Grey and Fin whales seen in satellite images

Grey whales (left image) and a fin whale (right) are spotted by a satellite orbiting at an altitude of more than 600 kilometres. Credit: 2018 DigitalGlobe, a Maxar company

Imaging

Thar she blows! Whales seen exhaling from space

Satellite used by intelligence agencies can identify some large whale species down to the flipper.

A high-resolution satellite can detect signs of whales splashing and pooping in the oceans — and can even pick out a humpback whale’s long flippers.

Previous studies have used satellite data to count whales, but the WorldView-3 satellite, which was launched in 2014, captures images in much higher resolution than its predecessors. Hannah Cubaynes and her colleagues at the British Antarctic Survey in Cambridge, UK, searched WorldView-3 images of waters off the coasts of Italy, Mexico, Hawaii and Argentina for fin whales (Balaenoptera physalus), grey whales (Eschrichtius robustus), humpback whales (Megaptera novaeangliae) and southern right whales (Eubalaena australis), respectively.

Body shape and even the size of the creatures’ flippers and tail fins were visible in some photos, as were whale faeces and spray from the animals’ blowholes. The team found that grey whales and fin whales appear paler in colour than the water, making it easier to confidently identify them than the other species.

Satellite data could be used to develop an automated system for detecting and monitoring whales, the authors suggest.