Notification of research-in-progress in an Australian tuna fishery of relevance to the conservation of Convention Area seabirds

This purpose of this document is to inform CCAMLR of work-in-progress in the Australian eastern tuna and billfish fishery (ETBF) of potential relevance to the conservation of Convention area seabirds. The research plan includes (a) a line weighting experiment on a chartered tuna vessel to determine the effect of line weighting regimes and bait type on the sink rate of longlines. This experiment was completed in April 2005. (b) a manipulative experiment testing the effectiveness of various combinations of line weighting and streamer lines as deterrent to fleshy-footed shearwaters. This experiment is scheduled for October and November 2005 when fleshy-footed shearwaters (the main seabird species taken in the fishery) are most abundant on fishing grounds. A summary of findings of the line weighting experiment is presented below. The experiment examined the effect of bait type, swivel weight and bottom length (distance between weighted swivel and hook) on the sink rate of branch lines used in Australia’s ETBF.