Midwest Fish & Wildlife Conference 2018

AUTHORS. Cynthia Nau, Dr. Patrick Forsythe, Dr. Karen Stahlheber - University of Wisconsin- Green Bay; Dr. Cari-Ann Hayer, U.S. Fish & Wildlife Service

ABSTRACT. Small, lower-order (1st-3rd) tributaries of the Great Lakes have been largely understudied relative to the open water and large rivers in the region. This is also true of the small tributaries to Green Bay, Lake Michigan. Nonetheless, recent research suggests that these aquatic ecosystems play a vital role as reproductive, nursery and foraging habitat for the highly varied assemblage of fish species resident to Green Bay. Additionally, the tributaries of Green Bay exhibit a wide range of stream morphology and condition due to diverse geologic and anthropogenic influences in each individual watershed. This large environmental gradient allows for exploration of ecology of resident fish species in relation to abiotic variability in intricate detail. The primary objective of this study is to quantify the diversity, distribution and habitat selection of resident fishes on a fine scale. This assessment will be carried out on eight tributaries of variable condition with direct connection to Green Bay. A fine scale survey will be conducted over a one-kilometer stream profile, divided into 20-meter sub-reaches. Preliminary results suggest that the fish community composition changes as distance from the stream’s mouth increases. Additionally, abundance of fishes may also exhibit a pattern across the longitudinal profile. This research will serve to inform restorative management actions that will provide the most benefit to individual streams and fish species. Due to the vast amount of variation found in the Green Bay sub-watershed, this information may be applied to tributaries across the Great Lakes region.