Coral bleaching and associated mortality in Mayotte, Western Indian Ocean

Abstract

Manta tows in fringing and barrier reef areas, together with observations, were used to estimate the extent of the bleaching and associated coral mortality in Mayotte between 1 and 24 of May 2010. Three areas around the island were surveyed. The results from fringing reefs in the north coast of Mayotte showed that nearly 80 % of coral benthos was either bleached or dead (covered with thin algal overgrowth), while 50 % and 35 % of coral was bleached or dead in the two other surveyed areas, highlighting this as a considerable bleaching event. The observations showed spatial and temporal heterogeneity in the extent of the bleaching and mortality. The most genera most susceptible to bleaching were Pocillopora and tabular Acropora, while Porites seemed to have suffered the least. Our observations of bleached genera were consistent with those of the 1997-1998 bleaching event.