NATURAL REPRODUCTION BY STOCKED LAKE TROUT (SALVELINUS-NAMAYCUSH) ANDHYBRID (BACKCROSS) LAKE TROUT IN SOUTH-BAY, LAKE HURON

In 1977, a study was begun in South Bay, Lake Huron, to assess the fit ness of lake trout (Salvelinus namaycush) and lake trout backcrossed t o splake (S. namaycush X S. fontinalis) for rehabilitating the lake. M ature lake trout were fivefold more abundant than mature backcross fro m paired stockings. Wild progeny consisting of 321 fry and 67 age-0 to age-2 juveniles were collected in 1986-1992. We estimate that surviva l from potential egg-deposition to age I averaged 0.00035. The size of the two best wild year classes was small, approximately only 2,000 ye arlings each. At current exploitation rates sufficient numbers of wild trout are unlikely to survive long enough to produce a second generat ion.