Mesozooplankton assemblages in two bays of the Beagle Channel (Argentina) during January, 2001

FERNÁNDEZ SEVERINI MELISA DAIANA; HOFFMEYER MÓNICA SUSANA

SCIENTIA MARINA

Institut de Ciències del Mar (CSIC)

Lugar: Barcelona; Año: 2005 vol. 69 p. 27 - 37

0214-8358

This paper describes the composition and abundance of mesozooplankton of Bahía Ushuaia and Bahía Golondrina. These small bays are located in the northern Beagle Channel. Sampling was carried out from January 20 to 23, 2001 and samples were collected from the upper layer at nine stations. This study is the first research on mesozooplankton in this part of the Beagle Channel. Due to their dominance in the mesozooplankton community, we compared our Copepoda data with those by other authors from Antarctic coastal environments. By applying cluster analysis, we found two stations groups in both bays: one in slightly polluted zones and the other one in undisturbed external zones. Four assemblages in Bahía Ushuaia and two in Bahía Golondrina were determined by using non-metric multidimensional scaling (MDS) and cluster analysis. Mesozooplanktonic assemblages showed a certain resemblance in zones with and without anthropogenic influence. Most of the copepods species in our samples are typical of the sub-Antarctic region. Oithona similis (=O. helgolandica sensu Ramírez, 1966), Oncaea curvata, and Ctenocalanus citer show either similar or higher abundances at Antarctic sites, including the upper layer oceanic areas, in comparison with sub-Antarctic coastal localities. This suggests that, in agreement with other findings, the Polar Front is probably not a major geographic boundary for the distribution of these species