Effects of Environmental Factors on Community Structure of Macrobenthic Bivalves in the Marine Protected Area of Jask (Gulf of Oman) Using the Redundancy Analysis (RDA)

In this study, macrobenthic bivalves were identified at 12 stations located in four regions (Markazi, Shahr no, Khalasi, and Gabrik creeks). The relationships between density of bivalves and non-biological factors were examined, as well. Sampling of sediments was done seasonally from autumn 2009 to summer 2010, by 0.04 m2 Van Veen Grab, in three stations including mouth, middle and end of each creek. Water physicochemical parameters (including dissolved oxygen, salinity, temperature and turbidity), as well as sediment grain size, and TOM (Total Organic Matter), were measured at each station. A total of 24 species belonging to 20 genera and 7 families were identified that was dominated by Paphia gallus (36.13%), Tellina sp. (13.32%), and Callista multiradita (8.35%). At different seasons, the highest density of bivalves was observed in the autumn with total of 10900 pcs per m2. The highest density of bivalves was observed in mid station of Markazi creek, in the autumn, with total of 3650 pcs per m2. The diversity index, Shannon – Wiener, showed a range between 0 to 2.2, and the maximum value of this index was observed in mid station of Markazi creek in the spring. The results of multivariate analysis (RDA), showed a significant correlation between abundance of bivalves species and dissolved oxygen, medium sand, spring, autumn and Markazi creek.