National Aquarium Releases Two Rescued Juvenile Grey Seals, Clearing Seal Rehabilitation Suites

On Thursday, June 26, two rehabilitated juvenile grey seals known to Aquarium staff as Evergreen and Remington made their way back into the ocean at Assateague Island State Park after receiving lifesaving treatment courtesy of the National Aquarium Animal Health and Rescue teams. With their release, there are officially no seals in treatment at the Aquarium's Animal Care and Rescue Center (ACRC) in Baltimore for the first time since February.

The final patients in treatment after a busy seal rescue season that saw the ACRC's rehabilitation spaces at capacity for all of spring and early summer, Evergreen and Remington arrived at the Aquarium under different circumstances but ended up recuperating thanks to similar courses of treatment.

Evergreen arrived at the ACRC on March 10 after stabilizing overnight at the National Aquarium's Stranding Response Center in Ocean City. Evergreen was collected by our partners at Marine Education, Research and Rehabilitation Institute (MERR) from Cape Henlopen State Park in Delaware on March 9 exhibiting puncture wounds that appear to be the result of an interaction with a shark. He was treated with antibiotics and pain medication and, as he recovered, he learned to swim, eat and forage for fish independently while gaining approximately 30.5 kg (about 67 lbs.)

Remington, another weanling male grey seal, was rescued by MERR after being found in Dewey Beach, DE on April 27 with lacerations to his hind flippers but also demonstrating clear respiratory distress which was found to be a result of a lungworm infection. He was transferred to the ACRC after spending a night in triage in Ocean City.

Both Evergreen and Remington were also treated for lungworm during their time at the Aquarium. Lungworm, a potentially fatal condition passed to seals and other species through their food supply in the ocean, is treated with a course of antiparasitic drugs that takes several weeks to effectively eradicate the infection. The respiratory distress seen in Remington's case is a typical—and dangerous—symptom of lungworm in very young seals.

The other seals successfully rehabilitated at the ACRC earlier this season include Woodberry, rescued by MERR in Fenwick, DE on February 25, and Waverly, rescued by MERR on Dewey Beach, DE on March 10, both of which were released from Assateague Island State Park on April 24; and Arcadia, who was rescued by National Aquarium Animal Rescue on March 13 in Ocean City and released on May 22 at Assateague Island State Park. All the seals successfully rehabilitated this year at the ACRC were young pups recently weaned from their mothers or, in the case of Arcadia, still maternally dependent.

Animals in this age range are especially vulnerable to malnutrition and dehydration as well as threats from other animals and a range of injuries and infections. Teaching these pups to forage for food and eat independently is a primary focus for the Aquarium's Animal Health and Rescue teams, while each seal also receives fluids, antibiotics, pain management and round-the-clock care specific to their needs.

Upon release, Arcadia and Waverly were both outfitted with satellite tags that allow Aquarium teams and partners to track the animals' paths as they reacclimate to ocean waters and resume natural migratory patterns. While Arcadia's tag malfunctioned and contact was lost after just a few days, Waverly is back in the swim.

So far, tracking signals have been received for more than 80 days as far away as Block Island, RI, and she has been spotted twice by Aquarium colleagues at Mystic Aquarium. Most recent action shows her circling off the shore of Cape Cod and possibly moving toward Nova Scotia in keeping with typical seasonal migration.

"Watching Waverly's movement up the East Coast to New England and beyond is its own reward after such an active rescue season that is naturally full of ups and downs as we work to save the lives of these animals," said National Aquarium Senior Rehab Biologist Margot Madden. "We work very hard to rehabilitate seals specifically so they can resume their natural behaviors and add to the stability of these species in our region and within ocean ecosystems."

The successful treatment and release of five seals in four months indicates a busy season for Aquarium teams who were juggling up to four seals at once for several weeks this spring. Increased seal rescue activity in our region over the past several years can be attributed to the natural establishment of a rookery (or colony) of harbor and grey seals off the coast of Cape Henlopen, DE. Due to these larger local populations, experts are reevaluating what a "typical" seal season in the mid-Atlantic might entail.

Previously thought of as several months from late winter through spring, this region's anticipated seal season is stretching out, and despite the Aquarium's seal rehab suites sitting empty at the moment, it is not out of the question that seal rescue activity could occur at any time.

Aquarium teams also encountered several seals that did not survive to receive treatment this season, including a geriatric adult male harp seal that expired naturally during his intake examination at the ACRC, and a female juvenile grey seal who passed after being found entangled in a fishing net on Assateague Island.

In total, 13 seals have moved through our Ocean City Stranding Response Center through this point in 2025, including two—Guilford and Montebello—who were released directly back into the ocean after treatment in Ocean City this winter. As a rule, seals suffering from less intense symptoms and injuries who can be effectively treated in fewer than 4 days can be managed in Ocean City without transfer to Baltimore. Some seals encountered by our team were too badly injured to benefit from treatment, so our team had to make the difficult decision to humanely euthanize these animals.

Animal Rescue personnel in Ocean City also responded to the aid of a dolphin spotted near 40th Street in Ocean City that did not survive to receive treatment.

Despite the onslaught of cases requiring treatment each year, the National Aquarium Animal Rescue program relies on funding from private philanthropic partners and coordination from the National Oceanic and Atmospheric Administration (NOAA) to effectively respond to the increasing number of seal strandings.

The Aquarium has occasionally benefited from funding through NOAA's John H. Prescott Marine Mammal Rescue Assistance Grant Program to support seal stranding response and rehabilitation. Funding for this grant program is vital for the research and recovery of stranded marine mammals in the Mid-Atlantic and beyond.

All seals treated by the Aquarium's Animal Health and Rescue teams will eventually be assessed by Aquarium staff and hopefully cleared for release back to the ocean by our partners at NOAA as soon as possible so that their natural foraging instincts stay intact.

To be considered eligible for release, each seal must weigh about 25 kg and recover from any injuries and infections, which, in the case of animals of this size and age, generally means a minimum of five to six weeks in rehabilitation.

NOAA plays a crucial role in overseeing the Marine Mammal Stranding Response Network, which helps coordinate emergency response and data collection with partners like the National Aquarium.