Long-term natural and human perturbations and current status of Clipperton Atoll, a remote island of the Eastern Pacific

Abstract

Clipperton Atoll is one of the most isolated tropical island in the world and the only atoll of the eastern Pacific. Its outer slopes also make the largest coral reef of this region. Clipperton is a remarkable site for the geochemistry of its closed eutrophic stratified lagoon, the influence of both tropical eastern Pacific and Oceania gene pool on coral reef communities, the low diversity of the marine and land fauna, and for the equilibrium of its land ecosystem. The three components of the Clipperton Atoll seascape (coral reef-lagoon-land) all appear to have remarkable properties and history. All components experienced important changes in the last century due to anthropogenic (importation of exogenous species) or natural perturbations (closing of passes, coral bleaching). Here, we review the history of these three systems (land-lagoon-coral reef) and provide new insights of the current status of the atoll based on recent surveys and high resolution IKONOS satellite imagery. Most dramatic changes occurring in the last decades include explosion in crab Gecarcinus planatus population, almost-complete desertification of the island and increase in Masked Boobies Sula dactylatra population, making Clipperton Atoll one of the most important sites for this specie in the world. This review intends to provide a sound basis to discuss the future of Clipperton balanced between conservation and development priorities, and to raise awareness on the future of a delicate ecosystem.