Great Barrier Reef in danger
THE Great Barrier Reef''s inshore coral and seagrass meadows are choking under a blanket of mud laced with toxic pesticides being washed off farmlands and many reefs are unlikely to survive the next five to ten years.
A World Wide Fund for Nature (WWF)report on Australia''s Great Barrier Reef released on Tuesday says increasing land-based pollution,coupled with bleaching due to global warming,was seriously threatening the world''s largest coral reef formation.
The Great Barrier Reef is the world''s largest living reef formation stretching 2,000km north to south along Australia''s northeast coast.
WWF said 28million tonnes of sediment flowed into the waters of the Great Barrier Reef each year,the equivalent of 3.5million dump trucks emptying soil onto the reef.
Farms with some 4.9million cattle were depositing 18million tonnes of sediment a year.Sugar cane farms which dot the coast resulted in another 1.3million tonnes.
WWF said thousands of tonnes of nitrogen and phosphorous from fertilizers,used on cane,banana and cotton farms,were being washed into the sea and poisoning marine life.
In 1994an estimated 8,800tonnes of nitrogen and 1,300tonnes of phosphorous was washed into the sea around the reef.Pesticides diuron,atrazine and ametryn,used to fight weeds,rats and diseases,were also found in coastal sugar cane areas.
But at the same time up to 80per cent of freshwater wetlands,which act as filters protecting the reef from pollution run-off,have been lost due to cane growing and coastal development.
Excessive nutrient from run-off has led to massive growth of unwanted organism,like blue-green algae,and nitrate fertilizer are causing reproduction problems for coral larvae.
Toxic dioxin was also found in sediment and estuaries from Cardwell south to Brisbane and in some endangered dugongs.But it was unclear the source of the dioxin.
WWF called for a stop to land clearing of the Great Barrier Reef catchment and for farming practices to change.