Toxic runoff poses risk to Reef

By Leigh Dayton
February 17, 2007 12:00am

SATELLITE images of flooding in the Top End have revealed that runoff from the land is a greater threat to the Great Barrier Reef than experts believed.

Until now, most scientists thought the sediment and pollutants that washed into coastal waters after torrential rain slowly dispersed along the coastline, affecting only coral living on the inner reef.

However, a group headed by remote sensing expert Arnold Dekker of CSIRO Land and Water claimed the images clearly showed that potentially polluting plumes of water quickly travel to the outer regions of the reef, putting coral at risk.

"I was surprised and impressed," Dr Dekker said, recalling his first look at the pictures.

"I knew we had something that needed to be known broadly."

"What these images are showing is that significant rainfall is causing substantial flows into the rivers, estuaries and into the lagoon (between the coast and the Great Barrier Reef).

"The material is going - within days - right out to the outer reef and beyond."

The telltale images were taken between the 9th and 13th of February by the Moderate Resolution Imaging Spectroradiometer.
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