To catch black cod, halibut and other fish, some fishing 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, according to a report of 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. 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. 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, Sea Grant bought 90 sets of streamer lines, with each set costing around $125. Assistant professor of practice and Sea Grant Extension fisheries 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. 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.