This Little Corner of the Ocean: Coral Reefs

Coral reefs are often called the “rainforests of the sea” because they support about 25% of all known marine species. The variety of species living on coral reefs is greater than almost anywhere in the world. Scientists estimate that more than one million plant and animal species are associated with the coral reef system.  However, just like rainforests, coral reefs are severely threatened and dying off at an alarming rate.  More than a quarter of the world’s coral reefs have been destroyed by pollution and global warming and unless drastic measures are taken, scientists estimate that most of the remaining reefs may be dead in the next 20 years.  In some areas of the Indian Ocean, over 90% of the coral reefs have been killed due to warmer water temperatures.  Global warming, destructive fishing practices, pollution and habitat destruction are all threats to coral reefs. Without coral reefs, many marine life species would become extinct. 

Corals are marine animals related to sea jellies; there are soft and hard corals. Soft corals are treelike and flexible while the hard corals form coral reefs.  Coral reefs are made up of millions of coral polyps and help other creatures, marine plants, and fish survive.  Corals can only survive under certain conditions in marine waters that are shallow, warm and stable. Coral reefs not only support lots of marine life, but they also help protect shores from the impact of waves and storms and provide millions of humans with food.  The destruction of coral reefs is leading to the extinction and endangerment of thousands of other species. 

One of the biggest threats to coral reefs is global warming and climate change.  As ocean temperatures increase, corals lose their symbiotic microalgae they need to survive. When they lose their zooxanthellae, they bleach and become white in color, lose their nutrients and often die.  A change in their ocean environment also makes corals more susceptible to diseases as well as oceans are becoming more acidic. As the water acidity rises, it is harder and harder for coral skeletons to form and grow.  Scientists estimate that the oceans could become 150 percent more acidic by the end of this century, making it very hard for corals to grow at all.  Corals are also being threatened by humans with pollution from sewage, agriculture, destructive fishing practices, overfishing, and habitat destruction.  Wildlife trade is also a severe threat as fish, corals, and various invertebrates are all taken from reef habitats to serve as aquarium pets or decorative items. Wildlife populations are often overexploited to feed the demand for these animals. Taking species away from coral reefs is also causing an increase in natural coral predators, which are destroying reefs at an alarming rate. Since corals only grow at a rate of about two inches a year, large reefs can never be replaced.  Fertilizer runoff, pesticides and other chemicals from land can poison our coral reefs.

Coral reefs are headed towards extinction and without them many other marine life species will go extinct. In order to help coral reefs there are many things we can do.  Recycle, participate in beach cleanups and pick up the trash you see on the streets so that it doesn’t get washed into our oceans. Keep our habitats clean and if you are near coral reefs, avoid touching them as human contact can kill them.  If you are a diver, never stand on coral reefs or drop a boat anchor on/or near the reefs. If you are a seafood eater, only eat sustainable seafood.  Use less energy by walking, riding a bike, and using energy efficient light bulbs or unplugging appliances not being used.  Also, conserve water, because the less water you use, the less runoff and wastewater will end up in our oceans. People, plants and animals are all interconnected and together we can help our coral reef communities survive and thrive.

Written by: Stefanie

**The photos were used with permission from owner.