Chronicle of marine fisheries in the Gulf of Thailand: variations, trends and patterns

Abstract

A comprehensive picture of marine fisheries in the Gulf of Thailand (GoT), within Thailand’s boundary, has been described by using fish landing data for 26 years, between 1984 and 2009. Thirty-five (35) species/groups of fish landings were used in analysis. Rastrelliger brachysoma showed the lowest long-term variation (CV) in fish landings at 15.53% and the highest CV was observed in Lates calcarifer at 146.16%. The relationship between CV and fish landings showed a negative trend with a high correlation (r = 0.62) and was associated with species life-history strategies. For short-term variations, the means of the relative variation (28%) were higher than the absolute variation (25%), indicating a higher uncertainty when catches are low. Three trends in fish landings were analyzed by Spearman’s rank correlation. Seven (7) and 3 species/groups trended to decrease and increase, respectively, over the studied period. Meanwhile, 15 species/groups showed a trend of inversion, i.e. increased then decreased. The self-organizing map was used to cluster patterns of fish landings, which indicated temporal trends of chronological order, i.e. 1985-1990, 1992-1998, 1999-2007 and 2008-2009.