The autumn copepod community at South Georgia Islands (Southern Ocean): composition, abundance, biomass, and link with physical forcing and phytoplankton

CEPEDA, G.; SILVA, R.; VIÑAS, M. D,

Bergen

Simposio; 6th Zooplankton Production Symposium; 2016

ICES

During autumn 2013 the plankton community was investigated at South Georgia Islands,aboard the RV Dr.Holmberg. Warmest SST (>3.1ºC). occurred northwest of the region. The temporal evolution of satellite chlorophyll a showed that by the time of sampling the spring-summer phytoplankton bloom was strongly decreased. Maximum chlorophyll a concentration, was observed southwestern South Georgia. It was mostly represented by the nanophytoplankton size fraction and dominated by Thalassiosira spp. andProrocentrum spp. Coincidently, in this sector the highest records of the dominant calanoid copepods Drepanopus forcipatus, Ctenocalanus vanus, Metridia lucens and Rhincalanus gigas were observed. Only C. vanus exhibited an inverse and significant relationship with the SST. Between the dominant copepods, Oithona similis s.l. and C. vanus were homogeneously distributed in the study region.