Benthic macrofaunal dispersion within different mangrove habitats in Hara Biosphere Reserve, Persian Gulf

Abstract

The community composition of benthic macrofauna and relationships between physiochemical parameters of the water and sediment texture were assessed in Hara Biosphere Reserve, Northern Persian Gulf. The spatial distribution and diversity of macrobenthos were sampled within three distinctive mangrove zones (deltaic, island and coastal) during two sampling seasons between August 2014 and January 2015. A total of nine transects perpendicular to the coastline were selected to cover over the entire study area. The counts of all macrofauna were recorded from each zone and station with three replicate sediment samples. The snails, Cerithidea cingulata and Asseminea sp., were observed throughout three mangrove zones, but their abundance varied among habitats. The bivalve Dosinia ceylonica found to be more abundant in delta, whereas burrowing crabs Ocypode and Uca were dominate in coastal zone. Terebralia palustris and amphipods were recorded frequently in island zone. The nonmetric multidimensional scaling ordinations and a three-way factor PERMANOVA indicated that macro-invertebrate species composition significantly differed among different mangrove zones. The results also showed the seasonal variations. The findings of diversity indices illustrated that deltaic zone had the highest abundance and diversity, while the coastal zone showed the lowest values among the three zones. Taken together, the observations demonstrated that the different hydrological conditions, temperature, salinity and sediment texture were the main factors determining dispersion of benthic faunal assemblages among different mangrove habitats at Hara Biosphere Reserve. There is a need to consider such variables in ecological studies to understand differences of macrofaunal diversities in these complex habitats.