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According to an Inside Climate News report, polar bear researchers at the US Geological Survey had trouble darting bears in the Southern Beaufort Sea in March-May of 2019 and 2021. They claim their research program was hampered by thinner-than-necessary ice for safely landing the nearly 4,000 lb. outfitted helicopter (with crew and gear) in 2019 but that conditions in 2021 were even worse (it is implied work proceeded in 2020 despite pandemic restrictions but no data for that year are discussed).

However, this claim of worse conditions in 2021 is not corroborated by reports from sea ice experts and ice charts for the Southern Beaufort this spring, where thick first year and multiyear ice was present from March through June. Ice didn’t begin to pull away from landfast ice to form patches of open water near the Canadian border until late April 2021 compared to early May in 2019 (as it did in 2016), as shown in the video and charts below. Moreover, the researchers oddly fail to mention that the presence of thin ice and open water in spring is essential for polar bear survival in the Southern Beaufort, a fact which has been documented and discussed in the scientific literature by their colleagues.

Polar Bears Are Suffering from the Arctic’s Loss of Sea Ice. So Is Scientists’ Ability to Study Them” (D. Hasemyer, Inside Climate News, 5 October 2021).

The reporter tries to paint a picture of polar bears suffering harm from these recent conditions but in fact there is no published data from the Southern Beaufort after 2016, and any effects claimed to have been documented in bears up to that year have not been conclusively demonstrated to have been caused by sea ice loss (Crockford 2021) because a correlation is not evidence of causation.

The ICN ‘story’ is really a big whine from researchers about not being able to work over the last three years because of weather conditions, used as a vehicle to reiterate their unfounded claims that these conditions have negatively impacted Southern Beaufort polar bears.

The condition of the sea ice has deteriorated so much that it’s been three years since Atwood and his colleagues have been able to physically examine a bear. When you’re studying polar bears, you need polar bears to study, is Atwood’s mantra.” 

The ICN headline blames “loss of sea ice” for the on-going problem with doing polar bear research in the Southern Beaufort but the story includes data that shows more than half of the problem is fog, although they don’t say at what time of year fog is a problem (March or May?).

The warmer Arctic waters have been linked to polar vortexes, unpredictable severe weather and heatwaves.

That’s on a global front. But in Atwood’s much smaller world the warming means more fog. And more fog means less flying time, because visibility drops to near zero in the dense, sheet-white vapor.

By his count, the number of suitable flying days has dropped by more than half over the last 20 years because of fog.

Looking back at flight logs, Atwood said, he found that fog grounded the center’s research helicopters about 24 percent of the time between 2000 and 2009.

That number increased to 46 percent between 2010 and 2015; and jumped to 56 percent over the last five years. It correlates with warming temperatures and disappearing sea ice. “We are losing over half of the time we could be in the air surveying the bears,” he said.

Read the entire sordid tale here.

S. Beaufort ice conditions 2021 Port Barrow to the Canadian Border March-May

Thick first year ice (>1.2m) and old, multiyear ice (dark green and brown) dominated with a few patches of thinner ice (light green and purple):

April 2021

May 2021

Western Beaufort ice conditions 2021, late May

The open water was not widespread across Alaska:

Southern Beaufort ice conditions 2019, March-May

Much more thin first year ice (light green) close to shore in early March 2019 compared to 2021:

By mid April 2019, that thin first year ice had become thick first year ice at least 1.2 m thick (dark green) with a few scattered thin patches in areas where polynya formation is routine:

By early May 2019, there were some patches of open water in between thick ice:

Western Beaufort 2019, late May

Not mentioned at all in this article is the fact that in spring in the Southern Beaufort, areas of thin ice or open water within regions of thick spring ice are essential to ringed and bearded seals as areas for breathing and resting on the ice between feeding bouts, and that polar bears are attracted to those areas because they are hunting hot-spots. I have discussed this extensively (with references) herehere, and most recently here.

Here is a quote from my 2015 post from a paper by Smith and Rigby (1981:24) on the development of open water in eastern Beaufort, 1975-1979:

“Some open water can be found in virtually all months somewhere in western Amundsen Gulf in the area of Cape Bathurst, Cape Parry, and Cape Kellet (Banks Island). Open water can appear as early as sometime in December, although it is not until April that a characteristic form to the polynya appears. 

During each of the 5 years [of the study: 1975-1979] an open lead developed off the eastern side of Cape Bathurst sometime in January (Fig.14a). This coincided with the appearance of open water just north of Cape Parry in 4 of the 5 years.

Open water remains in the general area, in some form, until late May to early June when, characteristically, the area between Cape Bathurst and Cape Kellett opens up to form a disintegration area. Until April, the size, shape, and location of open water is quite variable by month and by year (e. g. Fig. 14b). By April in most years, however, the polynya exhibits a more or less typical form (Fig. l4(c-f). With the advance of break-up, the open water between Cape Bathurst and Cape Kellett enlarges into Amundsen Gulf. In addition, open water develops northwards, along Banks Island, and westwards to Mackenzie Bay (see Fig. 14g. h).

The extent to which the shorelead polynya system in the Beaufort Sea is open is mainly dependent upon wind since this influences the movement of the Arctic pack. The coast was open to Mackenzie Bay in all five summers, and as far west as Barter Island in three.” [my bold]

In that 2015 post I also quoted this paragraph from a 1981 paper by Stirling and colleagues (Stirling et al. 1981:54) that explains why these Southern Beaufort spring polynyas are so important to polar bears:

“One useful approach is to ask what would happen if the polynya was not there? Obviously this is impossible to evaluate on an experimental basis, but by examining the consequences or natural seasonal variation, some useful insights can be gained. For example, the influence of rapidly changing ice conditions on the availability of open water, and consequently on populations of seals and polar bears, has been observed in the western Arctic. Apparently in response to severe ice conditions in the Beaufort Sea during winter 1973-74, and to a lesser degree in winter 1974-75, numbers of ringed and bearded seals dropped by about 50% and productivity by about 90%. Concomitantly, numbers and productivity of polar bears declined markedly because of the reduction in the abundance of their prey species. …If the shoreleads of the western Arctic or Hudson Bay ceased opening during winter and spring, the effect on marine mammals would be devastating.”[my bold]

Bottom line: The formation of patchy and/or thin sea ice in the Southern Beaufort close to shore in spring is a characteristic of the region known since the 1970s that is essential to the survival of seals and polar bears, not a dangerous anomaly that can be blamed on recent climate change. Not being able to land a 4,000 pound helicopter on spring ice whenever and where ever they prefer between early March and late May is a research constraint for scientists rather than a survival issue for polar bears. Furthermore, it is not apparent that sea ice conditions in 2021 were any “worse” that 2019 for either helicopters or polar bears although fog may have been worse in 2021.

References

Crockford, S.J. 2021. The State of the Polar Bear Report 2020. Global Warming Policy Foundation Report 48, London. pdf here.

Smith, M. and Rigby, B. 1981. Distribution of polynyas in the Canadian Arctic. In: Polynyas in the Canadian Arctic, Stirling, I. and Cleator, H. (eds), pg. 7-28. Canadian Wildlife Service, Occasional Paper No. 45. Ottawa.

Stirling, I, Cleator, H. and Smith, T.G. 1981. Marine mammals. In: Polynyas in the Canadian Arctic, Stirling, I. and Cleator, H. (eds), pg. 45-58. Canadian Wildlife Service, Occasional Paper No. 45. Ottawa.

Pdf of pertinent excerpts of above papers here.

via polarbearscience

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October 7, 2021