Map of the Month: Coetivy Atoll and Poydenot Shoal
Map boundaries: 0 to 10 degrees South; 56 to 64 degrees East
Countries: Mauritius and Seychelles
Overview
The northern part of the Mascarene Plateau, the largest submerged bank in the world, is covered with seagrass and interspersed with coral reefs. The plateau extends from the Granitic Seychelles southeast to Saya de Malha Bank, a series of shoals which would be a coral atoll if any of the area was above the ocean surface. Depths are as shallow as 8 m at Poydenot Shoal. To the west is a coral island, Coetivy Atoll. Coetivy is not connected to the Seychelles or Saya de Malha banks. Although the island is only 9.3 square km in area, it is surrounded by a platform reef providing shallow water of 14.2 square km. Covering much of the island are about 200 shrimp or prawn ponds operated by a Seychelles government corporation.
Terrestrial Ecoregions
Deserts and Xeric Scrublands
AT 1301, Aldabra Island Xeric Scrub. The interactive map at http://www.nationalgeographic.com/wildworld/terrestrial.html seems to indicate that Coetivy is in ecoregion AT 113, Granitic Seychelles Forests. However, the geographic position of the island (at 7 degrees South) and the low-lying coral nature of the island suggest that it would be better classified with desert islands such as Aldabra. Rainfall would likely be less at this latitude, and the winter dry season would likely be longer compared to more equatorial islands (Stoddart 1984).
Marine Ecoregions of the World
Western Indo-Pacific Realm, Western Indian Ocean Province
96. Seychelles. Includes the Mascarene Plateau and Coetivy Island.
Freshwater Ecoregions of the World
Africa and Madagascar Region, Oceanic Islands
585. Seychelles. Found on Coetivy Island.
References
Abell, Robin and 27 others. 2008. Freshwater Ecoregions of the World: A New Map of Biogeographic Units for Freshwater Biodiversity Conservation. Bioscience 58:403-414.
BirdLife International. 2008. BirdLife’s Online World Bird Database. Accessed 29/12/2008 at http://www.birdlife.org/
Kaplin, P.A. and P.A. Pirazzoli. 1988. A Geomorphological Reconnaissance of Coetivy Atoll (Seychelles, Indian Ocean). Smithsonian Atoll Research Bulletin No. 319.
Seychelles Tourism Board. http://www.seychelles.travel/ (accessed August 9, 2009).
Olson, David M., et al., 2001. Terrestrial Ecoregions of the World: A New Map of Life on Earth. BioScience 51:933-938. Ecoregion map at http://www.nationgeographic.com/wildworld/terrestrial.html
Spalding, Mark D. and 14 others. 2007. Marine Ecoregions of the World: A Bioregionalization of Coastal and Shelf Areas. Bioscience 57:573-583.
Stoddart, David Ross. 1984. Biogeography and Ecology of the Seychelles Islands. The Hague: W. Junk.
VDS Crustocean Feeds. http://www.crustocean.com/ (accessed August 8, 2009).
VLIMAR, the VLiz Marine Gazeteer. www.vliz.be/vmdcdata/vlimar.
Wise, Rosemary. 1998. A Fragile Eden. Princeton University Press.