NOAA Fisheries Analyzes Data on Incidental Catch of Killer Whales

Killer whale pods
Photo courtesy NOAA.

NOAA Fisheries officials are analyzing data regarding 10 killer whales caught incidentally in the nets of Bering Sea and Aleutian Island groundfish trawl fisheries that were required to carry two agency observers.

Only one of the whales was released alive.

Regarding the other incidents, NOAA Fisheries officials said they are attempting to determine the cause of injury or death, and which stocks these whales belonged based on a review of genetic information.

The agency said its findings would be made public once all analyses are completed.

NOAA Fisheries is also reviewing information regarding a killer whale incidentally caught during the Alaska Fisheries Science Center’s recent longline survey for sablefish and groundfish.

On June 7, a dead orca was observed entangled in gear on the Central Bering Sea slope. The incident was reported and was under review in accordance with required reporting procedures. The center has an incidental-take authorization under the Marine Mammal Protection Act and biological opinion under the Endangered Species Act.

The International Whaling Commission (IWC) has identified bycatch as a global conservation and fisheries management issue and the single most direct threat to cetaceans. Globally, it is estimated that at least 300,000 cetaceans are caught and killed as bycatch annually, the IWC said. 

Cetaceans can become entangled or wrapped in various types of fishing gear, including nets, ropes and lines. Smaller species often die immediately as they are unable to reach the surface to breathe. The large size of some cetacean species means entanglement may not kill them immediately, but instead can become a serious welfare issue as they tow heavy ropes, buoys and nets for weeks, months or years before dying.

“Killer whales are highly complex and intelligent animals that play a critical role in ecosystem health and diversity,” said Megan Williams, a fisheries scientist with the Ocean Conservancy, a science-based conservation nonprofit. “Recent whale mortalities in Alaska’s industrial trawl fisheries are tragic events that spotlight the urgent need for better bycatch and ecosystem management in the North Pacific.”

Killer whales are protected under the Marine Mammal Protection Act, which requires vessel owners and operators to report to NOAA Fisheries any incidental mortalities and injuries of marine mammals occurring in the course of commercial fisheries and survey operations.

Monitoring and evaluation of bycatch of protected species in commercial fishing gear is done by NOAA Fisheries through an analysis required under the protection act, to determine whether the animals caught in the nets were dead before being caught or were killed or seriously injured by fishing gear.