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PEBACC+ aims to strengthen the resilience of ecosystems, economies and people to the impacts of climate change. The Project will support the coastal protection of Ouvea (Loyalty Islands Province) the restoration of urban mangroves in Greater Noumea (South Province) and secure water provision in Kouaoua (North Province)

LE projet PEBACC+ (Pacific Ecosystem-based Adaptation to Climate Change Plus/Phase 2) est un projet régional mis en ouvre par le Secrétariat du Programme régional océanuen pour l'environnement (PROE) et financé par l'initiative Kiwa a travers l'Agebce francaise de développement (AFD) et la Facilité francaise pour l'environnement mondial.

Microbenthos and macrobenthos were quantitatively studied at 62 stations distributed regularly over the Uvea Atoll lagoon (850 km2). Sampling was performed using both SCUBA and a 0.1 m2 Smith Mclntyre grab. Mean estimates of ATP, chlorophyll a and phaeopigments were 297.3ng/cm2, 77.01 mg/m2 and 35.28 mg/m2 respectively. The mean macrobenthic biomass was 4.14 gAFDW/m2 of which the macrophytobenthos accounts for 39%. The benthic biomass decreased from the coast to the deepest parts of the lagoon. Macrophytes were most abundant in the coastal area and became progressively scarcer with increasing depth. By comparison, sessile species dominated on hard substrates in intermediate and deep zones. The abundance of the surface-deposit feeder group, that dominated the trophic structure of zoobenthos (33% of the macrofauna biomass), could be explained by a microphytic biomass six times higher than macrophytobenthic one in terms of carbon. Carnivores (32%) were mainly represented by necrophagous species, and filter-feeders (27%) by bivalves. Herbivores were rare. Four main benthic communities were identified on the basis of their macrobenthic assemblages using a Detrended Correspondence analysis. They corresponded to (1) a coastal zone, with the highest mud percentage in sediments, (2) an intermediate zone, with moderate depth and dominated by hard substrates, (3) a back reef zone, with thick sand layers, and (4) a deep zone dominated by hard substrates. Relative distribution of the trophic groups varied according to the different zones and suggests distinct functional characteristics for the different benthic assemblages. From a biogeographic point of view, this study highlighted the richness of the Uvea Atoll lagoon in terms of benthic species and biomass, compared to other central Pacific atoll lagoons.

The shorefishes of Ouvea, an isolated atoll in the Loyalty Islands group of New Caledonia, had not been surveyed prior to 1990. An extensive survey was conducted by ORSTOM between 1991 and 1992 to obtain baseline information on the shorefishes. A total of 653 taxa among 72 families are now documented from this area. The most diverse families are the Labridae (69 species), Pomacentridae (58 species), Gobiidae (54 spccies),Serranidae (39 species), Chaetodontidae (31 species) and Apogonidae (28 species). The absence or very low diversity of some families (Clupeidae, Nemipteridae, Siganidae) or genera (Abudefduf, Neopomacentrus) is similar to findings for other isolated islands of the Coral Sea. Of the 653 species recorded from Ouvea, 51 species have not been reported from New Caledonia, a large high island to the South. Only one endemic species, Luzonichthys williamsi, has been recognized among the shorefishes at Ouvea. A number of Pacific Plate endemic species were recorded at Ouvea. which is positioned on the Australasian Plate to the south of the edge of the Pacific Plate. Antennarius duescus, previously known from three specimens taken at the Hawaiian Islands, is recorded from a single specimen taken at Ouvea. Another antitropical distribution pattern is exhibited by Dinemalichthys riukiuensis, which is known to occur at Fiji, Ouvea and Queensland in the South and from Okinawa.