The Relationship of Bluegill Growth, Lake Morphometry, and Water Quality in Minnesota

Abstract

We evaluated the relationships between the growth rate of bluegill Lepomis macrochirus and lake morphometry and water quality at 1,146 Minnesota lakes to determine the potential strength of the latter two variables in a model of bluegill growth. Secchi depth and maximum depth were negatively correlated with bluegill length at ages 1–6, whereas total alkalinity, percent of littoral area, and mean maximum July air temperature were positively correlated with bluegill length at those ages. Secchi depth, maximum depth, and total alkalinity explained 16–33% of the variation in the growth of bluegill through their first 5 years. The lake morphometry and water quality variables did not explain more of the variation in bluegill growth among lakes because other variables, such as food resources, species interactions, and exploitation also affect bluegill growth. However, these two variables can be used to preliminarily sort candidate lakes for regulation of recreational angling for bluegill and should be considered when modeling bluegill growth.