Evaluating shifts in fish community production and predator abundance in northern Wisconsin lakes with different Walleye recruitment histories

Abstract

In recent decades, Walleye sander vitreus natural recruitment and production have declined in some lakes in the Midwestern United States and Canada, concurrent with increases in warmwater centrarchid abundance. Several factors have been implicated with these shifts in community structure and species dominance, including climate change and the harvest-orientation of fisheries. When shifts in fish species dominance occur, finite resources may become re-distributed within the food web to alternative species due to potential competitive effects, predatory advantages, or increased suitability of critical habitat for certain fish assemblages. Redistribution of finite resources and productive potential may perpetuate shifts in community structure and species dominance via feedback loops where recruitment and production potential is continually constrained for species with declining populations (depensation) and continually supported for species with increasing populations (cultivation). Understanding the distribution of fish community production among individual species or functional groups can aid in identifying potential trade-offs in management or management options focused on Walleye rehabilitation.