Gear aims to keep seabirds from getting hooked on fishing lines

 

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A dense group of birds flying behind a fishing boat. Streamers extend from the boat.

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To catch black cod, halibut and other fish, some boats set a long line of baited hooks on the seafloor. But seabirds, including the endangered short-tailed albatross, can get caught if they try to steal the bait near the surface of the water. Between 2013 and 2018, hook-and-line fisheries accounted for 50–63% of seabird mortality caused by U.S. West Coast fisheries, followed by trawl fisheries at 31–45% and pot fisheries at 2–6%, according to a report by the National Oceanic and Atmospheric Administration (NOAA). Estimated seabird deaths caused by hook-and-line fisheries during that time totaled 1,188 across all species.

In the North Pacific, the largest source of adult mortality for albatrosses is bycatch in fisheries. NOAA estimated that about 646 black-footed albatrosses, about six Laysan albatrosses and about two endangered short-tailed albatrosses died between 2012 and 2018 due to hook-and-line gear on the U.S. West Coast. Black-footed albatross and Laysan albatross are relatively common, with estimated breeding populations of 130,000 and 1.2 million, respectively, according to a Partners in Flight database. However, even small increases in adult mortality can pose serious threats to the population because albatrosses reproduce slowly and can live more than 60 years.

 

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A diagram of fishing lines with streamers running behind a fishing boat to scare away birds.

Streamer lines can reduce bycatch. A streamer line is an overhead rope that is towed from a high point on a boat with a weighted buoy to prevent it from tangling with the hooks. As it angles down to the water, a brightly colored, plastic tube or polyester line dangles from the streamer line about every 16 feet. The streamer line scares the birds away while allowing the hooks to sink to below the depth that seabirds dive.

U.S. regulations that took effect in January 2020 mandated the use of streamer lines for certain vessels that use longlines to catch groundfish along the seafloor off the U.S. West Coast. The rule is an expansion of a 2015 regulation that applied to boats over 55 feet. Under the new rule, nearly 400 smaller vessels might have to buy streamer lines if they fish during the day, for a total cost of over $48,000, according to an analysis.

Oregon Sea Grant helped fishermen comply with the new policy, with the goal of improving their economic resilience while ensuring environmental sustainability. With funding from the U.S. Fish and Wildlife Service, we bought 90 sets of streamer lines, with each set costing around $125. Our fisheries Extension specialist Amanda Gladics worked with marine suppliers and port authorities in Washington, Oregon and California to let fishermen know that these lines were available for free. Ninety fishing vessels accepted the offer. Gladics also gave them information about how to avoid catching albatrosses, and she taught some fishermen how to install the streamer lines on their vessels.

Fisherman Dick Ogg used the streamer lines, but then, based on outreach information Gladics provided, switched to fishing at night, when the lines aren’t required. “Those streamer lines work very well if you get them up high enough,” he wrote. “I used the bird lines in good weather, and they were very effective.”

For fisherman Calder Deyerle, the streamer lines are “easy to use” and a win for the albatrosses and for him because he loses less bait to the birds. “I think the biggest benefit is albatross safety over bait saving factor, which is definitely there, just really hard to be able to quantify how much bait the birds can actually grab,” he wrote.

To estimate the potential impact of these lines, Gladics looked north to Alaska, where streamer lines have been mandatory since 2004 for the hook-and-line groundfish fleet. Researchers found that adopting streamer lines in Alaskan longline fisheries resulted in 88% fewer albatross deaths and reduced other seabird deaths by 78%.

“Extrapolating the findings to Oregon, the 90 sets of streamer lines we gave away have the potential to prevent the death of up to 260 albatrosses and up to 750 other seabirds over seven years,” said Gladics, adding that streamer lines typically last five to seven years.

Text current as of January 2024. Written by Tiffany Woods.