Characterizing Historical Offshore Fish Communities in the Upper Laurentian Great Lakes

The upper Great Lakes (Superior, Huron and Michigan) are among the largest lakes in the world and form a continuous freshwater system comprising over 200,000 square miles.  The three lakes differ in the amount of anthropogenic influence, and represent a gradient of impacts.  The native offshore fish communities of the lakes are similar, although they have been altered by invasive species and several native species have become less common or have been extirpated.  Recent invasive species have drastically altered food webs in the upper Great Lakes, and the offshore fish community in Lake Huron has collapsed.  Restoration of these fish communities is an important management goal, but realistic restoration targets are unclear.  We demonstrate how the application of multivariate methods to reconstructed historical offshore fish communities of the upper Great Lakes can be used to assess potential restoration targets.