Seasonal Offshore/Inshore Migration of Round Gobies

Abstract

Since the invasion of round gobies (Neogobius melanostomus) in Lake Michigan, they have become integrated into both the nearshore and offshore food webs. Round gobies can be found in shallower water (30 m) until mid-May, when they began the return to nearshore habitat. The cues to start the offshore and return migrations were not the focus of this project, but the fall offshore migrations coincided with decreasing temperatures nearshore in the fall, and in spring, the offshore movement of the thermal bar. The offshore migration in fall provide an increase in forage opportunity for deep, cold-water predators such as lake trout, that cannot access nearshore habitat when the lake is stratified because of temperature barriers.