Seal Stranding 101
Why do seals strand—and what should you do if you see one of these pinnipeds on a local beach?
- Conservation •
If you think seals are rare in the mid-Atlantic, think again! From January through April, as these marine mammals are migrating along the coast, it's not unusual to spot a seal on our local beaches in Maryland and Delaware. Harbor, grey and harp seals are the most common species in our region, but hooded seals have been spotted as well.
Not every seal you see on the beach is stranded—in fact, most are just resting. As semiaquatic animals, seals don't spend all of their time in the ocean and will come ashore regularly to take breaks or wait out storms. Moms will also temporarily leave their pups on the beach while they go hunting in the ocean. If the animal is lifting its head and tail regularly or moving around the beach, it's most likely just resting.
On the flip side, stranded seals have hauled out of the water and onto beach because they're sick or injured. Sometimes there are obvious physical signs that a seal needs medical attention—wounds, for example—but other times it can be harder to tell, since some sick animals will present themselves as healthy to ward off predators that may see them as an easy target.
There are two important steps to remember if you see a seal on the beach:
It may be tempting to get up close to a seal on the beach, but it's imperative that these wild animals are given plenty of space—150 feet, to be exact, which is the length of about three school buses. If the seal notices your presence and reacts in any way, you're too close. If you have a dog, make sure it's leashed—seals will bite if they feel threatened and can transmit diseases to your pet.
Call our team at 410-576-3880 and be prepared to share your location and a physical description of the seal, which will help us determine if it's in need of medical attention or just resting. If the seal is sick or injured, National Aquarium Animal Rescue will respond, and the seal will be transported to our Animal Care and Rescue Center in Baltimore for rehabilitation. Even if the seal is healthy and resting, National Aquarium Animal Rescue is still interested in knowing about the sighting so that we can continue to learn about the population of seals in our area and how these animals are utilizing our beaches and waterways.
Seals—along with sea lions, whales, dolphins, porpoises, manatees, dugongs, sea otters and polar bears—are protected under the Marine Mammal Protection Act (MMPA), which generally prohibits the harassment, feeding, capturing, hunting or killing of these animals in U.S. waters. Getting too close to marine mammals is considered harassment, which is all the more reason to give them space on the shore.
The MMPA was passed 50 years ago to restore marine mammal populations and uphold the important ecological role these species play in the ocean. The law has been a key factor in the recovery of seal populations along the East Coast, which were decimated to the point of near extinction by the 1960s due to overhunting.
Populations of grey seals in particular have rebounded so strongly in the mid-Atlantic that it appears they have established a colony—otherwise known as a rookery—off the coast of Delaware. One clue to the establishment of a local rookery is the increase in maternally dependent grey seal pups that have stranded on local beaches. Maternally dependent pups rely on their mothers for nutrition and are unable to forage for fish on their own in their natural habitats. National Aquarium Animal Rescue has admitted three maternally dependent seal pups in recent years: Pippi Longstocking, admitted February 2020; Eloise, admitted February 2021; and most recently, Louis Armstrong, admitted earlier this year.
Louis stranded on Assateague Island National Seashore in February and was suffering from dehydration and wounds to his left flipper and face. When he arrived at the Animal Care and Rescue Center, Louis weighed 35 pounds.
Since his arrival, Louis has made great strides in his recovery! He began successfully eating on his own on April 9, has gained about 10 pounds while under our care and has been treated with antibiotics to address infections from his wounds. He developed a lesion on his cornea, which is now healing well, and on April 20 he was transported to Veterinary Neurology and Imaging of the Chesapeake in Annapolis for a CT scan to determine if he has a middle ear infection. Our team is still awaiting results from the CT scan; in the meantime, they will continue to monitor Louis' health and provide enrichment opportunities as he continues to gain weight. He'll need to weigh about 50 pounds before he's eligible for release.