This study investigates the sustainability of shrimp stock in the trawl fishery in the Tonkin Gulf, Vietnam. It is a small scale and multi-species fishery. The Verhulst-Schaefer and GompertzFox surplus production models are applied. There are two shrimp spawning seasons in a year in the Gulf | Applied Economics Journal Vol. 18 No. 2 (December 2011): 65-81 Copyright © 2011 Center for Applied Economics Research ISSN 0858-9291 Sustainable Management of Shrimp Trawl Fishery in Tonkin Gulf, Vietnam* Thanh Viet Nguyen** Faculty of Development Economics, VNU University of Economics and Business, Hanoi, Vietnam This study investigates the sustainability of shrimp stock in the trawl fishery in the Tonkin Gulf, Vietnam. It is a small scale and multi-species fishery. The Verhulst-Schaefer and GompertzFox surplus production models are applied. There are two shrimp spawning seasons in a year in the Gulf. Therefore, in this study, the surplus production models, associated to catch calendar and effort data, are applied for a half-year time interval. The results indicate that the fishing effort should be reduced by roughly 12-44% to achieve the maximum sustainable yield and 46-61% to reach the maximum economic yield. With a social discount rate of 10%, the effort should decrease by around 45-56% to achieve the optimal yield. The entry tax should be 92-279 USD/month/boat to achieve the maximum sustainable yield and 160-314 USD/month/boat to attain the maximum economic yield. Keywords: bioeconomic analysis, shrimp trawl fishery, fishery management, Vietnam JEL Classification: D24, H41, Q22 Introduction The Tonkin Gulf is a shallow, semi-closed gulf in the northwest South China Sea with an average depth of around 38 m and a total area of about 128,000 km2, and Vietnam’s marine water measures about 67,000 km2 in the western part of the gulf (Chinh et al., 2005; Xue, 2005). The Gulf is one of the most important fishing grounds in Vietnam’s marine water. It annually contributes around 16% of Vietnam’s marine resources, 30% of its total fishing boats, and about 20% of its total marine landings (Chinh, 2005). The Gulf has small-scale, multi-species and multi-gear fisheries. In 2003, about 26,000 fishing boats fished in the Gulf using 25 different types of gear; 86% of .
