Limiting similarity for coexistence of lake herring (Coregonus artedii) and chubs (Coregonus hoyi)

A simple food competition model was applied to calculate the limiting similarity for coexistence of lake herring and chubs in Lake Superior in terms of mortality and diet overlap. The results indicate that species can coexist over a wide range of diet overlap and mortality. In communities with high diet overlap change in mortality could have an effect on the outcome of competition, whereas in other communities the species would continue to coexist but with changes in relative abundances of species. The outcome of competition between lake herring and chubs was simulated with a moderate diet overlap which allows coexistence with a large increase in lake herring mortality. The patterns in the simulated abundances were similar to the patterns in the catch per unit of effort data.