The impact of longline fishing on seabirds in the north-east Atlantic: recommendations for reducing mortality

Dunn E, Steel C (2001) The impact of longline fishing on seabirds in the north-east Atlantic: recommendations for reducing mortality

This report describes an on-board observer study of the seabird bycatch taken by Norwegian offshore longline fishing vessels in the Norwegian Sea in 1997 and 1998. By establishing by-catch rates and extrapolating to the known fishing effort, we estimate that overall the Norwegian fleet takes a significant by-catch of northern fulmar Fulmarus glacialis, as must also the longlining fleets of Iceland and the Faeroes in their regional waters.
The total Norwegian longlining fleet (including the inshore fleet of smaller vessels) is conservatively estimated to take ca. 20,000 northern fulmars annually, but the actual total may easily be 50,000-100,000. The combined activities of the Norwegian, Icelandic and Faeroese longlining fleets are conservatively estimated to take a by-catch of 50,000-100,000 northern fulmars annually, but the true figure could be significantly higher (depending, e.g., on the deployment of mitigating measures).
While northern fulmars are caught in significant numbers by longlining, the estimated annual mortality is not thought to be status-threatening given that the north-east Atlantic breeding population of northern fulmars is ca. 2-4 million pairs and the overall population much higher when non-breeding adults and immatures are included.
Nevertheless, the application of some simple technical devices and procedures could easily minimise this needless incidental mortality of seabirds. The fieldwork included an evaluation of the mitigating measures used by the Norwegian fleet, including an underwater setting tube and streamer lines. This assessment leads to recommendations for improvements in longlining gear and practices that would substantially reduce seabird by-catch, thereby also reducing bait loss and improving fishing efficiency.
The study was carried out to give impetus to the development and implementation of FAO National Plans of Action (NPOAs) for Reducing Incidental Catch of Seabirds in Longline Fisheries. The report makes recommendations for the content of the NPOA that Norway is currently undertaking, and presents evidence that Iceland and the Faeroes also need to undertake a NPOA.