Records obtained by the Chicago Tribune indicate vast numbers of fish die when they are sucked into the screens of water intake systems, the newspaper reported Tuesday.
The billions of eggs, larvae and juvenile fish small enough to pass through the screens are cooked to death by the intense heat and pressure inside the coal, gas and nuclear plants.
The records show the plants returned the water to the other Great Lakes up to 30 degrees hotter, which encourages growth of oxygen-depleting algae that kills fish and befouls beaches.
The "once-through" cooling process is banned at newer plants. But for nearly 40 years, federal and state environmental regulators basically turned a blind eye regarding old plants, even as fish populations fell throughout the Great Lakes and states spent millions of taxpayer dollars to stock waters.
"These plants are consistent killers, plain and simple," Frank Reynolds, a commercial fisherman on Lake Erie, told the Tribune. "They're trying every way they can to avoid doing something to protect the fish."
Lawsuits have delayed the phaseout of once-through cooling at older plants, the Tribune said. Power company lobbyists said the expense would force plants to close, costing jobs and making the nation's electrical grid less reliable. Some plants have tried to correct the problem.
"It's not clear to me scientifically that there is a broad-based problem out there that needs to be fixed," said C. Richard Bozek, director of environmental policy for the Edison Electric Institute, a trade group for energy companies.