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EDGE Corals

Welcome to the unique and diverse world of EDGE corals! Scleractinian, or stony corals are the building blocks of the world’s tropical reefs and the 3D structures they create are ideal homes for a quarter of all marine life.

They have evolved as part of the diverse Phylum Cnidaria and share similar characteristics with related taxa such as jellyfish, anemones and hydroids. Each scleractinian coral species has a symbiotic relationship with tiny single-celled algae called zooxanthellae which lives within its polyps. In return for a safe and stable environment zooxanthellae utilizes light from the sun to photosynthesize, providing up to 98% of the coral’s energy requirements and bringing life into the ocean. Thousands of coral polyps sit side by side, slowly excreting calcium carbonate to create intricate reef habitats of all shapes and sizes which are essential to supporting an incredibly high level of marine biodiversity.

The subsequent reefs that corals produce cover less than 0.1% of the world’s surface, yet are a hub of marine biodiversity. Such iconic tropical reefs typically flourish within a strict set of environmental boundaries, requiring shallow (<30m), warm (18oC – 30oC) and clear waters typical of those found between the Tropic of Cancer & the Tropic of Capricorn.

Despite such a high level of biodiversity, a healthy and undisturbed coral reef can cope with, and recover from, almost any natural disaster (including hurricanes, large storm events and natural fluctuations in water temperature). However, when we introduce the cost of sustaining a human population of over 7 billion people the subsequent detrimental effects, such as rising sea temperatures and overfishing, are being felt on all reefs around the world.

Coral reef conservation efforts around the world are focused on the reef ecosystem as a whole, but we know little to nothing about how individual sclearctinian coral species live and grow on a reef and cope with an ever changing marine environment. Even basic information such as growth rates, spawning times and how they cope with disease is unknown at a species level.

In 2011 the EDGE programme produced the EDGE Corals list which highlights the top 25 Evolutionary Distinct and Globally Endangered coral species and is working to address this gap in coral science through our EDGE Coral Fellows. Our Fellows have been conducting 2 year coral projects on reef systems around the world using species focused research to gather basic biological data, to educate local communities that corals are indeed animals and to provide evidence towards increased marine protection.

Click here to explore the Top EDGE Corals.

When creating our EDGE corals list, we follow the taxonomy of the IUCN Red List.