Size composition of yellowfin and bigeye tuna in IOTC fisheries

The Indian Ocean Tuna Commission (IOTC) is responsible for managing tuna and tuna-like species in the Indian Ocean, including yellowfin tuna (Thunnus albacares) and bigeye tune (Thunnus obesus) throughout the IOTC area of competence. The report of the IOTC performance review panel highlighted that it is necessary for IOTC to adopt the FAO Precautionary Principle which requires that management advice is based on the best scientific evidence, taking account of uncertainty.

A clear understanding of the size distributions of yellowfin and bigeye tuna caught by the different fleets in the Indian Ocean, including impacts of different gear types and spatial differences will be vital in understanding the potential impact of any proposed spatio-temporal closures on fishing activities.

The purpose of this paper is to present data that already exist in IOTC datasets through a summary of the size frequency data, catch and catch distribution data for yellowfin tuna available for all Members to support any decision-making process at this Working Group.  This paper does not recommend any particular option or direction for management of FADs it is here purely for information.