Variação sazonal do fitoplâncton e parâmetros ambientais no Canal do Rio Palmital, Baía da Babitonga, Sul do Brasil Seasonal variation of phytoplankton and environmental parameters in the channel of the river Palmital, Babitonga Bay, Southern Brazil

Studies on potential production, spatial and seasonal variations, main groups of phytoplankton and determinant environmental conditions are essential for developing strategies for the conservation of estuaries. This study aimed to analyze the spatial and seasonal variation of phytoplankton and their interaction with environmental parameters in the Palmital river channel (Babitonga Bay - SC). In the area of the river channel, it was conducted four campaigns (May, August, November 2009, and February 2010) at three points. Both surface and bottom layers of water were analyzed for composition and abundance of phytoplankton, dissolved nutrients and physico-chemical parameters. Pennate and centric diatoms were the dominant components of the phytoplankton community, followed by dinoflagellates and cyanobacteria. Skeletonema costatum and Odontella sinensis were the most abundant species, especially in summer. Other genera were numerically important: Coscinodiscus, Cyclotella, Thalassionema, Navicula, Pleurosigma, Actinoptychus and Diploneis. Large amount of benthic taxa recorded in this study is due to the low depth associated with local circulation. In summer occurred a bloom of Skeletonema costatum. Significant correlations between the environmental variables and the phytoplankton abundance were observed in this pioneering work in the Palmital river area, suggesting further studies.