Phytoplankton Community and Physical-Chemical Characteristics of Seawater in the Bandar Abbas Coastal Water, Persian Gulf: An Environmental and Process Perspective

Seawater ecosystems are controlled by multitude various abiotic and biotic factors. These factors also affect the activities of coastal human communities and installations including coastal desalination plants. This research investigated a point environmental (physical and chemical) and biological (phytoplankton) parameters of Bandar Abbas coastal water in 3 depth layers of 1, 5 and 10 m carried out in September, 2015 and March, 2016. The obtained experimental results were analyzed using principal component analysis (PCA) method. Thirty four species belonging to 5 classes of Bacillariophyceae, Dinophyceae, Cyanophyceae, Euglenophyceae and Chrysophyceae were identified. The most representative class in terms of species richness was Bacillariophyceae represented by 21 species and dominated by Cyclotella sp., Nitzschia sp. and Navicula sp. Dinophyceae was represented by species with the dominant of Gymnodinium sp. in two seasons and all waters layers. The group cyanobacteria was represented by species of diverse morphological characteristics and the dominance of Anabaena. The other dominant class of Euglenophyceae and Chrysophyceae were represented by Eutreptia and Dictyocha, respectively. The coastal water exhibits high electrical conductivity (67,000 μS/cm), alkaline pH (8.26-8.29) and mean temperature of 22.2 - 22.8 °C, with no significant differences during sampling periods. The mean Shannon index value of the site sample was found to be 0.798. Two principal components were recognized which indicate that the coastal waters are mainly affected by parameters of pH, EC, nitrogen and phosphorus nutrients, and chlorophyll in the first principal component represented by high factors loading and gas solubility capacity with high factor loading of temperature and dissolved oxygen in the second principal component. These results may be useful to select required pretreatment systems to establish desalination plants in the Hormozgan province.