Limnological and Fisheries Studies of the St. Marys River, Michigan, in Relation to Proposed Extension of the Navigation Season, 1982 and 1983.

Abstract : The purpose of this study was to expand existing biological and physical/chemical data for the St. Marys River during 1982 and 1983 to help assess environmental impacts from proposed navigation season extension (January 31 2 weeks). This study builds upon previous data bases gathered during 1979 - 1981. Previous investigations were limited mainly to localities near Neebish Island, while the present study involves sampling sites ranging over some 64 km (40 mi) of the St. Marys River, including a site above the locks at Sault Ste. Marie. Similar techniques have been employed over the years whenever possible to assure comparability for assessing potential natural annual changes in the system's biota nd limnological characteristics. Thus, extensive pre - project data, involving collections carried out during 1979 through 1983, are available. This report contains data on the following topics: Physical and chemical aspects of water; winter sedimentation rates; benthic macroinvertebrates; aquatic macrophytes and primary productivity; ichthyoplankton; and, juvenile and adult fish. Keywords: St. Marys River system; Study stations; Aquatic plants; Primary production; Winter sedimentation; Benthic macroinvertebrates; Fish. (kt)