Tropical coral reefs are the most diverse marine ecosystems on earth, giving shelter to thousands of animal species. Many millions of people depend on fisheries, tourism and coastal protection provided by healthy coral reefs. Yet today, coral reefs are dying at an alarming rate all around the globe.
Corals build the reef structure and provide the basis for a functioning coral reef ecosystem. Without corals, reefs will degrade and vanish within years. At present, coral reefs are facing multiple issues such as pollution, overfishing, and the ongoing climate change, which leads to raising sea water temperatures and causing coral bleaching worldwide. As a result, over 50% of the world’s coral reefs have died in the last 30 years and up to 90% may die within the next century.
The impact of our changing climate on coral reefs was manifested by the third global bleaching event in 2015 and 2016. This event has caused a mass destruction of corals, for instance, along the Great Barrier Reef. Unfortunately, there is a clear pattern of severe bleaching events increasing in frequency, to a point where there are now inadequate intervals for corals to recover in between.
A world without corals means not only will we have a less diverse and less beautiful ocean, but it will also be an economic disaster for many people, predominantly in developing countries. Fisheries and tourism provide important livelihoods that directly depend on healthy coral reefs. Reefs are nurseries for many fish species, including commercial ones, and attract millions of tourists every year. Coral reefs offer natural coastal protection, especially in areas frequently impacted by hurricanes and tropical storms. The great biodiversity of coral reefs serves as an important source for new medicinal remedies.
Altogether, coral reefs comprise an area of almost 300 000 km² and are estimated to have an economic value of US$100000 to 600000 per km², thus providing one of the most high-value ecosystems. Coral reefs are among the most complex ecosystems and are revealing the degraded status of coastal environments. Their alarming status represents the poor health of our oceans and if coral reefs disappear other marine realms will follow.
Corals have existed for more than 400 million years, yet stresses and changes from human activities are happening faster than their ability to adapt. Corals may not survive the intensity and swiftness of these ongoing changes. If we want to give coral reefs a fighting chance to survive and thrive for generations to come, we need active restoration measures to complement coral reef conservation.