Too many seals?

Researchers and fishing community explore the "problem" during Outer Cape Seal Symposium in Chatham
Rebecca Gast, Associate Scientist at Woods Hole Oceanographic Institution, shares reseach results on water quality and seal population during the morning sessions of the Outer Cape Seal Symposium in Chatham, Saturday March 23. Photo by Teresa Martin.

In 1991, researchers counted six seal pups on Muskeget Island just northwest of Nantucket. In 2007 they counted 2,096.

That, in a nutshell, describes the trigger for this past Saturday's Outer Cape Seal Symposium. More than 200 scientists, fishermen, and other people involved in coastal activities gathered at the Chatham High School auditorium to learn, share, and work on a process for dealing with what can, at times, seems like a fish-eating flippered invasion.

Protected Mammals or Nuisance Animals?

From the 1880s until the 1960s, both Maine and Massachusetts used a bounty system to keep the state's fishing grounds seal-free. With a $1-5 payout for each seal nose turned in, hunters decimated the population of the region's gray and harbor seals.

With the passage of the Marine Mammal Protection Act in 1972, the seals' status changed from pest to protected, although many in the fishing community continue to see the pinnipeds as a threat. Fishermen warn that infect fish with parasitic cod worms, steal fish from nets, weirs, and lines, compete for fish, and disrupts fish spawning.

Here to Stay

The first presentation of the morning left no doubt that gray seals have arrived and thrived. Lisa Sette from the Provincetown Center for Coastal Studies presented research that shows a healthy - and booming - northwest Atlantic seal population stretching from Cape Cod to Nova Scotia.

Seals mature at the age of four and produce a pup a year. Seal bones and pelts appear in Native Amerian middens in the northeast, providing hints of historical range. With prime seal haul-out habitat like the sandy beaches of Muskeget Island and Monomoy protected and hunting outlawed, these adaptable and fast-breeding mammals have been returning to that range en masse.

Poop in the Water

With thousands of seals eating and, inevitably, pooping in Cape waters, observers naturally raise the question of water quality.

The state mandates water quality testing of bathing beaches. Beach closures due to bacterial count would wreck havoc on a seasonal, beach-based economy like the Cape's tourism industry.

Rebecca Gast, associate scientist and water researcher at Woods Hole Oceanographic Institution, explained that enterococci bacteria serve as a "proxy organism" for fecally-contaminated water.

"The water quality is NOT bad," she said, noting that, with the exception of Provincetown, findings of concern have actually decreased slightly on 89 beaches on the Lower and Outer Cape over the past 10 years.

Even when looking at beaches within range of the major seal haul-outs of North Beach in Chatham, Jeremy Point in Wellfleet, and High Head in Truro, the data show no spikes. Haul-outs are places where seals leave the seas where they spend 90% of their time for a short land-based rest.


Many in the audience reacted strongly to Gast's slides. "I've seen 600-900 seals in Chatham Harbor when a great white shark is nearby," shouted out one attendee, contesting the results.

"It smells, we know it smells," shouted another.

Fish Eaters

Seals eat crabs. Seals eat sea birds. Seals eat sea lance. But most critically, seals eat herring and cod - which puts them at odds with the fishing fleet.

Marine research director at Provincetown Center for Coastal Studies Owen Nichols and biologist Betty Lentell who works with the Cape Cod Commercial Hook Fishermen's Association (CCCHFA) defined the points of conflict.  

Squirrels at the   Birdfeeder

The term depredation describes a seal taking or eating catch directly from a net, weir, or line. The term competition describes the way seals may compete with fishermen to catch the same fish - typically the highly desirable groundfish, like cod.

Smart, opportunistic seals have become masters of depredation, stripping flesh off a bluefish as it is reeled in, snacking within a fishing weir, and taking bites of rich cod belly from a net.

Figuring out how to keep a seal away from a fishing weir is a bit like keeping a squirrel from a birdfeeder, joked Nichols, who also noted that seals have a lot of company in depredation. A booming population of dogfish and rays likely account for the substantial portion of the industry's very real depredation losses, he suggested.

The unknown

In what fast became a repeating theme, Owns and Lentell pointed out that no one really knows what seals eat. Stomach content analysis from dead seals, fecal analysis, and tissue samples make hints, but all three methods have major flaws.

People have seen them eat cod, bluefish, and stripers - but there's little to indicate that any of these fish forms the basis of their diet.

It turns out that we actually know very little about seals at all - not their diet, not their habits, not their lives.

They spend most of their time in the water, where they can't be easily observed and very little funding has been directed toward basic seal research. What we know comes largely through indirect methods.


That lack of knowledge, said Greg Early of Integrated Statistics in Woods Hole, shows exactly why the new Northwest Atlantic Seal Research Consortium (NASRC) formed.

NASRC hopes to develop a better understanding of seals in the northwest Atlantic and look at the population through regulation (legal), ethical (values), and science (biology/ecology) lenses.

Over the past decade, our ability to better gather information through transmitters and other technologies, to better share and combine data, and our improved tools for examining and communicating data, have grown dramatically, noted Early. By pooling research and knowledge the group hopes to build a better base for policy and seal management.

The Great White

Seals don't sit atop the food chain. That honor goes to the seal's top predator: the great white shark.

Cue theme song from Jaws. Enter the sharks. Lots of sharks.

Water quality and fishing issues aren't the only thing attributed to the seals. The appearance of great white sharks, including last year's shark attack in Truro, are changing our dynamics.

"If you open up the cafe, the predators will come," said shark expert Greg Skomal, from the Massachusetts Shark Research Program. "These sharks are here to stay as long as the seal population is robust."

The Debate, the Problem

The morning's informational sessions gave way to the afternoon's panel discussion, moderated by former state senator Rob O'Leary. The discussion began to expose the big elephant in the room: how to manage all these seals and the issues they swim in with.

"All this research is nice, but what are we going to do about the problem?" asked one of the first questions to the afternoon's panel.

"Define the problem," challenged NASRC member and panelist Early.

Between Us All

Clearly, the needs of the seals, the fishing community, and the residents don't mesh with each other. In other locations, where seal meets man, the community fallout has been brutal, with disagreements turning to hostilities.

Sponsors of Saturday's event hope to avoid that by keeping an open dialog and focusing on shared goals, this region can find some mutually workable options. The sponsors represented all facets of the seal-human tension, including the research focus of Provincetown Center for Coastal Research, the ecological focus of Friends of Pleasant Bay, the commercial needs of CCCAFHA, and the town needs represented by Pleasant Bay Alliance of Chatham, Orleans, Brewster, and Harwich.

With the oft repeated mantra of "good policy is based on good science" echoing in the air, it was perhaps the first step of many toward finding common ground between those who equate seals with mosquitos and those who value their role in a larger system. welcomes thoughtful comments and the varied opinions of our readers. We are in no way obligated to post or allow comments that our moderators deem inappropriate. We reserve the right to delete comments we perceive as profane, vulgar, threatening, offensive, racially-biased, homophobic, slanderous, hateful or just plain rude. Commenters may not attack or insult other commenters, readers or writers. Commenters who persist in posting inappropriate comments will be banned from commenting on