Sea Grant Extension documents whale movements to mitigate entanglements

Crab pots in Newport, Oregon.

Entanglements of blue, humpback and gray whales in fixed fishing gear along the U.S. West Coast have been on the rise for the past five years, often exceeding biologically sustainable levels under the Endangered Species Act and the Marine Mammal Protection Act. Entanglements can occur when whales come into contact with the lines attaching crab pots to surface buoys. The lines get stuck in the back of a whale’s mouth or wrap around a flipper or fluke, where they can become embedded and interfere with feeding.

Oregon Sea Grant Extension convened a working group consisting of fishermen, state and federal regulators and nonprofits organizations from May 2017 to July 2019 to develop short- and long-term options for reducing the risk of whales getting entangled in crab and other fixed gear. Sea Grant gathered information from technical experts, distributed information on how to report entangled whales, developed best practices, conducted fleet outreach, surveyed crab permit holders, and spurred action by state agencies. But the group identified a lack of data about distribution patterns of whales in Oregon waters as a key gap.

In response, with funding from the National Oceanic and Atmospheric Administration and the Oregon Dungeness Crab Commission, Sea Grant Extension specialist Leigh Torres and her team documented whales’ locations in Oregon waters during nearly 60 flights aboard U.S. Coast Guard helicopters over two years. From vessels, they also photographed whales to identify them and took tissue samples to describe the whales’ population structure. The aim was to use this information to develop models to predict where whales might be.

As a result, a preliminary analysis of whale sightings illustrates general patterns of distribution by species relative to the month, distance from shore and depth. The research team shared its findings with the Oregon Department of Fish and Wildlife to inform the agency’s regulatory decisions. Additionally, the team used presentations, flyers and brochures to educate citizen scientists about whale entanglement in Oregon and to encourage them to participate in the project by using the Whale Alert app to report sightings of whales.

Sea Grant’s work has also spread to northern waters: Amanda Gladics, an OSU Extension fisheries management specialist, and her team provided support and technical advice for similar efforts in Washington.

Torres is an associate professor in OSU’s Marine Mammal Institute and director of the Geospatial Ecology of Marine Megafauna Laboratory.

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