Ecosystem Change Indicators for Lobster

The Gulf of Maine has been warming rapidly over the past 30 years, a trend recently punctuated by more frequent ocean heatwaves. The region also experiences high levels of seasonal and interannual variability in physical conditions such as currents and winds. Further, the predator community for lobster has changed — fishing pressure has reduced groundfish threats, but warming waters bring new lobster predators to the Gulf of Maine. These ecosystem changes influence lobster biological processes, like molting and growth, size at maturity, fecundity, larval survival, and recruitment. Ultimately, these biological processes shape lobster populations and the Maine lobster fishery.

We are developing a suite of ecosystem indicators to identify changes in the ecosystem and analyze influences on lobster biological responses and fishery direction. Indicators will include physical and biological conditions such as surface and bottom temperature, salinity, stratification, position and strength of the Maine Coastal Current, and lobster predator indices. We will analyze trends over time within indicators, but will also analyze how the indicators relate to lobster population dynamics and fishery characteristics. We work through the Maine’s Lobster Research Collaborative to ensure insights from this project contribute to the collective understanding of lobster and the lobster fishery in a changing Gulf of Maine.