Abundance and distribution of the surface zooplankton of the coastal zone Arapito – Santa Fe, Sucre state, Venezuela

Abstract

The study of zooplankton in the coastal zone is fundamental to understand ecological processes. The coastal zone Arapito - Santa Fe, located in the Mochima National Park, Sucre state, Venezuela, is considered an area of great natural importance and therefore the study on zooplankton was carried upon. For this reason, the composition and community structure of zooplankton were determined in 20 stations, separated in a) coastal stations and b) away from the coast during December 2008. Samples were collected obliquely by dragging a Bongo net (500 and 300 μm, with a flow meter). The community was characterized by the presence of holoplanktonic organisms and
a lower proportion of meroplankton. The main holoplankton groups were cladocerans, copepods and gelatinous plankton (appendiculate, siphonophores and hydromedusae). The most abundant species were the cladocerans Penilia avirostris and Pseudevadne tergestina and the copepods Acartia tonsa and Temora turbinata. The high percentage of holoplankton in the study area let it to be considered as a growth and feeding zone. The AMOSIM-MDS showed significant differences (p <0.05) between the two environments with R = 0.27 but with low dissimilarity (17.4%), which suggests that mixing processes promote homogeneous distribution of zooplankton in the study area.