Northern Caribbean
103
Bdhamas
MAP 4c
The
Bahamas, an archipelago of some 700 islands
and numerous reefs, stretch over 1 225 kilometers
from north to south. Most of these islands are
scattered over two shallow banks, the Little Bahama Bank
and the Great Bahama Bank, with depths of 10 meters
or less bounded by extremely deep water of up to 4 000
meters. The Bahamas are named after these banks:
baja mar is Spanish for "shallow sea". The other islands
occur on smaller, more isolated, banks to the southeast
(principally the Crooked, Mayaguana and Inagua Banks)
and the west (Cay Sal Bank). To the south, Hogsty Reef is
one of the few atoll-type structures in the Caribbean. All
the Bahamian islands have low relief and are formed from
carbonate material, laid down by corals and calcareous
algae, or by physical deposition from saturated water.
Successive ice ages exposed these carbonate platforms,
and wind-blown sand dunes created at much the same time
subsequently lithified, further raising the elevation in
some areas.
Two major currents affect the Bahamas. The North
Equatorial Current, part of the North Atlantic Gyre, flows
up from the southeast where it diverges: part passes along
the east of the archipelago, while the remainder passes
through the Old Bahama Channel which separates the
country from Cuba. The Gulf Stream flows through the
Straits of Florida from the west, before flowing north
between Florida and the Bahamas. One effect of its powerful flow is that most of the land-based runoff from Florida
is diluted and dispersed without reaching the Bahamas.
Reef development in much of the Bahamas is
naturally limited by the exposure to hurricanes of the
windward sites, by unusually cold winters in the northern
islands and by turbid, high salinity waters on many leeward bank margins. However there are thousands of small
patch reefs, dozens of narrow fringing reefs and some
bank barrier reefs, such as the Andros Barrier Reef which
is one of the longest reef systems in the Western Atlantic.
Many Bahamian reefs are in fairly good condition, which
is probably due to limited anthropogenic disturbance associated with their remoteness and the country's low
population density.
White band and other diseases have affected corals
from San Salvador in the east to Andros in the west.
Macroalgal cover is usually low to moderate and the
abundance of both herbivorous and commercially
important fish is high. Corals of the central Bahamas
showed extensive bleaching in August 1998, with over 60
percent of all hard corals bleached to a depth of 20 meters
Left: Long Island. Bahamas ISTS055-73-38. 19931 Right: San Salvador, Rum Cay and Conception Island I5TS095-705-6 1, 19981.
103
Bdhamas
MAP 4c
The
Bahamas, an archipelago of some 700 islands
and numerous reefs, stretch over 1 225 kilometers
from north to south. Most of these islands are
scattered over two shallow banks, the Little Bahama Bank
and the Great Bahama Bank, with depths of 10 meters
or less bounded by extremely deep water of up to 4 000
meters. The Bahamas are named after these banks:
baja mar is Spanish for "shallow sea". The other islands
occur on smaller, more isolated, banks to the southeast
(principally the Crooked, Mayaguana and Inagua Banks)
and the west (Cay Sal Bank). To the south, Hogsty Reef is
one of the few atoll-type structures in the Caribbean. All
the Bahamian islands have low relief and are formed from
carbonate material, laid down by corals and calcareous
algae, or by physical deposition from saturated water.
Successive ice ages exposed these carbonate platforms,
and wind-blown sand dunes created at much the same time
subsequently lithified, further raising the elevation in
some areas.
Two major currents affect the Bahamas. The North
Equatorial Current, part of the North Atlantic Gyre, flows
up from the southeast where it diverges: part passes along
the east of the archipelago, while the remainder passes
through the Old Bahama Channel which separates the
country from Cuba. The Gulf Stream flows through the
Straits of Florida from the west, before flowing north
between Florida and the Bahamas. One effect of its powerful flow is that most of the land-based runoff from Florida
is diluted and dispersed without reaching the Bahamas.
Reef development in much of the Bahamas is
naturally limited by the exposure to hurricanes of the
windward sites, by unusually cold winters in the northern
islands and by turbid, high salinity waters on many leeward bank margins. However there are thousands of small
patch reefs, dozens of narrow fringing reefs and some
bank barrier reefs, such as the Andros Barrier Reef which
is one of the longest reef systems in the Western Atlantic.
Many Bahamian reefs are in fairly good condition, which
is probably due to limited anthropogenic disturbance associated with their remoteness and the country's low
population density.
White band and other diseases have affected corals
from San Salvador in the east to Andros in the west.
Macroalgal cover is usually low to moderate and the
abundance of both herbivorous and commercially
important fish is high. Corals of the central Bahamas
showed extensive bleaching in August 1998, with over 60
percent of all hard corals bleached to a depth of 20 meters
Left: Long Island. Bahamas ISTS055-73-38. 19931 Right: San Salvador, Rum Cay and Conception Island I5TS095-705-6 1, 19981.