top of page
  • Petrina Engelke

Dr. Arthur „Artie“ Kopelman talks about seals on Plum Island and Long Island

Updated: Feb 17

A seal on a big rock in New York Harbor
A seal in New York Harbor - from our earlier documentary Archipelago New York

During our visit to Plum Island last year, we stood on a cliff when a couple of harbor seal heads popped out of the water below - and they dived before our camera could catch them. That’s why the image accompanying this interview is photo from a film shoot close to NYC. Between September and May, you might spot seals from afar not only on Plum Island, but also on Long Island. Well, if you’re really lucky - or if you join a seal walk like the ones at Cupsogue Beach Park in Westhampton Beach, led by scientist Dr. Arthur H. (“Artie”) Kopelman. The president of the Coastal Research and Education Society of Long Island (CRESLI) is a SUNY Distinguished Service Professor Emeritus and a population ecologist who has researched local seals since 1995. That includes taking lots of photos, which you can view here. In our interview, Arthur Kopelman does not only explain why humans need to keep their distance to these animals, but also has a bunch of surprising observations to share.

Artie, what do researchers know about seals on Plum Island?


I don’t know of any sustained regular research of that kind there. My colleagues do aerial surveys, and I think they cover Plum Island as part of the group it forms with Great Gull and Little Gull Island. I have some knowledge of seals on these islands, but I don’t really have a regular sense. Over the years, I’ve been there about a dozen times on boat trips. I was there last week, actually. We only were able to get to a small region of Plum Island, but there were harbor seals. They are hanging out on the rocks and sometimes on the rocky shore. There seems to be an interesting progression: When you travel from Plum Island towards the islands further east, you go from more harbor seals than gray seals on Plum Island, to almost a 50:50 mix on Great Gull Island, and just another nautical mile east to Little Gull Island, it’s well over 90 percent gray seals. There have been reports of gray seal births on Great Gull and Little Gull, but that hasn’t been confirmed by any seal biologist.

How does Plum Island compare to the places on Long Island you know well, from a seal’s perspective?


I think because Plum Island is relatively remote, and because there is no development on it, it is an incredibly wildlife-friendly spot. Whereas at Cupsogue Beach, where I have been observing the seal population for 20 years, you can see that development has effects, even when it’s just in terms of dredging. The dredging of the canal and the nautical navigation route there has caused a lot of changes in the sandbar where seals haul out. I mean, sandbars move anyway, but today the sandbar is almost twice the distance it was a few years ago. The seals get used to the immediate effects, but this also changes the hydrodynamics in the long term.


What about coastal houses and other development, how does that affect seals?


Obviously, development on shore has all kinds of consequences. If you look at some of the work with whales, discovering microplastics and chemicals from microplastics in their blubber, my sense is the same thing happens in seals. Everything that we dump makes its way through the food web, all the way up to these top-level predators.


Haulout is the scientific term for seals spending time on land - on a beach, a rock, or a sandbar. What do they do there?


All pinnipeds - walruses, sea lions and fur seals - haul out, and there are several reasons. First, they all have to be out of the water to give birth, so they give birth on land or on ice. The second major reason would be to rest. When seals do not feel threatened on land, they go to sleep, and when that happens, they sleep like we do, shutting down both hemispheres of their brains. Unlike us, seals can also sleep in the water.


How do seals manage to sleep in the water?


They sleep in the water with their nostrils up. This behavior is called bottling, because they look like floating bottles, and I find it incredibly sad that we give a behavior a name based upon garbage. Anyway: When seals sleep in the water, they shut down only one half of their brain at a time, because they need some level of consciousness, otherwise they’ll drown. Only on land do they get this deep sleep. To some extent, they can also regulate body temperature on land, and interact with other seals. They choose haul-out places that provide a steep drop-off, so they can quickly get into deep water if they feel threatened. They also need access to get out to sea and feed.


How do seals react to people approaching from the water?


Hauled out seals are disturbed by people approaching on land, but on boats as well. And it might surprise you, but kayaks and paddleboards will cause the seals to leave the sandbar at Cupsogue Beach more often than motorized vessels. That’s because paddleboards, kayaks, and canoes move at the same speed as the seals’ natural predators. Seals will also leave if motorized vessels get too close. But if motorboats are far enough away, they may not leave, or they may return right away. That said, our best year at Cupsogue Beach was 2020, when we observed as many as 218 seals hauled-out at once, our highest single haul-out number in 19 years. That was when the marinas were closed because of the pandemic. They were no boats around to disturb the seals. This year is surprisingly one of the worst years that I’ve had in terms of seal presence at Cupsogue Beach. The numbers are lower than ever before, and I don’t know why. Although two seals that I know are back there for their 19th year.


Wait a minute: You can tell all those seals apart?


I can! I have a catalog of 232 harbor seals that I can identify based upon markings on their bodies or head, or a combination thereof.


What can people expect when they go on a seal walk with you?


When I take people to view seals on land, I will meet them far away from the seals and talk about seals for 20 minutes to a half an hour, depending upon the temperature. And then I bring them up to view the seals, but not everyone goes to the viewing area at once. We go in small groups until everyone is there, and we stay very quiet and far enough away so that the seals aren’t bothered. We put up telescopes and digital cameras that we convert into digital telescopes so everyone can see the seals from afar. And everyone is told to remain incredibly quiet and to be ready to get down on their knees if I ask them to, so that we reduce our visibility to the seals.


What are the most important rules for seal-watching?


The rules are very clear: Never approach closer than 150 feet to a seal or a group of seals. To do so would be a violation of federal law, and for harbor seals, a violation in New York state. It is also against the rules and federal and state law to do anything that would change the seals’ behavior - by definition, harassment. The fine is potentially $20,000 per harassment. Apart from that: These are wild animals. They may look cute, but they are not cuddly, they’ve got teeth! If you’re going to go see seals, go with a trained scientist or naturalist, someone who does this regularly, who can show you how to observe seals without disturbing them, and from appropriate distance. I recommend an old rule of thumb to measure the distance: Hold your thumb out in front of you in the seals’ direction. If your thumb covers all of the seals, you’re at the right distance. If you can still see them around your thumb, you’re too close.


Sounds like the easiest - and best - thing would be to leave seals alone, period. Why is it important to you to lead people on those seal walks, nevertheless?


Whether it’s seals or whales or dolphins: When people see these animals in the wild, they make a connection. It’s not a theoretical thing, it’s real and you see it, and that may have a really significant impact on you. I talk about arctic seals and I talk about climate change because of the connection. Arctic seals give birth on the edge of the ice, and in some years, a tremendous percentage of their pups drown because of rising temperatures. So I talk about making sure that our collective and individual greenhouse gas emissions are reduced, and how to do that with decisions that we make on an everyday basis.


If you want to experience this yourself: CRESLI offers seal walks at Cupsogue Beach Park and seal cruises at Shinnecock Bay from late November to April, often led by Arthur Kopelman himself. Find out more on their website.




bottom of page