Pacific walruses numbering thousands crowd at the northwest coast of Alaska in a phenomenon that scientists described as an annual sign of climate change.

Since 2007, hoards of walruses flock in Alaskan and Russian beaches with researchers saying it is likely the result of the melting of the sea ice caused by the warming of the planet.

For about eight years, walruses have been swimming to Point Lay in Alaska as the sea ice that they depend on for survival melts at record pace.

"Walruses haul out onto the shores of the Chukchi Sea in large numbers when the sea ice recedes north of the continental shelf," the U.S. Geological Survey (USGS) said. "During 2008 and 2012, walruses did not come ashore in Alaska, because sparse remnant sea ice persisted over the shelf."

The marine mammals are not capable of swimming for long stretches so they rest on ice and dive for food such as snails and clams in between with the mothers often leaving the pups on the ice as they hunt for food.

Before 2007, Pacific walruses prefer to go to the Hanna Shoal region during summer since the ice here remained solid all throughout the year even when sea ice elsewhere have melted.

By now though, the sea ice of Hanna Shoal is also gone by late summer forcing the walruses to go ashore until the ice starts to build up again in October.

Last year marks one of the largest gatherings of these marine mammals at Point Lay with an estimated 35,000 walruses crowding the area.

USGS officials advised residents to avoid large crowds of walruses given possibilities of stampedes that can be triggered by humans and polar bears.

Walruses are also easily scared when they hear loud noises such as those produced by planes and helicopters. Such noises can result in stampedes that could kill pups that fail to keep up. A stampede that occurred at the Icy Cape in Alaska in September 2009 killed over 130 walruses, most of them young.

Federal officials likewise warned that people who visit the area where the walruses now gather could end up violating the law. Disturbing the animals could be a violation of the Marine Mammal Protection Act.

"It's against the law to harass mammals," said wildlife biologist James MacCracken, from the U.S. Fish and Wildlife Service. "And harassment is defined very broadly to include any change in behavior."

Photo: Claumoho | Flickr

ⓒ 2024 TECHTIMES.com All rights reserved. Do not reproduce without permission.
Join the Discussion