Has a shark, seal or other predator caught your hooked fish? Scientists in Massachusetts want to know

Has a shark, seal, dolphin, bird or other predator caught your hooked fish while fighting it at the end of your line?

UMass Amherst researchers want to hear from fishermen about the growing concerns of recreational fishermen.

Depredation — the loss of a catch by an angler before the fish is landed — is becoming more common as conservation efforts lead to greater numbers of sharks, seals and other species along Cape Cod and the Northeast. Meanwhile, there are more fishermen on the water.

As a result, local scientists are trying to better understand the problem on the northeastern continental shelf, from North Carolina to Maine, and possibly find solutions that could help fishermen.

“These are interactions that an angler would previously encounter from time to time, but now it can happen multiple times during a single fishing trip,” said Evan Prasky, a researcher at UMass Amherst. “And it’s not just about sharks. There are a lot of seals that are starting to do this.”

The Cape’s seal population has been growing rapidly after government restrictions banned the killing of seals decades ago.

The seal population has since recovered, which has attracted great white sharks to the region.

“If we combine conservation success stories with an increase in catch rates, encounter rates will naturally be higher,” said Andy Danylchuk, a UMass Amherst researcher.

Over the summer, there were numerous reports off the coast of Massachusetts of great white sharks catching striped bass off the sides of fishing boats. Many other predators have also been observed taking away fishermen’s hooks.

“At the end of the day, it’s about changing people’s behavior,” Danylchuk said of any potential solutions. “We don’t deal with sharks and seals.”

One solution could be to fish in areas away from seal gathering areas.

Retrieving the fish faster may also help. When scientists studied hammerhead and tarpon sharks in the Florida Keys, they observed that depredation rates decreased if anglers caught fish sooner.

“The idea is to get the fish into the boat as quickly as possible,” Prasky said.

Shark deterrent devices – similar to those that some surfers wear around their ankles to prevent shark bites – could also be a technological solution.

Devices mounted on boats can produce an electromagnetic field that repels sharks. However, these devices are not effective against seals, birds and other animals.