A biodiversity-assessment survey was carried out on Saba Bank during 2006 and 2007, with a major goal being to improve knowledge of the biodiversity on one of the world's most significant, though poorly known, coral-capped seamounts. In an effort to record as many fish species as possible in the short period of time available for the survey, we utilized a variety of fish sampling techniques. These techniques included visual surveys by divers, use of SCUBA to apply ichthyocide (a natural fish toxicant consisting of dried and powdered Derris root - assayed at 7.5% rotenone), hand-line fishing, by-catch from lobster and fish traps taken by local fishermen, and port sampling observations of fish landings. During the surveys, an attempt was made to obtain a photograph documenting the fresh colors of as many species as possible, a tissue sample of each species, and preserved specimen vouchers that have been archived in the National fish collection (USNM) of the National Museum of Natural History (NMNH), Smithsonian Institution (SI). Specimens representing six or more undescribed species and two rare gobies, Pycnomma roosevelti and Psilotris boehlkei, were collected.
The habitats surveyed on the Saba Bank “atoll” during this study are classified as: fore reef, patch reef, lagoonal and Small Bank. Fore-reef areas are located around the outer rim of the submerged atoll. Patch reef is an isolated portion of “reef” situated on the lagoonal (interior) side of the fore reef. Lagoonal is the central portion of the atoll interior to the fore-reefs around the atoll rim and may have a variety of bottom types. Small Bank is a small, independent “seamount-like” structure located off the northwest corner of Saba Bank with its shallowest depth at about 11 m. Depth categories were arbitrarily assigned as shallow (11–24 m), mid-depth (25–34 m), and deep (35–38 m).
The primary goals of the overall biodiversity survey were to provide data and analysis to support designation of Saba Bank as a marine protected area, to support the development of a management plan, and to contribute to a petition to the International Maritime Organization to designate appropriate parts of Saba Bank as a Particularly Sensitive Sea Area.
Results
We occupied fish stations at 25 locations during a rapid assessment (RAP) survey, 2–16 January 2006; including: 20 ichthyocide stations, 12 roving visual surveys, two hook & line stations, and five by-catch stations from lobster traps; two fish-ichthyocide stations were occupied at two additional locations on 20 June 2007 (Figure 1). In 2007, Toller assessed the benthic communities and fish assemblages based in part on 40 visual surveys of the fish fauna at an area on the eastern side of Saba Bank.
doi:10.137/journal.pone.0010676.g001
Specimens collected during the RAP survey were preserved as vouchers and processed into the fish collection (available online at http://vertebrates.si.edu/fishes/fishes_collections.html) at the NMNH (as many species as possible were also tissue sampled
