Hook Pod: development and at-sea trialling of a ‘one-stop’ mitigation solution for seabird bycatch in pelagic longline fisheries
Hook of is an emerging mitigation measure that encapsulates the point and barb of baited hooks in pelagic longline fisheries before a pressure release system releases the hook at depth. The pod contains a light emitting diode (LED), incorporated to reduce the use of disposable chemical light sticks and to provide an economic benefit for fishermen for using the pod as a seabird bycatch mitigation solution. We present details and results of the development and at-sea trialling of the Hook Pod on commercial pelagic longline vessels targeting tuna between 2011 and 2015 in three regions (Australia, South Africa and southern Brazil). In this study, over 62,000 hooks were set, distributed across 127 sets, 19 trips and 3 regions. In total, twenty-five birds were killed in these trial, on 11 separate occasions. Twenty-four of the 25 bird deaths occurred on control branchlines at a catch rate of 0.77 birds/1000 hooks, compared to a catch rate of 0.034 birds/1000 hooks on the pod treatment. A generalised liner model was fitted to assess the catch rate of target and non-target fish species and their length distribution. This analysis indicates that there was no reduction in target catch rates of ‘Tuna’ or ‘Swordfish’. The hook pod has been tested and proven in a range of pelagic fisheries around the world and has in all cases been shown to be highly effective at reducing seabird bycatch and does not have a negative impact on target catch rates. The hook pod is cost effective and fits easily into standard fishing practices. Our findings suggests the pod has the potential to be become a ‘one-stop’ mitigation solution for seabird bycatch in pelagic longline fisheries.