Renewable energy from wind farms comes at the cost of scaring off porpoises, according to a German study of the country's first offshore wind farm. The marine mammals—who depend on their acute hearing for communication, orientation, and finding food—fled the area 30 miles off the German coast while the wind farm was under construction, and it's unclear whether they'll ever return, Der Spiegel reports.
Researchers say the noise from wind farm construction can damage porpoises' hearing and believe measures should be taken to protect the sensitive animals before work begins on the dozens of other offshore wind projects Germany has planned. One solution being suggested is a "bubble curtain" of artificially generated bubbles to absorb sound waves. (Read more cetaceans stories.)