Temperature fluctuations do not have an important effect on species composition, while salinity is the main physical parameter that can be attributed to the plankton diversity and acts as a limiting factorthatinfluencesthe distribution of plankton community as reported by (2006). Large salinity oscillations in the harbour were recorded spatially and temporally, ranging from 22.7 PSU
(St. 2) to 38.6 PSU (St. 7).