Scientists Learn to Count Whales from Space
In a world first, scientists have managed to harness satellite technology in order to remotely count the number of breeding whales in an otherwise difficult to navigate area.
Estimating whale numbers from land or the air has always been problematic, and even potentially dangerous. To tackle this problem, scientists from the British Antarctic Survey (BAS) have come up with a new method for counting whales by employing Very High Resolution (VHR) satellite imagery and image processing software to automatically detect the whales as soon as they come near to or actually surface. The research is published this month in the journal Plos One.
“This is a proof of a concept study that proves whales can be identified and counted by satellite,” lead author Peter Fretwell from the British Antarctic Survey (BAS), is quoted as saying.
The researchers were able to count breeding whales in sections of the Golfo Nuevo, Peninsula Valdes in Argentina, which is well known as a hotspot for calving southern right whales. To count the whales, they used the DigitalGlobe’s WorldView2 satellite, one of the most powerful satellites of its kind in use today. Even so, the whales only showed up on the satellite images as small pixels. Nevertheless, the satellite image counts were able to yield an 89% accuracy rate when compared to manual counts.
Trialing the automated method was in fact a great deal more complicated than this, with more in depth details available here, and the method is very difficult to get right. For instance, bad weather can disturb the imaging to the point where it renders the method unusable. There are also problems with wrongly identifying whales, but these could be remedied in future as the technology becomes more refined.
All that said, the applications of this method are perhaps just as interesting as the method itself. Southern right whales have been hunted to virtual extinction, partly because of their problems breeding but mostly because they made ideal hunting victims due to the fact that they tend to swim slowly and stay close to relatively shallow waters.
Thanks to conservation efforts, the whales’ numbers have slowly crept up but in recent years the number of dead calves found around the Peninsula Valdes has grown. The precise reasons for this aren’t clear. However, with this technology marine biologists believe they could finally begin to accurately track whale activity without having to risk life and limb. Prof Vicky Rowntree from the University of Utah is quoted by the BBC as saying:
“It’s going to be absolutely amazing. 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.”
The proof of concept study shows that this technology should be cost effective and, as noted above, would improve research safety, so potentially this kind of tracking could be rolled out to wider whale populations. Before that can happen, though, the process will have to be refined yet the researchers appear optimistic that this is a technique that will only get better as the technology it relies upon improves.
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