Large haulouts of walruses — such as the one making news at Point Lay, Alaska on the Chukchi Sea (and which happened before back in 2009) — are not a new phenomenon for this region over the last 45 years and thus cannot be due to low sea ice levels. Nor are deaths by stampede within these herds (composed primarily of females and their young) unusual, as a brief search of the literature reveals.
The attempts by WWF and others to link this event to global warming is self-serving nonsense that has nothing to do with science.
There is also a follow-up post on the situation here.
This may have been “one of the biggest onshore gatherings of the animals documented in Northwest Alaska“ that has been photographed but it is not the only time this has happened.
At least two documented incidents like this have occurred in the recent past: one in 1978, on St. Lawrence Island and the associated Punuk Islands and the other in 1972, on Wrangell Island (Fay and Kelly 1980, excerpts below).
These events included mass mortality associated with very large herds of females with calves.
First, here is a detailed map of the area, from a more recent status assessment by Fay and colleagues (Fay et al. 1997).
Here are the relevant excerpts from the mass mortality events for 1978 and 1972 described by Fay and Kelly (1980):
PAGE 239, below
PAGE 241, below
PAGE 244, below
PAGE 244 Conclusions, below – note that many of the victims of the stampede were thin and weak – in 1978. Was that due to low ice cover? It was before the satellite era record for sea ice, so that’s hard to determine.
And from Fay et al. 1997, their population increase estimates (Table 3):
Here is how the WWF is spinning this recent gathering at Point Lay:
“We are witnessing a slow-motion catastrophe in the Arctic,” said Lou Leonard, WWF’s vice president for climate change.”
As you can see, this is blatant nonsense and those who support or encourage this interpretation are misinforming the public.
Walrus numbers are up considerably from the 1960s, although they are notoriously difficult to count (Garlich-Miller et al. 2011).
Population sizes may fluctuate for a number of reasons that have little to do with the low ice levels: note these very recent incidents of large walrus herds and associated mortality events (2007 [added Oct.3], 2009, 2011 and 2014) have not coincided with the lowest level
s of summer sea ice in the area, which occurred in 2007 and 2012.
[the 2007 event took place in Russia (in “late summer and fall,” in the western Chukchi Sea, so I’ve amended the above list accordingly.]
Fay, F.H. and B.P. Kelly. 1980. Mass natural mortality of walruses (Odobenus rosmarus) at St. Lawrence Island, Bering Sea, autumn 1978. Arctic 33:226-245.
ABSTRACT: In October-November 1978, several thousand living walruses came ashore in at least four localities on St. Lawrence Island where they had not been present before in this century. They hauled out also at two other sites which they have occupied annually but in much smaller numbers. At least 537 animals died on the haulout areas at that time, and approximately 400 other carcasses washed ashore from various sources. This was by far the greatest mortality of walruses ever recorded in an event of this kind. At least 15% of the carcasses on the haulouts were aborted fetuses, 24% were 5-6-month-old calves; the others were older animals ranging in age from 1 to 37 years old. About three-fourths of the latter on the haulouts were females; in the non-haulouts areas the sex ratio was about 1:1. Forty of the best preserved carcasses were examined by necropsy. The principal cause of death was identified as extreme torsion of the cervical spine, with resultant cerebrospinal hemorrhage, apparently due to traumatization by other walruses. Nearly all of the dead were extremely lean, having less than half as much subcutaneous fat as healthy animals examined in previous years.
http://www.aina.ucalgary.ca/scripts/minisa.dll/144/proe/proarc/se+arctic,+v.+33,+no.++2,+June+1980,*?COMMANDSEARCH [open access]
Fay, F.H., L.L. Eberhardt, B.P. Kelly, J.J. Burns and L.T. Quakenbush. 1997. Status of the Pacific walrus population, 1950-1989. Marine Mammal Science 13:537-565.
Garlich-Miller, J., MacCracken, J.G., Snyder, J., Meehan, R., Myers, M., Wilder, J.M., Lance, E. and Matz, A. 2011. Status review of the Pacific walrus (Odobenus rosmarus divergens). US Fish and Wildlife Service, Anchorage, Alaska. PDF HERE.