Walruses, marine mammals with two large tusks that descend from the upper jaw, live on 25,000km2 in the Arctic. And to identify them, the teams of WWF and the British Antartic Survey (which manages five research stations in the Arctic) have found the solution: they offer the general public to help them count walruses one by one, from satellite images.
Over the next five years, photos of Russia, Greenland, Norway and Canada from space will be uploaded. The volunteers will be able to count from their computer screen, the small brown dots which each correspond to a walrus. An important observation because these mammals are threatened by global warming, and the melting of the sea ice on which they live.
With increasingly efficient image resolutions, smonitoring wild animals from satellite images is a method that is developing. Satellite images have already made it possible to count populations of African whales or elephants, to follow the movements of animals equipped with beacons, in particular birds, sea turtles, or reindeer in Russia.
It is also space observations that made it possible to locate last year, 11 new colonies of emperor penguins in remote areas of Antarctica. They have been spotted, and literally tracked, because of their droppings, which when viewed from space, leave dark spots on the white ice. More generally, satellite images are indeed very valuable for mapping and delimiting the habitats of wild species.
Beyond the observations of clouds and air masses, thanks to space images, we can better study the effect of climate change on the oceans and rivers. This by measuring the water level, their salinity, their temperature, which makes it possible to study the currents. Satellites also make it possible to monitor the health of forests, the evolution of their surface and to measure the amount of carbon stored and even calculate what mass of vegetation grows on each surface covered with trees.
Finally, thanks to certain wave spectra, such as infrared, these technologies also make it possible to see from space elements normally invisible to the human eye: methane emissions for example or the water stress of forests. When trees are stressed by a lack of water they emit a certain energy and certain waves which can be found from space.