Harbor seals are winter visitors to Maryland, not year-round residents, hauling out on sandbars and jetties near Assateague Island and the lower bay refuges after moving south from New England and Canadian pupping grounds each fall. Nearly all of the state’s records fall between January and April, tapering off fast after that.
That sharp seasonal drop-off is real biology, not a survey artifact: harbor seals largely withdraw from Chesapeake Bay waters by late spring. The species carries no NatureServe rank in Maryland since it’s only a seasonal visitor rather than a resident breeding population.
Full species profile
