Seal Interactions with Fisheries

Squid and menhaden partially eaten by seals

As local seal abundance increases, so does reporting of fishing gear depredation by seals and concern about the larger-scale ecological interaction (competition) between seals and commercial and recreational fisheries.

The perception of fishermen that significant ecological interaction occurs comes from declines in abundance of commercially exploited species and observations of depredation, during which seals directly remove target species from fishing gear. Depredation by seals is observed or reported in most Cape Cod fixed-gear fisheries. However, it is difficult to quantify the extent of these interactions and to determine if they represent significant competition on a scale greater than that of the area or gear fished.

In collaboration with the commercial fishing industry, we are studying seal depredation of catch retained in fixed fishing gear. Fishermens’ observations are placed in a broader ecological context incorporating hypotheses regarding diet, foraging behavior and movement. Research on seal/fishery interactions is conducted in collaboration with a variety of partners, including fishermen, students, and the Northwest Atlantic Seal Research Consortium, and has been supported by the Massachusetts Marine Fisheries Institute, Sailors’ Snug Harbor of Boston, and the U.S. Marine Mammal Commission.