Past stock status and conservation advice
(From ISC7 Plenary Report)
Previous scientific advice, based on the 2004 stock assessment, recommended that current fishing mortality rate (F) should not be increased. It was noted that management objectives for the IATTC and WCPFC are based on maintaining population levels which produce maximum sustainable yield. Due to updating, and improvements and refinements in data and models used in the 2006 stock assessment, it is now recognized that Fcur (0.75) is high relative to most of the F reference points (see Table 5a in Annex 5). On the other hand, the same analysis indicates that the current estimate of the SSB is the second highest in history but that keeping the current F would gradually reduce the SSB to the long-term average by the mid 2010s. Therefore, the recommendation of not increasing F from current (Fcur(2002-2004)=0.75) is still valid. However, with the projection based on the continued current high F, the fishing mortality rate will have to be reduced. The degree to which, when and how reductions should occur will depend on which reference points are selected and the desired probability and practicability of success of attaining these reference points in a timeframe to be agreed. The ISC requires additional guidance on these issues from the management authorities in a timely manner to work further on these issues.
Pacific Bluefin Tuna
It was concluded that the advice provided by the ISC Plenary in 2006 still holds.
Noting the uncertainty in the assessments, the ISC Plenary agreed with the WG recommendation that bluefin tuna fishing mortality∗ not be increased above recent levels as a precautionary measure.
∗“fishing mortality” refers to a rate which can be converted into effort or catch in management
While further guidance from the management authority is necessary, including guidance on reference points and the desirable degree of reduction, the fishing mortality rate of striped marlin (which can be converted into effort or catch in management) should be reduced from the current level (2003 or before), taking into consideration various factors associated with this species and its fishery. Until appropriate measures in this regard are taken, the fishing mortality rate should not be increased.