Non-native fish species richness and distributions in Great Lakes coastal wetlands

Session: Poster Session

Erin Bergen, Mary Griggs Burke Center for Freshwater Innovation, Northland College, [email protected]
Ella Shively, Mary Griggs Burke Center for Freshwater Innovation, Northland College, [email protected]
Matthew Cooper, Northland College, Mary Griggs Burke Center for Freshwater Innovation, [email protected]

Abstract

Coastal wetlands perform vital ecosystem functions in the Laurentian Great Lakes, including support of basin-wide fish communities. Unfortunately, many of these wetlands have been invaded by non-native species, which can disrupt food webs and alter ecosystem function. Using data from the Great Lakes Coastal Wetland Monitoring Program, we explored the influence of habitat, water quality, and native fish community structure on non-native fish richness (NNR) and the occurrence of several non-native fish species. The dataset included 388 coastal wetlands located throughout the Great Lakes, sampled from 2011 through 2015. Over half (59%) of the wetlands contained at least 1 non-native species and a total of 16 non-native fishes were collected basin-wide. NNR tended to be higher in submerged aquatic vegetation than other habitat types, though this relationship varied among Great Lakes. We identified hotspots of NNR (at least 4 non-native species) in the Duluth-Superior Harbor, Green Bay, Keweenaw Bay, St. Marys River, Western Lake Erie, and several points around Lake Ontario. These locations were in close proximity to shipping ports. Clearly, there are many factors influencing non-native fish invasion of GLCWs. Identifying these factors could aid in management decisions regarding coastal wetland rehabilitation and the prediction of invasion susceptibility.