Little did Lewis Carroll know, when he penned his gleeful nonsense poem, that rather than the shellfish – primarily clams, not oysters – scrambling to the shore in Alaska’s Bering and Chukchi Seas, it would one day be the walrus themselves. Walrus have been hauling out on the shores of northwest Alaska instead of cruising the seas on their customary ice floes in the last few summers, because the ice has melted away. Tens of thousands of walrus packed shoulder to shoulder along miles of beach have become a not uncommon sight. Impressive though it may appear, it bodes ill for these remarkable animals.
The ice has always provided a convenient diving platform for the walrus to graze the Continental Shelf for prey – shrimps, crabs, snails, and worms as well as up to 200 pounds of clams per day for a single walrus. Historically, walrus have used the broken ice in the Bering Sea, south of the Bering Strait, in the winter; then in summer most of the males have moved to shore while the females and their young have remained on the ice as it retreats into the Chukchi Sea to the north. This has both spread out the harvesting of prey and enabled the young to rest where they will be safe from predators while their mothers feed.
But in recent years the pack ice has retreated well beyond the edge of the Continental Shelf. As a result, walrus have been forced to haul out on shore, creating massive dense colonies that threaten to overharvest the near-shore food resources. Mothers may be forced to take more extended foraging trips, which leave their young vulnerable to predators. And the warmer waters may decrease the amount of plankton, which is a major food source for the shellfish themselves.
Even the denseness of the walrus colonies is a danger. A bear or a passing plane will often cause walrus to stampede into the water, which results in many being crushed to death, mainly the young. In 2007, the first year in which large numbers of walrus were seen on shore, between three and four thousand walrus – mostly calves – died in stampedes on the Russian shore of the Chukchi Sea alone. Anatoly Kochnev, a walrus researcher for Russia's Pacific Institute of Fisheries and Oceanography, said the loss of so many animals from one population could be disastrous.1
2007 was the year that Arctic summer sea ice dropped to the lowest extent ever recorded. Prior to that, walrus had not been seen hauling out on land in large numbers; but since then, it has become the norm, as summer sea ice has experienced a similar drop in most years. And it is not only the extent that has diminished. As substantial areas of ice melt, large portions of the sea must start over with new ice the next winter; and new ice is thin ice, much more likely to melt again come summer.2 Many scientists now predict Arctic summers will be altogether ice-free by 2030, while some predictions move that date forward to as early as 2013.3
Walrus are further threatened by the prospect of oil drilling in their home seas. 2011 saw the Obama administration approving plans to open both the Bering and Chukchi Seas to offshore drilling. An oil spill in these treacherous and challenging seas would be extraordinarily difficult to clean up, and potentially disastrous for the wildlife there.
An effort to grant the walrus Endangered Species status has resulted in a determination by the U.S. Fish and Wildlife Service that this status is warranted, but that due to the existence of so many more urgent cases, there will be no action on it at this time. An Endangered Species listing requires the designation of protected habitat and a plan for the species' recovery, a time-consuming procedure that limits the speed with which species can be listed. Species sometimes become extinct while awaiting an official listing or a recovery plan. Scientists hope that walrus population numbers, and the possibility of its adapting somewhat to an onshore habitat during part of the year, may enable it to get by for now.
In the meantime, USGS scientists have developed a radio tag that will help them study the species' foraging behavior, to see how they adapt to their new environment. The Fish and Wildlife Service and the World Wildlife Fund have also sponsored an international exchange program in which native Russians have shared their conservation strategies with Alaskan Arctic village elders, who as a result have restricted the hunting of the walrus and requested that flights avoid the areas where the animals are hauled out, to avoid causing stampedes.
Ultimately the walrus is suffering from the same phenomenon as the polar bear, as the loss of summer sea ice has prevented access to prey in both cases; but the walrus has received far less attention. This is partly a matter, no doubt, of charisma – not that the walrus lacks it; the heft, the whiskers, the long tusks that make it such a fine choice for a poem the likes of this one guarantees it a certain amount of attention. But it’s hard to compete with the polar bear. Besides, the polar bear is rapidly approaching extinction, with large regional extinctions expected by mid-century or sooner, while the walrus population is somewhat healthier for now.
Much will depend, finally, on the fate of the Arctic summer ice pack. While shipping companies exult over the boom in business that will result from ice-free shipping lanes, the goods they move will be gliding through an increasingly diminished world, in which the creatures that fire the imagination no longer lurk among the ice floes.
1 Labunski, Liz. “Marine mammals may be forced to remain on land.” Associated Press, 24 Dec 2007. http://www.msnbc.msn.com/id/22387800/ns/us_news-environment/t/loss-sea-ice-could-harm-walrus/#.TodqybK3PWI
2 Maslanik, J. A., C. Fowler, J. Stroeve, S. Drobot, J. Zwally, D. Yi, and W. Emery. “A younger, thinner Arctic ice cover: Increased potential for rapid, extensive sea-ice loss.” Geophysical Research Letters 34, L24501, doi:10.1029/2007GL032043. 2007.
3 Lean, Geoffrey. “For the first time in human history, the North Pole can be circumnavigated.” 31 Aug 2008. http://www.independent.co.uk/environment/climate-change/for-the-first-time-in-human-history-the-north-pole-can-be-circumnavigated-913924.html