Littler, M.M.

The Littler’s team [including Barrett Brooks, Don Hurlbert, Barbara Watanabe and Larry Gorenflo (Conservation International)] traveled to the island of Bonaire, Netherlands Antilles (1 Nov 06 to 14 Nov 06). The purpose of this expedition was to assist the Ministry of Nature Affairs for the Netherlands Antilles (MINA) and the Center for Applied Biodiversity Science at Conservation International to assess the current status of Bonaire’s marine flora. The team collected over 300 specimens from the upper reef to a depth of 56 m. This assessment increased the known species reported from Bonaire by 35% (Appendix II, List of Species). The marine flora is typical of many Caribbean reefs with no specific areas of extremely high diversity or unique species composition. Also included in this evaluation are over 100 digital images (Appendix III), properly identified to the species level in most cases. These images may be used by managers in web sites, oral presentation, training manuals, brouchures, etc., to make marine plant identification possible for Bonaire’s many divers, volunteers, conservationists or interested agencies.
The team surveyed the health of the reefs using key indicator species (recognized from our >30 continuous years of coral-reef research) in reference to the growing problems associated with eutrophication and overfishing along tropical and subtropical shorelines worldwide. The ecological responses of corals and macroalgae to nutrient enrichment and release from predation have been repeatedly cited as priority areas in need of further research (National Research Council, 2000; Littler & Littler 2006).

Background:

Located in the Dutch Windward Islands, Saba Bank is a flat-topped seamount (20–45 m deep in the shallower regions). The primary goals of the survey were to improve knowledge of biodiversity for one of the world’s most significant, but little-known, seamounts and to increase basic data and analyses to promote the development of an improved management plan.

Methodology/Principal Findings:

Our team of three divers used scuba to collect algal samples to depths of 50 m at 17 dive sites. Over 360 macrophyte specimens (12 putative new species) were collected, more than 1,000 photographs were taken in truly exceptional habitats, and three astonishing new seaweed community types were discovered. These included: (1) ‘‘Field of Greens’’ (N 17u30.6209, W 63u27.7079) dominated by green seaweeds as well as some filamentous reds, (2) ‘‘Brown Town’’ (N 17u28.0279, W 63u14.9449) dominated by large brown algae, and (3) ‘‘Seaweed City’’ (N 17u26.4859, W 63u16.8509) with a diversity of spectacular fleshy red algae.

Conclusions/Significance:

Dives to 30 m in the more two-dimensional interior habitats revealed particularly robust specimens of algae typical of shallower seagrass beds, but here in the total absence of any seagrasses (seagrasses generally do not grow below 20 m). Our preliminary estimate of the number of total seaweed species on Saba Bank ranges from a minimum of 150 to 200. Few filamentous and thin sheet forms indicative of stressed or physically disturbed environments were observed. A more precise number still awaits further microscopic and molecular examinations in the laboratory. The expedition, while intensive, has only scratched the surface of this unique submerged seamount/atoll.