No information is available on the stock structure of Indo-Pacific king mackerel stock structure in Indian Ocean. The IOTC coordinated Stock Structure Project, which commenced in early-2015, aims to supplement gaps in the existing knowledge on biological data, and in particular provide an insight on whether neritic tuna and tuna like species should be considered as a single Indian Ocean stock.

Following a first data-poor assessment in 2015, Indo-Pacific king mackerel was again assessed using SRA techniques (Catch-MSY and OCOM) in 2016. The OCOM model, considered the more robust of the two SRA models applied in terms of assumptions and treatment of priors, indicates that overfishing is not occurring and the stock is not overfished (Fig. 1; Table 1). Moreover, the average catches (c. 45,000 t) over the last 5 years have been within the estimated MSY range (43,000 – 46,000 t). However, catches have increased in the last 2 years and in 2014 exceeded this MSY range. The continuing low levels of catch reporting for this species, coupled with the highly variable and uncertain estimates of growth parameters used to estimate model priors, prompted the WPNT to exercise caution in interpreting model results for king mackerel. Consequently, and similar to 2015, the WPNT considered that stock status in relation to the Commission’s BMSY and FMSY target reference points remains uncertain (Table 1), indicating that a precautionary approach to the management of Indo-Pacific king mackerel should be adopted.