RUNOFF from recent floods in northern Australia (澳洲) is flowing onto parts of the Barrier Reef (大堡礁), starving coral of light and providing fodder for the crown-of-thorns starfish.
Parts of northern Queensland (昆士蘭省) are still reeling after nearly two weeks of unprecedented rainfall that turned roads into rivers and inundated hundreds of homes with floodwater.
Scientists at James Cook University say the floods swelled rivers along hundreds of kilometres of coastline, spilling sediment onto the reef, which has reduced water quality and much-needed sunlight.
“Coral reefs and seagrass need light to maintain their growth and health,” researcher Jane Waterhouse said, adding that the current calm weather means the murky water is yet to disperse.
It threatens to ‘smother’ coral in areas worst hit, like at the mouth of north Queensland’s Burdekin river, where a brown flood plume has spread some 100 kilometres offshore.
“If that were to stay there then eventually, it would not take that long for some of those systems to die off,” Waterhouse added.
The predatory crown-of-thorns starfish, which eat coral, have also proliferated on the reef due to pollution and agricultural runoff.
The recent floods have exacerbated the runoff, causing algae to grow in some areas, providing a food source to allow those populations to thrive.
(This article is published on Junior Standard on 25 February 2019)
Marine water quality in Hong Kong
Great Barrier Reef – Australia’s great natural wonder