The gatherings of walruses on land are so huge that they can be seen from space. Unfortunately, the reason behind this does not speak well for the future of the creatures. Large groups of walruses can be seen invading Earth’s coastlines in recent satellite imagery obtained by Planet, which operates the world’s most giant pack of Earth-observing satellites.
The photograph depicts a smattering of confusing “distinctive red-brown” blobs adorning the Alaskan coast. Previously, walruses would congregate in large groups of up to tens of thousands on Arctic sea ice far from the shore, known as “haulouts.” However, because sea ice is disappearing at an alarming rate due to climate change, they have little alternative but to congregate on land. According to new research published by the United States Geological Survey (USGS), satellite photos like those acquired by Planet could be beneficial for monitoring the impact of climate change on these walrus populations.
“They’re forced to assemble on land rather than their regular sea ice due to climate change,” Planet wrote on Twitter with the USGS findings. The walruses aren’t visible in the image provided in the original tweet, but they can be seen in the photos and data in the study they noted in a follow-up Twitter. For these walrus populations, the repercussions of this transition are significant. The Arctic creatures could feed, rest, and live in peace because they were grouped on sea ice.
They now have to contend with humans on land. Humans can quickly startle the walruses in these haulouts, causing them to stampede into the sea. Stampeding in such huge groups can kill many walruses, as Planet explained in a statement. USGS researchers used data from PlanetScope, a constellation of about 130 Earth-observing satellites operated by Planet, and TerraSAR-X, a satellite operated by a partnership between the German Aerospace Center and Astrium, a part of the European Aeronautic Defence and Space firm, to study these populations in a remote coastal area in Alaska (EADS).
They compared this information to drone photographs of the same region shot at the same time. They discovered that the walrus groups were “readily visible in satellite imagery,” according to Planet. Their research demonstrates how satellite observations, such as Planet’s, may be essential for monitoring populations like these as they adapt to climate change. Since the early 1980s, the average area of Arctic sea ice has been shrinking at a pace of roughly 10% every decade, according to statistics from the National Snow and Ice Data Center. According to NASA, the proportion is closer to 13%.
The loss of sea ice is aided by a phenomenon known as ice-albedo feedback. The great majority of sunlight that strikes white sea ice is reflected. Darker seawater, on the other hand, absorbs the majority of it. It means that as the ice melts, this effect becomes more intense, reinforcing the melting pattern. The USGS researchers wrote in their report, “These findings suggest that satellite reconnaissance may provide a tool for monitoring walrus haulout occupancy and dynamics, as may be required by resource managers.” The analysis of walrus populations using Planet’s data was published in the journal Remote Sensing on Oct. 23.