Bioeconomic analysis of the shrimp trawl fishery in the Tonkin Gulf, Vietnam

Abstract

The objective of this study is to investigate the sustainability properties of the stock and management of the shrimp trawl fishery in the Tonkin Gulf, Vietnam. Surplus production models of Verhulst-Schaefer and Gompertz-Fox are applied to the shrimp trawl fishery, which is a typical tropical fishery with the characteristic properties of small scale and multi-species fisheries. There are two shrimp spawning seasons per year in the Gulf. This implies that it is appropriate to divide the time scale into a half year in accordance with the biological year of the stock. The surplus production models which are usually associated with calendar year catch and effort data, in this study are applied for a half year time interval data. Empirical data were collected from the enumerator project (ALRMV), which was supported by DANIDA and carried out in Vietnam from 2000 to 2004. The catch and effort data aggregated from the data of the project were monthly collected by the questionnaire methodology in local fishing ports. Standard reference points with and without discounting are analyzed and policy implications of the findings are indicated. Entry tax and closing seasons may be reasonable regulations for the fishery in order to achieve maximum economic and sustainable yield.