N
NEW CALEDONIA
Guy Cabioch
IRD (Institut de Recherche pour le Développement),
Bondy, CEDEX, France
Introduction
New Caledonia is located in the South West Pacific Ocean
and comprises several islands and islets and a broad diversity of oceanic and continental reef structures including
(non-exhaustive list) shoals, atolls, uplifted reefs,
drowned reefs, patch reefs, fringing reefs, and barrier reefs
(Andréfouët et al., 2009). In the recent review by
Andréfouët et al. (2009), the mapping by high spatial resolution optical remote sensing data indicated that the 161
unit types of the New Caledonian coral reef complexes
were distributed across 4,537 km
2 of reef area and
31,336 km
2 of non-reef area. More specifically, between
the coastlines of the main island, called the Grande Terre,
and the barrier reef, a more or less wide lagoon of approximately 30 m depth extends along both sides. The Grande
Terre is bordered along the 500-km-long coastline by one
of the longest barrier reefs in the world (1,600 km), double
or triple in several parts (Guilcher, 1988), interrupted by
passes, often in front of rivers, and by drowned segments,
especially along the east coast. This barrier reef extends
northward, enclosing the North lagoon and the Belep
islands; it also extends southward, enclosing the southwest lagoon or lagoon of Nouméa enclosing several coral
islets and the Ile des Pins (Figure 1). The coastlines of the
Grande Terre are bordered by fringing reefs particularly
well developed on the east coasts while mangroves alternate with fringing reefs on the west. For instance, our
knowledge on the development and history of coral reefs
in New Caledonia is focused on the Grande Terre and
Loyauté islands. Little is known regarding the reef evolution of the shoals, atolls, and drowned reefs.
Climatic conditions
Two marked seasons can be reported: (1) from November
to April during the austral summer, the climate is tempered
by the prevailing southeast trade winds and (2) from May to
October, during the austral winter, the trade winds are disturbed by westerlies generated by polar air masses. Moreover, New Caledonia can be affected by tropical cyclones
from November to May with some damages to reefs as
recently reported (Guillemot et al., 2010). Due to its location, New Caledonia is in the south of the West Pacific
Warm Pool (WPWP) under the influence of the interannual
climatic variations resulting from the El Niño Southern
Oscillation (ENSO) phenomenon. In this region, the fluctuation of the south branch of the Intertropical Tropical Convergence Zone (ITCZ), the South Pacific Convergence
Zone (SPCZ), is marked by variations in the oceanographic
parameters. During the “La Niña” events, New Caledonia
experiences high rainfall and variations in sea surface salinities (SSS) (Delcroix and Lenormand, 1997). During the
last decades, ENSO events and climatic variability were
investigated using analyses of isotopes (d
18
O) and trace
elements (Sr/Ca, U/Ca, Ba/Ca) at a monthly resolution on
corals, to reconstruct the past sea surface temperatures
(SST), SSS and nutrient inputs (Beck et al., 1992; Quinn
et al., 1996, 1998; Corrège et al., 2001; Stephans et al.,
2004; Ourbak et al., 2006; Delong et al., 2007).
Geological setting
New Caledonia is located on the Australian tectonic plate,
which dips beneath the North Fiji Basin microplates and
Pacific tectonic plate. The subduction zone (Vanuatu
trench) is situated eastward of the Loyauté islands
(Figure 1). The resulting deformation of the Australian
David Hopley (ed.), Encyclopedia of Modern Coral Reefs, DOI 10.1007/978-90-481-2639-2,
# Springer Science+Business Media B.V. 2011
NEW CALEDONIA
Guy Cabioch
IRD (Institut de Recherche pour le Développement),
Bondy, CEDEX, France
Introduction
New Caledonia is located in the South West Pacific Ocean
and comprises several islands and islets and a broad diversity of oceanic and continental reef structures including
(non-exhaustive list) shoals, atolls, uplifted reefs,
drowned reefs, patch reefs, fringing reefs, and barrier reefs
(Andréfouët et al., 2009). In the recent review by
Andréfouët et al. (2009), the mapping by high spatial resolution optical remote sensing data indicated that the 161
unit types of the New Caledonian coral reef complexes
were distributed across 4,537 km
2 of reef area and
31,336 km
2 of non-reef area. More specifically, between
the coastlines of the main island, called the Grande Terre,
and the barrier reef, a more or less wide lagoon of approximately 30 m depth extends along both sides. The Grande
Terre is bordered along the 500-km-long coastline by one
of the longest barrier reefs in the world (1,600 km), double
or triple in several parts (Guilcher, 1988), interrupted by
passes, often in front of rivers, and by drowned segments,
especially along the east coast. This barrier reef extends
northward, enclosing the North lagoon and the Belep
islands; it also extends southward, enclosing the southwest lagoon or lagoon of Nouméa enclosing several coral
islets and the Ile des Pins (Figure 1). The coastlines of the
Grande Terre are bordered by fringing reefs particularly
well developed on the east coasts while mangroves alternate with fringing reefs on the west. For instance, our
knowledge on the development and history of coral reefs
in New Caledonia is focused on the Grande Terre and
Loyauté islands. Little is known regarding the reef evolution of the shoals, atolls, and drowned reefs.
Climatic conditions
Two marked seasons can be reported: (1) from November
to April during the austral summer, the climate is tempered
by the prevailing southeast trade winds and (2) from May to
October, during the austral winter, the trade winds are disturbed by westerlies generated by polar air masses. Moreover, New Caledonia can be affected by tropical cyclones
from November to May with some damages to reefs as
recently reported (Guillemot et al., 2010). Due to its location, New Caledonia is in the south of the West Pacific
Warm Pool (WPWP) under the influence of the interannual
climatic variations resulting from the El Niño Southern
Oscillation (ENSO) phenomenon. In this region, the fluctuation of the south branch of the Intertropical Tropical Convergence Zone (ITCZ), the South Pacific Convergence
Zone (SPCZ), is marked by variations in the oceanographic
parameters. During the “La Niña” events, New Caledonia
experiences high rainfall and variations in sea surface salinities (SSS) (Delcroix and Lenormand, 1997). During the
last decades, ENSO events and climatic variability were
investigated using analyses of isotopes (d
18
O) and trace
elements (Sr/Ca, U/Ca, Ba/Ca) at a monthly resolution on
corals, to reconstruct the past sea surface temperatures
(SST), SSS and nutrient inputs (Beck et al., 1992; Quinn
et al., 1996, 1998; Corrège et al., 2001; Stephans et al.,
2004; Ourbak et al., 2006; Delong et al., 2007).
Geological setting
New Caledonia is located on the Australian tectonic plate,
which dips beneath the North Fiji Basin microplates and
Pacific tectonic plate. The subduction zone (Vanuatu
trench) is situated eastward of the Loyauté islands
(Figure 1). The resulting deformation of the Australian
David Hopley (ed.), Encyclopedia of Modern Coral Reefs, DOI 10.1007/978-90-481-2639-2,
# Springer Science+Business Media B.V. 2011