provide suggestions that nearshore water quality may reflect the quality and nature of adjacent watersheds. We have demonstrated that the adaptation of electronic instrumentation and towed survey strategies are effective in providing rapidly collected and spatially extensive data for nearshore assessment of the Great Lakes.