Whale watching from space
Scientists have used detailed high-resolution satellite images to detect, count and describe four different species of whales.
A satellite image of grey whales in Mexico ©2018 DigitalGlobe, a Maxar company
The researchers, from the British Antarctic Survey (BAS) – part of UK Research and Innovation’s Natural Environment Research Council (NERC) – say the study is a big step towards developing a cost-effective method to study whales in remote and inaccessible places, that will help scientists to monitor population changes and understand their behaviour.
The imagery, provided by Maxar Technologies’ DigitalGlobe, is sharp enough to capture the distinctive shapes of different species, even when taken 385 miles up.
The team plan to conduct an audit of fin whales in the Mediterranean. The first-of-its-kind assessment will be partly automated by employing a computer programme to search through the satellite data.
The Ligurian Sea, north of Corsica, is a protected area for cetaceans, and the regional authorities want to understand better the animals’ movements in relation to shipping to try and avoid collisions.
Lead author Hannah Cubaynes, a whale ecologist at BAS and University of Cambridge explains:
A satellite image of a fin whale in the Mediterranean image ©2018 DigitalGlobe, a Maxar company
“This is the most detailed imagery of whales captured by satellites to date. It’s exciting that the improved resolution (now at 30 cm) reveals characteristic features, such as flippers and flukes, which can be seen in the images for the first time.
“Whales live in all oceans. Many areas are difficult to access by boats or planes, the traditional means of monitoring whales. The ability to track whales without travelling to these remote and inaccessible areas, in a cost-effective way, will be of great benefit to conservation efforts for whales.”
The study also shows some species are easier to identify by satellite. Fin and grey whales are the easiest to identify due to their body colouration, which contrasts with surrounding water. Humpback whales and southern right whales are more difficult to detect as they are a similar colour to their environment. In particular, the acrobatic behaviour of humpback whales makes them harder to see as they splash about so much and so their body shape is often obscured.
Previous studies have played with the idea of spotting whales from orbit, but with limited success.
The work was funded by NERC and the MAVA Foundation.