America’s Caribbean Island: Navassa

Looking for a new exploratory dive? I suspect that one of these days some live-aboard will have a look at one of the least known American possessions, Navassa Island, 35 miles west of Haiti, 89 miles east-northeast of Jamaica, and 104 miles south of Guantanamo Bay, Cuba. The 1.9-square mile island rises from a submerged bank (100 feet deep at the island and extending 2 miles offshore to 160 feet at the outer drop-off). It has no beaches and is isolated from boats by overhanging, 30 to 50 foot cliffs that completely encircle the hard, pot-holed, fossilized limestone island.

In 1998, an expedition headed by Dr. Michael Smith, Senior Scientist with the Center for Marine Conservation, made 78 dives to more than 110 feet. They found “spectacularly colorful, mixed communities of sponges, coralline algae, tunicates, bryozoans, hydroids and low-growing iridescent algae: along the under-cut walls that drop to 115 feet, saying “these submerged over hanging ledges and cave systems rank among the most impressive of the tropical Unites States continental and insular coastal dive sites that we have encountered during our more than thirty years of scuba surveys. ”

The coral varieties around the island change dramatically, due to wave action, guano, and runoff from the island. In some places sponge growth was “remarkable for abundant barrel, tube, rope and encrusting sponges” and in other places uninteresting. Grazing by the abundant herbivorous fishes — parrotfishes, chubs and surgeonfishes — and sea urchins was high. “The marine biota, although teaming with life, is most remarkable for what it lacks.” In addition, they found “historical debris from two former onshore operations, mining and the lighthouse — submerged railway track, mining-cart wheels, twenty large acetylene tanks, and large ship anchors . ”

What’s the potential? The scientists say, “Although these waters have not been explored and documented, a survey of geographic features indicates that there may be sea mounts whose crests reach the shallow depths at which corals and the richly associated biota would be expected. The island platform and sea mounts appear to harbor relatively undisturbed populations of coral and reef fishes and are subject only to low technology level fishing . ”

More information at www.cmc-ocean.org/navassa/navassa.php3.