Spatial and temporal variability in zooplankton community at Valdés Biosphere Reserve (Patagonia-Argentina): the Nuevo Gulf case study

NOCERA, ARIADNA C.; D'AGOSTINO, VALERIA C.; SCHLOSS, IRENE R.; GONÇALVES, RODRIGO J.

Congreso; 5th World Conference on Marine Biodiversity Virtual Conference; 2020

Zooplankton diversity has been identified as one of the biological Essential Ocean Variables (EOVs) to detect temporal and spatial changes in marine biodiversity and ecosystem health. The present study evaluated the zooplankton community composition and abundance associated withoceanographic variables in Nuevo Gulf (42° 42’S, 64° 30’W), a World Heritage Site in Argentinian Patagonia and part of the Valdés Biosphere Reserve. We found that > 43 % of the total zooplankton community abundance was composed by copepods, followed by cladocerans (24 %) in spring, while copepods represented more than 98 % of this community in summer. Most of the zooplankton groups were related with chlorophyll a and temperature. The dominating copepods belonged to the Calanoida order, mainly reflecting high densities of Ctenocalanus vanus, especially in summer. Sex ratio was highly biased towards dominance of females and was up to three times higher in summer than in spring. In addition, we report for the first time the presence of the copepod Drepanopus forcipatus in this Gulf. Zooplankton information for this region is scarce and fragmented, therefore a short review of zooplankton studies from NG similar Patagonian areas is presented for comparison purposes. Our study emphasizes the importance of continuous and long-term monitoring to better represent and understand the zooplankton community under future changes.