USGS Cooperative Ecosystem Studies Unit, Great Rivers CESU Grant

Nursery environments are areas where fish spend their early life history, which is the most sensitive life stage of most fishes. For example, the scarcity of nursery environments is thought to limit fish populations in highly channelized rivers. Within the Upper Mississippi River and Illinois River, source locations of fishes have only recently been explored, with an emphasis on a relatively small number of species of concern and species with recreational interest. Although source locations have been identified for these species, the contributions of particular source locations to population recruitment is not well understood. With over 150 fish species, advancing our understanding of natal environments and their contributions to recruitment represents an important step towards understanding habitat characteristics that support early life stages.