August 17, 2006
Streamer line innovation saves seabirds from that sinking feeling
Globally each year, hundreds of thousands of seabirds looking for a free lunch end up snagged on baited hooks as commercial longline vessels set their gear. With fishing lines being plied out behind vessels at speeds up to 7 knots, or about 8 miles per hour, the birds rapidly disappear below the surface, dragged to the depths where they drown.
In the waters of Alaska, that accidental bycatch of seabirds by the longline fishing industry has been cut by more than 80 percent since 1998 as fishermen adopted strategies that UW research proved were effective. Further, in that time there’s been no observed bycatch of short-tailed albatrosses, a bird so endangered that the accidental killing of six of them in any two-year period triggers severe restrictions on the longline industry.
Working collaboratively with fishermen, including those who’d been trying on their own to find ways to deter the birds, a UW Washington Sea Grant team led by Ed Melvin documented the effectiveness of using streamer lines consisting of polyester rope from which brightly-colored plastic streamers dangle. Strung above the water on each side of a fishing line as it is being deployed, this visual “fence” can cut seabird bycatch from 88 to 100 percent the UW team found.
In keeping with Washington Sea Grant’s commitment to not only do research, but also to get information into the hands of those who can use it, Melvin produced a video showing fishermen how to individualize and set the streamers on their vessels. He also designed streamer lines that have been made available to the longline fleet at no cost, courtesy of the U.S. Fish and Wildlife Service.
The effectiveness of the research program in Alaska, and its growing importance internationally, earned Melvin one of the inaugural “Stewardship and Sustainability Award” from the National Oceanic and Atmospheric Administration earlier this year. The awards, which NOAA intends to give annually from now on, went this year to two individuals and four organizations that have advanced conservation and sustainable use of U.S. marine resources.
The hallmark of his Alaskan work has been collaboration with fishermen and fisheries managers, NOAA says.
“It’s been especially rewarding to have worked closely with fishers through the North Pacific Longline Association in testing and fine tuning their ideas and in developing the recommendations,” Melvin says. “The response of fishermen has been remarkable given that longline fishermen in Alaska slashed the bycatch of all seabirds two years before regulations went into effect forcing them to do so.”
The longline commercial fishery in Alaska is a $300 million a year industry involving some 1,600 vessels. Large vessels can trail continuous lines, with baited hooks every 3 feet or so, that are 15 to 25 miles long. Smaller vessels use lines 2 ½ to 3 miles long.
The streamer lines used to deter birds are considerably shorter, needing only to reach from a high point on the vessel out 130 to 200 feet behind vessels to the point where the fishing line has sunk enough that diving birds can no longer reach the baited hooks. The fishing line actually sinks quite quickly, Melvin says, but most birds are in danger until it gets 6 feet deep.
While the most effective deterrent is two streamer lines, one on either side of the fishing line, UW research has shown other effective steps. A single streamer line, for instance, reduces bycatch 71 to 96 percent. Not dumping excess bait and offal near the sinking hooks is another. A roundup of the work is at http://www.wsg.washington.edu/pubs/seabirds/seabirdsolvinghr.pdf.
Initially funded through Washington Sea Grant by the U.S. Fish and Wildlife Service and National Marine Fisheries Service, Melvin’s Alaskan work has involved UW faculty members Associate Professor Julia Parrish and Professor Loveday Conquest, both with the School of Aquatic and Fishery Sciences.
Kim Dietrich, an experienced fisheries observer, was recruited to join Melvin for two seasons aboard large and small fishing vessels in the Aleutian Islands, Bering Sea and Gulf of Alaska. Dietrich and Michelle Wainstein are the current staff members of Melvin’s team based at the School of Aquatic and Fishery Sciences.
The first of its kind in the Unites States when it was launched in the mid-’90s, Melvin’s research program is the largest and most comprehensive in the world today. The group is studying ways fishermen using a variety of different gear can avoid seabird bycatch. Sometimes suggestions are made about the best times to fish, for instance, avoiding fishing at dawn if susceptible seabirds are especially active then. Other work involves gear such as researching ways gillnets, usually made with near-invisible nylon filament, can be more visible to birds to helping the fishing-line industry figure out how much weight to add to lines as they are manufactured so they sink ever faster than today’s line.
Melvin is looking forward to further work in Alaska with the trawl fisheries, a $500 million fishery, with some ships over 300 feet, and having an opportunity to work with longline fishing vessels in open ocean, which involves foreign fleets.