The Rocky Zone
The rocky zone follows cliff faces which extend to a depth
of 5 m or more below sea level. There are also regions of flat lying rock
surfaces at cliff bases and in restricted shallow channels. In regions
of current movement, the exposed rock is covered by large patches of the
red-orange boring sponge Cliona lampa. On cliff faces
below the intertidal zone, rocky ledges and collapsed blocks at their base,
a variety of algae and animals attach. A mossy coat of calcarious (Padina,
Amphiroa) and non-calcareous algae generally overlie
an encrustation of other algae, bryozoans and serpulid worms, Corals (Agaricia,
Isophyllia, Siderastrea, Millepora)
and bivalves (Chama, Anomia,
Spondylus) occur. Many kids of boring organisms live
within the rock, including sponges (Cliona lampa,C.
vastifica) and bivalves (Lithophaga bisulcata).
In some areas a few feet below tide level, large patches are browsed by
the echinoid Lytechinus.