Report details 37 known incidents of killer whale entanglement in Alaska over 30 years

renew: 19 hours ago Posted by: 20 hours ago

A new report released by the National Oceanic and Atmospheric Administration shows that 37 killer whales have become entangled in fishing gear in Alaska over the past three decades, resulting in 25 deaths.

The NOAA Fisheries report covers cases recorded from 1991 to 2022. It does not include an unusually high number of cases this year in which 10 killer whales were found trapped in fishing gear and nine were found dead. The incidents triggered special inspections by the agency.

Cases recorded between 1991 and 2022 involved a variety of fishing gear. Trawl gear was responsible for 20 cases of entanglement, longline gear was responsible for 10 cases, and other cases involved various other fishing gears.

Killer whales, also known as killer whales, are found in oceans around the world but generally prefer cooler waters. Some groups of killer whales swim in Alaskan waters; some eat only fish, while others feed on hunted marine mammals. They are among the marine mammals that are occasionally killed by human activities in ocean areas.

[NOAA Fisheries releases more information about high level of killer whales caught this year by Alaska trawl fleet]

Killer whales have been known to follow ships to feed on fish caught in nets, hooks, pots or traps, sometimes to their peril. Reports say some people died of suffocation due to being trapped underwater, and even if they escaped alive, some ended up with serious injuries that could ultimately lead to death.

But the report notes that some gear modifications and devices have the potential to reduce harm to whales. Barrier ropes that prevent whales from swimming into nets, sleeves that cover hooked fish hauled up on longlines, acoustic instruments that repel whales and other devices should be further studied to see if they are effective in reducing killer whale deaths, the report said. explain.

Not all of the 37 reported incidents of entanglement during the three-decade period involved any type of fishing or marine gear.

In two reported cases, the whales were determined to be entangled in kelp. The decisions were based on analysis of photographs, demonstrating the importance of gathering photographic evidence, the report said.

Killer whales and other whales are known to interact with kelp and have been observed playing with it. There is also evidence that rubbing kelp can soothe whales’ skin. Reports suggest there may be many more cases of kelp entanglement than the two recorded.

The report notes that as kelp and seaweed farming proliferates, the affinity for kelp signals potential future problems. The report says killer whales have the potential to interact with human material at kelp farms, as well as agricultural crops.

Alaska killer whales are classified by group and prey type. Retaining whales feed on fish, while transiting whales prey on marine mammals. Multiple populations are found in Alaskan waters.

NOAA Fisheries scientists used genetic testing to identify the group of 12 entangled whales. Nine are from the larger Northeast Pacific Alaska resident population, and three are from the Northeast Pacific, Gulf of Alaska, Aleutian Islands, and Bering Sea transient populations.

NOAA Fisheries estimates there are 1,920 individuals in Alaska’s resident population in the eastern North Pacific, where they swim in the Gulf of Alaska and the Bering Sea, and 587 in the ephemeral population in the eastern North Pacific, Gulf of Alaska, Aleutian Islands and Bering Sea. Past analyzes by NOAA Fisheries have found that resident populations in Alaska in the eastern North Pacific can sustain the loss of 19 animals per year, while smaller transient populations can sustain an average loss of 5.9 animals per year.

Originally by Alaska Lighthousean independent, nonpartisan news organization covering Alaska state government.