No mammal in Maine has more records than the harbor seal, which counts 4,770 across the state. Only 1,480 of them are iNaturalist observations. The rest come through GBIF, likely from boat surveys and long-running monitoring work, so the totals mostly track where researchers have counted seals rather than how the animals spread along the coast.
Hancock County, home to Acadia National Park, holds 3,447 records on its own. Lincoln, next down the list, has 76, with Cumberland, Washington and Knox close behind. Most of the remaining records carry no county at all, plotted out on the water and offshore ledges beyond the county lines. Acadia is also the most often named place, though only 18 records tie to the park itself, and Rachel Carson National Wildlife Refuge, Laudholm Farms, and Crescent Beach State Park add a few more.
The calendar is sharply summer-heavy. Reports jump in May, peak in June at 1,191, and stay high through August, the stretch when pups are born and adults molt on the rocks. After that they fall away fast and, apart from a brief January bump, bottom out in February. Farther south along the Atlantic coast the pattern flips, and harbor seals show up mainly as winter visitors, a sign that many shift away from Maine’s waters in the cold months. In Maine the species is native and ranked S5 by NatureServe, the secure end of its scale.
Full species profile
