Model simulations to determine optimal fishing effort and season duration for a tropical shrimp fishery

Abstract

Kuwait’s shrimp fishery presents typical tropical shrimp fishery characteristics with highly variable recruitment, fast growth and strong seasonal patterns. Both the General Production Model and Age-structured Model were chosen to assess the stock status of the Kuwait’s shrimp fishery. The estimated Maximum Sustainable Yield (MSY) was 2 518 metric ton (t) with a corresponding fishing efforts ( fMSY ) 7 265 standard boat-days from the General Production Model. Similar results from the Age-structured Model were 1 936 t and 6 449 boat-days respectively. Comparing these results with the average annual shrimp landings (1 772 t) and average fishing effort (9 710 boat-days) in the past 10 years, we concluded that the fishery was overfished. Model simulations to show the changes of recruitment, biomass and possible catch under different fishing effort scenarios indicated possible stock collapse if the fishing effort continually increase. But both shrimp recruitment and biomass will increase if the current fishing effort is reduced. Model simulations also showed a possible increase of MSY by delaying the opening or by closing the season earlier. Based on these results, recommendations to improve the management of Kuwait’s shrimp fishery are presented.