A 100-kilometre coral reef might sound hard to miss. But that is exactly what has just been discovered off Australia鈥檚 northern coast, extending westward from Mornington Island in the Gulf of Carpentaria.
It has been missed till now because it lies a long way from shipping routes and population centres. Remote-sensing satellites can spot reefs if they are less than 20 metres below the surface, but deeper ones are hard to find unless ships survey the area with suitable instruments, says Arthur Dahl, director of the UN Environment Programme鈥檚 coral reef unit in Geneva. The new reef is in 20 to 30 metres of water.
Until two years ago, only fringing reefs and isolated coral colonies were known in the shallow gulf. Then a survey ship carrying researchers from the national research agency Geoscience Australia found patch reefs covering 80 square kilometres at depths of 30 metres, now followed by the long platform reef. The reefs flourished from about 110,000 to 40,000 years ago, when sea levels were typically 30 to 50 metres lower than today, survey leader Peter Harris told New 杏吧原创. 鈥淐oral growth has been sluggish in the last 10,000 years.鈥�
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