Researchers have figured out a way to count whales from space.
The team used the Very High Resolution (VHR) satellite imager along with image processing software to detect the number of whales breeding at the Golfo Nuevo, Peninsula Valdes in Argentina, a British Antarctic Survey news release reported.
These aquatic mammals are difficult to keep track of, this new method could introduce and easier way to estimate population size.
"This is a proof of concept study that proves whales can be identified and counted by satellite. Whale populations have always been difficult to assess; traditional means of counting them are localized, expensive and lack accuracy. 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," Lead author Peter Fretwell from the British Antarctic Survey (BAS) said in the news release.
In the past satellites have proven to be relatively unsuccessful in monitoring whale populations, but their accuracy has recently improved.
The team looked at the bay where southern right whales (which have yet to recover from rigorous whaling) mate using the WorldView2 satellite. An increase in calf mortality has been seen in this species in recent years.
The bay has calm shallow water, which makes it easier to spot the whales.
The criteria used to pinpoint whales in the images were: "objects visible in the image should be the right size and shape; they should be in the right place (where whales would be expected to be) and there should be no (or few) other types of objects that could be mistaken as whales," the news release reported.
The team spotted 55 "probable whales," 23 "possible whales", and 13 "sub-surface features." Automated methods were then used to test these numbers; the team found a "threshholding" of the Coastal Band of the WorldView2 was most successful.
"Future satellite platforms will provide even high quality imagery and Worldview3 is planned to be launched this year. This will allow for greater confidence in identifying whales and differentiating mother and calf pairs. Such technological advancements may also allow scientists to apply this method to other whale species," the news release reported.
