Last Call for Seals at Sandy Hook

Early spring around Lower New York Bay, including Sandy Hook Bay and Raritan Bay, often means a time when plants start to show new flowers, trees start to grow new leaves, and people start to plant new things.  Yet, it’s also a time to say farewell to our favorite winter wildlife visitors.

The first full week of spring brought with it not only some light snow, but another sight of Harbor Seals at Sandy Hook Bay. I counted about 60 seals, at the same spot doing what they had been doing all winter long. They were enjoying a nap and using the sun's energy to warm up. They all looked quite comfortable on a remote sandy beach in the bay located downstream from lower Manhattan.

But we shouldn’t get used to this view much longer. As the weeks more forward, more and more seals will be heading off to make the long migration northward to the coastal waters of eastern Canada and Maine to start breeding. Usually, adult seals are out of here by mid to late April.

At breeding sites up north, adult females will soon be arriving to give birth. Since gestation usually lasts 10 to 11 months for Harbor Seals, there is no doubt that at least some of the seals seen this past winter in Lower New York Bay and Sandy Hook Bay were pregnant females. Only a single pup is born to a single female each year, which will weigh around 30 pounds.

Pupping occurs principally from mid May to late June. The mother will nurse her young  with a rich, fatty milk. After about a month, the pup is then left to fend for itself and to forage for its own food, including shrimp and small fish. It will not be an easy life for a young seal. The pups are vulnerable to shark attacks and even assaults from foxes and large birds of prey. As it grows, the pup will become a faster swimmer and a more skilled at avoiding predators, and catching larger fish such as herring and flounder, and finding mollusks including clams and squid.

It will take between four and six years for a Harbor Seal to be fully grown, at which time it may reach over five feet in length and 250 pounds. Harbor Seals live to be about 35 years of age, perhaps more.

After the pups are weaned, mating will take place during the summer months in the waters off Maine and southern Canada. Males will attempt to mate with as many females as possible. The seals are not monogamous, and males will mate with several females during the breeding cycle to spread genetic diversity.

After mating, Harbor Seals will then spend late summer and fall molting, the shedding and regeneration of hair. Molting occurs after every breeding season. This is when the highest number of seals can be seen on a beach in Maine and southern Canada since during this period they rest more.

After molting, many Harbor Seals will swim long distances southward, following their prey, to the warmer waters and to arrive at familiar resting spots or haulout sites in the winter to feed, forage and relax before another busy breeding and molting season begins up north. Never a dull moment.

In Lower New York Bay, the most easily viewed haul-out site for Harbor Seals is in Sandy Hook Bay. Anyone looking to catch a glimpse of the seals in their wild habitat should venture out to Spermaceti Cove at Sandy Hook, NJ.

Yet, it’s best to be quick. Nothing lasts forever. The sight of seals stretched out in the sun taking a snooze on a sandy beach will soon conclude for another season. The need to move and the need to breed will become stronger in wild animals as spring moves forward.

If you see a seal that appears injured, entangled, sick, or being harassed by a person, in New Jersey call the Marine Mammal Stranding Center at  609-266-0538. In New York, call the Riverhead Foundation for Marine Research and Preservation at 631-369-9829.  These two organizations have the authority to help stranded or sick marine mammals and sea turtles. Wildlife experts with the help of trained volunteers will determine if an animal is in need of medical attention, needs to be moved from a populated area, or just needs time to rest.

For more information, pictures and year-round sightings of wildlife in or near Sandy Hook Bay, Raritan Bay, and Lower New York Bay, please check out my blog entitled, Nature on the Edge of New York City at  http://natureontheedgenyc.blogspot.com