Ecological Implications of a Northern Range Expansion of Black Sea Bass

Black sea bass historically ranged from the Gulf of Mexico to Cape Cod, but in recent years it has been reported as far north as midcoast Maine. This apparent northern range expansion is likely due to increasing water temperatures in the Gulf of Maine; however, the ecological impacts of sea bass range expansion are uncertain. We conducted SCUBA surveys to quantify sea bass range expansion and used video and stomach content analyses to determine impacts on benthic community structure throughout the coastal waters of the Gulf of Maine. Preliminary results suggest that adult sea bass range as far north as midcoast Maine, while juvenile sea bass are rare north of Massachusetts. Furthermore, the territorial nature of sea bass, and their preference for nearshore rocky habitat, may potentially have large density- and behaviorally-mediated effects on community structure. As regions such as the Gulf of Maine undergo climate-induced warming and shift to an ecosystem approach to fisheries management, a greater understanding is needed of how range expansions and contractions will impact food web dynamics and fisheries productivity of native species.