Q#1

What are coral reefs?

Coral reefs are large underwater structures composed of the skeletons of colonial marine invertebrates called coral. 

Each individual coral is referred to as a polyp. Coral polyps live on the calcium carbonate exoskeletons of their ancestors, adding their own exoskeleton to the existing coral structure. As the centuries pass, the coral reef gradually grows, one tiny exoskeleton at a time, until they become massive features of the marine environment.

Corals are found all over the world's oceans, from the Aleutian Islands off the coast of Alaska to the warm tropical waters of the Caribbean Sea. The biggest coral reefs are found in the clear, shallow waters of the tropics and subtropics. The largest of these coral reef systems, the Great Barrier Reef in Australia, is more than 1,500 miles long (2,400 kilometers).

Q#2

Are the coral reefs in danger?

Coral reefs are critical marine habitat on which many ocean species depend. Additionally, coral reefs provide an estimated $30 billion annually in direct economic benefit to people worldwide though food, fisheries and tourism, according to the Hopkins Marine Station of Stanford University.

But coral reefs are imperiled by several threats.

The increasing acidification of the ocean — caused when oceans absorb immense amounts of carbon dioxide released into the atmosphere through the burning of fossil fuels — inhibits coral's ability to produce the calcium carbonate exoskeletons they rely on for shelter.

Water pollution, too, is wreaking havoc on coral reefs. Agricultural pesticides and fertilizers, oil and gasoline, sewage discharge and sediment from eroded landscapes make it difficult for coral to thrive, and therefore damage the complex relationships that exist among the plants, coral and other animals that are part of the reef ecosystem.

As the temperatures of the world's oceans increase due to global warming, coral polyps expel the zooxanthellae they depend on for food. Once the zooxanthellae are gone, the coral loses its brilliant color, and all that can be seen is the white exoskeleton; this is referred to as coral bleaching. Coral colonies subject to bleaching usually die off, according to CORAL.

Fishing practices such as cyanide fishing (spraying cyanide in the water stuns the fish to make them easier to catch), "blast fishing" with explosives and overfishing with trawlers can destroy a thousand-year-old coral reef in a matter of minutes.

"Overfishing, ocean acidification and pollution are pushing coral reefs into oblivion," Roger Bradbury, an ecologist at the Australian National University in Canberra, wrote in his New York Times opinion article. "Each of those forces alone is fully capable of causing the global collapse of coral reefs; together, they assure it."

Summary

By working together we can help save the coral reefs. Don’t stand by idly and let this important part of our world wither and die. Take action now by donating to causes that help save the coral reefs!