Evaluation of coastal and marine ecosystem services of Mayotte: indirect use values of coral reefs and associated ecosystems

Coral reefs of Mayotte (342 km²), seagrass beds (7.6 km²) and mangroves (8.5 km²) provide important ecosystem services of which the most important are the coastal protection, fish biomass production, carbon sequestration and water purification. The quantity and quality of these services have been decreasing steadily for several years and should continue to do so if no action is taken to contain anthropogenic pressures. The coral cover of the fringing reefs and the barrier reef has thus declined respectively by 60 % in 15 years and 15 % in 8 years. The pioneer front of Sonneratia for mangroves has declined by 13 % in 6 years, and for seagrass beds, the water quality suggests a degraded state. The estimated annual value of these services amounts to EUR 124 million. It would be EUR 162 million if the ecosystems were in pristine conditions. The article shows that the preservation of coastal ecosystems is essential from an economic point of view.