THE STRUCTURE OF CORAL COMMUNITIES AT HURGHADA IN THE NORTHERN RED-SEA

The community structure of hard and soft corals, with an emphasis on h ard corals, was determined by means of line-transects on 9 on- and off -shore reefs of different type and different wave exposure in the Nort hern Red Sea near Hurghada in Egypt. Coral communities were found to d ifferentiate along a horizontal wind- and wave-exposure gradient. Expo sed communities were dominated by Acropora species, sheltered communit ies by Porites species, and semi-exposed communities by Millepora spec ies. Also, vertical within-reef zonations following a depth gradient w ere observed; these were unique for each exposure-determined community type. Average transect diversity was highest on semi-exposed reefs, l owest on sheltered reefs. Reef slopes were more diverse than other ree f zones. The observed community structure was compared with data from the literature, and widely distributed, roughly comparable hard and so ft coral communities were identified.