Diet and Movements of Age-1+ Pink Salmon in Western Lake Huron

Abstract

Abstract Yearling pink salmon Oncorhynchus gorbuscha were collected from the Lake Huron sports catch from June through August 1985. We documented a northward movement of these fish from the St. Clair River in late spring to the Mackinac Straits area by late August. Pink salmon fed predominately upon rainbow smelt Osmerus mordax (45% by weight) and alewife Alosa psuedoharengus (38%). Other important food items were the adult stages of aquatic and terrestrial insects (5%), primarily of the orders Diptera, Ephemeroptera, and Lepidoptera. Zooplankton, of which primarily Daphnia pulex and Pontoporeia hoyi were eaten, were relatively unimportant (<1%). The diet of pink salmon overlaps those of other salmonids in the Great Lakes, and abundant year classes of pink salmon may adversely affect the growth and abundance of other species in the Great Lakes salmonid complex.