Elkhorn coral

엘크혼산호

A Caribbean coral with broad, branching arms like elk antlers, growing in shallow, wave-swept water. It once dominated the region's reefs but has crashed because of disease and warming seas, and is critically endangered.

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At a glance

Class: Jellyfish & corals
Conservation status: Critically Endangered (IUCN CR)
Habitat: coral reefs

Quick answers

Where does the Elkhorn coral live?

It lives in coral reefs of the Atlantic Ocean.

Is the Elkhorn coral endangered?

It is listed as Critically Endangered (IUCN CR).

Elkhorn coral is an important reef-building coral of the Caribbean. It grows broad, flat, branching arms that look like elk antlers, which is how it got its name. The structure is hard calcium carbonate and can be over 2 metres high and 13 metres wide, in a dull brownish-yellow colour.

Its branches make shelter for many other reef animals. It grows quickly for a coral, about 5 to 10 cm a year, and prefers shallow, wave-swept water where sunlight is strong. Healthy elkhorn reefs also protect shores by breaking waves, which is one more reason people want to bring them back.

How does a coral eat?

Elkhorn coral gets most of its food from tiny algae called zooxanthellae that live inside its cells and make sugar from sunlight. In return, the coral gives the algae a home. That is why it needs clear, sunny water.

If the algae are lost during bleaching or the water turns cloudy, it can also filter food from the water.

A crash in numbers

In the early 1980s elkhorn coral dominated Caribbean reefs. Between 1980 and 2006 its population fell by about 97 percent because of disease, algae growth, climate change, ocean acidification and human activity. It was listed as threatened under the US Endangered Species Act in 2006.

After a marine heatwave in 2023 it is considered functionally extinct on Florida's coral reef. The IUCN lists it as critically endangered. People are now working to protect it and to boost its genetic variety.