CHATHAM, Mass. (NBC) — On an given day, in the waters off Cape Cod, you can see thousands of seals. Tourists line the shores, and gawk, drawn here by the promise of sighting the whiskered sea mammals.

While visiting the Cape with her family, Alexa Morris, 9, stood with her face pressed against a coin-operated telescope.

“Very awesome because I don’t really see seals a lot,” said Alexa, who had traveled to Massachusetts from Canada.

Captain Rob Wissman of Blue Claw Boat Tours makes three runs a day, bringing visitors out to Monomoy Island to see the seals. He calls the exploding population a phenomenon that has made tourism boom.

"People want to see the seals," explained Wissman. “They’ve been around for hundreds of years, but lately they’ve been growing in such great numbers.”

The National Marine Fisheries Service roughly estimates there are 16,000 seals that now call Cape Cod and its nearby islands home, and those numbers are growing.

But it’s not just the visitors the seals are attracting, it’s the sharks.

On Monday, beaches in Wellfleet were closed for an hour after people spotted a shark 30 yards out.

Last August a swimmer was bitten by one just up the coast in Truro.

The nonprofit shark research group Ocearch tagged two Great Whites off the Cape last year: a 2,300-pound, 14-footer named Genie, and a 3,500-pound, 16-foot shark named Mary Lee.

It’s enough to keep many out of the water.

But even though everyone is talking about the sharks, ask the local fishermen and they will tell you the sharks aren’t the problem. It’s the seals.

John Pappalardo, Chief Executive Officer of the Commercial Hook Fisherman's Association, explains great white sharks are being lured into shallow waters by the seals on which they prey and it's become a big issue in Cape Cod along the Massachusetts coast.

Bill Amaru has been fishing here since the 1970's. Like more than 400 other fishing families on the Cape, he had only seen an occasional seal. Now, they are everywhere. Amaru believes they are depleting an already strained fishery.

“It's indicative of an environment which is somewhat out of balance,” said Amaur.

Amaru said the seals are threatening his livelihood by eating the fish faster that the fishermen can catch them.

“We’re convinced, even though some of the Ph.D. scientists don’t believe they have enough information, [the seals] eat a considerable amount of fish,” said Amaru. “We see the evidence of it every day we are out fishing.”

Now Amaru and others want the federal government to take another look at the 1972 Marine Mammal Protection Act, which they say has worked too well — allowing the seal population to go unchecked. Their idea? To thin the population.

“We are asking in the bigger picture to take a look at the laws that currently restrain us from doing anything to seals, other than protect them, and see if that law should modified and corrected,” said Amaru. "[The Marine Mammal Protection Act] has been in effect for a long time and it’s done a wonderful job.”

John Pappalardo of the Cape’s Commercial Hook Fisherman’s Association argues more research is needed.

“We have some stocks like cod that are at all-time lows, and there's a concern that the ability to raise those cod back up to profitable and sustainable levels can be challenged by the seals,” said Pappalardo. “So one of the things we'd like to see is accounting for these seals and their impacts on the marine ecosystem.”

It’s a tough sell, the notion of culling a sea creature that's considered so cute — but it’s one many fishermen around here say could solve two problems at once: protect their livelihood and give sharks less incentive to stalk Cape Cod beaches.

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