The Great Barrier Reef, a wonder of the world created by nature, stretches along the northeastern coast of Australia for 2500 km. This is the largest reef on earth, formed by the life of tiny living creatures - coral polyps. Spread over a vast area of almost 345 thousand square kilometers, the Great Barrier Reef is a unique ecosystem, which is not like anywhere else in the world.
Reef formation history
Once the modern Australian mainland was part of Antarctica, and the water around it was too cold for coral to live. But about 65 million years ago, dramatic changes took place on the world map: Australia broke away from Antarctica and began to shift to the north. The movement of the mainland to the tropics coincided with rising sea levels, creating ideal conditions for the growth and reproduction of corals.
Reef-forming corals can only exist in shallow water in salt water with temperatures not lower than 18 ° C, and the ideal temperature for coral growth is 22-27 ° C. That is why the Great Barrier Reef is limited in the south by the Tropic of Capricorn - it gets too cold beyond it. In the north, the coral islands end off the coast of New Guinea, where the Fly River flows into the ocean and desalinates the water.
The main backbone of the reef was formed on the territory that once served as a watershed for now flooded rivers. Scientists determine the age of the oldest parts of the reef at 400 thousand years, and the youngest reefs are built on the peaks of the oldest ones over the past 200 years. The main formation period of the Great Barrier Reef dates back to 8 thousand years ago.
The Great Barrier Reef consists of 2,900 individual reefs of various sizes, which are surrounded by barriers from many islands. Between the reef and the coast there is a huge lagoon with kilometer-long shoals.
Inhabitants of the coral islands
The Great Barrier Reef is included in the UNESCO World Heritage List and is part of the Marine National Park. This is due not only to the uniqueness of the object itself, but also to the fact that the reef is the largest ecosystem in the world, inhabited by amazing inhabitants of various species and forms.
The reef is made up of 400 species of coral in all colors of the rainbow, which are home to 1,500 species of fish. Of this number, 500 species of fish are exclusively reef, that is, they are adapted to life only in this part of the world.
It is here that humpback whales come from June to August in order to breed. The southern part of the reef serves as a breeding ground for sea turtles, all seven of which are endangered. The largest fish in the world lives here - the whale shark, which feeds only on plankton, and killer whales and dolphins hunt. A huge number of crustacean species: crabs, shrimps, lobsters, lobsters have found shelter in the coral thickets. In addition, huge bird colonies live on the reef.
The wonderful world of the Great Barrier Reef attracts tourists and divers from all over the planet. Employees of the Marine National Park have divided the territory of the reef into six zones, not all of which are accessible to tourists. This is due to the fact that the ecosystem of coral islands is extremely fragile and, in addition to anthropogenic impact, is endangered by tropical hurricanes, changes in temperature or salinity of sea water and starfish eating coral polyps.
