Clark Fork in Montana. Proposed mine threatens fish and wildlife. Mussels hurt Hudson ecosystem Experts have discovered a serious threat posed by zebra mussels, a foreign species that migrated to the northeastern United States in the late 1980s and sharply reduced food supplies for freshwater clams. Scientists at the Institute for Ecosystem Studies in Millbrook, NY, say the mussels are sucking up so much oxygen from the Hudson River that much of the ecosystem is approaching a danger point at which other aquatic creatures begin to flee or die. Mussels also remove from water small particles that cloud the water and reduce the penetration of sunlight.
More sunlight helps water celery, an underwater native plant that gives off oxygen.
Although Americans are recycling waste in unprecedented fashion, the amount of trash making its way to landfills is on the rise, according to a report by the GrassRoots Recycling Network. Americans generated 217 million tons of municipal solid waste in 1997, the report says. A record 61 million tons of waste was recycled in 1997, leaving 156 million tons disposed of at landfills and incinerators. Though significantly lower than what was discarded in 1990, the 1997 total is 4.4 million tons higher than 1996. Earth's ozone layer thinned to record low levels around the Arctic region this past winter, according to a study by the National Aeronautics and Space Administration and the European Union.