The image is impressive: thousands and thousands of walruses (Odobenus rosmarus) piled on top of each other along the beaches of northwestern Alaska. The shot, made by photographer Gary Braasch, is rapidly going around the world and has already become one of the symbols of global warming.

Yes, because according to the experts of the US Geological Survey this mass stranding would be due to global warming and the consequent melting of ice.

Get ahead. Walruses usually rest on the pack ice and floating ice blocks. This behavior is therefore rather unusual: so massed on land they risk trampling each other and too close to the coast do not find enough food.

But for the past eight years the coasts of Alaska have been increasingly taken by storm by these large mammals: last year they were more than 35, 000 and a fortnight ago they were counted at least 5-6.000 on Point Lay beach, a small village on the peaceful coast of the country.

The walruses do not have a particularly exciting life: they wake up, look for something to eat and then lie down on the ice to mate and socialize. They can swim for a short time and for this reason they prefer shallow and calm waters. The rising temperatures are confining the ice more and more to the north, where the ocean waters are deeper, and for this reason the walruses fall back on the southernmost beaches.

Image | Gary Braasch /

Man, what a stress. A gathering of these proportions and so close to human settlements, however, exposes the animals to strong stresses: they are in fact constantly disturbed by boats, planes and helicopters but also by tourists, photographers and the merely curious. And when they are frightened they can have rather violent reactions: for this reason the local authorities have asked the population to stay away from the beaches.

"The ever-growing ice-free season has intensified human activities: shipping, fishing, drilling and tourism. Walruses and their young must now compete with the human presence, "reads the report of the US Geological Survey.

And by 2017 the walrus could be included in the list of endangered species.