Asian Journal of Advances in Research

Seasonal changes in chlorophyll a phytoplankton abundance and physico-chemical factors affecting these parameters were investigated in this study. Quantitative and qualitative phytoplankton and nutrient analysis were carried out in 2018 at two sampling stations in northern part of lattakia coastal waters in the northeastern Mediterranean coast of syria. Sampling was performed monthly from january to dezember of 2018 Nutrient concentrations were high in winter but low in summer. The concentration of, PO4-P, NO3+ N and [Si (OH)4]-Si in surface water varied in the range of 0 -1.1 μM, 0.2-9.1 μM and 0.06-13.5 μM, respectively. Surface water phytoplankton abundance reached the highest level (23.1×106 cells l-1) in March mainly due to the increase of a diatoms. It reached the lowest level in December (0.001×106 cells l-1). Chlorophyll a concentration ranged from 0.01 to 7.4 mg l-1 in surface water. Nutrient concentrations and phytoplankton biomass of the research area were found higher than those of the previous studies of other coastal areas in Syria.