The Great Barrier Reef, blessed with its breathtaking beauty, is one of the most remarkable natural gifts of Australia. Considered as one of the seven wonders of the natural world, it is larger than the Great Walls of China and the only living thing on earth, which is visible from the space. It is the largest coral reef in the world, stretched down the Queensland coast for over 2000 km and is made up of 300 coral cays and 2,900 coral reefs and consists of 600 continental islands and 150 inshore mangrove islands.
Coral reefs are formed by little creatures, called Corals. The corals on the reef dates back to around 18 million years. There are nearly 400 types of coral in the reef and they excrete calcium, which forms the limestone skeleton on which they live and which we call coral reef.
As these limestone skeletons or coral reefs erode, the tiny particles are swept away by moving water and are deposited, as and when the water stops moving. Gradually, the deposited sand-like small particles build up a ‘Cay’, which can be termed as a desert island. Eventually soil and vegetation develop on the cay’s surface, assisted by seabirds as they start to nest and deposit their excrement. In fact, Cays are ideal places for the turtles and birds, as they provide a safe place to lay eggs.
The Great Barrier Reef in Australia is situated along the Australian continental shelf with the channel between the coastline and the reef, with a depth of about 60m. Since it is an outer reef, it is called the ‘Barrier Reef’. There is another type of reef, which lies along the coastline of land and islands, which is a ‘Fringe’ reef. The 2000 km long Great Barrier Reef is not a single reef, it is actually made up of more than 2900 different reefs. Just from the south of the Tropic of Capricorn, it stretches along the Queensland coastline - from just north of Bundaberg to the far north Queensland and the Torres Strait.
The Great Barrier Reef supports a wide diversity of life and a large part of it is protected by the Great Barrier Reef Marine Park. Apart from the vibrant corals, seventeen species of sea snake, six species of sea turtles, saltwater crocodiles and large populations of marine mammals called dugongs, more than 1,500 fish species live on the reef, which include the clownfish, red bass, red-throat emperor, and several species of snapper and coral trout. The Great Barrier Reef is also the home of 215 species of birds, including 22 species of seabirds and 32 species of shorebirds.
Selected as a World Heritage Site in 1981, the reef is a very popular destination for the tourists, where one can enjoy many experiences including snorkeling, scuba diving bare boats, glass-bottomed boat viewing, semi-submersibles and educational trips, cruise ship tours, whale watching and swimming with the dolphins. Exploring the stunning Whitsunday Islands, trekking the ancient Daintree Rainforest or relaxing on luxurious tropical islands, such as Hayman and Lizard bring extraordinary experience in life.
However, global warming and the climate change are perhaps the biggest threat to the Great Barrier Reef, as warmer ocean temperatures put stress on the corals and lead to coral bleaching.