Using satellites to whale watch from space

Recent research has shown that satellite imagery is an effective and viable way of identifying and tracking the movement of large baleen whales. It could be set to revolutionise the way we monitor these ocean giants in the future.

whales from above
Whales are can actually be far easier to find and identify from above than on the surface

Accurately locating and tracking marine animals is one of the biggest limiting factors in our ability to study and protect them. Especially for long lived and vulnerable creatures like the great baleen whales, who have been historically hunted and are only just beginning to show signs of recovery. It is important to be able to accurately assess changes in their numbers, movement and behaviours over time, so we can see how our own activities are impacting upon them and how we can mitigate that. However, despite their incredible size, locating and tagging these ocean giants can be incredibly time consuming, financially costly and infuriatingly difficult. Therefore new methods of monitoring that can increase the ease with which we track them will be extremely beneficial in helping protect them in the future. That is why a recent breakthrough in satellite imagery technology could be set to revolutionise the way we track these cetaceans forever.

Evolution of satellite tracking

Orbital satellites already play a big part in monitoring the great baleen whales, thanks to the emergence of satellite telemetry (tracking using electronic GPS tags) in marine biology research in the 1990’s. Initially massive clunky devices often unethically attached to creatures including whales, sharks and trutles, satellite tags have now evolved into tiny technologically-advanced attachments that can record a wealth of information on just about any marine animal you can think of. All of which is now easily transmitted to a vast network of satellites and made accessible to researchers from the safety and comfort of their office desk chairs.

tagging bowhead whale
Tagging whales by hand, like these polar researchers tagging a bowhead whale, poses a lot of logistical challenges

However despite this incredible advance in technology there are still limitations. The main one of which is that in order for satellites to track whales, you first have to find and physically tag them. This puts a constraint on our ability to research them because it takes time, money and effort to do so. Therefore to fully be able to monitor and protect these ocean giants the next step is to be able to use satellites to track them without having to attach a satellite tag at all. The main way in which we can do this is via satellite imagery where rather than looking for tag signals the orbital technology searches out the actual whales instead.

Proof of concept

Last year a new paper, by a group of researchers from Cambridge University and the British Antarctic Survey and published in Marine Mammal Science, made a major breakthrough in using satellites to track large whales in this way. It was by no means the first attempt to do so, multiple studies dating back to 2002 have attempted to use this technology and to some extend succeeded, but the new study managed to significantly improve on the accuracy and efficiency of previous groups. This was thanks mainly to the advances in technology over the last two decades. Whereas the satellites used by past studies had low resolutions of around 50-80cm, the much newer WorldView-3 satellite used by the researchers had a much greater resolution of 31cm. This may not sound like much of a difference, but the result of the increase is that twice as many pixels per area can be generated meaning images are much more detailed, which can be the difference between successfully identifying one species of whale over another.

whales from space
One of the images captured by the WorldView-3 satellite used in the study, in the past it would have been hard to differentiate between the boat (right) and whales (left)

In the study this allowed the researchers to successfully identify 4 baleen whale species in different locations across the globe, including – fin whales (Balaenoptera physalus) in the Ligurian Sea, humpback whales (Megaptera novaeangliae) off Hawaii, southern right whales (Eubalaena australis) off Península Valdés and gray whales (Eschrichtius robustus) in Laguna San Ignacio. Certain species such as fin and gray whales were easier to spot because of their colour contrast against the ocean and proximity to the surface, but all identifications were made in complete confidence by the researchers who were sorting through the data manually. It proves that satellite imagery can be a reliable and effective way of increasing our ability to monitor and hopefully protect large baleen whales.

A game changer

Of course the beautiful thing about this new study method is that as time goes by it is only going to get easier and more accurate. Further increases in the resolution and quality of images produced by orbital satellites will allow more species of marine creatures to be monitored in the same way including smaller whales and dolphins, sharks and maybe even turtles. In addition to this advances in artificial intelligence will mean satellite images can also be sorted automatically and allow researchers to track many more individuals than ever before. It may be some time before satellite imaging really takes off, but already large projects including a joint venture by New England Aquarium and tech company Draper are already well underway. As we continue our fight to save our oceans from our own widespread impacts, it is  vital that we continue to innovate and incorporate new technologies and methods like this to help turn the tide.


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