Shallow subtidal habitats

The distribution of subtidal habitats is given in the map opposite, which includes the depth contours to 5 m. A number of different habitats can be distinguished based on the nature of the substrate involved - soft: sand or mud, and hard: rock or coral reef. Each habitat has its own special community of animals and plants.


Stretches of sand are often colonised by seagrass beds but may also contain green algae. Sponges, sea squirts and fan shells (59) are common inhabitants as are shrimps and gobies. Bare sand or silt substrates may be dominated by bivalves, polychaetes and high densities of snails. Seabirds which feed here include the surface divers such as the great crested grebe and black-necked grebe (56).


Rocky reef tops support a flourishing population of large algae (57,58) although there are seasonal changes in species, types and abundance. The sea urchin (60) is the most obvious grazer in this community although many fish species also form part of the community. The pearl oyster and other bivalves can be found attached to the rocks.


Corals dominating the fringing reefs include massive poritids (63) and encrusting forms with several different species present. During the winter months these corals are partially overgrown by large algae. A wide range of crabs are found between the corals and the sea urchin is again common as are cone shells (65) and cowries (62). Examples of butterfly fish (66), parrot fish (61) and angel fish (64) are all likely to be sighted over the reefs. To the north of Abu Ali, in water from 5 to 10m, rare whip coral beds may be found.



More about shallow subtidal habitats:

Alphaeid shrimp and goby
Nearshore coral reef with sea urchins
Doublebar bream
Coral crab
Map of the subtidal habitats of the Sanctuary area