SCIENTISTS are scratching their heads to figure out an explanation for a mysterious fish plague which has led to the deaths of millions of pilchards along Australia's eastern coastline. Australia's pilchard fish industry earns the US $7.4 million annually; but the plague threatens to disrupt salmon and tuna exports (worth US $29.6 million per year), since pilchards are used as baits for these fish catches.

The Department of Primary Industries and Energy and the Commonwealth Scientific and Industrial Research Organisation have set up a task force to determine the cause of the disease. Scientists across the country have reached conflicting conclusions on what has been described as "the biggest ever marine science story in Australia". The disease -- which affects adult pilchards only -- chokes the fish by building up mucus in their gills. While Tasmanian scientists have identified an amoeba which could be the reason behind the fatalities, researchers in Victoria claim that a mucus-generating algae bloom was the probable cause.