Netherlands Antilles – Windward Islands
Saba, St. Maarten, St. Eustatius, Saba Bank
Preliminary Report

Kristi Klomp

General Information

A team of six researchers, in cooperation with marine park managers and fisheries officials from St. Maarten, Saba, and St. Eustatius, conducted an AGRRA assessment of the reefs of the windward Dutch Antilles in November/December, 1999. The assessment encompassed a region of the leeward Lesser Antilles that included reefs of Dutch St. Maarten, Saba, St. Eustatius, and the Saba Bank. These islands (including Saba Bank) represent distinctly different areas in terms of geophysical aspects and degree of human impact.

St. Maarten is a limestone island of Pleistocene to recent origin. It is situated on the Anguilla Bank (a carbonate shelf) along with the islands of Anguilla and St. Barthelemy. St. Maarten is a major port of call for Caribbean cruise ships and coastal development continues to expand to support a growing tourism industry. As the island’s infrastructure struggles to meet the demands of development, St. Maarten’s reefs are increasingly threatened by devegetation, siltation and eutrophication from sewage input. A marine park has recently been established and officials are in the initial stages of developing a management plan.

Saba is a volcanic island of late Pleistocene to mid-Holocene origin. A narrow submarine platform fringes the island near shore before sloping steeply to the sea floor. Corals occur on boulders that have eroded from the island and on lava formations that extend seaward from the island. While Saba has become a popular dive destination in recent years, there is very little coastal development on this island and human impact to Saba’s reefs are minimal. Saba has, however, been subjected to a number of hurricanes in recent years and, as a result, corals in shallow, high surge areas have suffered physical damage. Since 1987, Saba’s fringing reefs have been protected and are regulated by the Saba Marine Park.

St. Eustatius is situated on a submerged platform shared with the island of St. Kitts and Nevis. A flat, sandy plateau, limiting the range for coral development, surrounds much of the island. The island consists of two extinct volcanoes, an older (late Pliocene), eroded volcano on the northwest and a younger (early Pleistocene) on the south. Lava flow formations from the southern volcano are overlaid with coral growth on the island’s southwest side. St. Eustatius’ coastline is relatively undeveloped with the exception of its capital city, Oranjestad, and a trans-shipment oil terminal, both situated on the western coast. St. Eustatius Marine Park, established in 1997, provides protection to the island’s reefs.

Saba Bank is a submarine plateau that rises nearly 1000 meters above the surrounding sea floor, and has been described as a sunken atoll. Its eastern edge lies about 5 km southwest of Saba and, in it’s entirety, the bank is 60 to 65 km long and 30 to 40 km wide. Coral reefs are present on the bank’s eastern and southeastern rim. Because of it’s distance from the islands, information collected from Saba Bank allows us to make conjectures regarding the potential for coral condition in this region in the absence of perturbation associated with land masses. Although the bank is not subjected to coastal processes, it has been impacted by intense fishing pressure in recent years, resulting in declining catches.

Results

Although there are interesting distinctions between the four areas surveyed, preliminary results are reported for the region as a whole. A comprehensive report will address the spatial contrast more thoroughly.

Twenty-four sites were surveyed using the AGRRA protocol. Additional data was collected to document hurricane damage to corals since the assessment was executed within days after Hurricane Lenny (a category 4 hurricane) passed through the area. In total, 2930 coral colonies were examined in 284 transects, 1242 algal quadrats were evaluated, 240 fish belt transects were conducted, and 29 rover diver surveys completed. Survey depths ranged from 5-20 meters.

Live coral coverage for the region averaged 18% (range between sites: 10-47%) and is represented by 24 scleractinian species. The most frequently encountered species were Montastrea annularis faveolata (18%), Diploria strigosa (14%), Porites astreoides (12%), and Montastrea annularis franksi (11%).

Given the strength of Hurricane Lenny and the degree of structural damage to the coasts of St. Maarten and Saba, resulting damage to corals was remarkably lower than expected. Less than 2 percent of the corals sustained physical damage as a result of the hurricane. This is probably due to the small size and low vertical relief of these colonies (average height: 19 cm; average diameter: 37 cm). Bleaching was noted, however, in colonies throughout the region, which may be a response to increased turbidity from suspended sediment following the hurricane. Although the incidence of bleaching was variable between areas (44% in St. Maarten and 8% on Saba Bank), over 23% of the colonies exhibited some degree of bleaching.

Corals in this region are in generally good condition with low rates of recent mortality (< 2%), 15% old mortality, and low incidence of coral diseases (< 1%). Turf algae (53%) dominated algal communities, followed by crustose algae (40%). Macroalgae relative abundance (7%) for the region was fairly low, and never exceeded 17% at any of the sites. Coral recruitment was variable (1-18 recruits/m²) but was documented at all sites.

Diadema antillarum were not detected at any of the sites, and herbivorous damselfish were associated with only 1.4% of the coral colonies. Herbivorous fishes from the Acanthuridae and Scaridae families were present at all sites in densities of 5-71 individuals/100m² (mean = 20 individuals/100m²for the region). Fishes with commercial significance (families: Serranidae, Lutjanidae, and Haemulidae) were not abundant throughout the region, 0-8 individuals/100m² (mean = 4 individuals/100m²). Overall, 133 species of fish were recorded.

Survey Team

Kristi Klomp, Alice Deschamps, Ken Marks, Christopher Moses, Sascha Steiner, Pamela Fletcher. Local assistance provided by: Paul Ellinger, Andy Caballero, David Kooistra, Faisal Dilrosun, Laurens Duiveman.

Kristi Klomp

Results

Survey Team

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