LAKE TROUT (SALVELINUS-NAMAYCUSH) POPULATIONS IN LAKE-SUPERIOR AND THEIR RESTORATION IN 1959-1993

Naturally-reproducing populations of lake trout (Salvelinus namaycush) have been re-established in most of Lake Superior, but have not been restored to 1929-1943 average abundance. Progress reward lake trout re storation in Lake Superior is described, management actions are review ed, and the effectiveness of those actions is evaluated; especially st ocking lake trout as a tool for building spawning stocks, and subseque ntly, populations of wild recruits. Widespread destruction of lake tro ut stocks in the 1950s due to an intense fishery and sea lamprey (Petr omyzon marinus) predation resulted in lower overall phenotypic diversi ty than was previously present. Stocking of yearling lake trout, begun in the 1950s, produced high densities of spawners that reproduced whe rever inshore spawning habitat was widespread. Sea lampreys were great ly reduced beginning in 1961, using selective chemical toxicants and b arrier dams, but continue to exert substantial mortality. Fishery regu lation was least effective in Wisconsin, where excessive gillnet effor t caused high by catch of lake trout until 1991, and in eastern Michig an, where lake trout restoration was deferred in favor of a tribal fis hery for lake whitefish (Coregonus clupeaformis) in 1985. Restoration of stocks was quicker in offshore areas where remnant wild lake trout survived and fishing intensity was low, and was slower in inshore area s where stocked lake trout reproduced successfully and fishing intensi ty was high. Inshore stocks of wild lake trout are currently about 61% of historic abundance in Michigan and 53% in Wisconsin. Direct compar ison of modern and historic abundances of inshore lake trout stocks in Minnesota and Ontario is impossible due to lack of historic stock ass essment data. Stocks in Minnesota are less abundant at present than in Michigan or Wisconsin, and stocks in Ontario are similar to those in Michigan. Further progress in stock recovery can only be achieved if s ea lampreys are depressed and if fisheries are constrained further tha n at present.