The lake trout (Salvelinus namaucush) population at Stannard Rock, Michigan, an isolated offshore reef in eastern Lake Superior, was monitored each spring from 1959-79 using a permit assessment gill net fishery. This population, like nearly all of those in inshore waters, declined to low levels during the years of intense predation by the sea lamprey (Petromyzon marinus) in the late 1950's and early 1960's. After sea lamprey control began in 1961, the abundance of native lake trout at Stannard Rock began to increase slowly in the 1960's and was limited to recruitment into the fishable stock of native fish that were juveniles during the years of high sea lamprey activity. By the early 1970's lake trout abundance increased sharply and remained at a high level. This rapid recovery resulted from several strong year classes produced by the small spawning aggregations that reached maturity in the 1960's. Reproduction occurred in all years during and after the peak of sea lamprey activity in 1959. The strengths of year classes produced in 1963-1968 were related to the relative abundance of spawners the previous fall.
Additional publication details
Recovery of an offshore lake trout (Salvelinus namaycush) population in eastern Lake Superior