Australia's environmentally sensitive Great Barrier Reef is under threat from the toxic and polluting waters swept into the sea by the devastating floods, according to marine experts.
Pesticide-containing floodwaters and sediments have seeped into the ocean as far as Keppel Island Group, south of the reef and around 40km away from the coastline
Water is being spilled out into this region by the overflowing Fitzroy and Burnett rivers in Queensland state, which is struggling under the impact of the floods.
The World Wild Life Fund said in a statement: "Toxic pollution from flooded farms and towns along the Queensland coast will have a disastrous impact on the Great Barrier Reefs corals and will likely have a significant impact on dugongs, turtles and other marine life."
The 345,000 square km Great Barrier Reef, a World Heritage listed site, is home to thousands of marine species including corals and fish.
It is extremely sensitive to environmental changes and the corals can easily be damaged or stressed by changes in temperature, salinity, nutrients and sediment levels.
The threat of bleaching, which happens when corals die and leave behind their white outer skeleton, is becoming a major concern.
Andrew Skeats, general manager of the Great Barrier Reef Marine Park Authority, said: "It's fair to say the floods are not good news for the coral reef."