20 Wonderous Coral Reef Facts

By Karin Lehnardt, Senior Writer

Published December 8, 2019

Corals are not plants. They are relatives of jellyfish and anemones._[4]
Coral reefs are the most diverse marine ecosystems on earth and have existed for over 400 million years._[4]
There are three types of reefs: barrier reefs, fringing reefs, and atolls. Atolls are often mistaken for islands, but they are actually reefs._[4]
Nicknamed the Earth's medicine cabinet, coral reefs have led to the creation of many medicines, including antiviral drugs Ara-A and AZT, and the anticancer agent Ara-C. Other medical compounds could still be discovered there._[4]
The Great Barrier Reef is one of the largest living things on the planet, and it can even be seen from outer space._[3]

The Great Barrier Reef can be seen from space

Because they are so diverse, coral reefs have been nicknamed the "rainforests of the sea."_[3]
Over 70% of the world's reefs have been threatened or destroyed by shoreline development, runoff, physical damage, over-harvesting of fish, destructive fishing techniques, diseases, and warmer seawater temperature._[3]
Coral reefs cover less than 1% of the ocean but are home to 25% of all marine species._[4]

Coral reefs teem with life

Scientists estimate that at current rates of decline, most of the world's coral reefs will be completely destroyed in the next few decades._[4]
Over 80% of the world's shallow coral reefs are overfished._[4]
Tropical coral reefs border around 109 countries. However, dramatic reef degradation has occurred in 93 of these countries._[2]
Only about 1% of the world's oceans contain coral reefs. This is about the size of France._[4]

At night, coral polyps emerge from their skeletons to feed. They stretch their long, stinging tentacles to catch small animals, such as zooplankton, as they float by

Coral reefs are animals, which means that, unlike plants, they are unable to make their own food. At night, the polyps extend their tentacles to sting and ingest tiny organisms called plankton and other small creatures._[3]
The Great Barrier Reef is made from billions of tiny organisms known as coral polyps._[1]
Over 2 million people visit the Great Barrier Reef each year._[3]
There are over 2,500 kinds of corals. An estimated 1,000 are the hard corals that build coral reefs._[4]
Abandoned fishing nets (ghost nets) can entangle and kill reef organisms and break and damage reefs._[4]
Coral reefs have an annual global economic value of $375 billion. They also provide food for over 500 million people in 94 countries and territories._[5]
Coral reefs help protect coastal communities from storm surges and erosion._[5]
Coral reefs provide millions of jobs to local people through tourism, recreational activities, and fishing._[5]