Things to know about coral reefs around the world

Corals are marine animals that exist in the form of small polyps resembling sea anemones, often living in colonies consisting of many identical individuals.

On April 15, the US National Oceanic and Atmospheric Administration (NOAA) warned that the world is experiencing the second largest coral bleaching episode in the past 10 years, in which the coral reef system stretches from Australia to Florida (USA) are on the brink of disaster after months of record heat in the ocean.

The current bleaching episode is the fourth on record, following previous episodes in 1998, 2010 and 2016.

Expert Derek Manzello working at NOAA said: 'As the world's oceans continue to warm, coral bleaching is becoming more frequent and more severe. When these conditions become severe or prolonged, they can cause coral death, harming people who depend on coral reefs for their livelihoods.

Corals are marine animals that exist in the form of small polyps resembling sea anemones, often living in colonies consisting of many identical individuals.