Caribbean atoll reveals unique marine treasures

Posted: 16 February 2006

An underwater mountain that forms the world's third-largest atoll has some of the richest diversity of marine life ever found in the Caribbean, according to scientists who recently explored the area.

The giant barrel sponge, Saba Bank Atoll, Netherlands Antilles, Caribbean. Photo: Robert Thacker/Conservation International
The giant barrel sponge, Saba Bank Atoll, Netherlands Antilles, Caribbean. Photo: Robert Thacker/Conservation International
The giant barrel sponge (Xestospongia muta) is abundant on the seamount and shows no signs of the disease and bleaching that are common elsewhere in the Caribbean. Saba Bank Atoll, Netherlands Antilles, Caribbean.© Robert Thacker/Conservation International
The two-week expedition in January encountered new species of fish, seaweed and other ocean life at little-studied Saba Bank Atoll, a coral-crowned seamount 250 kilometers southeast of Puerto Rico in the Dutch Windward Islands.

In a series of dives buffeted by high winds and strong currents, scientists from Conservation International (CI), the Netherlands Antilles government and Smithsonian Institution's Museum of Natural History found scores more fish species than previously known in the region and vast beds of diverse seaweed, including a dozen or more possible new species.

"We discovered a new species literally every day we were there," said Michael Smith, director of CI's Caribbean Biodiversity Initiative. Among the apparent new fish species found were two types of gobi, while the total number of fish species recorded reached 200, compared to fewer than 50 before the expedition.

The unprecedented richness of marine life and vulnerable status of the atholl's coral beds make Saba Bank a prime candidate for designation as a Particularly Sensitive Sea Area (PSSA) under the International Maritime Organization (IMO).

Tanker threat

Mark Littler, marine botanist of the Smithsonian Institution's National Museum of Natural History, declared Saba Bank the richest area for seaweeds in the Caribbean basin, including as many as a dozen new species along with commercially valuable species that will facilitate the creation of economic activity zones under PSSA designation.

Paul Hoetjes, marine biologist with the Ministry of Nature Affairs for the Netherlands Antilles (MINA), called the expedition crucial to getting the area protected to benefit local populations.

"The community of about 1,500 people on nearby Saba Island derives a large part of its economy from the atoll, and the atoll is being damaged," Hoetjes said.

A petroleum trans-shipment depot on neighbouring St. Eustatius Island causes significant marine traffic, including oil supertankers in the area around the submerged atoll. The fragile ecosystems of Saba Bank get damaged by anchors and chains of ships that avoid anchoring fees in territorial waters of St. Eustatius.

The large ships also endanger local fishermen of Saba in their small boats, forcing them away from traditional fishing grounds and causing the loss of fish pots that become so-called ``ghost traps" that harm fish stocks.

No-anchor zones

Leroy Peterson, a Saba fisherman, called the expedition crucial for protecting Saba Bank's unique marine life.

"Some of the scientists actually found new species not located anywhere else," Peterson said. "There should be no-anchor zones. For things to survive there must be stricter controls."

Funding for the expedition came from the Netherlands Ministry of Traffic and Water Management, Royal Caribbean's Ocean Fund, and Conservation International. The Saba Island community including the Saba Marine Park staff provided logistical support.

Next month, the Hydrographic Service of the Royal Netherlands Navy will launch a six-week survey of Saba Bank by the HNLMS Snellius, an 82-meter research vessel capable of conducting comprehensive bottom coverage using sonar and other technology. Information from the diving expedition and hydrographical survey will help prepare the campaign to get Saba Bank designated as a PSSA.

The Dutch Caribbean Nature Alliance (DCNA), an umbrella group representing six Dutch Caribbean islands including Saba, also calls for PSSA status for the Saba Bank atoll.

Source: Conservation International. This Washington-based conservation agency applies innovations in science, economics, policy and community participation to protect the Earth's richest regions of plant and animal diversity and demonstrate that human societies can live harmoniously with nature. See: www.conservation.org