Cape Cod’s Seal Problem

The population of gray seals on the Cape has exploded in recent years. Is it time to cull the herd?

gray seal population problem cape cod

Photo via Thinkstock

A few summers ago, after my family and I had moved to Cape Cod from the Washington, DC, area, we were introduced to an unexpected treat: seal watching. Plopped on our chairs at Nauset Beach, a short drive from our home, in Orleans, we watched groups of cute gray seals frolicking offshore. Other beachgoers joined us in this happy pastime. To behold a seal’s face when it bobs up out of the water—those large, imploring eyes; that splay of whiskers; the dark, glistening nose—is to have the feeling you’re looking at a lovable Labrador retriever, with flippers. Seal watching is so popular around here, in fact, that special tours are offered out of Chatham. “Seeing these adorable mammals in their natural habitat,” one tour operator promises, “will make your family vacation one to remember.”

Not everybody loves the local seals, though. “Wolves that went into the water” is what my neighbor Bill Amaru calls them. Amaru is a fisherman who operates his boat out of Chatham harbor and has been working the Cape waters for a living since the early 1970s, when he was just out of college. He began noticing seals in the late 1980s, and then watched as their numbers gradually increased over the years—until the mid-2000s, when the population exploded. These days, he says, he can see between 4,000 and 5,000 seals on a single fishing trip in the area around Monomoy Island, south of Chatham. The National Marine Fisheries Service very crudely estimates that nearly 16,000 seals now inhabit the Cape and Islands, and one local marine biologist, Betty Lentell, who works with the Cape Cod Commercial Hook Fishermen’s Association, projects that the population will grow at a rate of about 20 percent annually for the foreseeable future.

That’s a lot of seals. And they all love to eat seafood, including the kinds of fish—striped bass, bluefish, and cod—sought out by area fishermen and local restaurants. According to the National Marine Fisheries Service, gray seals consume between 4 and 6 percent of their weight per day. A mature male can weigh 800 pounds and up, which translates roughly into a daily diet of 32 to 48 pounds of seafood—an amount that, multiplied by thousands, has fishermen concerned, especially since the rise of the seal population in the area has coincided with a precipitous decline in fish stocks.

The burgeoning seal population isn’t the only thing decimating those stocks, of course. Global warming has led to higher temperatures and increased acidity in local waters, which has reduced the biomass, such as plankton, that sustains fish populations. Commercial fish stocks have suffered from the predations of dogfish, too, the numbers of which have been rising in recent years. But the most significant cause—decades in the making—is human overfishing. Strict quotas are now in place to help stocks rebound, but many populations are so depleted that fishermen can’t even reach the quotas. And not surprisingly, they’re unhappy about sharing the fish that are still out there with a rapidly growing population of seals.

Seals also attract sharks—including the mightiest of them all, the great white, for which a gray seal is a superb high-calorie meal. Greg Skomal, the principal investigator for the Massachusetts Shark Research Program, recently discussed the relationship between seal and shark numbers at a symposium in Chatham. Twenty-one great-white sightings were reported in 2012, up from only four in 2004, before which whole years would often pass without any sightings at all. And just last summer, off Ballston Beach, in Truro, a great white bit a swimmer on the leg.

“We have a direct relationship,” Skomal told an audience of marine biologists, fishermen, conservationists, and local residents. “If you open up the café, the predators will come.” Given how easy it is for a shark to mistake a person for a seal, Skomal has even started to worry about the wisdom of letting people swim in areas populated by seals. “I’m not sure I would allow my son to swim in certain parts of eastern Cape Cod,” he told me on the sidelines of the conference.

Add it all up, and you’ve got what more and more Cape residents are now delicately referring to as “the seal problem.” During the Chatham symposium, Greg Early, a marine biologist representing the Northwest Atlantic Seal Research Consortium, raised the question that’s increasingly been on everybody’s mind.

“How much of a good thing,” he asked, “is too much?”


On a chilly Sunday this past April, I took a trip to Muskeget Island, on Nantucket Sound, in order to have a look at a big seal herd myself. Muskeget is the single largest breeding ground for the gray seal in the region. I rode out in a small motorboat with Crocker Snow, who owns a cottage on the island. Snow, the director of the Murrow Center for Public Diplomacy, at Tufts’ Fletcher School, is something of an anti-seal activist. He calls Muskeget’s seals “golf-course geese,” because of how they poop everywhere, and he worries that they’re upsetting the ecological balance on the island by fouling several small freshwater ponds and trampling the habitat and nests of the beach vole, a small rodent unique to the island.

  • Archie Bunker

    no one is going to like to hear it. but a seal cull is what is needed. we do it up in canada because it has to be done, not for fun. the only thing i cannot support is if the animal is only being skinned for its pelt. would like to see oil and food come from the animal as well.

    • borehead

      I agree. Food for the hungry.
      This has been over looked, while the discussion has been about vanity from the people that oppose utilizing this growing natural resourse

      • Person

        you can’t even spell “resource” correctly. We need seals to keep the ecosystem in balance. You clearly do not know the importance of seals. They were here before humans ever stepped foot in North America, so we are the ones taking their food. The human race needs to stop being selfish. We share this planet with billions of other species. These seals are just trying to eat and survive.

        • borehead

          Well damn me all to Hell for a misspelled word! Clearly, you don’t know a damn thing about the eco system or predator prey relationships. Humans are the superior beings, and we share the same food source. They have bred rampantly for forty years under MMPA. Time to lock and load and blast the shit out of ’em.

          • Person

            Actually, I am a scientist who specializes in the environment, ecology, and physics, and I have worked with several researchers who are trying to bring knowledge to the public about these seals. I just spent three months in nantucket seeing dead seals washed up everywhere. And yes, they have increased in numbers, which may not be great, but that does not mean we just go and kill them. Human interaction almost always makes things worse. Don’t believe it, whatever. But people these days are too narrow minded and wish to kill anything that disturbs their “peace”. Humans are not superior beings, we are just good at taking things that do not belong to us.

          • borehead

            You’ve made two discuss comments, both directed at me. If you were what you claimed to be, you’d bring facts, instead of emotional hyperbole. Fact is about ecologists. They don’t understand the real world. Only believing in how the world should be, if in fact, it could be that way. You want a perfect world? Build an aquarium. Want to grow say, fancy guppies, but have a soft spot for Angel fish? Chances are, the Angel fish will eat your fancy guppies. Oh My! A dilemma! What to do?! If you want the guppies you’ll off the Angels. You, being the superior being can fix the situation as you see fit. Now. Cod and seals,,,,

          • susie kathryn

            Children’s Pool La Jolla CA. Built for disabled people and children, now overrun with seals and fecal contamination blocking access to the only ocean pool we have for the disabled.

          • Andrew Dowling

            Instead of killing the seals there why don’t you push for increased beach access for children and the disabled? You are fighting for the scraps instead of demanding more seats at the table.

          • Jeff Kolovrat

            Do you mean you are a marine biologist with a minor in physics? Taking seals can be managed…much like taking whitetail deer. We, too, are a part of the food chain. The outright prohibition of any animal that has had its predators eliminated, or reduced in number, will lead to over-population and eventually starvation.

          • Herbii

            Humans have bread rampantly for 100 years… we are the cause of seals increasing in population.. most likely bc everywhere else WE depleted all the fish so they move to other areas where conservation efforts work… yes we need a balance but everytime we initiate a balance we get carried away before understanding what is happening.. if we did this it may be an unnecessary slaughter… its amazing to hear “seals decimate fish populations” but the 8 billion people on the planet who take in som 1000000metric tons of fosh from the oceans EVERYDAY is doing nothing?!!! The problem is NOT over population in seals…its over population of humans!!!

          • borehead

            Don’t breed.
            And. You don’t know what you’re talking about when talking seals.

          • Herbii

            Hi borehead, no I dont know a whole lot…. do you?? As a fisherman myself I see everyday how we have disrupted thousands of species just from over fishing.. seasls are NOT the problem.. we are! And we are using them as an excuse for our mistakes and greed! An example of how we never learn nor listen to scientists…. Just like Cod.. so many said oh the cod are doing fine, plent remain and Canadian govts tried banning cod fishing temporarily…. then people like you complained saying the scientists who study these things have NO clue what they are talking about…that there are plenty of fish… so they lifted the bans out of feeling bad for them losing their jobs….then in 1992 an entire ecosystem collapsed and the cod nearly disappeared in Newfoundland! So what went from a temporary job loss was not only an extinction of an ecosystem, it was an extinction of an industry – PERMANENTLY! then people tried blaming the Govt for all those who lost their jobs… When in fact it was the fishermen themselves who ruined a 500 year tradition of Cod fishing bc they couldnt control themselves and overfished.. now the same thing is happening in New England.. Cod have been decimated, people are sayimg the sciemce is wrong.. so in order to protect an industry and specie, we need a temporary ban… bc New England has perhaps the best conservation efforts in the world there is a fishing industry…albeit still declining.. but as a fishermen myself I see numbers dropping eith my own eyes, I also know its a fact Seals are following the food bc THERE MUST BE LIMITRD FOOD SUPPLIES ELSEWHERE! SO they are coming to Cape Cod where stripers and blues are plentiful… so again, we are to blame.. Seals are not.. they are doing the logical thing following the food… if we atart hunting them, they may have NO where else togo.. thats how bad the situation is with fish stocks declining! Conservation works… there will come a time in the next decade or two we will see a 100% ban on all localized, coastal fishing… bc a finite supply of dwindling fisheries, can not sustain infinite growth of the human population!!!

          • borehead

            Here’s the seal deal.
            There were no seals on Cape Cod forty years ago. There was a bounty on them.
            Forty years ago, there were plenty of cod there.
            There are now an estimated 16,000 seals that eat something, and they enjoyed easy picking of cod that was in nets waiting to be hauled.
            They would eat the bellies where the liver is and ruin the catch, causing massive discards.
            There cannot be a fishery management plan to increase cod if someone else is fishing them.
            The unregulated fishing community thrives today, thanks to MMPA.
            Not sure how much you read about this stuff, but I look at a couple hundred articles per day for our website.
            There are other opinions about seal/cod interaction.
            One guy on the Cape that is in the tourism business there, argues the seal don’t eat cod, but eat sand lance.
            NOAA NEFSC came out with an opinion about sand lance and a switch in cod diet preference changing around 2007.
            Where they come up with this, I can’t say.
            However, if that’s true, and they used the point to post a disclaimer that the fishermen were right saying they were seeing plenty of cod,
            and the scientists were correct when it came to saying there was a cod crisis, because the cod had aggregated into one small area, and not spread out.
            Now if that’s true, it says one thing. That is that cod and seals are competing for the same food. Sand Lance!
            Onward to Canada!
            The real reason for the cod collapse in Canada was also one of feed.
            They crashed around that time, and there’s no doubt, heavy pressure from fishing.
            People believe that there are no cod in Canada.
            Nothing could be further from the truth as today, listening to the Fisheries Broadcast, they are developing a new fishery management plan.
            They are having a cod renaissance. And, the Caiplin are back. In huge numbers!
            What’s interesting to note is, while New England’s cod numbers have supposedly dropped, theirs have dramatically increased during the same time period.
            The scientist won’t tell you that because they have not figured it out.
            Their computer models would never tell them what the fishermen could!
            How, you may ask, do I know about the fish in Canada, that gave me the anecdotal evidence to make these claims?
            Old Tony Doyle told us, he’s never seen the amount of fish he’s seeing today in over fifty years!
            I can even provide a link so you could here it for yourself.
            Find me here

          • Joe Perrone Jr.

            Well, I guess we just need to cull the human population then, right? Wrong. Man shall have dominion over all the beasts of the earth. Case closed.

        • Jeff Kolovrat

          We are part of that ecosystem…though some may believe we are an non-native species from somewhere else in the galaxy! I have no problem with seal hunting…provided it is done on a one-on-one basis…that is, without large-scale netting, etc. In addition, the entire animal should be used…hide, blubber, and meat!

          • Shoe

            I agree. But we have a real talent for fucking things up and warping language to allow us to think it’s not our fault.

  • 7worldtraveler

    Naw…the great whites will take care of the cull.

  • Shoe

    Being that nothing bad has ever happened from human intervention, such as the eradication or endangerment of other species, I say go for it. Cull those damn pesky seals and let the sharks starve. Great Idea Sir!

  • susie kathryn

    The Children’s Pool in La Jolla CA was built by Ellen Brownin Scripps. An Ocean Pool with a breakwater to serve Children and the Disabled. In 1992 Sea World began to drop off rehabbed seals by the dozens for years on end. No EIR was done first to ascertain if our local ecoystem could sustain so many new marine mammals never there in such numbers or the subsequent birth exlosion. Now our fish stocks are serverly depleted even the CA State Marin Fish the Garibaldi. The mussel population is depleted as are the Tide Pool Creatures that feed on them. The fecal contamination is terrible and a potential health hazard in our urban area. Please go to enter ADA Access and please sign the ADA Children’s Pool petition to try and save the only ocean pool on the Contental United States and the only safe entry and exiit for wheelchair swimmers. The money made from the view of seals has trumped the needs of the disabled to the only safe access on the West Coast for a wheelchair swimmer. So we have two important issues at our only ocean pool, Disabilty access restored and the over population of seals polluting and decimating fish stocks and species. If one loves seals one must love their home and the balance of the Ocean. Thank you. RAMP Commitee to Restore Access To Many People.

  • DiamondDiver

    The cod crashed from overfishing and habitat distruction. large commercial trawlers pulled millions of tons of cod and menhaden from the ocean while leveling the ocean floor, removing all structure and cover that marine life use for breeding and anchoring egg clutches. the large trawl nets with the large wire cables and anchors that resemble field plows were dragged across the bank for decades. Fish landings crashed in the 1970’s and have not recovered despite extreme fishery management.

    Seal population was at its highest when fish stocks were high. Human mismanagement and marine ecology damage are responsible for low fish stocks, not seals. If the seals are a nuisance that is a separate issue and requires its own solution, seperate from fishery management.

    • Borehead

      Total bunk. Menhaden in Canada? Seals are part of the eco system. They eat cod livers. They waste the rest. They also eat the cods food, sand lance, competing with cod for forage.

      • pustulio

        Unrelated to this post, but related to previous post that is now closed. You simply replied to me “You don’t know what you’re talking about” when I was referencing overfishing. See, there’s a problem. I do know. I work closely with the people that go aboard fishing vessels and monitor/log the catches. They’ve been saying that the trips have had to go further away in areas the don’t normally fish and they have to change the type of fish they catch to the less regulated ones. They know it’s been overdue to enforce strong quotas. Fish isn’t getting more expensive because of the quotas; it’s because there no where near as many fish to catch. Ask any fisherman. Only the larger vessels that steam out for days to get to fishing grounds are able to keep up.
        In reading your other posts, you seems pretty knowledgable on similar subjects, would you like to clarify more than just a “you’re wrong cause I said so.”

  • RobinOfTheWest

    It’s always some animal’s fault isn’t it ?

    Too bad they can’t vote … or set traps … or shoot back … or sink whaling vessels …