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

SILVA, R.I.; VIÑAS, M. D.; CEPEDA, G. C.

Simposio; 6th Zooplankton Production Symposium; 2016

ICES/PICES

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 thespring-summer phytoplankton bloom was strongly decreased. Maximum chlorophyll aconcentration, was observed southwestern South Georgia. It was mostly represented bythe nanophytoplankton size fraction and dominated by Thalassiosira spp. andProrocentrum spp. Coincidently, in this sector the highest records of the dominant calanoidcopepods Drepanopus forcipatus, Ctenocalanus vanus, Metridia lucens and Rhincalanusgigas were observed. Only C. vanus exhibited an inverse and significant relationship withthe SST. Between the dominant copepods, Oithona similis s.l. and C. vanus werehomogeneously distributed in the study region.