A comparison of predator diets in Lake Michigan and Lake Huron

Session: Exploring Predator-Prey Relationships and Feeding Ecology in the Great Lakes (3)

Brian Roth, Michigan State University, [email protected]
Jory Jonas, Michigan Department of Natural Resources, [email protected]
Katie Kierczynski, Michigan State University, Department of Fisheries and Wildlife, [email protected]
Matthew Kornis, U.S. Fish and Wildlife Service, [email protected]
Benjamin Turschak, Michigan Department of Natural Resources, [email protected]
Edward Roseman, USGS-Great Lakes Science Center, [email protected]
Jixiang He, Michigan Department of Natural Resources, Lake Huron Research Station, [email protected]
Kevin Donner, Little Traverse Bay Bands of Odawa Indians, [email protected]

Abstract

The Great Lakes have changed rapidly in the last 20 years.   In particular, lakes Michigan and Huron have demonstrated drastic declines in preyfish populations that have led to questions regarding the sustainability of predator populations in both lakes.   Together with the invasion and subsequent expansion of round goby populations, there is a need for updated diet information that can inform management of piscine predators in lakes Michigan and Huron through predator demand modeling.  We will present results of a comprehensive diet study of salmonine predators and Walleye in both lakes conducted during 2017 and 2018.   Our results indicate that most salmonine predators in Lake Michigan continue to rely heavily on alewife, but nearly all are relying on round goby than previous studies indicate.  The increased reliance on round goby was also observed in Lake Huron, but to a greater degree.  In particular, Round Goby now comprise the majority of Lake Trout and Walleye diets in Lake Huron, but all predators are consuming a greater diversity of prey items compared to Lake Michigan.  The comparison between lakes highlights how Great Lakes predators will adapt to declining prey abundances, and help managers develop strategies for sustaining a robust fishery.

Twitter handle of presenter
@JonasJory