Macrofaunal assemblage in the intertidal area of Saudi Arabian Gulf Coast

Abstract The Saudi Arabian Gulf coast is witnessing many industrial, recreational and other developmental activities. Impact of these activities on the intertidal macrofaunal communities of this region has not been documented well. Thirty four stations falling under four zones along this coast were sampled to study the benthic macrofaunal community. A total of 81 taxa were recorded and the species richness varied between the zones. Among the 48 polychaetespecies found, Exogone heterosetosa, Dialychone collaris, Ophelina longicaudata, Paraprionospio pinnata, Perinereis falsovariegata and Scololepis squamata were dominant. Species such as Littoraria scabra, Bullia vittata, Incatella cingulata, Meretrix meretrix, Donax sp. and Maoricardium setosum were dominant among the twelve gastropod species. The thirteen species of macrofauna identified to occur in all the zones comprised eight species of gastropods besides two species each of amphipods and isopods and one species of cumacean. ANOSIM showed significant differences in assemblage overall among the four zones and in pairwise comparison. Distance based linear modeling (DISTLM) showed the environmental parameters to explain 55.67% of the variability in macrofauna with variables such as pH, salinity, temperature, pebble and gravel showing significant relationship with macrofauna and explained higher variability. The alpha diversity values were comparatively lower in zone 3 which had high anthropogenic pressure. Shannon–Wiener​ diversity, Margalef richness and more importantly the M-AMBI showed the healthy nature of the study area. The findings of the present study are helpful in tracing the future changes in the intertidal habitat due to anthropogenic activities in this fast developing geographical area.