Coral reefs are a type of marine ecosystem formed by large colonies of coral polyps and limestone. These are called the ‘rainforest of the sea’ as it provides the habitat for more than 25% of all marine species. Coral reefs should be protected and conserved in order to maintain the biodiversity of the marine ecosystem, to provide jobs and businesses for people, and to protect coastal areas.

Coral reefs are very delicate animals as they only form in areas that satisfy all their strict conditions. They need tropical sea conditions with warm water and therefore are only distributed between the tropic of Cancer and the tropic of Capricorn, within 30° near the equator. The most preferred temperatures are over 18°C, and the temperature has to be maintained all year round. Also, coral reefs only form at shallow depths, less than 50 metres deep. If the ocean gets deeper beyond 50 metres, algae are not present due to lack of sunlight and the water temperature gets lower. Due to its strict conditions for formation, it covers less than 1% of the ocean floor but is a home for over 25% of marine species. Thus, coral reefs play a very significant role in maintaining biodiversity in the ocean as they provide abundant food supply and shelter for marine life. Also, the oxygen content of the ocean is maintained as a massive volume of oxygen is produced by algae in coral reefs. This allows marine life to sustain their lives. Coral reefs also act as highly effective coastal protection as they can reduce up to 95% of wave energy and prevent the waves from causing damages in coastal areas. Over 500 million people rely their income on those coral reefs through businesses such as fisheries or tourism, which make them very valuable. The reefs are estimated to have a global value of over £6 trillion.

Currently, coral reefs are facing the risk of death due to the increase in ocean temperature and ocean acidification. Algae, which have a symbiotic relationship with corals reefs leave their habitat when the water gets warmer. Without the algae that provide food for the corals, they face ‘coral bleaching’, start to lose their colour, and die as they cannot regain the algae until the ocean becomes cooler. The Great Barrier Reef of Australia, which is the world’s largest coral reef system has lost over half of its coral since 1995 as it has faced mass coral bleaching due to the sudden increase in ocean temperature. Also, the rise of carbon dioxide level of ocean water leads to its acidification. As the water gets more acidic, the availability of calcium carbonate which is needed for the corals to form reefs gets reduced, and it becomes more challenging for large coral reefs to form. There is also a chance that the coral reefs will start dissolving if the water becomes too acidic in the future.

Conservation of these coral reefs is very important to maintain the oxygen content and the biodiversity of marine ecosystems. Protection of the reefs is also needed to preserve the source of income for many people who depend on the reefs. The most important thing to do is to reduce greenhouse gas emissions which cause global warming. In the long term, a decrease in the rate of global warming would stop the rise of ocean temperatures, slow down the speed of coral bleaching and give time for bleached corals to recover. Members of the global society should try to promote more eco-friendly transportations which do not emit greenhouse gases in our everyday lives to stop global warming. Commonly known methods of conservation such as recycling and reusing items are also essential since it can reduce the toxic gases released during the combustion of different materials. Also, while enjoying marine activities, tourists should be careful not to touch and damage the coral reefs.

Coral reefs, the ‘rainforest of the sea’, is an essential part of the marine ecosystem as it provides a home for more than 25% of marine life and contributes to maintaining biodiversity. They also provide various jobs and businesses to society and protect coastal areas. If global warming continues to happen, coral reefs will face difficulties in their survival. Humans should take action to stop pollution and global warming to conserve coral reefs and the marine ecosystem.


Mina Yoon
Mina Yoon

Student of NLCS Jeju
Chair of NLCS Jeju Conservation Society

Hannah Hoyeon Lee
Hannah Hoyeon Lee

Student of NLCS Jeju
Member of NLCS Jeju Conservation Society


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