NOAA Fisheries has issued a report on 31 years of killer whale entanglements in Alaska, saying that additional research is needed to learn more about the behavior of the orcas, to speed development of innovations that reduce the number of whales trapped in commercial fishing nets.
Researchers noted that suggestions and innovations by harvesters to reduce killer whale gear interactions could be applied statewide.
The summary report covers 37 orca entanglements from 1991 through 2022, including 30 in the Bering Sea, one in the Arctic, one in the Gulf of Alaska, and five in Southeast Alaska. The reported cases included 20 whales entangled in trawl gear, 10 in longline gear, two in pot gear, two in kelp gear and one each in a mix of gear, anchorage line and unknown line.
Of the trawl net entanglements, 12 were in commercial flatfish trawls and seven were in commercial pollock trawls, all in the Bering Sea and Aleutian Islands.
Fifteen of the trawl net entrapments resulted in death. Five of the trawl net entanglements were categorized as alive, disentangled or partially disentangled and released with serious injuries.
Longline entanglements were the second most frequent type of killer whale entanglements in Alaska. They included six in commercial Pacific cod longline and three in Greenland turbot longline, both in the Bering Sea and Aleutian Islands, with one in the commercial halibut and sablefish longline in Southeast Alaska.
Longlines reported in this technical memorandum were using hooks on their gear at the time of the entanglements. Just two of the longline entanglements involved killer whales who were released alive, including one who was seriously injured and one whose injuries were not considered serious.
Of the two pot gear entanglements, one involved a serious injury. In the other case, involving recreational shrimp pot gear, the whale was able to escape on its own.
NOAA Fisheries conducts and oversees entanglement responses for all cetaceans in domestic waters, including killer whales. The agency said proper response to entanglements is crucial for the welfare of whales, the safety of responders, and for gaining information that might mitigate threats related to entanglement in the future.
In cases where entanglements can’t be prevented, NOAA Fisheries collects data to help with stock management, including skin samples, photos of the whale and the entanglement and detailed descriptions regarding the entanglement.