Most alarming is the precipitous drop in the number of dugongs, marine mammals also known as sea cows. WWF will release a report this week showing that 16 per cent of the dugongs died from disease and more than half from unknown causes. Many scientists are linking the decline to the destruction of their main food source, sea grass. The WWF report says 38 million tonnes of sediment are released on to the reef each year, and about 70 per cent of freshwater coastal wetlands in the northern 'wet tropics' region have already been lost. The reef is also being eroded by an outbreak of the crown of thorns starfish and there is evidence to link that, too, with polluted run-off from the land.
Farmers say they are reducing sediment run-off and chemical pollution.
If stronger action is not taken to further reduce run-off of sediment, nutrients and biocides, the present precarious situation for these habitats will worsen, perhaps catastrophically,' he said.