Analysis of Sea Turtle Mitigation Measure Effectiveness in Tuna Longline Fisheries

Clarke S, Nicol S, Swimmer Y (2015) Analysis of Sea Turtle Mitigation Measure Effectiveness in Tuna Longline Fisheries. WCPFC, Pohnpei, Federated States of Micronesia

An analysis of mitigation options for tuna longline bycatch of sea turtles will be launched in late 2015 by SPC with funding provided by the ABNJ (Common Oceans) Tuna Project. WCPFC members are invited to contribute relevant data on a voluntary basis in order to construct a comprehensive Pacific dataset for analysis. Similar to the shark mitigation analysis conducted by SPC in 2014-2015, this analysis will quantitatively assess the potential for a variety of mitigation measures (e.g. changes in gear designs and fishing methods) to reduce mortality and injury, either singly or in combination. The first stage of the analysis will focus on characterizing baseline sea turtle interaction and mortality rates under existing fishing operations. A data preparatory workshop is planned to facilitate compilation and interpretation of national datasets, with special procedures developed for sharing of data for which there may be confidentiality concerns. The second stage of analysis, to be finalized in a second workshop, will alter the baseline scenario to explore various mitigation options, and if possible, combine these with estimates of absolute impacts, to determine whether any of the simulated mitigation schemes would be able to reduce any unacceptable impacts to sea turtle populations to acceptable levels. The analysis will be coordinated with an ongoing NOAA study of sea turtle mitigation in Pacific and Atlantic fisheries in order to broaden the geographic scope of the findings. This study will inform Pacific bycatch management discussions as well as demonstrate methods and indicative results for other regions.