The incidental catch of seabirds by longline fisheries: Worldwide review and technical guidelines for mitigation
The content of this report was originally prepared as three separate background papers describing longline fisheries of the world, the nature and extent of incidental catch of seabirds in those fisheries and a description of technical and operational measures that can mitigate such incidental catch. An FAO appointed Technical Working Group (TWG) of experts in the field of fishing technology, seabird biology and fisheries management reviewed the content and decided to compile it into one document. The report, first in general terms, describes the interaction of seabirds with longline fisheries with reference to typical behaviour patterns of seabirds and why and how the incidental longline catch of seabirds has become an international issue. The various longline fisheries (demersal and pelagic) of the world are described with regard to technology and effort. The pelagic fisheries, which mainly target tunas, swordfish and billfishes are operated widely from temperate to tropical waters in all oceans. The most important demersal fisheries are found in the North Atlantic and the North Pacific but a longline fisheries for Patagonian tootfish has been developed in the Southern Ocean over the last few years. Certain longline fisheries result in large numbers of seabirds being hooked on setting lines. The major "problem" fisheries are the demersal fisheries of the Northeast Pacific, North Atlantic, Southern Ocean and the Atlantic coast of South America, and the tuna pelagic fisheries of cool temperate seas in the North Pacific and the Southern Ocean. However, data on the incidental catch of seabirds are lacking for a number of longline fisheries, including the Pacific coast of South America, the Mediterranean Sea and in tropical waters of all oceans. Species of seabirds most commonly taken are the albatrosses and large petrels of the family Procellariidae. A comprehensive number of mitigation measures for reducing the incidental catch of seabirds in longline fisheries has been developed during the past 5-10 years. These are all described in detail in the report. With widespread use of such mitigation measures, a significant reduction in incidental catch of seabirds is achievable at a minimal cost and with much potential financial benefit to longline fisheries.