Typically, scientists count whales from a ship's bridge or an airplane, but those techniques come with a number of downsides: They cost a lot of time and money and they can be inaccurate, the Los Angeles Times notes. What's more, "many marine mammal researchers have been killed flying in small planes while surveying whales," an expert says. Now, scientists have a potential solution to the problem. A team has successfully counted whales at or near the water's surface using satellite imagery, the BBC reports. They bought a single picture from the WorldView2 satellite, which can spot items just 20 inches long on Earth's surface.
The image, showing 70 square miles, focused on a breeding area used by southern right whales off the coast of Argentina. Whales made up just a few pixels in the image. When scientists counted the whales themselves, they spotted 55 likely candidates—as well as 22 that may have been whales and 13 underwater shapes that looked like the animals, the Times reports. A computer program also counted the images, finding 89% of the probable whales. "As the resolution of the satellites increases and our image analysis improves, we should be able to monitor many more species," says a researcher, noting that "total population counts" should eventually be possible.