The Pride of Australia: The Great Barrier Reef

As the world’s largest coral reef, there is no doubt that the Great Barrier Reef of Australia has earned its place as one of the seven wonders of the natural world. This reef system, which is important for world ecology and the Australian economy, is actually made up of over 2,900 individual reefs in an area that is greater than 300,000 square kilometers. Visible from earth’s orbit, the Great Barrier Reef is unfortunately under severe threat from pollution and other human activities. Only a concerted effort by Australians and other countries around the world will be able to preserve this wonder of nature.

Like other reefs, the Great Barrier Reef owes its existence to circular animals called coral that can live individually or, more commonly, in colonies. These creatures form limestone shells for themselves out of calcium carbonate, creating the physical structure of the reef. Over time, a coral reef grows increasingly larger as corals die, and leave their shells behind. New coral attach themselves to these existing shells and form their own new shells, increasing the surface area of the reef. A reef that has a lagoon of seawater between it and the shoreline is known as a barrier reef, hence the name the Great Barrier Reef.

Coral reefs serve the needs of the entire world, and the Great Barrier Reef is no exception. It helps keep the carbon dioxide levels of the Pacific Ocean constant because corals extract the chemical from the water to produce their shells. Australia’s reef also slows waves and strong currents from the ocean before they reach the shore, protecting the continent from more severe erosion and other problems.

The Great Barrier Reef is a shelter for many different species of fish and other sea creatures. In fact, there are 4,000 species of mollusks, including the giant clam, cowrie, octopus, and others who depend on the reef. The yellow burrowing sponge and thick yellow fan sponge are just two of the 400 species of sponges on and around the Great Barrier Reef. The crown-of-thorns starfish provides a natural population control for the coral as it eats the polyps from the 360 species of hard coral on the reef and surrounding area. Six of the seven species of sea turtles, including green turtles, can also be found near the reef. All sixteen species of sea snakes on the reef are venomous, and the commonly seen olive sea snake is no exception to this rule. Humpback whales use the reef for a breeding ground. This tremendous diversity of life, which also includes 1,500 species of fish — ten percent of the entire world’s fish species — make it one of the world’s most mature ecosystems. One million people visit the reef annually to view the fish species like angelfish, damselfish, gobies, as well as the rest of its animal life, and to otherwise enjoy this natural wonder.

Over the years, however, human activity has taken a great toll on the reef itself. Ship anchors have done their damage, as have fishermen trawling for shrimp and prawns, tearing up the seafloor with their equipment. Visitors walking on the reef have also broken off coral in some of the reef’s weaker spots. Still, one of the most significant threats to the reef is chemical pollution, especially runoff from nitrogen and phosphate-based fertilizers that rivers carry into the ocean. These manmade disasters have had a particularly great impact on the Great Barrier Reef’s loggerhead turtle population, which has declined between 70 and 90 percent in the last 30 years alone. Pesticides have impacted many of the mammals that also live in and around the reef, with the population of Dugong declining dramatically in the past forty years. Global warming is thought to be the cause of severe coral bleaching. Normally, coral lives in a symbiotic relationship with tiny protozoa, which provide much of the coral’s nutrients and pigmentation. The sudden death or expulsion of these protozoa causes a loss of coloring for the coral, which results in a bleaching effect. Entire sections of the reef can die off when bleaching occurs.

In addition to its importance for world ecology, tourism related to the Great Barrier Reef generates 6 billion dollars each year for the nation and provides 63,000 jobs. Because of its ecological and economic importance, there is a concerted effort underway to preserve and protect the reef and all of its native species. If this effort is not successful, then there could be drastic consequences for the world economy and environment.

To learn more about the Great Barrier Reef and find out what you can do to help preserve it, please visit:

• Australian Culture: Great Barrier Reef — An Australian Government Culture Portal page on the Great Barrier Reef can be found here.

• Coral Reef Connections — Here is an interactive page that highlights native coral species and other information about the Great Barrier Reef.

• Encyclopedia of Earth — On this site, users can find an in-depth article about the Great Barrier Reef World Heritage Area.

• Great Barrier Reef Foundation — Follow this link to the homepage for a foundation dedicated to saving the Great Barrier Reef.

• Great Barrier Reef Gallery — Here is a collection of pictures from the Great Barrier Reef.

• Great Barrier Reef Marine Park Authority — This is the official Australian government website for the Great Barrier Reef Marine Park Authority.

• Human Impact on the Reef — The impact of humanity on the Great Barrier Reef is measured on this site from the University of Michigan.

• Pressure on the Great Barrier Reef — This page details the decline of certain animal species that depend upon the Great Barrier Reef.

• Rainforests of the Sea — Coral reefs are critically important to the ocean’s health and well-being, as this site on different reef types explains.

• Seven Natural Wonders: Great Barrier Reef — This page from a grassroots environmental organization has some basic facts on the Great Barrier Reef

• UNESCO: Great Barrier Reef — The United Nations Educational, Scientific and Cultural Organization has put together this website on the Great Barrier Reef.

• USGS: Coral Reefs — The U.S. Geological Survey sponsors this page on coral reefs in the Pacific ocean, and it includes an image of the Great Barrier Reef.

• Virtual World Great Barrier Reef — On this page from National Geographic, there is an interactive model about the Great Barrier Roof that allows users to get “hands-on” information about the reef.

• Visible Earth — Here is a NASA website with information on the Great Barrier Reef as well as satellite pictures of it.

• WWF: Great Barrier Reef — This page on the Great Barrier Reef from the World Wildlife Federation explains the species variation of the reef and gives tips for helping to preserve it.