Les récifs coralliens de Wallis et Futuna : suivi biologique, état de santé et perspectives d’avenir

Abstract

Coral reefs of Wallis and Futuna : biological monitoring, health and future. – Wallis and Futuna is a small tropical overseas French territory located in the South Pacific Ocean 450 km North from Fiji and 400 km North-East from Samoa. It is composed of three main islands : Uvea, Futuna and Alofi, and inhabited by around 15 000 people. A long-term coral reef monitoring program was implemented in 1999 on six outer slopes sites. Live coral coverages and genus diversity were sampled every 3 years. The initial results suggested a relative stability of these aspects with no significant changes between 1999 (first surveys) and 2005 (most recent surveys). A comparative study of the three sampled islands shows that highest coral coverages on Wallis’outer reefs are isolated (by a 1 km or more wide lagoon) from the inhabited land, and therefore are protected to an extent from natural and human perturbations. The lower coral coverage observed on Futuna and Alofi may be attributable to the proximity to higher frequency of human and natural terrestrial stresses due to the absence of a lagoon on these two islands. Anthropogenic activities inducing stresses such as sewage, land erosion, poisoning and blast fishing have been identifi ed on the sampled islands. Relative to other Pacific island countries, Wallis and Futuna has a low density human population and a high GNP/inhabitant. Ongoing French and European monitoring, research and development programmes, provide Wallis and Futuna with a level of understanding with regard to the status of its coral reef resources. These factors should contribute signifi cantly to the implementation of effective management of reef resources in Wallis and Futuna.