(Two killer whales are seen breaching in Alaska waters on June 9, 2005. So far this year, nine killer whales have died after getting caught in trawl gear in the Bering Sea and Aleutians region. A 10th whale was entangled in trawl gear but survived and was freed, and another killer whale was found dead in longline gear used for a National Oceanic and Atmospheric Administration survey. Photo by David Ellifrit/NOAA Alaska Fisheries Science Center)
An unusually high number of whales have died in trawl fishing gear in Alaska waters, spurring a federal investigation and new criticism of the industry that uses big nets to scoop fish from the bottom of the ocean.
Ten killer whales, also known as orcas, were ensnared in trawl gear this year in the Bering Sea and along the Aleutian Islands, and nine of them died, according to the National Oceanic and Atmospheric Administration’s National Marine Fisheries Service. The toll compares to six killer whale deaths in Alaska fisheries documented over the five years spanning from 2016 to 2020, according to NOAA Fisheries records.
While pollock makes up the biggest volume of fish harvested in the Bering Sea and Aleutians, all of the trawlers involved in this year’s killer whale deaths were harvesting different types of groundfish. Those vessels, participants in what NOAA Fisheries classifies as the Amendment 80 trawl fishery, harvest yellowfin sole, Pacific ocean perch and other bottom-dwelling species.
Critics of bottom trawling speculate that the whales are dying after chasing fish discarded as bycatch by the vessels. Bycatch is the incidental harvest of non-targeted species.
It is possible that climate change has disrupted normal food supplies, said Jon Warrenchuk, a senior scientist with the environmental group Oceana.
“The food web is so out of whack in the Bering Sea and Gulf of Alaska,” Warrenchuk said.
That means that orcas are turning to the food they find around trawl ships, he said. “The whales now have been conditioned to be feeding off the discards of the factory trawlers,” he said.
Halibut may be a particularly fatal attraction for the whales, Warrenchuk said.
He cited a relatively new practice called “halibut deck sorting,” which is allowed exclusively for the non-pollock Amendment 80 trawlers through a rule enacted in 2019.
The practice, a response to reduced halibut stocks, is intended to reduce impacts of halibut bycatch. Under the rule, trawlers within a particular fleet are allowed to send incidentally caught halibut back into the sea without penalty as long as certain requirements are met. The halibut must be alive, they must be returned to the water within 35 minutes and the entire process must be monitored by an onboard fisheries observer, according to the rule.
In practice, halibut shorting “hasn’t turned out so well,” Warrenchuk said. “You really haven’t saved any halibut because now you’ve got these transient orcas that are eating them.”
But the Groundfish Forum, the association for the 18 vessels in the Amendment 80 group, disputes the claim that halibut discards are drawing the whales and creating the unusually high number of deaths.
Something else appears to have driven a change in the whales’ behavior, which is new and “has not been previously documented,” the Groundfish Forum said in a statement.
“Our fishermen believe that the killer whales are attracted to fishing gear because fishing activities aggregate fish and allow killer whales to feed on the catch. In 2023, our captains have reported an increase in the number of killer whales present near our vessels, where they appear to be feeding in front of the nets while fishing,” said a statement released by the organization.
It is wrong to blame halibut deck sorting, according to the Groundfish Forum. “These assertions are not true because our vessels do not conduct deck sorting when killer whales are present,” the statement said.
There was a marked decrease since 2020 in Bering Sea observations of marine mammals feeding on Amendment 80 trawlers’ discards, according to a report reviewed at a North Pacific Fishery Management Council planning meeting held last week in Seattle. The report said observed incidents fell from 310 in 2020 to 104 in 2022.
But this year’s spike in killer whale deaths has prompted a NOAA Fisheries investigation, a spokesperson said.
“NOAA Fisheries is analyzing collected data to determine the cause of injury or death and determine which stocks these whales belong to through a review of genetic information. The agency is working quickly to evaluate these incidents and will share findings as soon as possible, after all required analyses are completed,” Julie Fair, a public information officer for the agency, said by email.
The agency itself was involved in an additional killer whale death this year. A dead whale was discovered in June entangled in gear used by a NOAA Fisheries vessel conducting surveys of sablefish and groundfish in the Bering Sea. That incident involved longline gear – lines equipped with hooks that catch individual fish – rather than trawl equipment, which includes nets that fishers drag.
While NOAA Fisheries holds a permit that allows for “incidental take” of killer whales during its longline surveys, this was that program’s first incidental catch of an orca since its inception in 1990, said a spokesperson for the agency’s Alaska Fisheries Science Center.
Warrenchuk said the killer whale issue is likely to come up at the upcoming meeting of the North Pacific Fishery Management Council, to be held next week in Anchorage. The council is charged with managing fisheries in a zone that stretches 200 miles offshore.
“I don’t know exactly what happens next. But this is clearly something that has to change,” Warrenchuk said.
The Groundfish Forum said its fleet is trying to avoid future killer whale deaths and “is committed to finding solutions to this unprecedented challenge.” Changes already made include movements of vessels away from places where whales are found, investments in research to better understand the whales’ behavior, experiments with gear modifications and the drafting of a new research proposal presented to NOAA, the statement said.
The deaths have angered some of the industry’s critics.
An organization called Stop Factory Trawling Bycatch was planning a “Rally for the Orcas” protest Thursday outside the Seattle hotel where an association of pollock harvesters were scheduled to hold its annual meeting.
Already, one pollock-harvesting organization has sought to distance itself from the Amendment 80 trawlers involved in the whale bycatch.
The Midwater Trawlers Cooperative used Facebook to clarify that its pollock-catching vessels are not part of the fleet with orca catch. Its vessels are smaller and do not process fish on board, the post said. “These catcher vessels have no and do not have incidental catch of orcas,” the post said.
Criticism of the trawling industry for killer whale bycatch predates the latest death reports.
Information and allegations about other incidents have circulated in recent years on social media, including Reddit and Facebook; a Facebook site has posted numerous photos of whales it says were killed in trawler bycatch dating back to at least 2020.