Biotic and Abiotic Factors Affecting Feeding Success of Early Juvenile Lake Whitefish in Lakes Michigan and Huron

Abstract

Feeding success is associated with increased growth and survival during early life stages for fish, and understanding the factors that influence feeding success is a critical step toward predicting future recruitment to the fishery. The goal of our study was to test whether various biotic and abiotic factors, including prey abundance, fish abundance, and water temperature, affected the feeding success of early juvenile Lake Whitefish Coregonus clupeaformis from Lakes Michigan and Huron. Higher feeding success, which was determined using residuals from average weights of consumed prey for a given length fish, was associated with more rapid growth rates in length and depended on multiple factors. Although the relationships were not overly strong, one factor that was most consistently associated with increased feeding success was available zooplankton biomass in combination with some other factor(s) such as water temperature and/or total fish or Lake Whitefish density. There was no difference in diet composition or the available zooplankton community composition among four different levels of feeding success. Feeding success measures help integrate complex environmental factors that can vary with fish ontogeny. In turn, feeding success has the potential to be an important metric for Lake Whitefish fishery management strategies that critically need to account for the myriad factors influencing survival and growth of prerecruits to the fishery.