New England Lobster Under Changing Climate: An Evaluation of Temporal Variability in Lobster Suitable Habitat

The American lobster (Homarus americanus) distributed along the coast of northeastern United States is a major commodity throughout the species’ range. We hypothesize that the ongoing warming trend in New England waters is changing the availability of suitable habitats for American lobsters in the Gulf of Maine (GOM) and Southern New England (SNE). To test this, we developed a Habitat Suitability Index (HSI) model to quantify the spatio-temporal variability of suitable habitat for GOM and SNE stocks.  Fisheries and corresponding environmental data from 1963/1982 to 2010 were used to develop a suitability index (SI) in the form of a linear transfer function based on species abundance (CPUE) for each habitat variable. To validate our model, data from 2011 and 2012 were used to estimate the spatial distribution of HSI. We used ArcGIS to create continuous raster maps of the HSI model, and evaluated the impact of climate change by calculating spatio-temporal changes in the amount of suitable habitat over the past 30 years for the GOM and SNE lobster stocks. This study will contribute to the development of modeling framework to incorporate habitat information for current lobster management given the expected changes in the northeastern US marine ecosystem.