Variation in relative abundance and mean size of the sailfish Istiophorus platypterus caught by the artisanal fleet in the Gulf of Tehuantepec, Mexico

Abstract

The sailfish Istiophorus platypterus is abundant in tropical coastal areas of the Pacific Ocean. It is targeted by both sport-fishing and commercial (artisanal) fleets in Mexico, Guatemala, Costa Rica, and Panama. The Gulf of Tehuantepec is one of the main areas of abundance of I. platypterus, where it is caught incidentally by artisanal vessels. The objective of this study was to analyze the size structure and the variability in the catch-per-unit-effort (CPUE) of sailfish caught in the Gulf of Tehuantepec from 2000 to 2008. The size structure was analyzed using eye-fork length (EFL) and CPUE was estimated as the number of individuals per fishing trip. Individuals ranged in size from 55 to 240 cm EFL and varied in total weight from 1.6 to 69.7 kg. The size structure was unimodal, and the variability over time showed a negative tendency (F(0.05(1),8,4967) = 6.8E + 8; P < 0.05). The CPUE of I. platypterus showed seasonal changes: values were lower from January to April and higher during the summer, and then decreased again in early winter.