It takes a lot of water to create electricity. Power plants use hundreds of billions gallons of water a day to run their turbines, much of it taken directly from rivers and lakes, used once in the plant, and then passed back out. These so-called pass-through systems are hell on fish which get chopped and shredded by the turbine mechanisms.
There are closed-cycle cooling systems that both preserve water and keep fish safe but they cost money to install. If there is anything powerplant owners are loath to do it's to spend money replacing systems that work just fine, at least from the point of view of the bottom line.
The Sierra Club is promoting an awareness campaign called Fish Chopper to help pressure Washington to toughen regulations requiring power plants to use closed-cycle systems. If you'd like to add your voice you can swing over to their site and send your elected representatives your thoughts. Here's a great video they put together explaining the problem.
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