CRYING RIVERS.

On January 30, an estimated 100,000 cubic meters of polluted mud and wastewater escaped from a break in the dam of the Baia Mare gold mine in Northwest Romania, and spilled into the adjacent Lapus River. From there, it swept through the Somes and the Tisza Rivers, crossed the border into Hungary, flowed into the Danube River, and crossed the border again into Yugoslavia. Little was left living in its path.

The wastewater from the Australian- and Romanian government-owned venture was a product of the extraction process in which cyanide is used to separate gold from tailings, or residues, left by other mining operations. By the time the near-25-foot wave of contamination had reached Hungary, the level of cyanide in the Tisza River was still peaking at 300 times the threshold of the Hungarian "highly polluted" standard.

An extremely diverse freshwater ecosystem, according to the World Wildlife Fund (WWF)-Hungary, the Tisza is home to 19 of the country's 29 protected fish species. Not long after the spill, 100 tons of dead fish were swept from the river's polluted surface. But the dissolved cyanide also wreaks havoc throughout the entire food chain of birds and mammals. The Foundation for Otters estimates that since the spill, 300 to 400 otters living in the Somes and Tisza Rivers--a major portion of Europe's already fragmented and declining otter population--have completely disappeared, probably the result of eating tainted fish.

Then on March 10, just as a team of 16 experts organized by the United Nations Environment Programme finished sampling and assessing the 500-mile stretch of affected waterways, mine water spilled again in the breach of another Romanian dam. This time, more than 20,000 tons of sediment heavily laden with lead, zinc, copper, aluminum and cyanide were washed from a mine near the city of Borsa, flooding the upper segment of the Tisza River which had been spared by the previous spill. On March 14, a third, smaller spill occurred from the same mine.

In Europe, however, these are hardly unprecedented events. Toxic waste from a mine breach flowed into the Donana wetland in southern Spain just two years ago. Phil Weller, director of the WWF Danube-Carpathian Programme, called the latest incidents "one more warning signal of potential time bombs that are waiting to go off all over Europe." In the last 50 years, more than half of Europe's freshwater ecosystems have been lost. CONTACT: European Freshwater Programme, c/o WWF-Denmark Ryesgade 3F, DK-2200 Copenhagen N, Denmark, (45) 3524-7842, www.wwf.dk/freshwater.