Joint Analysis of Sea Turtle Mitigation Effectiveness

Also published as IOTC-2017-WPEB13-38

To support the Western and Central Pacific Fisheries Commission’s (WCPFC) ongoing sea turtle conservation and management, the Common Oceans (ABNJ) Tuna Project provided funding for an analysis of the effectiveness of sea turtle mitigation in 2016. The analysis was conducted jointly by the Pacific Community (SPC) and WCPFC members (CCMs) from 13 countries as well as IGOs and NGOs in the form of two four-day workshops. The workshops were focused on estimating current interactions and mortalities in Pacific longline fisheries and examining how these estimates could be reduced through improved mitigation. The primary outputs were an evaluation of the effectiveness of various packages of mitigation measures (see attached workshop report pp. 69-76).
One of the ancillary findings of the workshops is that currently under the WCPFC’s sea turtle conservation and management measure (CMM 2008-03) less than 1% of Western and Central Pacific Ocean (WCPO) longline effort is subject to mitigation, even though approximately 20% of the WCPO longline effort consists of shallow sets (see pp. 17-18). This situation arises from the applicability of the measure to “longline vessels that fish for swordfish in a shallow-set manner”, with each CCM authorized to formulate their own definition of “shallow-set”. While mitigating <1% of WCPO longline effort is marginally better than not mitigating at all, it does raise the question of whether this is consistent with the intention of the Commission in adopting CMM 2008-03.
As early as 2009, SC5 discussed the view of some CCMs that: “…much of the language [of CMM 2008-03] was too flexible to really allow its effectiveness to be monitored.”
and
“...the focus of the requirements under the measure to use circle hooks or fish bait is on shallow-set swordfish fisheries. These fisheries have the highest encounter rates for turtles but deep-set longlines also catch turtles, so it is not appropriate to exempt such fisheries from all possible measures designed to minimize fishing-induced mortality on turtles.”