CONICET | Buscador de Institutos y Recursos Humanos

This paper analyzes the first results about the composition, abundance and spatial distribution of mesozooplankton in Nuevo Gulf, Argentina. Sampling was carried out from July 16 to 17, 1997, and samples were collected from the upper layer at ten stations. A total of 32 taxa was recorded. Highest total abundances were found close to Nueva Bay whereas the lowest values were detected in the center of the gulf. Holoplankton dominated at all stations in terms of number of taxa and abundance, and evidenced a homogeneous spatial distribution. In contrast, meroplankton showed a heterogeneous pattern. Ctenocalanus vanus was by far the most abundant taxa followed by Paracalanus parvus. Gastropoda veligers dominated the meroplanktonic fraction. Cluster analysis and MDS plot revealed three groups of stations, namely, one formed by the northern and northeastern stations; another formed by the southern and southwestern stations; and another formed by only one station located in the center of the gulf. Our results showed that the spatial distribution of mesozooplaknton could be influenced, among other factors, by the depth of each station, the distance to the coast, the hydrological circulation pattern, and the variability of abiotic conditions.