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The Mozambique Channel
The Comoros close off the northern entrance to the Mozambique Channel, an arm of the sea about 400 km wide that separates Africa from Madagascar. Its waters are warm and crossed by eddies that bring nutrients up from the depths. This richness attracts tuna, dolphins, whales and seabirds, and makes the region one of the hotspots of marine biodiversity in the western Indian Ocean.
Young reefs and old reefs
Around Grande Comore, the recent volcanic coasts offer only narrow fringing reefs: the seabed drops quickly towards the abyss. On Mohéli and Anjouan, the reefs are more developed. In Mayotte, the oldest island, the corals have built a true lagoon of about 1,100 km², enclosed by a barrier reef more than 150 km long and doubled, in the south-west, by a rare double barrier.
The great visitors of the ocean
- Humpback whales: from July to October, they come to mate and give birth in the warm waters of the archipelago.
- Green and hawksbill turtles: they nest on many beaches, especially on Mohéli and in Mayotte.
- Dugongs: these herbivorous mammals survive in very small numbers in the lagoon of Mayotte.
- Coelacanths: these “living fossil” fish live in caves on the volcanic slopes, between 150 and 250 m deep.
Protecting the sea
Several marine protected areas have been created: Mohéli National Park, the first marine park in the Comoros, Coelacanth National Park off Grande Comore and the Mayotte Marine Nature Park, which covers the island's entire economic zone. They often involve fishermen in managing resources.
