Îlots du lagon sud (21822)
New Caledonia (to France), Australasia
Site overview
KBA status: confirmed
Global KBA criteria: B1, D1a
Year of last assessment: 2012
National site name: Îlots du lagon sud
Central coordinates: Latitude: -23.0000, Longitude: 167.0000
System: marine, terrestrial
Elevation (m): 0 to 40
Area of KBA (km2): 0.92565
Protected area coverage (%): 100.00
KBA classification: Global
Legacy site: Yes
Site details
Site description: Le lagon de la Nouvelle-Calédonie se divise, au sud, en deux cornes. La première contient la réserve Merlet, la passe de la Sarcelle et l’île des Pins. La seconde, identifiée comme une IBA et communément appelée corne Sud, contient 23 îlots, situés au sud de la commune du Mont Dore. Le récif barrière, qui ceinture l’IBA, est distant de 70 km de la côte. A cet endroit le lagon est donc le plus large du territoire, sa profondeur varie quant à elle entre 20 et 80 m.
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: Les inventaires ornithologiques de cette partie du lagon ont identifié 19 espèces, dont 12 sont marines, et sept terrestres. Toutes les espèces marines contactées s’y reproduisent. On peut donc y observer les Pétrels à ailes noires et de Tahiti, le Puffin fouquet, le Fou à pieds rouges, les Noddis noir et brun, la Mouette argentée ainsi que les Sternes bridée, huppée, de Dougall, néréis et diamant. La Sterne fuligineuse est connue sur d’autres îlots du lagon, mais n’a pas été contactée dans cette IBA. Parmi les sept espèces terrestres, seul le Balbuzard australien s’y reproduit tandis qu’un autre rapace, le Faucon pèlerin y chasse. Les cinq autres espèces sont des limicoles migrateurs. Pour compléter cet inventaire on mentionnera des espèces terrestres, régulièrement observées sur les îlots dont les plus fréquents sont les Siffleur itchong, Méliphage à oreillons gris, Zostérops à dos gris et vert, Gérygone mélanésienne et Martin-chasseur sacré. L’intérêt de cette IBA réside principalement dans la présence de la plus grande concentration de Puffins fouquets du territoire, avec près de 200 000 couples. Elle abrite également la seule population majeure connue de Noddis noirs nichant à l’intérieur du lagon (50 500 couples). On y dénombre également 1 500 couples de Sternes de Dougall. A l’échelle de la Nouvelle-Calédonie, il est essentiel de souligner l’importance des populations de Pétrels à ailes noires et de Sternes bridées. C’est aussi le seul endroit du lagon où le Fou à pieds rouges continue de se reproduire. Enfin, la Sterne néréis y a été observée nicheuse (une vingtaine de couples). Non-bird biodiversity: Les autres richesses naturelles de cette zone sont essentiellement marines. Un inventaire en a été fait lors d’un atelier d’identification des aires de conservation prioritaires (Cros et al. 2005). Il y est en outre signalé que cette région abrite les plus importantes biomasses de poissons de toute la Nouvelle-Calédonie, la présence de tortues (Chelonia mydas et Caretta caretta) et de vastes herbiers de Caulerpe.
Delineation rationale: 2012-12-17 (BL Secretariat): original polygon clipped to hi-res coastline (marine areas removed) following identification in October 2012 of new marine IBA offshore this site; site area consequently changed from 385000 ha to 88 ha.
Threats
Summary of threats to biodiversity at KBA: Climate change is listed as the third greatest threat to seabirds globally (Croxall et al. 2012). It is predicted to decrease the land area of low-lying Pacific islands and cause complete inundation of some islands (IPCC 1997) leading to substantial population declines (Hatfield et al. 2012). Although no current data or predictions are available specific to this IBA climate change represents a potential threat to this site owing to the risk of future sea level rise leading to inundation, and increased frequency of storms. Invasive Alien Species represent the greatest threat to seabirds globally (Croxall et al. 2012), causing adult mortality and reduced productivity owing to egg and chick predation. Extensive rat eradication programs have been successfully implemented on the islets within the IBA (Spaggiari et al. 2007). There is the risk of re-invasion through unregulated visits to the islets. Polynesian Rat is ubiquitous throughout the Pacific (IUCN SSC Invasive Species Specialist Group 2012) and has been recorded predating adult seabirds as well as eggs and chicks (Kepler 1967). They have precipitated island extinctions in small-bodied, ground-nesting seabirds, but their impacts on larger or arboreal nesting seabirds appear to be lower (Atkinson 1985, Jones et al. 2008). Black Rat, Brown Rat, Feral Cat, are all plausible and potentially serious future invasive species. Each can potentially cause declines in seabird colonies, and cause habitat modification (Atkinson 1985, Rodríguez et al. 2006, Jones et al. 2008, Duffy 2010). Overall, invasive mammals are not suspected to be currently present but would cause population declines if they were to re-invade. Human disturbance and direct harvesting of seabirds are listed as threats to 26 and 23 of the 97 globally threatened seabirds respectively (Croxall et al. 2012). For Near Threatened and Least Concern species it is likely that human disturbance and consumption affect an even greater proportion, particularly of tropical species, for which major reductions in populations and/or breeding sites are increasingly indicated but seldom quantified, especially across the whole range of the many wide-ranging tropical seabird species (Croxall et al. 2012). Human disturbance (such as recreational activities) and direct harvesting may occur at this site. The sustainability of such harvests is unknown but it may represent a threat to this population. Seabirds are highly visually oriented and known to become disorientated at night in the presence of artificial light (Bruderer et al., 1999). On archipelagos worldwide, thousands of fledglings of different petrel species are attracted to artificial lights during their first flights from nest-burrows to the sea, a phenomenon called ‘fallout’ (Reed et al. 1985, Telfer et al. 1987, Le Corre et al. 2002, Rodríguez & Rodríguez 2009, Miles et al. 2010, Rodrigues et al. 2011). Grounded birds are vulnerable to starvation, predation, dehydration and collision with vehicles. The prevalence of this potential threat at this site is not known but it may be having a negative impact.
Additional information
References: Atkinson, I. A. E. (1985) The spread of commensal species of Rattus to oceanic islands and their effect on island avifaunas. Pages 35-81 in P. J. Moors, editor. Conservation of island birds. International Council for Bird Preservation, Cambridge, United Kingdom. Bruderer, B., Peter, D. and Steuri, T. (1999) Behavior of migrating birds exposed to Xband radar and a bright light beam. Journal of Experimental Biology 202: 1015–1022. Le Corre, M., Ollivier, A., Ribes, S. and Jouventin, P. (2002) Light-induced mortality of petrels: a 4-year study from Réunion Island (Indian Ocean). Biol. Conserv. 105: 93–102. Croxall, J. P., Butchart, S. H. M., Lascelles, B., Stattersfield, A. J., Sullivan, B., Symes, A. and Taylor, P. (2012) Seabird conservation status, threats and priority actions: a global assessment. Bird Conservation International 22: 1-34. Duffy, D. C. (2010) Changing Seabird Management in Hawai‘i: from exploitation through management to restoration. Waterbirds 33: 193-207. Hatfield, J. S., Reynolds, M. H., Seavy, N. E. and Krause, C. M. (2012) Population dynamics of Hawaiian seabird colonies vulnerable to sea-level rise. Conservation Biology 26: 667-678. IPCC – Intergovernmental Panel On Climate Change (1997) The Regional Impacts of Climate Change. An Assessment of Vulnerability. Geneva. IUCN SSC Invasive Species Specialist Group (2012) Rattus exulans. Global Invasive Species Database. Downloaded from http://www.issg.org/database/species/ecology.asp?si=170&fr=1&sts=sss on 8th October 2012. Jones, H. P., Tershy, B. R., Zavaleta, E. S., Croll, D. A., Keitt, B. S., Finkelstein, M. E. and Howald, G. R. (2008) Severity of the effects of invasive rats on seabirds: a global review. Conservation Biology 22: 16-26. Kepler, B. (1967) Polynesian rat predation on nesting Laysan Albatrosses and other Pacific seabirds. Auk 84: 426-430. Miles, W., Money, S., Luxmoore, R. and Furness, R.W. (2010) Effects of artificial lights and moonlight on petrels at St Kilda. Bird Study 57: 244–251. Reed, J.R., Sincock, J.L. & Hailman, J.P. (1985) Light attraction in endangered Procellariiform birds: reduction by shielding upward radiation. Auk 102: 377–383. Rodrigues, P., Aubrecht, C., Gil, A., Longcore, T. and Elvidge, C. (2011) Remote sensing to map influence of light pollution on Cory’s Shearwater in São Miguel Island, Azores Archipelago. Eur. J. Wildl. Res. doi: 10.1007/s10344-011-0555-5. Rodríguez, A. and Rodríguez, B. (2009) Attraction of petrels to artificial lights in the Canary Islands: effect of the moon phase and age class. Ibis 151: 299–310. Rodríguez, C., Torres, R. and Drummond, H. (2006) Eradicating introduced mammals from a forested tropical island. Biological Conservation 130: 98-105. Telfer, T.C., Sincock, J.L., Byrd, G.V. and Reed, J.R. (1987) Attraction of Hawaiian seabirds to lights: conservation efforts and effects of moon phase. Wildl. Soc. Bull. 15: 406–413. Spaggiari J, Chartendrault V & Barré N.2007. ZICO de Nouvelle Calédonie. SCO/Birdlife International.213p