Aug 27, 2002 — Back in the 1970's Lake Erie was considered dead. Too many nutrients were flowing into the lake, causing algae blooms that used up the oxygen. Massive fish kills were one result. Until recently, scientists thought they had the problem licked. But a few years ago, researchers began to realize those conditions were returning. Zebra mussels could be one culprit, but scientists aren't sure. So the U-S EPA has launched a research ship to gather data that might help to unravel the mystery. The Great Lakes Radio Consortium's Karen Schaefer reports.