Abstract

Isla del Coco is the summit of a seamount 500 km southwest of Costa Rica’s mainland. The island is surrounded by a platform about 18 km long that trends in a southwest-northeast direction with a break in slope at around 180 m deep. Since 2006 the DeepSee submarine, with a 450 m depth capability, has been exploring the deep-water environments of Isla del Coco. Videos have been taken and several preliminary conclusions reached about the deep-water fauna of the island. First, the fauna changes rapidly at about 50 m depth; second, the fauna is highly diverse, with many new species likely; third, even though the distance between the north and south sides of the island is less than 8 km, the faunas seem to be different, possibly due to the influence of differing deep-water currents on each side of the island; and fourth, groups of organisms that where thought to be absent in the eastern Pacific Ocean have now been photographed. DeepSee has opened a new window to a very little known world of Isla del Coco. More studies are necessary to understand the deep-water faunas, and their relation to shallow water organisms and environments. This information will be important for management and conservation of the marine biodiversity of Isla del Coco. Rev. Biol. Trop. 56 (Suppl. 2): 189-206. Epub 2008 August 29.
Keywords: Isla del Coco, Cocos Island, Costa Rica, deep environments, submarine