Areas substrate at different depths in the Chagos Archipelago

A large proportion of world's reefs are at risk. In such circumstances, monitoring of the condition of coral reefs around the world is crucial, and a vital element of this is the estimation of reef area. Many attempts to estimate reef areas around the world have been made, but their results are crude. The present work on the Chagos Archipelago provides the most accurate area determinations of a large reef region to date. The results create a very detailed picture of amounts of substrate at all depths, focusing on depths within the illuminated region. With data on biotic coverage, a full picture of amount of area covered by different taxa or assemblages can easily be created. A Geographic Information System was used to model the ocean bed from integrating several bathymetric charts. In order to estimate areas at different depths, the initial irregularly distributed data representing spot observations of soundings were converted to a continuous surface by means of interpolation techniques. Two common methods are compared for accuracy and utility. From this, the areas of each depth span were calculated. Chagos shows a considerable amount of submerged substrate which is discussed in terms of its function in the Indian Ocean as a whole.
Dumbraveanu D , Sheppard Charles .
Scleractnia (hard corals),Octocorallia (soft corals), reef area, GIS, Geographic Information system, bathymetry, coral reef