Phytoplankton Diversity and Community Composition along the Salinity Gradient of the Massa Estuary

Abstract

The aim of this paper is to determine the seasonal succession, overall structure, diversity spatial and temporal of phytoplankton populations of the Massa-lagoon estuary, situated in the biological reserve of Massa. This reserve is situated in the heart of the National Park of Souss Massa in southern Morocco and indeclared in the area protected by the Ramsar Convention in 2005. The phytoplankton characteristics were studied at four sampling sites on the basis of the data collected monthly intervals, at low and high tides during a 12 months sampling period. Species diversity (Shannon-Weaver, H), Simpson’s index and evenness were calculated. A total of 105 species of phytoplankton were recorded during the study period, showing a well-diversified taxonomy. Diatoms (64%) contributed more towards the percentage composition of different groups of phytoplankton at all stations, followed by Dinophyceae (14%), Chlorophycaea (10%), Cyanophyceae (9%) and Euglenophyceae (3%). Diversity index show a large heterogeneity of the phytoplankton composition. High cellular densities essentially represented by the diatoms that show high productivity of Massa estuary.