Phytoplankton in a tropical estuary, Northeast Brazil: composition and life forms

We aimed verify the composition of the phytoplankton community and this life forms that occur in the Capibaribe River estuary, Pernambuco, Brazil. This is a highly impacted ecosystem by anthropic activities. We collected samples of the phytoplankton community at three stations, during three months of each season: dry, from October to December 2010; rainy, from May to July 2011. We collected samples during the low and high tide, at the spring tide. We classified the species based on life forms. We identified 127 taxa, and the majority of species were freshwater planktonic form (FP; 30%), followed by marine oceanic planktonic (MOP; 25%), marine neritic tichoplanktonic (MNT; 22%) and planktonic (MNP; 19%,), and tichoplanktonic  estuarine (TE; 3%) and freshwater (TF; 1%). The majority of species identified were diatoms, since it assumes the most variability of life forms, therefore enabling its presence in the different portions at the estuary.