Examination of the meroplankton community in the south-western Ross Sea, Antarctica, using a collapsible plankton net

Abstract

The meroplankton community in the coastal Antarctic has been poorly studied, in part due to the presence of extensive sea-ice cover during the summer months. In this study, a collapsible plankton net was used to examine the meroplankton community at two sites in the south-western Ross Sea: at Cape Evans on Ross Island, and at Cape Roberts on the Victoria Land coast. Three samples were taken on 5 consecutive days in the early summer at each site (26–30 November and 8–12 December 2001) and 11 operational taxonomic units (OTUs) were quantified from the phyla Annelida, Mollusca, Nemertea, Echinodermata and Sipuncula and the early developmental stages of undetermined phyla. Multivariate analysis showed that there were distinct differences in the meroplankton communities at the two locations, but because there was a 2-week difference in the time of sampling between sites, location and time are confounded variables. On average, a total of 16 larvae/eggs/embryos were collected per tow (3.92 m3) at Cape Evans and 27 larvae/eggs/embryos at Cape Roberts, with a significant difference in total larval numbers and in numbers of 4/6 larval types tested between location and time. This research has shown that a collapsible plankton net can be used for meroplankton work in remote locations in the coastal Antarctic and that a diverse meroplankton community is evident in the south-western Ross Sea in the early summer.