Smaller, Younger, Sicker Seals
These cases are just two examples of a huge shift in the population of rescued seals that our team has cared for in recent years. Ten years ago, a standard rescued seal was a harbor seal with medical issues that were relatively easy to treat; they were typically underweight with mild respiratory infections. Over the past five years in particular, this has changed dramatically.
In the northwest Atlantic, the population of grey seals has steadily pushed the population of harbor seals out of their traditional range. This trend seems to be moving south along the coast, as 15 years ago, rescue organizations in New England were seeing this same population shift. After that, the Long Island area began to see more greys than harbors, and now our team in the mid-Atlantic is consistently caring for more sick grey seals.
This is due in part to the establishment of a grey seal rookery off the coast of Cape Henlopen, Delaware. As a new herd has emerged from this rookery, our team is seeing more pups than ever before; the grey seal pup who was in our care this season was only two months old. These younger seals come with a whole new set of medical issues and needs.
"These seals are smaller and younger, with more complex medical problems, than those we were seeing in the past," Senior Rehabilitation Biologist Margot Madden explained. "Serious infections, like lungworm and ear infections, can be detrimental for these young pups that don't have fully formed immune systems."
This shift in the regional seal population has resulted in cases that are much more challenging for our team to treat, but they're learning as much as they can from experience and collaboration with colleagues in other regions. The future of the changing seal demographic in the mid-Atlantic—and how it will continue to impact the seals in our care—may be unclear, but one thing is for certain: Our team remains committed to saving every seal that comes through our doors, no matter how challenging the case may be.
All National Aquarium stranding response and seal rehabilitation activities are conducted under NOAA permit 18786-04.