Project
Quantifying relationships between preyfish abundance and piscivore foraging and growth
Fisheries management actions in the Great Lakes, and particularly in Lake Michigan, often rely on the assumption that predators respond proportionately to preyfish abundance. However, this assumption has not been evaluated with empirical data. Quantification of relationships between preyfish variation (in abundance and size) and synchronous variation in predator responses (e.g., diets, stable isotope ratios, and growth) is needed, and recent efforts to quantify predator foraging ecology provide an opportunity to explore uncertainties regarding how consumptive patterns and growth respond to preyfish variation. Further, uncertainty surrounds which of numerous preyfish surveys offer the best predictor(s) of predator outcomes. Lake Huron offers the opportunity to contrast observations to Alewife-dominated Lake Michigan. This study represents an important step towards establishing how predatory fishes in the Great Lakes partition available resources along multiple resource gradients, such as prey abundance, size, and spatial distributions.