Climate change is causing the pastures of Svalbard to freeze and forcing local deer to feed on seaweed.
Svalbard Rangifer tarandus platyrhynchus are representatives of the northernmost, small and short-legged subspecies of reindeer, endemic to the islands of the Svalbard archipelago. They are the largest land mammals, constantly living at such high latitudes, not too far from the North Pole. They have lived here for several thousand years and have perfectly adapted to extreme conditions, but in recent years, due to global climate changes, they have to get used to completely new conditions.
For example, in an article published in the journal Ecosphere, Brage Hansen and his colleagues at the Norwegian University of Science and Technology in Trondheim report unexpected changes in the diet of Svalbard reindeer. At first, the authors noticed animals feeding directly on the ocean shore, which is very unusual for them. Taking samples of feces, scientists confirmed their guesses: they found isotopes of sulfur, carbon and nitrogen, characteristic of algae - primarily kelp, "seaweed", which grows in abundance here.
Apparently, the expansion of the diet of Svalbard reindeer is associated with the rapid warming and humidification of the climate of these islands. The increased temperature and humidity lead to the formation of a dense and hard ice crust on the snow, which makes it difficult for animals to reach common mosses, lichens and plants. Such "ice-locked" pastures often lead to serious fluctuations in reindeer populations and force them to make especially long migrations. However, the residents of Svalbard are inaccessible to such crossings, which forced them to replenish part of the missing food from a new source - the sea.
Expansion of the "ice fields" of Spitsbergen, scientists have confirmed on the basis of satellite observations. At the same time, they emphasize that the transition of deer to algae cannot be called complete. They are not able to survive entirely on such a diet and every day they move between the available pastures inside the islands and the coastline full of kelp. In addition, animals have yet to adapt their digestion to this unusual, extremely salty food.