Effect of Abiotic Factors on Bluegill Size Structure in Nine Central Minnesota Lakes

Bluegill are the most targeted species of fish in Minnesota. In recent years, the abundance of slow growing, small Bluegill has increased within the state. Angler harvest of Bluegill can reduce the average length of Bluegill up to four times the original length. Abiotic factors such as maximum depth, average water clarity, littoral area, and percent littoral area can influence the dynamics of a lake system. There has been limited research on whether these abiotic factors can influence the size structure of a Bluegill population. The objective of this study is to determine if there is a direct relationship between each of these abiotic factors and the average size of Bluegill in Central Minnesota lakes. Each abiotic factor measured was related to average length of Bluegill through linear regression analysis. It was concluded there was not enough evidence to suggest there is significant relationship between any of the abiotic factors and the average length of Bluegill. This conclusion suggests other factors such as angler harvest may have a larger influence on Bluegill length in these systems.