Over the past year, great white shark sightings along the Cape have soared, primarily due to the exploding seal population. According to David W. Johnson, a professor of marine conservation ecology at Duke's Nicholas School of the Environment, there are currently between 30,000 and 50,000 gray seals off the southeastern Massachusetts coast.
The exponential growth is largely due to the passage of the Marine Mammal Protection Act of 1972. Before then, gray seals were hunted for their furs and to keep them from depleting the fish stock. Massachusetts even paid a bounty of $5 per nose. While some refer to this as a "conservation success," others are growing increasingly concerned, especially Cape Cod fishermen.
"The seals are causing a lot of problems," said Doug Brown, captain of the sportfishing charter boat Jennifer Ann, which fishes the waters of Cape Cod Bay for striped bass, bluefish and bluefin tuna from Rock Harbor in Orleans. "They eat several pounds of fish each day. They eat small bait, lobsters, striped bass, fluke, flounder. They eat anything. It's going to get to the point where they are going to have to make a decision."
Brown said the seals are drawing the sharks, and while tourists are fascinated by them, they can be a challenge. "The sharks come right up out of the water to grab the bait. They are not bashful. I have been out in the bay all my life, but I've never seen great whites to this amount. They are sometimes right under my boat."
Justin Daly, an avid fisherman and summer resident of Orleans, agrees that something needs to be done to cull the seal population. In the past he often only saw seals while deep-sea fishing, but they are a common sight along the shoreline now, making it a challenge for those directly fishing off the beach, he said.
Nevertheless, it has become a boon for scientists and educators, who are benefiting as Cape Cod has evolved into a mecca for great whites. Until now, they had to go to California and other areas of the world to learn more about these legendary predators.
For the very first time, scientists have predictable access to white sharks in the Atlantic Ocean, said leading shark expert and biologist Dr. Greg Skomal of the Massachusetts Division of Marine Fisheries.
"We know about white sharks in other parts of the world … but in the Atlantic, we know virtually nothing about white sharks when it comes to their basic biology and … how this animal lives. We think of the white shark as a species that is out to get us. But that is not the case. White sharks need our help. We need to collect the data that is necessary to conserve this species," said Skomal, a regular contributor to PBS, National Geographic and SharkWeek.