Mapping and modeling habitat to determine drivers of dramatic shifts in American lobster demography in the Gulf of Maine
Date:
Abstract: The American lobster naturally prefers to occupy shelters and populations have historically been concentrated in shelter-providing boulder habitat. However, this paradigm has shifted resulting in fundamental change in their behavior, ecology, and distribution. From 1997 to 2019, population densities in shallow zones (~10 m) of coastal Maine surveyed via scuba declined over 66% in boulder habitats but increased 202% in relatively featureless habitats, and lobsters found using rocky shelters declined 30%. Remotely operated vehicle (ROV) and multibeam echosounder (MBES) surveys were conducted at several of the same sites to expand depth and spatial coverage. The ROV surveys were used to groundtruth MBES data in a random forest model to classify and map benthic habitat. The demographic data, habitat maps, laboratory experiment results, and environmental data are being used in a spatial-explicit individual based model to understand the drivers of lobster habitat use and behavior changes.
Authors: Jarrett, R., Steneck, R.
Ph.D. Dissertation Research at the University of Maine