Coral Reefs

By Jasmine Risser and Savanah Agape

Animals That Live Nowhere Else

Published in 2013

Coral reefs have a variety of species living on coral reefs, the variety is greater than almost anywhere else in the world. Coral reef ecosystems are like bustling cities, with buildings made of coral and thousands of marine occupants coming and going, interacting with one another, doing their business. Because of this, coral reefs are the sea's major city. Coral reefs provide shelter for nearly one quarter of all known marine species. And over the last 240 million years, reefs have changed into one of the largest and most complicated ecosystems on the planet. The reefs are home to more than 4,000 types of fish, 700 species of coral, and thousands of other plant and animal life. Scientists estimate that, in total, more than one million species of plants and animals are joined with the coral reef ecosystem.

Coral Bleaching

Published in 2013

Increased water temperatures, which may be linked to global warming, can cause massive coral bleaching. This happens when coral polyps, stressed by heat or ultraviolet radiation, expel the algae that live inside them. These algae, called zooxanthellae (zo-zan-THEL-ee) usually provide the coral with up to 80% of its energy, making zooxanthellae essential for coral survival. The algae are also usually responsible for the color of coral, so when they are gone, the coral appears white or "bleached." There is a slight chance that bleached coral can recover if conditions return to normal quickly enough. However, if the coral is exposed long enough to other human-induced pressures, corals can become vulnerable. Most of the time, bleached coral colonies die.

Water Pollution
Published 2013

One of the leading causes of coral reef dangers is water pollution. Oil, animal waste, fertilizer, gas, and pesticides poison the coral and marine life. These examples carry pollutants to reef waters which then increase the level of nitrogen. The nitrogen around coral reefs causes an overgrowth of algae. It then smothers the coral reefs by cutting off their sunlight. Trash also destroys coral reef and marine life by being mistaken for food and eat them. For example, turtle's will mistake plastic bags for jellyfish and eat them which blocks the digestive system and causes them to starve to death.

Carbon Dioxide
Published 2013

Carbon Dioxide has increased in the air by one third in the past few decades. The carbon dioxide dissolves into the water and causes the skeletons of corals to dissolve. Large amounts of carbon dioxide form weaker skeletons which make them more vulnerable to damage from waves, tourists, and fishers.

Published 2013

Construction along coasts, inshore construction, mining, and logging can all lead to erosion. When this happens, particles end up in the ocean and cover coral reefs. This 'smothers' coral and deprives it of the light it needs to survive. Mangrove trees and seagrasses, which normally act as filters for sediment, are also being rapidly destroyed. This all has led to an increase in the amount of sediment reaching coral reefs.

Careless Tourism

Published in 2013

Wastes kept in very poorly maintained septic tanks can leak into surrounding ground water, which then seeps out to the reefs. Careless diving, boating, fishing and snorkeling can also damage coral reefs. When people kick, grab, walk on, or stir up sediment in the reefs, they help to contribute to coral reef destruction. Corals are also killed or harmed when people drop anchors on them or when people collect coral for their own uses.

Coral Reefs Protect the Beaches

Published in 2013

Without coral reefs, many beaches and buildings would become vulnerable to waves and storm damages. Reefs serve as a buffer, protecting in-shore areas from brutal ocean waves. In the tsunami of December 2004, some coastlines were spared slightly as a result of healthy coral reefs. In another instance, when coral and sand was mined away in the Maldives, it cost $10 million per kilometer to build a wall to protect their coastline (Wilkinson, C. and F. Talbot, 2001, Coral Reefs, Mangroves and Seagrasses: A Sourcebook for Managers).

Coral reefs benefit a healthy world by providing:

Published in 2013

Habitat: Home to more than 1 million diverse aquatic species, including thousands of fish species.
Billions of dollars and millions of jobs in more than 100 countries around the world.
Food: For commercial fishing enterprises and for people living near coral reefs, especially on small islands.
Protection: A natural barrier protecting coastal cities, communities, and beaches.
Medicine: Potential treatments for many of the world's most dangerous illnesses and diseases including some types of cancer.