Seals hunted down to a few hundred are back to 27,000 and anglers are losing their catch

Grey seals on the Northeast Shelf have climbed from a few hundred survivors decades ago to as many as 27,000 individuals today, according to a University of Massachusetts Amherst release on the population’s recovery. The rebound has a cost attached: anglers along the same stretch of coast are increasingly reporting fish taken off their lines before they can land them, and the university’s researchers are now tracking how often that is happening and why.

“There were only several hundred left in the Northeast Shelf a few decades ago, they had bounties on their heads and hunters could kill as many as they wanted. But now, there are up to 27,000 individuals,” the University of Massachusetts Amherst said in its release on the recovery.

From a bounty on their heads to 27,000 animals

Grey seals were hunted to near-disappearance along the New England coast under bounty programs that Maine and Massachusetts ran for the better part of a century, paying hunters per animal on the theory that fewer seals meant more fish left for people. By the time the Marine Mammal Protection Act of 1972 ended the practice and made it illegal to kill seals without authorization, a 1973 census found only about thirty gray seals left along the entire coast of Maine. The population has been climbing ever since — slowly at first, then rapidly enough that a species counted in the dozens now numbers in the tens of thousands across the wider Northeast Shelf.

That recovery is being treated as an unambiguous conservation success by the researchers behind the release. It is also the direct cause of the second half of the story.

Sharks are following the seals north

Seals are a major prey source for great white sharks, and as the seal population has rebuilt itself, shark activity along the same coastline has grown alongside it. The University of Massachusetts Amherst release describes a shift that is happening “especially as shark populations continue to recover and their distributions move north because of climate-warmed waters,” pulling both predators into waters they used to visit only rarely, if at all.

Warmer water is doing double duty here. It is expanding the range where sharks can comfortably hunt, and it is doing so in the same corridor where the seal population has already rebuilt itself to a size that can support them.

Cape Cod sits at the center of both trends. The same beaches where grey and harbor seals now haul out in large numbers are the beaches where great white shark sightings have climbed most sharply over the past decade, and researchers studying the two populations generally treat the shark increase as downstream of the seal recovery rather than a separate, coincidental trend.

Anglers are reporting fish stolen right off the line

The practical result for people fishing these waters is depredation: a striped bass or other target species hooked, fought, and then taken by a seal or shark before it can be landed. A University of Massachusetts Amherst survey run out of fisheries ecologist Andy Danylchuk’s lab has been collecting reports from recreational anglers between North Carolina and Maine on exactly how often sharks, seals, birds, or other predators intercept their catch, treating a problem long dismissed as bad luck as a measurable trend instead.

Anglers describe the same pattern from Cape Cod to points well south of it: a fish fights hard, comes boat-side, and disappears in a way that leaves no doubt what happened. The growing seal population on the Northeast Shelf is a large part of why that scene has become more common.

The conflict this creates is not new in kind, only in scale. Fishing communities pushed for the original bounty programs because they believed seals and fishermen were competing for the same fish, and the same argument resurfaces today whenever a striped bass disappears at the side of a boat. Federal protection settled the legal question in 1972; it did not settle the argument about who the recovered seal population’s growth actually costs.

A research program built around measuring what predators take

Danylchuk’s group has also published on the shark side of the same conflict. A study in the ICES Journal of Marine Science, co-authored by Danylchuk, traced a century of shark depredation trends in United States Atlantic recreational fisheries, concluding that anglers, target fish, and sharks are crossing paths more often now than at almost any point in that history. Combined with a growing seal population on the same grounds, the university’s researchers frame the current moment less as a single seal story and more as two recovered predator populations converging on the same fishing grounds at the same time — a dynamic they say their ongoing survey work is still measuring the full size of.

A survey like this is built to run for years, not one season, because a single summer of angler reports cannot separate a genuine upward trend from ordinary year-to-year variation in where fish, seals, and sharks happen to overlap. That is the gap the University of Massachusetts Amherst release leaves open: it establishes that the seal population has rebuilt itself to 27,000 and that anglers are losing fish to predators more visibly than before, without yet putting a number on how much of the recent catch loss the seal recovery specifically accounts for.

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This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.