Rapid Assessment of Stony Coral Richness and Condition on Saba Bank, Netherlands Antilles

Abstract

The benthic habitats of Saba Bank (17°25′N, 63°30′W) are at risk from maritime traffic, especially oil tankers (e.g., anchoring). To mitigate this risk, information is needed on the biodiversity and location of habitats to develop a zone use plan. A rapid survey to document the biodiversity of macro-algae, sponges, corals and fishes was conducted. Here we report on the richness and condition of stony coral species at 18 select sites, and we test for the effects of bottom type, depth, and distance from platform edge. Species richness was visually assessed by roving scuba diver with voucher specimens of each species collected. Coral tissue was examined for bleaching and diseases. Thirty-three coral species were documented. There were no significant differences in coral composition among bottom types or depth classes (ANOSIM, P>0.05). There was a significant difference between sites (ANOSIM, P<0.05) near and far from the platform edge. The number of coral species observed ranged from zero and one in algal dominated habitats to 23 at a reef habitat on the southern edge of the Bank. Five reef sites had stands of Acropora cervicornis, a critically endangered species on the IUCN redlist. Bleaching was evident at 82% of the sites assessed with 43 colonies bleached. Only three coral colonies were observed to have disease. Combining our findings with that of other studies, a total of 43 species have been documented from Saba Bank. The coral assemblage on the bank is representative and typical of those found elsewhere in the Caribbean. Although our findings will help develop effective protection, more information is needed on Saba Bank to create a comprehensive zone use plan. Nevertheless, immediate action is warranted to protect the diverse coral reef habitats documented here, especially those containing A. cervicornis.

Unforeseen importance of historical collections as baselines to determine biotic change of coral reefs: the Saba Bank case

“…Saba Bank, part of the Caribbean Netherlands (former Netherlands Antilles), is a large submerged atoll covered by species‐rich benthic assemblages, which are under threat by anchoring oil tankers (Hoetjes & Carpenter 2010; McKenna & Etnoyer 2010). So far, relatively little explorative research has been carried out on the reef assemblages here in relation to neighbouring areas (Klomp & Kooistra 1999).…”

“…Five stony coral species collected from a total of 17 reef sites in 1972 were not found in 2006, i.e. Diploria clivosa Ellis & Solander, 1786, from one site, Madracis asperula Milne Edwards & Haime, 1849, from five sites, Mycetophyllia lamarckana Milne Edwards & Haime, 1848, from four sites, Scolymia lacera Pallas, 1766, from one site, and Solenastrea bournoni Milne Edwards & Haime, 1848, from one site (van der Land 1977; McKenna & Etnoyer 2010). Three of these five missing species were rare (each at one site), and the three other ones (at four and five sites, respectively) moderately rare in comparison with the most common species, Siderastrea radians Pallas, 1766, which was observed at 13 Saba Bank sites in 1972 (van der Land 1977).…”

“…Three of these five missing species were rare (each at one site), and the three other ones (at four and five sites, respectively) moderately rare in comparison with the most common species, Siderastrea radians Pallas, 1766, which was observed at 13 Saba Bank sites in 1972 (van der Land 1977). Some of the species lacking in 2006 may have been listed as unidentified corals in the later survey (McKenna & Etnoyer 2010) because, in addition to 43 listed species, 10 records from 2006 are of uncertain identity, which implies that both collections should be re‐examined jointly for a better comparison.…”

“…2010). Although T. coccinea is so far the only Tubastraea species recorded from Saba Bank, recorded in 1972 and 2006 (van der Land 1977; McKenna & Etnoyer 2010), additional field surveys and collection studies may indicate further invasive coral species.…”

Status and trends Saba Bank fisheries: 2015

“…Very little is so far known about the biodiversity and ecology of the bank. Ecological research on the bank has only recently begun and the first preliminary biological inventories for the bank only date from 2010 , Hoeksema et al, 2011, McKenna & Etnoyer, 2010, Littler et al, 2010, Thacker et al, 2010, Williams et al, 2010 In recent years the fleet size of Saba involved in fishing on the bank has generally fluctuated between eight (2012) and ten vessels (2007) (Toller & Lundvall, 2008). The boats are currently all fiberglass, imported New England-style lobster boats.…”