Nuclear bomb detectors reveal hidden blue whale population

Blue whales may be the largest animals on the planet, but they are difficult to spot. The commercial whaling industry in the 20th century drove them to the brink of extinction, and today they are listed as endangered under the Endangered Species Act. An individual blue whale may weigh as much as 33 elephants, but many go unnoticed as their numbers are few, and they live mostly solitary lives spread across all oceans except the Arctic. Yet earlier this year, a team of scientists reported finding a new population of pygmy blue whales right in the middle of the equatorial Indian Ocean, thanks to nuclear-test-detection equipment.