Stock assessment of Scomberomorus commerson (Kingfish) fishery of Oman: Perspectives of sustainability

Scomberomorus commerson (here after ‘Kingfish’) is the choicest table fish of the Gulf Cooperation Council (GCC) region and the most valuable finfish of Oman. Catch-effort data from 2000 to 2019 of Oman's Kingfish fishery was fit to Schaefer model (log-normal assumption) for estimating maximum sustainable yield (MSY) and biological reference points (BRPs). Carrying capacity (K), catchability coefficient (q), population growth rate (r) and MSY of Kingfish were 36,745 tonnes, 0.0000161, 0.382 and 3,507 tonnes, respectively. At present, fishing effort (E_NOW) (i.e. number of boats) is 18,982, which is beyond the sustainable limit i.e. E_MSY= 11,846 and if the number of boats reaches to 23,692 then Kingfish stock may collapse. All the BRPs are higher than their sustainable limits, which indicate Kingfish stock is overfished. Stock Reduction Analysis suggests that the stock was in the safe zone between 2005 and 2007, it was in the overfishing zone from 2008 to 2012 and 2013 onwards the stock is in the overfished zone. A complete ban on Kingfish fishing in Oman may allow the stock to rebuild to Biomass at Maximum Sustainable Yield in three years or limiting the annual catch at 1,500 tonnes/year till 2026 may yield the same result. A transboundary management of Kingfish fishery is suggested for the GCC region. Forming a joint scientific council for monitoring and facilitating data availability, similar ban periods, mesh size regulations and a ‘payment for ecosystem services’ scheme may lead Kingfish fishery of the GCC region towards sustainability.