Whale watching can now be performed from outer space thanks to a new method scientists have developed to aid conservation efforts.
The findings, published in the journal PLOS ONE, explain how high-resolution satellite photos and image processing software can see the giant mammals from space as they approach or break the ocean’s surface. The study involved counting a group of southern right whales breeding halfway up the coast of Argentina.
"Whales populations have always been difficult to assess, traditional means of counting them are localized, expensive and lack accuracy,” Peter Fretwell, from British Antarctic Survey, said in a statement. “The ability to count whales automatically, over large areas in a cost effective way will be of great benefit to conservation efforts for this and potentially other whale species."
For the study, researchers took a single image captured by WorldView2, a satellite capable of imaging at extremely high resolutions. The photo was of a 40 square mile area in the ocean. Researchers first looked at the image manually to see any whales. They then used image-processing software that was programmed with a whale-recognizing algorithm, the Smithsonian Magazine reports.
A manual search of the scene found 55 probable whales, 23 possible whales and 13 sub-surface features. The computer successfully identified 89 percent of the whales the researchers found by hand. But, the program had a 24 percent false-positive rating where it would identify other objects such as boats, as whales. Researchers hope to improve the algorithm’s accuracy in the future.
"Our study is a proof of principle," Fretwell said. "But as the resolution of the satellites increases and our image analysis improves, we should be able to monitor many more species and in other types of location.”
Researchers hope the method will be used to track total whale populations and their trajectories involved in whale conservation. At the moment, the satellite image works best in calmer waters, but a new satellite that is expected to launch later this year will capture images with an even higher resolution that will provide clearer images in choppy waters, Fretwell said.
Southern right whales were nearly driven to extinction by whale hunters -- where in 1997 a global population of 7,500 was counted. Today, the population appears to have grown strongly, and counts such as these may help understand their exact status.
"It's going to be absolutely amazing,” University of Utah professor Vicky Rowntree who is also director of the Ocean Alliance's Southern Right Whale Program, told the BBC. “The other dimension of it is that many marine mammal researchers have been killed flying in small planes while surveying whales. So my great desire is to get us out of small planes circling over whales and to be able to do it remotely. Satellite data is wonderful."