Progress report on the BS30 Underwater Bait Setter for pelagic longline fisheries Rev 2

Following four years research and development a prototype version of the underwater bait setter (Figure 1) was trialed in the Uruguayan swordfish fishery in September/October 2010. The project was a collaboration between Amerro Engineering, the Australian Antarctic Division, the Direccion Nacional de Recursos Acuaticos (DINARA) and Golden Star Fisheries S.A (Uruguay). This fishery was chosen because the waters of Uruguay are frequented by large numbers of seabirds (from South Georgia/Islas Georgia del Sur, the Falkland Islands/Islas Malvinas and Tristan da Cuhna), including white-chinned petrels and black-browed albatrosses. In 35 days fishing 15,000 hooks were set by hand and 15,000 hooks set underwater with the bait setter. Seabird catch rates and catch rates of target and non-target fish species were compared head-to-head.

There were no statistical differences between setting methods in catch rates of target and non-target fish. Two birds were caught by underwater setting compared to 11 seabirds caught by hand setting. Both birds caught by underwater setting were a consequence of secondary interactions. The prototype version of the machine set hooks no deeper than 4-6 m (depends on sea state), which obviously was not deep enough to deter deep diving petrels and shearwaters. Still, the experiment accomplished what was intended, which was to give the machine a thorough workout in real fishing operations against difficult-to-deter seabirds. Operationally, the prototype performed well, indicating the design concepts and build quality were up to the standard required for the South Atlantic.