Rivière des Marsouins - Grand Etang (6765)
Réunion (to France), Africa
Site overview
KBA status: confirmed
Global KBA criteria: B2
Year of last assessment: 2001
National site name: Rivière des Marsouins - Grand Etang
Central coordinates: Latitude: -21.6667, Longitude: 55.6333
System: marine, terrestrial
Elevation (m): 83 to 1334
Area of KBA (km2): 31.70018
Protected area coverage (%): 99.98
KBA classification: Global
Legacy site: Yes
Site details
Site description: This is a mid-altitude site that includes the steep-sided ravine of the Rivière des Marsouins, together with a lake (Le Grand Etang) created by the blockage of a valley by a lava-flow from Le Piton de la Fournaise volcano. The ravine cuts into the Bébour plateau, a forested area due west of Le Piton des Neiges, at the Caverne des Hirondelles (at 1,334 m). The site extends from this point down the river to the lowlands at 83 m, and also over the ridge to the south to include Le Grand Etang and its surroundings. Most of the site is remarkably unaltered ecologically, with extensive, rich native plant communities, especially mixed moist evergreen lowland forest; a few stands of exotic vegetation are present. The lake covers about 30 ha. No land-uses are known, although the lake and part of the ravine are accessible by road or track.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs.
Additional biodiversity: See Box and Table 2 for key species. The site is particularly important for Puffinus lherminieri (common breeding visitor), Circus maillardi (8–12 pairs in 1998) and Collocalia francica (several colonies known), but also supports a typical community of native, forest-living birds, most at notably high densities. Non-bird biodiversity: Endemic plant communities: wide diversity of native plant species.
Delineation rationale: Type 1 marine IBA: suitable for the seaward extension approach.
Habitats
Land use: not utilised
Threats
Summary of threats to biodiversity at KBA: The precipitous terrain provides natural protection to this site, and no site-specific threats are known.
Additional information
References: Anon. (1998), Barré (1988), Barré et al. (1996), Cadet (1980), Cheke (1987b), Clouet (1978), Dupont et al. (1989), Ghestemme et al. (1998), Guillermet and Guillermet (1986).