Diatoms are indisputably the major component of many food webs, and so estimating their seasonal abundance, fluctuations and growth rate have been, and will be, an important component of marine science studies. Aquatic environments are subject to high temporal variability, with frequent reorganization of relative abundance and species composition of phytoplankton, as a result of interaction between physical, chemical and biological variables (Reynolds et al., 2000). Like all other marine organisms, diatom ecophysiology Temperature is an important factor controlling the algal growth in natural environments (Lund, 1949; Talling, 1955) and growth response to temperature may be essential in regulating the predominance of phytoplankton species. It is well known that salinity is an important abiotic factor affecting phytoplankton growth. Wide ranges of salinity and temperature may explain frequent appearance of phytoplankton throughout the year in the ocean (Hoshiai et al., 2003). is influenced by water temperature, salinity, light intensity and nutrient concentrations