Report: Killer whales 'harass' fishermen, steal fish

June 21 (UPI) -- Pods of killer whales are "harassing" fishermen in Alaska, forcing them to leave the area and lose 20,000 to 30,000 pounds of fish per day.

"It's kind of like a primordial struggle," fisherman Buck Laukitis told the Anchorage Daily News. "It comes at a real cost."

Fishermen say killer whales in the Bering Sea are able to recognize certain fishing boats. Pods of up to 50 whales or more will then swoop in and strip the fishermens' hooks clean. They sometimes then surround the boat or chase it down if it tries to move to another area.

"The pod tracked me 30 miles north of the edge and 35 miles west (while) I drifted for 18 hours up there with no machinery running and they just sat with me," fisherman Robert Hanson wrote in a letter to the North Pacific Fisheries Management Council.

Hanson wrote that his crew was "harassed nonstop."

They have not been the only ones.

Fisherman Michael Offerman told the National Post that he has also been stalked by whales. "I've had the same sperm whale follow me 70 miles," he said.

Killer whale depradation – the act of killer whales taking fish off of fishermens' lines – has been a known problem for some time in the fishing industry.

"These interactions increase direct costs and opportunity costs associated with catching fish and reduce the profitability of longline fishing in western Alaska," stated a 2014 study by the School of Fisheries and Ocean Sciences at the University of Alaska in Fairbanks.

With the additional costs for fuel, food, and opportunity loss, fisherman were losing up to $1,000 per day, the study found.

Although fishermen are losing money because of whales. overfishing could also be killing killer whales, according to Junichi Sato of Greenpeace Japan.

"Scientists working with the International Whaling Commission estimate that 300,000 cetaceans (whales, dolphins and porpoises) die each year by entanglement in fishing gear" he wrote. "Ships strikes, pollution, ocean noise and climate change bring additional threats."