Macrobenthos monitoring in the Gulf of Suez, Egypt

The biogeography of macrobenthic communities with large-scale differences in species distribution and abundance was studied along the eastern and western coastal regions of the Gulf of Suez to indicate biodiversity of benthos in relation to the prevailing environmental conditions. In general, benthos have a wide variety of species of mainly polychaet worms, crustaceans, bivalves, and other bottom invertebrates living in burrows in/or on the sediment surface. Coastal development clearly affects the ecosystem after the construction of coastal projects. The highest values of benthic diversity, evenness, richness and dominance are found at the Gulf of Suez (WG 1, WG 3), Ras Gharib (WG, 7, WG 8) and Ras Shukier (WG 9a) by contrast to others. The abundance of macrobenthic organsims along the coasts of Gulf of Suez can be arranged in the following sequence: other groups (34%) greater than crustaceans (25%) greater than polychaetes (22%) greater than molluscs (17%) greater than echinoderms (2%). The biomass of benthic assemblages at different sampling sites can also be ranked as follows: echinoderms (52%) greater than molluscs (27%) greater than crustaceans (16%) greater than polychaetes (2%) greater than other groups (3%). Some benthic groups or species indicated a distinctive correlation to pollution sources in the marine ecosystem which obviously increased in the coastal areas due to the extension of the coastal development. These activities needed regular information to establish database for the biology and distribution of marine benthic communities. The density and diversity of benthos are significantly affected by eutrophication at Ain Sukhna, whereas the benthos in the open Gulf of Suez do not seem to be adversely affected by pollution.