Seals are a common and increasingly visible presence along the U.S. East Coast, particularly from the Mid-Atlantic region northward. The Atlantic waters off the Northeast have seen a notable recovery in marine mammal populations since federal protection laws were passed. Seals are now regularly observed resting on beaches, rocks, and isolated jetties, demonstrating their successful return to historical habitats. Coastal visitors have a greater chance of encountering them, making it important to understand which species are present and how to safely view them.
Identifying Common East Coast Seals
The East Coast is primarily home to two species of true seals, each with distinct physical characteristics. The most frequently sighted animal is the Harbor Seal, a smaller species identified by its short, rounded, dog-like head and prominent V-shaped nostrils. Adults typically measure between five and six feet in length and weigh up to 285 pounds. Their coat color ranges from light gray to dark brown, often displaying distinct spots or speckles. When resting on land, these seals often elevate both their head and rear flippers into a distinct “banana-like” arch.
The second major species is the Gray Seal, which is significantly larger and often referred to as the “horsehead” seal due to its long, straight snout and broad muzzle. Adult males can reach lengths of over eight feet and weigh up to 800 pounds. Gray Seals possess W-shaped nostrils and a silver-gray coat with irregular dark blotches, which is darker in males. Less common visitors, such as the Harp Seal and Hooded Seal, are generally sighted further north, though young Harp Seals occasionally migrate down the coast during winter.
Coastal Distribution and Seasonal Habits
The primary distribution of East Coast seals centers around the New England region, particularly off Maine and Massachusetts, where both Harbor and Gray Seals maintain year-round populations. These northern areas serve as their main pupping and breeding grounds, with large colonies often observed on remote islands and ledges. Their presence extends much further south due to seasonal migration patterns tied to foraging and weather.
Harbor Seals undertake an annual southward movement beginning in the late fall, traveling to winter feeding grounds in Southern New England and the Mid-Atlantic states. During the coldest months (November through April), individuals are commonly reported in areas like New Jersey, New York, and Virginia. These animals utilize specific “haul-out” sites—coastal areas like rocky ledges, sandbars, or isolated beaches—where they temporarily leave the water to rest, regulate body temperature, or molt.
Haul-out sites are crucial for the seals’ survival, providing a safe space to digest food and conserve energy away from aquatic predators. The number of animals hauled out can fluctuate significantly, depending on environmental factors such as tide level and weather conditions. Seals exhibit strong site fidelity, often returning to the same favored locations year after year.
Federal Protections and Public Encounters
All marine mammals in United States waters, including seals, are protected by the Marine Mammal Protection Act (MMPA), a federal law enacted in 1972. This legislation makes it illegal to harass, hunt, capture, or kill any marine mammal. Harassment is broadly defined as any act that has the potential to injure an animal or disturb its normal behavior patterns.
When encountering a seal on a beach or shoreline, the public must maintain a safe distance to avoid causing disturbance. Federal guidelines recommend staying at least 50 yards (about 150 feet) away from seals, whether they are in the water or resting on land. This distance minimizes stress on the animals and prevents them from fleeing their haul-out site, which wastes valuable energy.
Never attempt to feed, touch, or pour water on a seal, as these actions are considered illegal harassment and can habituate the animals to humans, putting them at risk. If a seal is spotted alone on the beach, it is typically not abandoned; young seals may be left while the mother forages and should be left undisturbed. Any seal that appears sick, injured, or entangled should be reported immediately to a local authorized marine mammal stranding network.