Phytoplankton spatial distribution on the continental shelf off Rio de Janeiro, from Paraiba do Sul River to Cabo Frio

• Published in: Hydrobiologia 2014-05, Vol.728 (1), p.1
• Main Authors: Moser, Gleyci A.O, Takanohashi, Robson Alves, Braz, Mariana de Chagas, de Lima, Domenica Teixeira, Kirsten, Fabiana Vasconcelos, Guerra, Josefa Varela, Fernandes, Alexandre M, Pollery, Ricardo Cesar Goncalves
• Format: Article
• Language: English
• Subjects: Silicates
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1007/sl0750-013-1791-3

Given the heterogeneous oceanographic conditions observed in the continental shelf and slope off Rio de Janeiro, the phytoplankton community is expected to adapt to the diverse trophic conditions using distinct strategies. Considering the C-S-R triangle, distinct phytoplankton taxa are expected to occur in Tropical Water (TW), in South Atlantic Central Water (SACW) and in Coastal Water (CW). The study area extends from Paralba do Sul River mouth to the region of Cabo Frio. Samples were collected on 28 stations, in 2011 austral summer. 209 phytoplankton taxa were observed, mainly dinoflagellates (93), diatoms (71), and coccolitophores (30). TW dominated the surface waters of the continental shelf and slope, 13 December 2013/Published online: 4 February 2014 and a typical tropical phytoplankton community, composed by stress-tolerant taxa, was observed. The rise in nitrate concentration caused by SACW uplift in the shelf and in the continental slope, at subsurface waters, and in silicate, associated with the Paraiba do Sul riverine plume, led to shifts in the phytoplankton community, increasing the contribution of ruderal taxa. The grouping of phytoplankton assemblages only in traditional groups would result in loss of information about the factors that determine community dynamics since the different species in each of these groups frequently share specific traits.