Friday, September 05, 2008

Death by Turbine: exploding bat lungs

SO you thought wind power was the future? Not if you are a small furry mammal with fangs it isn't. H/T to Common Tragedies for pointing out a recent Scientific American article on bat deaths due to wind turbines.

There is something about the concept of exploding lungs at high altitude that make this article blogworthy.

On a Wing and Low Air: The Surprising Way Wind Turbines Kill Bats [Scientific American]

Instead, 90 percent of the 75 bats the researchers ultimately dissected had been killed by burst blood vessels in their lungs, according to results presented in Current Biology—suggesting that the air pressure difference created by the spinning windmills had terminated them, not contact with the blades.

So where is the science bit:

As the wind moves through a wind turbine's blades, pressure drops behind them by five to 10 kilopascals (a pascal is a unit of pressure), and any bat unlucky enough to blunder into such an undetectable low pressure zone would find its lungs and blood vessels rapidly expanding and, quickly, bursting under the new conditions.

I think we still need a little more detail:

"If bats have a lungful of air as they fly through the air-pressure change, there's nowhere for the air to go," Baerwald explains. "The small blood vessels around the lungs burst and fill the lungs with fluid and blood."

The implications are potentially important. Building very high wind farms in bat migration zones may be a bad idea and certainly generates bad publicity. Bats have a good PR department and hundreds of dead flying mammals is bad for business and it turns out the Eco-system:

The full impact of these bat-killing pressure zones extends far beyond the wind farm, however. Such migrating bats travel from Canada as far as Mexico, eating thousands of insects en route, including crop pests such as moths and beetles. "They are one of the only things that fly around at night and eat bugs," Baerwald notes. "Bats killed in Canada could have a detrimental impact in America or Mexico. It's not local. It's an ecosystem-wide issue."


No comments: