Identification and investigation of species diversity and richness of the Gastropoda in intertidal zone of Bushehr Port coastal area (the Persian Gulf waters)

This study aims to identify and determine species diversity and richness of the Gastropods of the intertidal zone of Bushehr seaport coastal area and assess the ecological status of this area using Welch index. Sampling was carried out at 6 stations in Bushehr seaport in the winter and summer seasons during 2013-2014. Bed sediment sampling was done three times in each station and Gastropod samples were collected using Quadrate (25×25 cm), and were then preserved using 4 % buffered formalin. The preserved samples were transported to the laboratory and were identified and counted by using valid identification keys. Furthermore, physicochemical properties of water including temperature, pH, dissolved oxygen (DO) and salinity were also measured in each station. According to the results obtained from this study, there were totally 14 species identified from 12 families belonging to 7 orders. The most abundantly identified species in the studied stations belonged to Planaxis sulctus, Cerithidea cingulate, and Anachis misera. In this study species diversity was determined by using Shannon-Weiner index, dominant species were investigated using Simpson index and species richness was calculated using Margalef index. The results of Shannon and Margalef indexes showed significant differences between the sampled stations and seasons (p˂0.05). Moreover, the results of Simpson index showed no significant differences between the sampled stations and seasons (p<0.05). Results of Welch index showed that based on the mentioned indexes in the sampled stations the status of the water quality was classified as average and rather low/weak pollution.