If all goes well, I’ll be visiting a tiny part of the immensity of the Great Barrier Reef within a few weeks. Such a huge number of fish, marine mammals, turtles, mollusks, and birds live in and around coral reefs that the reef is known as the rainforest of the sea.
Coral polyps – a few centimeters long
Great Barrier Reef – the world’s largest single structure made by living organisms (2,600 kilometers long)
“Coral cover” is the proportion of reef surface covered by live, stony coral. The Great Barrier Reef has lost more than half of it cover since 1985. Two-thirds of the loss occurred since 1998. The loss is attributed to a few different factors. One is increased water temperature from global warming.
Mass “coral bleaching” events have happened in 1998, 2002, and 2006. Coral bleaching occurs when high water temperature causes the coral polyps to eject an internal organism which weakens and can eventually kill the polyp. Another factor in coral decline is pollution via farm run-off. Run-off also helps boost the population of the crown-of-thorns starfish, which eats coral. Yet another factor is cyclones (hurricanes) which can cause a lot of damage.