Perhaps the folks on the platform couldn’t see it, but sea ice wasn’t far off on Monday when a polar bear came to visit the Hibernia oil platform southeast of St. John’s, Newfoundland. See the map below (composite from Heritage Newfoundland and Canadian Ice Service):
UPDATE 26 March 2015: Ian Stirling has added his expert comment on this incident, see below.
UPDATE 28 March 2015: Newfoundland’s Director of Wildlife has commented on this incident, see below.
According to a recent CBC story (23 March 2015):
“This polar bear was photographed from the Atlantic Merlin offshore supply vessel early Monday morning. It later attempted to climb onto the Hibernia gravity base structure. “
“Crew aboard the offshore supply vessel Atlantic Merlin got quite the surprise early Monday when they spotted a polar bear in the water not far from Hibernia.
The massive oil platform is located in the Atlantic Ocean some 315 kilometres east-southeast of St. John’s.
Sources say the bear was swimming far from any sea ice. It attempted to climb aboard the 600,000-tonne gravity base structure.
Margot Bruce-O’Connell, spokesperson for Hibernia’s majority owner ExxonMobil Canada, said one and possibly two bears were spotted in the area near Hibernia and the West Aquarius drill rig over the past few days.
…
Recent studies have shown that polar bears can swim distances of several hundred kilometers.“ [my bold]
Looking at the Canadian Ice Service map I copied above, makes me wonder who their “sources” were. Read the whole story here.
UPDATE 26 March 2015: CBC late yesterday published a follow-up article (“Expert says polar bear near Hibernia platform likely lost his way”) in which they quote polar bear biologist and adjunct professor (same as me!) Ian Stirling extensively. However, again, neither the article writer nor Stirling mention where the sea ice actually was in relation to the platform on Monday. In fact, Stirling intimates (but doesn’t actually say) that the bear originally came off ice that was very far away, in Davis Strait — and the CBC chose that sentence, highlighted in red below, to enlarge and emphasize beside the article (also screencapped and copied below). Have a look:
“Ian Stirling, an adjunct professor at the University of Alberta, said at this time of year, there are large numbers of harp and hooded seals offshore, and sometimes polar bears will leave sea ice in pursuit of their favourite prey.
Stirling said often the animals lose track of where they are.
“I think this is probably a fairly regular event. It’s not as common to actually see them,” he told the St. John’s Morning Show.
…
Stirling said polar bears start to feed on harp seals offshore and there are hundreds of thousands of them.
“Some of the bears get out there — and they’ve never had it so good. And they [the seals] don’t run away like a ring seal. But what they don’t notice is that sometimes the ice, with a bit of wind, is blown out and goes out to Davis Strait — and all of a sudden they’re far away from anywhere,” he said.
…
“It’s well-known that animals can swim on average long swims, 150 kilometres is what that they can handle. I think it’s touch-and-go even if he went in a straight line, whether he’ll be able to make it back to land at some point,” said Stirling.
“If he could see the platform from a distance, he would have gone over to it to check it out as a place to climb out. That’s what they do all over the Arctic,” he said.
“If they’re out on the sea ice and there’s a small island or a rocky cape, they’ll come in off the sea ice and head for those places. He was looking at that rig as a potential refuge.” [my bold]
There’s more — read the rest here.
Sidebar Stirling quote enlarged in March 25, 2015 CBC article.
UPDATE 28 March 2015: Newfoundland’s Director of Wildlife commented on this incident in a local radio interview this morning, confirming that at least some experts know that there was plenty of ice near the oil platform on Monday, when the incident occurred (as there has been all week):
“The province’s Director of Wildlife says polar bears spotted near the Hibernia platform last week may not necessarily be in trouble. John Blake says polar bears are extremely strong and well-adapted swimmers and can cover some very large areas. He says the bears need an ice platform to hunt from, and there’s plenty of ice off the coast of Newfoundland and Labrador this year.
He says polar bears are known to cover thousands of kilometres in a single week.” [my bold]
Listen to the rest here.
Blake says while it’s not common to see a polar bear that far offshore, the animals should have little trouble getting back to ice or land.
Regarding distances that polar bears are able to swim (i.e., reference to “recent studies”), I have copied below my “Featured Quote” #38. Turns out “several hundred kilometers” was a maximum of almost 700 km (by a mother and yearly cub).
Featured Quote #38 posted April 25, 2013
“…most of the long-distance swimming events that we identified involved bears swimming from unconsolidated sea ice to the main pack ice or to land.” Pagano et al. (2012).
From this study on polar bear swimming prowess:
Pagano, A.M., Durner, G.M., Amstrup, S.C., Simac, K.S. and York, G.S. 2012. Long-distance swimming by polar bears (Ursus maritimus) of the southern Beaufort Sea during years of extensive open water. Canadian Journal of Zoology 90: 663-676.
Tip: See the excellent summary of this study from the NIPCC (12 June 2012), excerpt below [my bold, quote above, in red below]:
“Pagano and colleagues calculated the mean distance between the mainland coast and the sea ice edge at the end of September for each year of the study period. This distance varied from a low of about 200 km (achieved in 2005, 2006, and 2009) and a high of about 430 km (achieved in 2008). Mean distance from the shore to the ice in 2004 was about 300 km and in 2007, it was about 380 km. Each of these measurements varied somewhat depending on the configuration of the shoreline, but in 2008 the ice edge was definitely the furthest away than in all other years back to 1979. However, the largest number of long-distance swimming events took place in 2009, when the ice edge in this region was about the same distance offshore as in 2005 and 2006.
The longest swim was recorded in late August/early September of 2008 at a point where the sea ice was >500 km offshore: a female with a yearly cub swam 687.1 km in just over 9 days, as described in detail by Durner et al. (2011). This bear was one of only two individuals in the Pagano et al. study described here that swam from land to the main pack ice edge; after a few weeks meandering around at the edge of the pack ice, this bear then walked back to shore on the rapid-forming ice, arriving on land at the end of October. The second longest swim (366.0 km) was recorded in 2005, when the pack ice edge was about the same distance offshore as in 2009.
Pagano et al. conclude: “we show that both adult female polar bears and their dependent young possess an ability to swim long distances.” They also state that “most of the long-distance swimming events that we identified involved bears swimming from unconsolidated sea ice to the main pack ice or to land.” In other words, few swims recorded were from land to sea ice, indicating that during the open water season, most southern Beaufort and Chukchi Sea polar bears are on the sea ice, not on land –– a point also made by Durner et al. (2011). In addition, the results of this study suggest that despite there being little or nothing for female polar bears and their cubs to eat on shore during the late summer months in the southern Beaufort Sea, the few bears that remain on shore are apparently not so hungry that they are undertaking long-distance swims to the pack ice to relieve their fast, although they appear able to do so. Despite an overall decline in September sea ice levels between 1979 and 2010, this study found no significant correlation between increased long-distance swims and increased amounts of open water in this region over time. [Archived 12 June 2012]”
See the entire NIPCC summary here.
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