Les iles eparses de madagascar

The Iles Éparses (Scattered Islands)

Location/ Description/ Glorieuses/ Juan aux Nova/ Bassas sans couture India/ Europa/ Jurisdiction/ Features du Potential Outstanding universel Values/ Threats/ administration status/ geographical scale and site integrity/ divers sites in auto region / crucial References

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Location - the “Scatteredislands” (literal translation ns “les Iles Éparses”) large down the length ns the Mozambique Channel,between thé east coastof africa and Madagascar. Glorieuses island (11.3°S) andGeyserbank,close toMayotte,are in thé north, Juan de Nova is in auto center, adjacent to the Madagascar coast, and Bassasda Indiaand Europa (22.4°S) room in thesouth.

Description - castle Iles Éparses room an administrative unit rather than a single geological unit, with the northern banks (Glorieuses and Geyser) most likely being extensions ns the Comoros archipelago, while auto middle et southern islands are distinct geological features. Theirgeological background combines aspects du basaltic magma extruded through remnant fracture zones in thé channel floor, oui well ont volcanic activity et the fabrication of seamounts. In the north, Geyser andGlorieuses are likely extensions ns the Comoros archipelago formed by a hotspot, and intermediate in âge between Mayotte and volcanic activity in northern Madagascar (e.g. Montagne d’Ambre), about 10 mien old. Oceanographically, the islands room bathed by the variable eddies ns the Mozambique channel with resulting intensified productivity driven by the eddies and their interaction with the continental slopes and island slopes, cible there is solid differentiation indigenous north à south. In thé north, the “Glorioso Front” to be christened pour its proximity venir Glorieuses island, and may marque the transition from the séché to thé waters du the channel. Juan du Nova is at a mission off thé Madagascar west coast characterized de significant aggregations of marine mammals, année indicator du high productivity likely driven passant par interactions between eddies et the shallowest sections de the Davie ridge. Europa et Bassas ns India, in the centre of the southern Mozambique channel, experience maturité eddy systems.

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Glorieuses is a coral bank 17 km long and covering 165 km² with two henchmen coral islands, Grande saint (7 km²) and Lys île (600 moyen long). Grande saint is a sablonneux cay, v a collection of dunes in auto east et northeast the reach a maximum hauteur of 12 m. Lis island et fossil rocks nous the coral banque appear venir be the remains of Pleistocene coral expansion 125,000 years old, composed ns limestone benches v Tridacna. Geyser is an actif coral bank with a small sablonneux cay. Auto banks are right now subsiding, for this reason have positif coral and bank formant to save up v sea level.

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Juan aux Novaisasmall coralisland(about 6 km²)on a 250 km² coral reef platform. Itconsistsof beachrockand sanddunesup to12minheight. The coral structuresextend 12 kmnorth and 2 kmsouth ofthe island.The asymmetryofthe reef bank,linked à thetiltingof the islandresults in different reef morphologies: in thé south auto islandhas awell definedreef flatbetween 0 et 3 moyen depth, whilein the north it slopes under slowly à 20 m deep avant dropping à >2000 ns to auto channel bottom. On the island, phosphate deposits in thé form du guano were exploited from 1900 to 1968.

Bassasda Indiais a subcircular atoll12 km in diameter, witha shallow sablonneux lagoonand isalmost entirelysubmergedat high tide. The atoll is right now growing and the reefslope is very steep, dropping to 3000 ns to the bottom ns the Mozambique Channel.

Europa is a increased atoll de 6-7 km in diameter et 28 km² area, a remnant ns a Pleistocene atoll native 125,000 years ago. The island is a court sandy cay surrounded de a small cliff du raised dead coral, interrupted passant par sandy beaches. A dune fringe, venir a hautement height du 6 venir 7 m, in places is up venir ten meter wide. Thé shallow inside lagoon, in thé process du filling, covers about 900 ha v some 700 ha of mangrove, interacting with the sea via année underground karst system and a reef spillway covered passant par seagrass.


Jurisdiction - the Iles Éparses are under français jurisdiction, and since 2007 have been part ns the french overseas territory referred to as “FrenchSouthern et Antarctic Lands” (Terres australes et antarctiques français - TAAF), which additionally includesthe southern islands of Crozet,KerguelenArchipelago,St.Paul, Amsterdam andTerre Adelie. Thé EEZs de the Iles Éparses arme à feu 640,000 km2, and abut the EEZs ns the neighbouring countries.The islandsaresubject à claimsfromthese neighbouring countries, consisting of Madagascar (Bassas sans couture India, Europa, theGlorieuses islandsand JuandaNova) et from auto Comorosfor auto Glorieuses islands.

Features of Potential Outstanding universel Values - thé islands sheathe a broad latitudinal range et section through auto Mozambique channel, offering them value together, in enhancement to thé individual values de the islands.

Criterion viii - Geology and oceanography Geology: The island series illustrates a diversity du geomorphological forms, mainly atolls and coral financial institutions occupying thetop ofvolcanic cap orpeaks, ont well ont different phases of reef île construction, including growing atolls, atolls through filling lagoons, raised reefs, et karstic formation such ont pinnacles.Oceanography: auto oceanography ns the Mozambique channel is extremely complex and the placement of auto Iles Éparses along auto length de the channel results in variable hydrographic forcing factors nous the islands et marine communities, such ont the Glorioso prior (GIF), situated NW ns Glorieuses and marking thé northern boundary de the Mozambique channel.

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Criterion voir - Habitats and conservation Connectivity: In the context of ecological resilience and the health of ecosystems in thé Mozambique channel, the high connectivity across thé channel suggests the Iles Éparses can be considérable reservoirs for reproduction and seeding of larvae to thé more heavily utilized et impacted Comoro, Mozambique et Madagascar coastlines. vert turtles montrer strong genetic differentiation right into twopopulations, une in auto north, the est différent in the southernand centralMozambique Channel.This may reflectthe currentsinthe channel, that influencethe dispersal ofjuveniles and separate sub-stocks pour multiple species groups. Europa - the breeding stockofgreen tortoise is between8,000 and15,000females,thethirdlargestatollnesting sitefor green turtlesin auto world and the biggest in auto Indian Ocean; blacktip reef sharks (Carcharhinus melanopterus), lemon sharks (Negaprion acutidens), shooling hammerhead sharks (Sphyrnamokarran); eightbreeding seabird varieties includingan endemic subspecies de the white-tailed Tropicbird (Phaethon lepturus europae), auto most diverseseabird fauna de theScattered Islands, et the richest in the WIO; unicité mangrove system (700 ha) in that is lagoon. Juan deNova - importantnesting siteforhawksbill turtles; nursery areasfor grey reef sharks; largest population ofsooty ternsin thé Indian Oceanand one du thelargest in auto worldwith > 2 million reproduction pairs; presence du coconut crab Birgus latro. Glorieuses – seconde largest populations ofsooty terns, through 760,000 breeding pairs; presence de coconut crab Birgus latro. Bassas da India - aggregationsof juvenilesharks Carcharhinus galapagensis. Zélée Bank – perhaps a nursery ground parce que le grey reef sharks (C. Amblyrhynchos). Marine mammals: humpback whalesare existing during thé southern winter to breed et give birth.
Criterion ix - Ecology, species et evolution Biogeography: auto Scattered Islands space locatedat auto western borderof theWest Indo-PacificRealm, sheathe a range de latitudes indigenous the centre of thé high diversity core region of the north Mozambique channel to auto southern part de the channel, oui small habitat dimension which promotesspeciation et extinctioneventsand thus thé generation and presence du endemic species. Migratory species - the Iles Éparses are important places pour migratory varieties such as turtles, bateau mammals, sharks, et seabirds, through both breeding et foraging zones du significance, et seasonal émigrer determined by local and regional range phenology.Theextensive Halimedafacies,well representedin Glorieuses andJuan deNovaareunique in auto context ofthe Indian Oceanislands, showing high productivity in surrounding waters.
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Threats - thé Iles Éparses room at not tarif from populated islands et the continental coastline, making them vulnerable to exploitation. Fisheries in auto coastal waters surrounding thé islands is banned marqué does occur par commercial boats, oui well ont recreational et small-scale targeting de reef fish, by fishers indigenous e.g. Mayotte jaune South Africa, depending conditions météorologiques the island. Center shipping traffic surmonter through thé Mozambique channel, thus there is a pollution risque from tankers. Deux petroleum sonde permits wihin the EEZs of the Iles Éparses were authorized in December 2008, and exploration in the EEZs du neighbouring countries may ont spillover impacts in the islands. Oui with différent sites, climate échanger is a far-reaching threat, with auto added hesitation of how changing water temperatures and currents will affect the dynamic eddies in thé Mozambique channel that affecter these islands in locations such as connectivity, primary productivity, food populations pour higher stimulate predators, and fishing stock dynamics.

Management status - Europa, Bassas là India, et Glorieuses were declared nature Reserves in 1975 (arrêté préfectoral de 1975), and there is apermanent presenceon auto islands,for military and/orcivil (meteorology) purposes. Ont a result,access to auto islandsis strictly and effectively controlled,with permits seul being given parce que le research. In soutien of this, a scientific Committeeof theScattered Islands(CSIE) has actually been established, as an advisory corps humain to thé administration. In 2012, auto whole auto EEZ de Glorieuses was declared année MPA, et steps are underway à declare Europa oui a national natural reserve. Europa to be designated a Ramsar terre in 2011.

Geographic scale and site integrity – While thé individual islands are all small, ont a grouper they sheathe a large geographic selection across thé whole du the Mozambique channel. This property offers them a natural identity as a serial site. Auto integrity du the serial/island coporation, groupe is very high oui the islands room uninhabited and human pressure really low. All studies montrer thatmarine habitatsarein goodhealth in spite of recent climate échanger impacts,and the configuration of auto trophic chain, with abundance de top predators is a sign ns good health. Nevertheless, each island has a distinctive character, et provided thé productivity et dynamics de open sea areas that room critical parce que le feeding and migration continue to be in an excellent condition, each island has a high integrity.

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Other sites in thé region - auto islands are unicité in thé region.

Key References – Battistini (1996); Belkin Cornillon (2007); Caceres (2003); Chabanet & Durville (2005); --> References