
The plight of thousands of walruses forced to crowd on to an Alaska
beach because of disappearing sea ice has set off an all-out response
from the US government to avoid a catastrophic stampede.
The Federal Aviation Authority has re-routed flights, and local
communities have called on bush pilots to keep their distance in an
effort to avoid setting off a panic that could see scores of walruses
trampled to death, federal government scientists said.
Curiosity seekers and the media have also been asked to stay away.
An estimated 35,000 walruses were spotted on the barrier island in
north-western Alaska on 27 September by scientists on an aerial survey
flight.

The biggest immediate risk factor for the walruses now is a stampede –
especially for baby walruses – but they have been facing a growing
threat from climate change, the scientists said.
The extraordinary sighting – the biggest known exodus of walruses to dry
land ever observed in the Arctic under US control – arrived as the
summer sea ice fell to its sixth lowest in the satellite record last
month.
“Those animals have essentially run out of offshore sea ice, and have no
other choice but to come ashore,” said Chadwick Jay, a research
ecologist in Alaska with the US Geological Survey.
Until 2007, it was unheard of for walruses to leave the sea ice for dry
land for prolonged periods of time. But the retreat of sea ice has seen
“drastic changes” in behavior, Jay said.
Walruses have struck out for beaches in six of the last eight years.
He said there was no doubt the migration – or “hauling out” as it is
called – was caused by climate change.
“It is really a reduction in the sea ice that is causing the change in behavior, and the reduction of sea ice is due to global warming,” Jay
said.
But the immediate concern was to avoid a stampede –
a leading risk factor for walruses when they crowd onto beaches and
barrier islands.
The FAA is asking pilots to remain above 2,000ft and half a mile away
from the walruses. Helicopters – a bigger risk to the walruses because
they are noisier – have been asked to remain 3,000ft up and a mile away.
News crews, which have been clamoring to film the walruses, have also
been asked to stay away. “The government and local communities are
respectfully asking you to leave the haul-out alone,” Joel Garlich
Miller, a Walrus biologist with the US Fish and Wildlife Service, said.
Walruses are naturally skittish animals, unused to being closely packed
together. They also spend 80% of their time on water. Those in the
Chukchi sea this time of year are generally females and juveniles and so
at greater risk of being trampled to death.
“You have all these animals that are normally distributed on a flat
surface. When they lose their sea ice habitat and come ashore in places
that are accessible – like flat, sandy beaches – they gather in large
numbers, and it becomes like a giant pig pile,” said Margaret Williams,
managing director for the World Wildlife Fund’s Arctic program. “When
they are disturbed it can cause stampedes in large numbers.”
In addition to the stampede risk, it is also much harder for the
walruses to hunt from the beach. The walruses typically disperse over
large expanses of water, uses ice floes as a platform to hunt for the
clams and other shell fish that are their main food source.
No comments:
Post a Comment