Management and assessment of spotted mackerel (Scomber australasicus) biomass in the Pacific Ocean

Spotted mackerel (Scomber australasicus) is an important economic species in northwest Pacific. The paper evaluates the Pacific stock biomass by age structure virtual population analysis (VPA) and yield per recruit model, and analyses the utilization of stock biomass by using the mackerel catch and CPUE data of the Pacific group which is supplied by Japan’s central fisheries research institute from 1995 to 2015. The results show that the biomass of spotted mackerel remains at a high level. The stock biomass is about 650000 tons in 2015, the average fishing mortality shows a trend of falling volatility and fishing mortality of 2015 is 0.15, the current fishing mortality (F_cur) is 0.33, the spawning potential ratio (SPR) remains 36.5%. There is no growth overfishing and recruitment overfishing. It is also discussed that the fluctuations of natural mortality caused by water temperature change and different fishing age affect the resources of spotted mackerel. The study suggests that the fishery is currently utilized in the sustainable way and has great potential for development. It also suggests that the fishery resources could be developed and utilized by using the management reference point F_0.1.