Distribution and abundance of euphausiids in the gulf of tehuantepec during wind forcing

Abstract

The Gulf of Tehuantepec in the Mexican tropical Pacific, is forced during autumn and winter by strong intermittent northerly winds. According to its temperatureand salinity characteristics during wind forcing, the Gulf of Tehuantepec can be divided into three regions. Of these, the western had the highest mean euphausiid concentrations (28,000 ind./1000 m 3) and the lowest were to the east (11,400 ind./1000 m 3). The higher densities were those of the frontal stations and of those of the coastal eastern sector. The coastal species Euphausia lamelligera dominated over the more oceanic Euphausia distinguenda (91.6 vs 7.3%, respectively). The highest zooplankton biomass (22.3±19.3 g/1000 m 3) was that of the central area. That of the western sector had a lower variability (19.6±9.4 g/1000 m 3).