My power plant is on the Hell Gate section of the East River in NYC. It can have strong currents at times. I like to watch the birds land in the water in front of the plant, shoot down the river bobbing nearly uncontrollably, then when they get to the end of the power plant fly out of the water to the other end of the plant and shoot down the river again. Tons and tons of birds would do this, and I thought it was the funniest thing.
I asked a coworker what the hell was wrong with all the birds. They looked drunk or crazy. He just said the birds like the fish, and the fish like discharge tunnel temperatures.
Fast forward nine years, and the NYC Department of Environmental Conservation mandated that all of our units have variable speed drives on the circulating water pumps to "save the fish." I'm not making that up.
The pumps used straight 440 VAC 60 Hz to the motors, but now we installed rectifiers and static inverters to control the pump speed to slow it down and reduce temperature rise. They're really complicated GE variable frequency units made in Mexico... we're still commissioning them. The formally robust pumps are tripping out a lot. I can't wait until summer when running at top load and one trips out and fails to start on straight 60 Hz. We'll lose units. Perhaps cause a black out.
But hey, if it saves just one fish...
unfreeking crazy enviro-Nazis