Saba Bank Research 2011-2016
This book will let you dive into the underwater worl of the Saba Bank and gives you an introduction to its amazing biodiversity. At the same time you will get a quick overview of the various research projects carried out between 2011-2016 and their significance for the management of the area.
The Saba Bank is a unique nature area in the Netherlands, yet we still know very little about it. Our knowledge has improved somewhat in the past five years, but for sustainable management of the Saba Bank an adequately equipped local management organization and continued research are necessary.
The Saba Bank is a submerged bank fringed by coral reefs on its eastern and southern flanks, sometimes called an atoll. More than 2600 km2 of protected area is located near the islands of Saba and St. Eustatius in the eastern region of the Caribbean Sea. The coral reefs are easily the largest within the Caribbean Netherlands. It is the furthermore the largest marine protected area of the Kingdom of the Netherlands and harbours the highest biodiversity.
Since 2012 a port sampling programme has been in place to document the characteristics of the Saban fishery on the Saba Bank. The main target species of the trap fisheries are Caribbean spiny lobster and deep-water snappers or “redfish.
The reefs of the Saba Bank and neighbouring islands of Saba, St. Eustatius and St. Maarten provide important habitat for multiple species of sharks. In order to effectively protect shark populations, it is important to examine their migratory patterns and habitat use. Such information is essential to determine the size and location of marine reserves and to establish effective fisheries measures.
The Saba Bank is created and maintained by the growth of tiny organisms. Coral colonies, each built by many coral polyps, consist of calcium carbonate skeletons that form the fundament of the Saba Bank. The Saba Bank is a hotspot of biodiversity and an important reservoir of diversity for other coral reefs in the region.
The Saba Bank has been visited by a few expeditions since the 1970s and during some of them marine fauna and flora could be investigated with the help of specimen collecting.
Reef fish and elasmobranch assemblages were studied using conventional methods such as underwater visual census (UVC) using Scuba but also with innovative baited remote underwater stereo video (BRUV) surveys. The status of sharks appeared to be reasonable; however, the status of key ecological fish families like herbivorous parrotfish and surgeonfish and the commercially important snappers and groupers was poor.
Sponge diversity, cover and health status were determined in photo-transects along on the southeastern rim of Saba Bank. In addition molecular analysis was done to determine genetic diversity and population connectivity. At present, the cover and diversity of sponges indicate a resilient community, yet a significant portion of barrel sponges is affected by white spots.
The Saba Bank is an important wintering area for humpback whales and other cetaceans. For proper protection measures, however, information about densities, seasonal migration patterns, species composition, and background noise levels is needed. Noise loggers allow us to listen to these animals and extract valuable information.
Climate change is causing the oceans to warm up and become more acidic. This may exacerbate chemical erosion of corals, coralline algae and other calcifying organisms, threatening the structure and health of the reef. To test whether the reef at the Saba Bank grows or erodes, we performed incubation experiments near Saba.
The Saba Bank and its ecosystem depend on –and influence– the chemistry of the seawater that flows around and over it. We infer ecosystem functioning from chemical changes observed in the seawater, accounting for flow dynamics.