The the near-shore waters along the west coast lined by cliffs
or steep terrain, are often littered with large rocks.
Large enough that they are not turned by a storm or hurricane,
at least not within a few decades or centuries. These rocks provide
the stable substrate for corals and other reef organisms. The
lack of coral accretion on these structures does however tell
a story, and it is that calcareous organisms are chronically killed/removed
by the abrasive effects of sediment-laden storm surges, physical
damage or removal by fishing practices (fish pots) and coral mining,
and the constant work of bioeroders and biocorroders.
Nevertheless,
these habitats provide a great variety of marine life for snorkelers
and SCUBA divers. Isolated rocks also attract reef fishes, and
the rocky "boulder fields" are ideal nurseries for many
fish species. The further away they are from rivers or other sources
of chronic sediment input, the more diverse the epilithic community
tends to be. The abundant presence of the grazing echinod D.
antillarum in some areas, also contributes to reduced overgrowth
by algae and a greater abundance of sessile animals. These habitats
are also easily accessed and fishing pressure has taken its toll,
as can be seen in the paucity of certain fishes and larger size
classes of most fish species.
Along
the west coast, this is the most common coral habitat easily accessible
to snorkels. It generally forms a band of up to 30 meters. Depending
on the location, sand flats and seagrass beds are found beyond
the rocky areas. Along the east coast, the turbulent near-shore
waters make for rather barren or oligospecific assemblages and
one must go deeper and farther out (SCUBA) to view comparable
assemblages.
Not all areas that are characterized by uncosolidated rocky habitats
bare rich sessile epibenthic communities. In fact, the vast majority
of such near-shore habitats harbor communities dominated by encrusting
calcareous red algae or turf algae, and few sponges, corals, polychaetes
and tunicates.
SCCS07