Reducing mortality

How can seabird mortality in longline fisheries be reduced?

Practices by fishing vessels

Reducing seabird kills in longline fisheries is helped by

• lines of streamers trailing behind vessels over the area where hooks enter the water
• setting lines in total darkness

The combination of night setting and streamer lines can reduce mortality of most seabird species by up to 90%. Mortality can also be reduced by adding weight to longlines to expedite sink rates, and by setting longlines deep underwater through a tube. The latter method is relatively new and is still in the formative stages of development, but promises to be the best option to date, because underwater setting eliminates the visual cues that seabirds rely on to take bait. Dyeing baits blue (to disguise them against the water) is also effective.

Albatross feed frantically on processed fish expelled from the boat. Photograph: Graham Robertson

The setting of longlines at night with effective streamer lines in use and weights near hooks would almost certainly reduce seabird deaths to levels that are safe for most seabird species. Unfortunately most fisheries have shown reluctance to embrace wholeheartedly effective mitigation which has meant that other actions have been necessary. For instance, in the Patagonian toothfish longline fishery at South Georgia (an island in the south-western Atlantic Ocean) incomplete compliance with mitigation measures has resulted in the closure of the fishery during the seabird breeding season (September–April, inclusive). This most heavy-handed of measures that neither the fishery management agency nor fishery wanted, is indicative of the reluctance by vessel operators to adopt the easy-to-use mitigation practices.

International agreements

As well as the existence of seabird bycatch mitigation measures and the research that underpins the efficacy of these measures, international agreements are necessary to achieve global objectives regarding seabird conservation in longline fisheries. Several initiatives exist. The United Nations Food and Agricultural Organisation (FAO) has requested that all longline fishing nations produce plans of action to minimise seabird seabird mortality in their longline fisheries. In effect, this requests that nations assess the extent of the problem, adopt standard mitigation measures as an interim measure, conduct research into mitigation practices by fishery type, adopt independent observer programs and include seabird conservation provisions in fisheries management legislation.

The Agreement on the Conservation of Albatrosses and Petrels (ACAP) has been developed in recognition of the fact that albatrosses and petrels on migration flights traverse the waters of many nations, not only those from their country of origin. The terms of the Agreement apply to nations with longline fisheries and to distant water fishing nations that interact with albatrosses and petrels while fishing. Parties to the ACAP will be obliged to achieve and maintain the favourable conservation status of albatrosses in both terrestrial and marine environments. This initiative is complementary to that by the FAO since the protection of albatrosses in marine environments will require the production and implementation of action plans as sought by the FAO.

The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) is a 23-nation organisation that presides over fisheries in the Southern Ocean. In 1995 CCAMLR developed a conservation measure especially designed to minimise seabird mortality in the Patagonian toothfish longline fishery, which occurs, principally, around sub Antarctic islands. The CCAMLR members meet annually to review trends in seabird bycatch, to discuss advances in mitigation technologies and practices and how best to achieve seabird conservation objectives.