Spatial Pattern of Macrobenthos Distribution in Chabahar Bay before Monson

Abstract In the present study, the structure of macrobenthos communities of Chabahar Bay prior to monsoon in 2016 was investigated.  We identified 87 species contain 22 amphipods species, 14 species of other crustaceans, 31 species of molluscs, and 20 polychaets species, where amphipods followed by polychates were dominant taxa. The PERMANOVA test revealed that there is a significant difference in the community structure of macrobenthos at different depths (P <0.05). PERMANOVA Pair-Wise test indicated that this difference is between the communities living in the middle depths (3-15 meters: group C) with intertidal communities (group A, P = 0.008) and shallow areas (group B, P = 0.013). The SIMPER test showed that the two species of Indischnopus herdmani, Ampelisca persicus Momtazi, 2020, as well as Donax cf. bipartitus are the cause of 30% of the difference of dissimilarity between depth groups of C and B.  For depth group C and A the Ampelisca persicus Momtazi 2020 and polycatches, especially Pectinaria sp. are responsible for 30%dissimilarity. Our results revealed that the northern and especially the southwest coasts of Chabahar Bay are more structurally diversity than to the middle parts of the bay, therefore extensive environmental studies in middle parts of the bay are recommended with emphasis on sediment pollutants.  The results of the present study also point to the importance of the role of depth factor in the distribution of macrobenthos communities, which can help in monitoring strategies and arrangement of sampling stations.