A working hypothesis suggests that wild rainbow stocks in monoculture and coarse fish lakes represent two fundamentally different management situations. Within these two categories the ratio of lake area to stream spawning and rearing area is the key driving variable. In comparison with monoculture lakes, coarse fish lakes are hypothesized to have lower stock productivity and an exacerbated effect of size on survival. As a result, rainbow stocks in coarse fish lakes are more prone to population collapse and more dependent on streams as rearing areas for juveniles. If true, this implies that avoiding population collapse and protection of stream rearing habitat are key management problems on coarse fish lakes. In contrast, excessive juvenile recruitment and insensitivity to high rates of exploitation should be more characteristic of monoculture lakes.
Parkinson, Eric A.. 1990. A Framework for Wild Stock Management of Rainbow Trout in Small B.C. Lakes. BC Ministry of Environment. Fisheries Project Report. RD-23