The Comoro Islands are a group of volcanic islands in the

Mozambique Channel The Mozambique Channel (, , ) is an arm of the Indian Ocean located between the Southeast African countries of Madagascar and Mozambique. The channel is about long and across at its narrowest point, and reaches a depth of about off the coa ...

, an arm of the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

lying between

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

and the African mainland. Three of the islands form the Union of the Comoros, a sovereign nation, while

Mayotte Mayotte ( ; , ; , ; , ), officially the Department of Mayotte (), is an Overseas France, overseas Overseas departments and regions of France, department and region and single territorial collectivity of France. It is one of the Overseas departm ...

belongs to France.

Geography

The Comoro Islands are located in the

to the north-west of Madagascar and facing Mozambique. These volcanic islands, covering a total area of 2034 km², are as follows: * Ngazidja (also known as ''Grande Comore''): the largest island of the Union of the Comoros, with its capital Moroni * Ndzuwani (also known as ''Anjouan''): part of the Union of the Comoros * Mwali (also known as ''Mohéli''): part of the Union of the Comoros *

(also known as ''Maore''): a French

overseas department The overseas departments and regions of France (, ; DROM) are the five departments and regions of the French Republic which are located outside European France (also known as " metropolitan France"). These overseas entities have exactly the s ...

. Mayotte is composed of two islands,

Grande-Terre Grande Terre or Grande-Terre (, French for "large land") is a generic term used in French to designate the main island of any given archipelago. As a specific toponym, it may refer to the following: * Grande-Terre, Guadeloupe, the eastern half of ...

and

Petite-Terre :'' Petite Terre is also the name of Petite Terre Islands, a group of islands in Guadeloupe.'' Pamanzi, also known as Petite-Terre (; literally "Little Land" in French language, French), is an island of Mayotte, an overseas department and oversea ...

(also known as ''Pamanzi''), where the

Dzaoudzi–Pamandzi International Airport Dzaoudzi–Pamandzi International Airport is an airport located in Pamandzi, Mayotte, France on the southern tip of the island of Petite-Terre (or Pamanzi), east of Grande-Terre, the main island of Mayotte. It is the only airport in Mayotte wi ...

is located. The Glorioso Islands, comprising ''Grande Glorieuse'', '' Île du Lys'' and eight little rock islets, were administratively attached to the archipelago before 1975, and, geologically speaking, form a part of the archipelago. Notable reefs that are part of the archipelago are as follows: * Banc Vailheu, or ''Raya'', a submerged volcano located 20 km west of Grand Comoro * Banc du Geyser, a reef measuring 8 by 5 km in area, situated 130 km North-East of Grande-Terre * Banc du Leven, a former island between Madagascar and Grande-Terre which is now submerged

History

The Comoros may have been settled as early as the 6th century; among the peoples who crossed the sea to populate the islands are Bantu-speaking peoples, Austronesian (including Malagasy),

Arab Arabs (, , ; , , ) are an ethnic group mainly inhabiting the Arab world in West Asia and North Africa. A significant Arab diaspora is present in various parts of the world. Arabs have been in the Fertile Crescent for thousands of years ...

Somalis The Somali people (, Wadaad's writing, Wadaad: , Arabic: ) are a Cushitic peoples, Cushitic ethnic group and nation native to the Somali Peninsula. who share a common ancestry, culture and history. The Lowland East Cushitic languages, East ...

, Portuguese, French, and Indians. Islam probably arrived during the 10th century. The Comoros islands formed, with

Zanzibar Zanzibar is a Tanzanian archipelago off the coast of East Africa. It is located in the Indian Ocean, and consists of many small Island, islands and two large ones: Unguja (the main island, referred to informally as Zanzibar) and Pemba Island. ...

, Pemba, Lamu, and the coastal towns of Kenya and Tanzania, a united and prosperous region of Swahili culture, trading in local goods which were exported to the African coast, Madagascar, the Middle East and India. In that period, political power was in the hands of local rulers. During their explorations of the Comoros region, the Portuguese made landfall on the Islands of the Moon, in 1505; ''kamar'' is Arabic for ''moon''. During the colonial period, French settlers established plantations, initially producing sugar, an intensive process dependent on the labor of numerous Africans. In the twentieth century, they cultivated perfume plants and spices, such as ylang ylang,

vanilla Vanilla is a spice derived from orchids of the genus ''Vanilla (genus), Vanilla'', primarily obtained from pods of the flat-leaved vanilla (''Vanilla planifolia, V. planifolia''). ''Vanilla'' is not Autogamy, autogamous, so pollination ...

and cloves, as well as

copra Copra (from ; ; ; ) is the dried, white flesh of the coconut from which coconut oil is extracted. Traditionally, the coconuts are sun-dried, especially for export, before the oil, also known as copra oil, is pressed out. The oil extracted ...

. In 1946, France redefined the Comoros as a

French overseas territory Overseas France (, also ) consists of 13 French territories outside Europe, mostly the remnants of the French colonial empire that remained a part of the French state under various statuses after decolonisation. Most are part of the European ...

. In 1974, France organized a referendum for

self-determination Self-determination refers to a people's right to form its own political entity, and internal self-determination is the right to representative government with full suffrage. Self-determination is a cardinal principle in modern international la ...

in the archipelago. Except in Mayotte, the population voted overwhelmingly in favour of independence. Following the unilateral declaration of independence in 1975, France maintained sovereignty over Mayotte. The three remaining islands formed the ''Etat Comorian'', which later became the ''Federal Islamic Republic of the Comoro Islands'' and is today the Union of the Comoros. In 1996, Ethiopian Airlines Flight 961 was hijacked and crashed off the shore of the grande island. 125 people died on board, including the three hijackers who caused the crash. 50 people survived. In 1997, demands for increased autonomy on the islands of Ndzuani (Anjouan) and Mwali (Moheli) led to the breakup of the Federal Islamic Republic. In 2001, the government reformed as the ''Union of the Comoros'' under a new constitution which gave each of the three islands more autonomy than had been enjoyed previously. In 2008, the President of Anjouan refused to hold free elections. He was forced to flee following military intervention by troops of the Comorian Union and the

African Union The African Union (AU) is a continental union of 55 member states located on the continent of Africa. The AU was announced in the Sirte Declaration in Sirte, Libya, on 9 September 1999, calling for the establishment of the African Union. The b ...

. The island country continues its present form of confederal government, albeit with minor changes approved in referendums in 2009 and 2018. Mayotte, which had voted to retain French suzerainty in the 1975 referendum, expressed a wish to accede to the status of a ''département d'outre-mer'' (DOM) (

Overseas Department The overseas departments and regions of France (, ; DROM) are the five departments and regions of the French Republic which are located outside European France (also known as " metropolitan France"). These overseas entities have exactly the s ...

) following another referendum held on the island on 29 March 2009. Mayotte officially became France's 101st department on 31 March 2011.

Geology

The Comoro Archipelago consists of volcanic islands. These volcanic islands, together with the high mountains in the north of Madagascar, were formed in the

Tertiary Tertiary (from Latin, meaning 'third' or 'of the third degree/order..') may refer to: * Tertiary period, an obsolete geologic period spanning from 66 to 2.6 million years ago * Tertiary (chemistry), a term describing bonding patterns in organic ch ...

and

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

periods. The island of Mayotte is the oldest one still above sea level and underwent three volcanic phases between 15 million and 500,000 years ago. The ages progressively decrease from east to west. Grande Comore is the youngest island and is still volcanically active. Karthala, a shield volcano occupying some two thirds of the island, rises to 2361 meters. The summit

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the str ...

is quite large, being approximately in size at the rim (2007).

Climate

The Comoro Archipelago enjoys a tropical maritime climate, characterized by slight daytime temperature variations throughout the year of around at sea level and by abundant precipitation: a year. The average temperature of the sea water is . There are two seasons in the Comoros: the hot and humid season flowing in from the north-west from November to April and the dry season from May to October. The climate on Mayotte is, nevertheless, noticeably warmer and drier. The climate is also characterized by important local variations in temperature and precipitation according to altitude, relief and the degree of exposure to the elements. Annual precipitation therefore varies in the region of and the absolute minimum of is reached on the summit of Karthala. The hot, dry season is caused by a vast low pressure area which extends over a large part of the Indian Ocean and Central Africa. This low pressure favours gusty winds and

cyclone In meteorology, a cyclone () is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above (opposite to an ant ...

s. The last cyclone was Cyclone Gafilo, which passed close to the Comoros on 5 March 2004 causing great material damage. During the hot and humid season it can rain as much as in twenty-four hours. The dry season is calmer. The low pressure moves towards the continent of Asia (this is the

monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in Atmosphere of Earth, atmospheric circulation and precipitation associated with annu ...

, the wind blowing from the south-east) and an

anticyclone A high-pressure area, high, or anticyclone, is an area near the surface of a planet where the atmospheric pressure is greater than the pressure in the surrounding regions. Highs are middle-scale meteorological features that result from interpl ...

forms below the Comoros. This still does not prevent the islands from having a few gusts of wind, but their intensity is a lot less than during the hot season. The two winds that bring the two different seasons are called the Kashkasi (in November) and the Kusi.

Terrestrial ecology

Partly as a result of international pressure during the 1990s, the government of the Union has begun to take greater care of the environment. Measures have been taken not only to preserve the rare fauna, but also to check the destruction of the environment, especially on Anjouan, which is densely populated. More precisely, in order to minimize the felling of trees for fuel,

kerosene Kerosene, or paraffin, is a combustibility, combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in Aviation fuel, aviation as well as households. Its name derives from the Greek (''kērós'') meaning " ...

has been subsidized, and efforts are underway to replace the lost forest cover caused by the distillation of

Ylang-ylang ''Cananga odorata'', known as ylang-ylang ( ) or cananga tree, is a tropical tree that is native to the Philippines, Malaysia, Indonesia, New Guinea, the Solomon Islands, and Queensland, Australia. It is also native to parts of Thailand and Vie ...

for perfume. The Fund for the Support of Community Development, sponsored by the International Development Association (IDA, a subsidiary of the

World Bank The World Bank is an international financial institution that provides loans and Grant (money), grants to the governments of Least developed countries, low- and Developing country, middle-income countries for the purposes of economic development ...

) and the Comorian government, is applying itself to improving the water supply on the islands.

Flora

Like most islands, the diversity of the local flora suffers from two pressures, on the one hand the reduction of available space caused by humans settling in what used to be the wildest areas, and the invasion of exotic plant species such as

guava Guava ( ), also known as the 'guava-pear', is a common tropical fruit cultivated in many tropical and subtropical regions. The common guava '' Psidium guajava'' (lemon guava, apple guava) is a small tree in the myrtle family (Myrtaceae), nativ ...

trees. Much of the remaining habitat is not protected, and the islands' growing population puts more pressure on the remaining wild lands.

Fauna

The islands are home to eight species of native terrestrial mammal – three species of fruit bat, three insectivorous bat species, and two lemur species. Two bat species, Livingstone's fruit bat (''Pteropus livingstonii'') and the

Comoro rousette The Comoro rousette (''Rousettus obliviosus'') is a species of megabat in the family Pteropodidae endemic to the Comoros Islands. Its natural habitats are subtropical The subtropical zones or subtropics are geographical zone, geographical ...

(''Rousettus obliviosus''), are endemic. Livingstone's fruit bat, discovered by David Livingstone in 1863, was previously abundant, but has now been reduced to a population of about 1,200 specimens restricted to Anjouan and Moheli. A British preservation group sent an expedition to the Comoros in 1992, with the object of transporting some specimens to Great Britain, in order to form a reproducing colony. Native lemurs include the mongoose lemur (''Eulemur mongoz'') and the common brown lemur (''Eulemur fulvus''). The common brown lemur or maki, known as ''Kima'' in Shikomori, is present on Mayotte, where it is believed to have been introduced from Madagascar. It is protected by French law and by local tradition. Mammals introduced to the islands by humans include the Javan mongoose (''Urva javanica'') and tailless tenrec (''Tenrec ecaudatus''). Twenty-two species of birds are endemic to the archipelago. Endemic species include the Karthala scops-owl (''Otus pauliani''), Anjouan scops-owl (''Otus capnodes'') and Humblot's flycatcher (''Humblotia flavirostris''). Native invertebrates include '' Scolopendra'', venomous centipedes that can reach up to 25 centimetres long. No large African animals (

elephant Elephants are the largest living land animals. Three living species are currently recognised: the African bush elephant ('' Loxodonta africana''), the African forest elephant (''L. cyclotis''), and the Asian elephant ('' Elephas maximus ...

giraffe The giraffe is a large Fauna of Africa, African even-toed ungulate, hoofed mammal belonging to the genus ''Giraffa.'' It is the Largest mammals#Even-toed Ungulates (Artiodactyla), tallest living terrestrial animal and the largest ruminant on ...

lion The lion (''Panthera leo'') is a large Felidae, cat of the genus ''Panthera'', native to Sub-Saharan Africa and India. It has a muscular, broad-chested body (biology), body; a short, rounded head; round ears; and a dark, hairy tuft at the ...

crocodile Crocodiles (family (biology), family Crocodylidae) or true crocodiles are large, semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term "crocodile" is sometimes used more loosely to include ...

zebra Zebras (, ) (subgenus ''Hippotigris'') are African equines with distinctive black-and-white striped coats. There are three living species: Grévy's zebra (''Equus grevyi''), the plains zebra (''E. quagga''), and the mountain zebra (''E. ...

s or

antelope The term antelope refers to numerous extant or recently extinct species of the ruminant artiodactyl family Bovidae that are indigenous to most of Africa, India, the Middle East, Central Asia, and a small area of Eastern Europe. Antelopes do ...

s) are found on the Comoros, despite the islands being relatively close to the mainland.

Freshwater ecology

Freshwater habitats on the islands include streams originating in the islands' forested highlands and flowing into the sea, as well as crater lakes. These habitats are home to species of freshwater and brackish water fish, frogs, waterbirds, dragonflies, and caddisflies."Comoros - Mayotte"
Freshwater Ecoregions of the World (FEOW). Accessed 10 August 2021. Mayotte and Moheli have

perennial stream A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long, large stream ...

s and lakes. Mayotte is the oldest of the islands, and has many meandering streams which descend from mountain forests, as well as two lakes – Dziani Karehani and Dziani Dzaha. Mohéli also has freshwater streams, and the freshwater but sulfurous lake Dziani Boundouni. Grande Comore, the largest and youngest island, is volcanically active and has thin and rocky soils, with no perennial streams or large stream valleys. Anjouan also has few permanent freshwater habitats. All of the freshwater fish on the Comoros are from secondary families, i.e. families of fish which can tolerate salt water. No primary families – fish families adapted to freshwater and intolerant of salt water – are native to the island, on account of the islands' oceanic origin and relatively recent geologic origins.

Marine ecology

Mayotte, the oldest island, is surrounded by a

barrier reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. C ...

, with extensive reefs and lagoons between the reef and the island. The reef and lagoon cover over 1,000 km². They are home to more than 760 species of marine fish, including 17 threatened species, 581 species of marine

arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

s, more than 450 cnidarian species, and 24 marine mammal species."Mayotte (France)"
IUCN. Accessed 10 August 2021 The other Comoro Islands are surrounded by

fringing reef A fringing reef is one of the three main types of coral reef. It is distinguished from the other main types, barrier reefs and atolls, in that it has either an entirely shallow backreef zone (lagoon) or none at all. If a fringing reef grows direc ...

s, which form a narrow platform extending a short distance from the coast. Reefs fringe about 60% of the coast of Grande Comore, 80% of Anjouan's coast, and 100% of Mohéli's coast. The Sima Peninsula on Anjouan is surrounded by a vast reef. The islands also have rocky reefs on

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

substrates."Biodiversity"
Comoros Country Profile, Nairobi Convention. Accessed 10 August 2021. Mayotte has 7.6 km² of

seagrass Seagrasses are the only flowering plants which grow in marine (ocean), marine environments. There are about 60 species of fully marine seagrasses which belong to four Family (biology), families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and ...

beds.Ewan Trégarot, Pierre Failler & Jean-Philippe Maréchal (2017) Evaluation of coastal and marine

ecosystem service Ecosystem services are the various benefits that humans derive from ecosystems. The interconnected living and non-living components of the natural environment offer benefits such as pollination of crops, clean air and water, decomposition of wast ...

s of Mayotte: Indirect use values of coral reefs and associated ecosystems, ''International Journal of Biodiversity Science, Ecosystem Services & Management'', 13:3, 19-34, DOI: 10.1080/21513732.2017.1407361 The extensive seagrass beds in Moheli Marine Park account for about 90% of the remaining seagrass beds in the Comoros. Other seagrass beds occur at Mitsamiouli, Malé and Ouroveni around Grande Comore and at Bimbini and Ouani around Anjouan. There are eight seagrass species in the Comoros. The islands' seagrass beds have been degraded by sedimentation and

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

. Between 1993 and 1998 the ''

Thalassodendron ciliatum ''Thalassodendron ciliatum'', the sickle-leaved cymodocea, is a species of plant in the ''Thalassodendron'' genus of seagrasses in the family Cymodoceaceae Cymodoceaceae is a family of flowering plants, sometimes known as the "manatee-grass fa ...

'' beds at Moheli Marine Park were destroyed by a large sediment influx into the lagoon from upland deforestation coupled with high rainfall. Mayotte has 8.5 km² of mangroves. There are approximately 120 ha of

mangrove A mangrove is a shrub or tree that grows mainly in coastal saline water, saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen a ...

s on the other Comoro islands, 75% of which are on the south coast of Mohéli, particularly around Damou and Mapiachingo. Smaller areas of mangrove are also found on Grande Comore and Anjouan. There are seven mangrove species in the Comoros, with ''

Rhizophora mucronata ''Rhizophora mucronata'' (loop-root mangrove, red mangrove or Asiatic mangrove) is a species of mangrove found on coasts and river banks in East Africa and the Indo-Pacific region. Description ''Rhizophora mucronata'' is a small to medium si ...

'' and '' Avicennia marina'' the most abundant. Marine mammals in the Comoros' seas include the

humpback whale The humpback whale (''Megaptera novaeangliae'') is a species of baleen whale. It is a rorqual (a member of the family Balaenopteridae) and is the monotypic taxon, only species in the genus ''Megaptera''. Adults range in length from and weigh u ...

(''Megaptera novaeangliae'')

sperm whale The sperm whale or cachalot (''Physeter macrocephalus'') is the largest of the toothed whales and the largest toothed predator. It is the only living member of the Genus (biology), genus ''Physeter'' and one of three extant species in the s ...

(''Physeter macrocephalus''),

dugong The dugong (; ''Dugong dugon'') is a marine mammal. It is one of four living species of the order Sirenia, which also includes three species of manatees. It is the only living representative of the once-diverse family Dugongidae; its closest ...

(''Dugong dugon'') spinner dolphin (''Stenella longirostris''), pantropical spotted dolphin (''Stenella attenuata''), Fraser's dolphin (''Lagenodelphis hosei''),

bottlenose dolphin The bottlenose dolphin is a toothed whale in the genus ''Tursiops''. They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus contains three species: the common bot ...

(''Tursiops'' sp.), Risso's dolphin (''Grampus griseus''), melon-headed whale (''Peponocephala electra''),

short-finned pilot whale The short-finned pilot whale (''Globicephala macrorhynchus'') is one of the two species of cetaceans in the genus ''Pilot whale, Globicephala'', which it shares with the long-finned pilot whale (''G. melas''). It is part of the oceanic dolphin ...

(''Globicephala macrorhynchus''),

pygmy killer whale The pygmy killer whale (''Feresa attenuata'') is a poorly known and rarely seen oceanic dolphin. It is the monotypic taxon, only species in the genus ''Feresa''. It derives its common name from sharing some physical characteristics with the orca ...

(''Feresa attenuata''), Blainville's beaked whale (''Mesoplodon densirostris''), and Longman's beaked whale (''Mesoplodon pacificus''). Other marine fauna include the

green sea turtle The green sea turtle (''Chelonia mydas''), also known as the green turtle, black (sea) turtle or Pacific green turtle, is a species of large sea turtle of the family Cheloniidae. It is the only species in the genus ''Chelonia''. Its range exte ...

(''Chelonia mydas''), most abundantly on Mohéli and Mayotte where they still come to lay eggs, and the

coelacanth Coelacanths ( ) are an ancient group of lobe-finned fish (Sarcopterygii) in the class Actinistia. As sarcopterygians, they are more closely related to lungfish and tetrapods (the terrestrial vertebrates including living amphibians, reptiles, bi ...

, a deepwater fish known from fossils over 300 million years old.

Marine protected areas

Four marine national parks were established in 2010 – Coelacanth National Park (92.76 km²) along the south shore of Grande Comore, Mitsamiouli Ndroude National Park (23.14 km²) along the north shore of Grande Comore, Mohéli National Park (643.62 km²) around Mohéli, and Shisiwani National Park (64.97 km²) around Anjouan's Sima Peninsula.

Politics

The Comoro Archipelago is divided between: * The Union of the Comoros, a sovereign nation formed by the three islands of Grande Comore, Anjouan and Mohéli. *

, an

of the French Republic (''département d'outre-mer''). This island is also claimed by the Union of the Comoros according to Article 1 of its Constitution. Mayotte became a French Department on 31 March 2011. The United Nations General Assembly continued to condemn the French presence in Mayotte until 1994. France, however, used its power of veto in the UN to prevent the Security Council from passing a resolution condemning France. The

judged the French presence on Mayotte to be illegal.# ↑ document de l'Union africaine rchive/ref> The Comoros underwent a political crisis that started off in 1997 with the separatism on Anjouan. The political authorities on the island had turned the population of the island against the central government, advocating at first reunification with France, and later a greater autonomy bordering on independence. Since 2006, the former president of the Union of the Comoros, Ahmed Abdallah Sambi, who is originally from the island of Anjouan, has been in open conflict with the authorities of Anjouan, a conflict which ended in a landing of the National Army of Development in order to re-establish the authority of the Union on the island.

Geography

History

Geology

Climate

Terrestrial ecology

Flora

Fauna

Freshwater ecology

Marine ecology

Marine protected areas

Politics

See also

References

Further reading

Geology