“Sea ice gone; walruses come ashore”, not unusual

A story today in the Arizona Daily Star notes that “Tens of thousands of walruses have come ashore in northwest Alaska because the sea ice they normally rest on has melted. Federal scientists say this massive move to shore by walruses is unusual in the United States.” The “federal scientists” in this case are from the Biological arm of the U.S. Geological Survey (USGS).

The U.S. Fish & Wildlife Service (FWS) says, however, that this is not unusual:

The Pacific walrus mainly inhabits the shallow continental shelf waters of the Bering and Chukchi seas. The distribution of Pacific walruses varies markedly with the seasons. Virtually the entire population occupies the pack ice in the Bering Sea in the winter months. Through the winter they generally congregate in two areas, one immediately southwest of St. Lawrence Island and the other in outer Bristol Bay. As the Bering Sea pack ice begins to loosen in April, walruses begin to move northward and their distribution becomes less clumped. By late April the distribution extends from Bristol Bay northward to the Bering Strait. During the summer months, as the pack ice continues to recede northward, most of the population migrates into the Chukchi Sea. The largest concentrations are found near the coasts, between 70 degrees North and Pt. Barrow in the east and between Bering Strait and Wrangel Island in the west. Concentrations, mainly of males, are also found on and near terrestrial haulouts in the Bering Sea in Bristol Bay and the northern Gulf of Anadyr throughout the summer. In October the pack ice develops rapidly in the Chukchi Sea, and large herds begin to move southward. Many come ashore on haulouts in the Bering Strait region. Depending on ice conditions, those haulout sites continue to be occupied through November and into December, but with the continuing development of ice, most of them move south of St. Lawrence Island and the Chukchi Peninsula by early to mid-December.

 

The Alaska Fish & Game department also says that concentrations of walrus on beaches is not unusual. “Best known among the Walrus Islands is Round Island, where each summer large numbers of male walruses haul out on exposed, rocky beaches.” “Walrus return to these haulouts every spring as the ice pack recedes northward, remaining hauled out on the beach for several days between each feeding foray. Up to 14,000 walrus have been counted on Round Island in a single day. However, the number of walrus using the island fluctuates significantly from year to year.”

Perhaps the discrepancy between the USGS and other agencies lies in the fact that the USGS has relied on satellite tracking of tagged walrus over a relatively short time frame, whereas the other agencies rely on ground and aircraft observation over much longer periods. And perhaps the fact that the feds are considering putting walrus on the endangered species list has some bearing on the alarm story from the always politically correct biological arm of the USGS. While, I suppose, one could quibble about the frequency of occupation for particular beaches, the fact that these animals occupy beaches from time to time is not at all unusual.

See the current state of Arctic sea ice here and here.

One comment

  1. Data Analysis of Recent Warming Pattern in the ArcticMasahiro Ohashi1) and H. L. Tanaka2)1) Graduate School of Life and Environmental Sciences, University of Tsukuba2) Center for Computational Sciences, University of TsukubaAbstract:In this study, we investigate the mechanism of the arctic warming pattern in surface air temperature (SAT) and sea ice concentrations over the last two decades in comparison with global warming since the 1970s.According to the analysis result, it is found that the patterns of SAT and sea ice before 1989 are mostly determined by the Arctic Oscillation (AO) in winter. In contrast, arctic warming patterns after 1989 are characterized by the intensification of the Beaufort High and the reduced sea-ice concentrations in summer induced by the positive ice-albedo feedback.It is concluded that the arctic warming before 1989 especially in winter was explained by the positive trend of the AOI. Moreover the intensified Beaufort High and the drastic decrease of the sea ice concentrations in September after 1989 were associated with the recent negative trend of the AOI. Since the decadal variation of the AO is recognized as the natural variability of the global atmosphere, it is shown that both of decadal variabilities before and after 1989 in the Arctic can be mostly explained by the natural variability of the AO not by the external response due to the human activity.http://www.jstage.jst.go.jp/article/sola/6A/SpecialEdition/6A_1/_articleAuthor’s Commentary“According to our result, the rapid warming during 1970-1990 contains a large fraction of unpredictable natural variability due to the AO. The subsequent period of 1990-2010 indicates a clear trend of the AO to be negative. The global warming has been stopped by natural variability superimposed on the gentle anthropogenic global warming. The important point is that the IPCC models have been tuned perfectly to fit the rapid warming during 1970-1990 by means of the ice-albedo feedback (anthropogenic forcing) which is not actually observed. IPCC models are justified with this wrong scientific basis and are applied to project the future global warming for 100 years in the future. Hence, we warn that the IPCC models overestimate the warming trend due to the mislead Arctic Oscillation.”

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