Simulated consumption of submersed aquatic vegetation by grass carp in representative coastal wetlands of eastern and northern Georgian Bay, Lake Huron

Grass carp are a major, immediate threat to the Great Lakes basin with reports of sightings and captures throughout Lakes Erie and Huron. In Georgian Bay, the many pristine wetlands are already under threat from climate change and a deviation from historic water level regimes. A model Grass carp consumption at specific densities and throughout decades are analyzed at multiple water levels that are possible in the future. Water levels provide a unique context for grass carp invasion, and those with less biomass (very low and very high) present the quickest decimation of wetlands throughout Georgian Bay. Given expected movements of an invasion, these data show that Georgian Bay wetlands are at risk of decimation within 25-100 years. While these high-quality wetlands provide more resistance to grass carp invasion than those found in the lower Great Lakes, we must work to preserve the pristine habitat that is left in eastern & northern Georgian Bay.