Pilot test of techniques to mitigate seabird interactions with catcher processor vessels in the Bering Sea pollock trawl fishery: final report

We carried out a pilot research program in collaboration with industry to identify techniques for future testing that are likely to reduce seabird interactions with catcher processor trawl vessels operating the Bering Sea fishery for pollock (Theragra chalcogramma) and that are practical and safe. Emphasis was placed on reducing seabird interactions with trawl cables: nets warps, as well as the netsounde cable (3rd wire). Third wire mitigation techniques included pulling the third wire as close as possible to the water at the stern with a snatch block, paired streamer lines and various deterrents attached directly to the third wire (3rd wire scarers). Warp deterrents included a boom array or a buoy placed in the offal stream forward of the warps. Results showed that both the snatch block and paired streamer lines have great potential to reduce seabird interactions with the 3rd wire, but both require refinement for practical and safe application. Deterrents applied directly on the third wire were less effective and impractical. The boom array effectively excluded birds from the area around the trawl warps. Buoys were less effective and were difficult to position effectively. Formal testing of streamer lines, the snatch block, and the warp boom on two factory trawlers retrofitted to allow for the safe and practical deployment of the seabird interaction deterrents was proposed for 2005. Limited tests suggested fish oil has great potential as a seabird deterrent.