Coral reefs are natural tourist attractions found in some of the most beautiful vacation spots on earth. However, these reefs offer much greater benefit than simply their tourism value. The problem is, their existence is being threatened.

What is coral?

Coral reefs are underwater formations composed of calcium carbonate (CaCO3). The calcium carbonate is released from an individual coral colony, which is a living organism comprised of genetically identical polyps. Polyps reproduce asexually to form individual heads of coral.

Did you know? According to the U.S. Coral Reef Task Force (CRTF), coral reefs are one of the most diverse and biologically intricate ecosystems on earth and support 33 percent of marine fish species.

The hard calcium carbonate skeleton secreted by each immobile polyp serves as a protective base for the colony. The calcium carbonate is continuously deposited so the size and structure of coral reefs are always increasing. This is a slow process occurring over a long period of time.

Most reefs are formed in warm climate areas in the Indo-Pacific region, Southeast Asia, the Pacific, the Atlantic, and the Caribbean.

Did you know? The majority of coral reefs on earth were formed after the last glacial period, between 110,000 and 10,000 years ago.

Coral's contribution to underwater life

In addition to contributing to the local economies by attracting tourists, coral reefs supply essential food and shelter to an array of underwater species.Coral reefs are sensitive to changes in the water conditions, especially pH, which makes coral reefs excellent environmental monitors. Coral reefs protect coastlines from ocean storms and floods, and their biodiversity makes them potential sources for new medicinal ingredients.

The coral crisis

Coral reefs around the world are threatened with extinction. Most threats to reefs are from human activities such as global warming and air pollution. The ocean is one of the world’s biggest carbon dioxide (CO2) absorbers. Excess absorption of CO2 changes the water chemistry and actually breaks apart coral. This is called ocean acidification.

When coral reefs are threatened, many fish and invertebrate sea creatures lose their home and risk going extinct. The coral algae will stop growing on the corals resulting in the coral losing its source of food (the algae) and subsequently losing its color. This effect is called coral bleaching, which decreases the growth and reproduction of corals, making the problem worse. Rising sea levels, as a result of global warming, can also have a negative impact because the deeper water inhibits sunlight from reaching the reefs. Coral reefs depend on warm, shallow water and sunlight to survive. This video explains the coral crisis in greater detail.

Did you know? The U.S. Coral Reef Task Force(CRTF) estimates that 70 percent of the earth’s coral reefs have been threatened or completely destroyed by human activities and sudden climate changes.

Reef Relief: What you can do

· Don’t break off coral reefs when SCUBA diving and snorkeling.

· Get involved in coral reef clean-ups and global warming awareness groups.

· Support organizations that work to protect coral reefs.

· Reduce carbon emissions by taking the bus or riding your bike.

· Don’t waste electricity! Turn off lights when you are not in the room.

· Share this information with your friends!

Learn more!

WWF Impacts of global warming on corals

Reefbase: A global information system on coral reefs


United States Environmental Protection Agency - Coral

ARC Center of Excellence for Coral Reef Studies

First published July 19, 2011

Photo Credit:National Oceanic and Atmospheric Administration (NOAA) photo library, courtesy of NASA Earth Observatory

Sherry Boodram

Sherry is a graduate student in the Department of Chemistry at York University.  Her research focuses on protein structure determination and biomolecular interactions. Previously she attended the University of Toronto as an undergraduate student where she studied Biological Chemistry.  

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