Scientists have developed a new method for keeping track of the planet's whale population by counting the huge aquatic mammals from space using satellites.
Using ultra-high resolution pictures and image processing software, the new technique automatically detects the animals when they are at or near the water's surface.
In a test count conducted in the Golfo Neuvo on the Argentinian coast on southern right whales the new system spotted 90% of the animals catalogued by a manual search. The result was a marked improvement on previous attempts to monitor whale populations from space and could mark a watershed moment in the way whale populations are estimated.
At the moment, experts' ability to keep track of whale populations is limited by the fact that counts must be done for a shore position, from a ship or from a plane. By using satellites, searches would be able to cover much greater areas at greatly reduced costs.
Peter Fretwell of the British Antarctic Survey said, "Our study is a proof of principle. 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.
“It should be possible to do total population counts and in the future track the trajectory of these populations.”
The team used DigitalGlobe's WorldView-2 platform, one of the most powerful commercial Earth observation platforms in operation, which can see surface objects down to 50 centimetres in size when in its black and white mode.
But Fretwell cautions that the technique, however impressive, does have its limitations.
Rough seas or murky waters will confuse a satellite search, but Fretwell believes, based on the trial run, that the new method may become a vital tool.