#Status of Coral Reefs 2002 - International Coral Reef Action Network

Status of Coral Reefs in the Eastern Caribbean
and 60m. The southern facing shore contains buttresses, which slope steeply to the
sediment platform at 100m. The reefs on Klein Bonaire are very mixed and some drop
steeply only a few metres from the shore to the first sediment platform at 25-30m. Over 50
species of coral and 350 species of fish have been recorded on Bonaire’s reefs.
Reef structures in Curaçao are similar to those in Bonaire, except that along the eastern
half of the island vertical drop-offs are common, starting at 6 to 10m with a vertical face
down to about 35m where the gently sloping sediment platform starts. As in Bonaire, the
north-western part of the leeward coast is characterized by very large coral heads several
meters in diameter and high, mostly M. faveolata, at 8-20m depth.
On the windward (eastern in Bonaire, north-eastern in Curaçao) shore the terrace extends
generally 100-200m off shore to a depth of 12m. It is covered primarily with crustose
coralline algae and Sargassum, and also some gorgonians. The reef slope is generally far
less steep than on the leeward shore with less coral cover and abundant brown algae.
Saba is a volcanic island with steep slopes above and below water, which reflect past
volcanic activity, with underwater lava flows and hot springs. The sheer walls are covered
with sponges and the only ‘true’ coral reefs are on the east side of the island. Human
pressures on the reefs have always been slight, even while the island population has
increased, and there has been limited coastal development.
The dominant hard corals are Montastrea anularis, M. cavernosa, and Diploria strigosa as
well as 35 other hard coral species and several species of gorgonians. Coral cover at 0-7m
is low due to the rough seas. Densities of Acropora palmata are very low in relatively calm
shallow areas because of storms in 1998 and 1999. Coral cover does not exceed 20%
because of high sediment loads and frequent benthic algal blooms. Bioeroding sponges
overgrow large areas of star and brain corals. Saba Bank is a shallow submarine plateau, 3-
5km southwest of Saba and 25km west of St. Eustatius. It is a submerged but living atoll,
with corals growing on the eastern and south-eastern windward edges covering
approximately 20-40km 2 . Surveys in 1996 concluded that reefs on the eastern edge have
rich coral cover (60-90%) and diversity (28 hard coral species). AGRRA surveys in
December 1999 found only 24% live coral cover with the highest coral cover at 21m
depth. The average of 27.5% dead coral cover suggests that these shallower reefs have
deteriorated badly, possibly due to disease and bleaching.
St. Eustatius is on the same submerged volcanic platform as St. Kitts and Nevis. Corals
form true reefs as well as grow on volcanic rocks. The coastline is relatively undeveloped,
except for an oil terminal on the north-western coast, and some developments on the midleeward
coast. The leeward side is mostly a sandy plateau with large populations of Queen
Conch extending to 17m depth. The offshore coral reefs begin at approximately 25m with
complex spur and groove formations that extend to about 60m. There are steep buttresses
on the northern part with coral cover of approximately 80% with 35 different species. The
northern complex has a labyrinth of encrusted ridges, sand channels and huge encrusted
rocks. There is a fringing reef on the exposed Atlantic side.
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