Production of Wild, Domestic, and Interstrain Hybrids of Brook Trout (Salvelinus fontinalis) in Natural Ponds

Abstract

Hatchery-reared wild and domestic strains of brook trout (Salvelinus fontinalis) were released in natural lakes, and survival and growth estimated at semiannual intervals throughout the life span. Angling was restricted. Four experiments with two year-classes involved three different Adirondack Mountain (New York) wild strains and two domestic strains, a fifth experiment included two wild strains from James Bay, Quebec and a hybrid between one of these (Assinica Lake) and a New York domestic strain. Wild and hybrid strains consistently exhibited greater longevity (5–7 yr) compared with domestic (few recovered after 3 yr). Climax sizes were not much different, except the Domestic × Assinica hybrid that was substantially larger than either of the two parents. Gross production and yield to angling of any given strain cohort was correlated (r = 0.93) and life-span gross production was 50% greater for wild and hybrid groups per unit fish stocked. Biomass stocked per recruit was much larger for domestic strains, and taking this into account, the ratio of gross production to weight stocked was about 6 times greater. Increased costs of rearing nondomesticated strains, if any, must be taken into consideration in an economic evaluation, but use of wild and/or hybrid strains of trout offers significant benefits under management conditions of these experiments.