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From Polar Bear Science
Dr. Susan Crockford
NOAAs annual Arctic Report Card is, for probably the most half, a valiant effort to show good and ambiguous information into harbingers of local weather change catastrophe. Main productiveness is up throughout a lot of the area (excellent news for wildlife) and regardless of Arctic temperatures being “twice as excessive” as the remainder of the world lately, the summer time sea ice ‘dying spiral’ has didn’t materialize.
Oddly, there isn’t any unhealthy information about polar bears (final point out was 2014). Nevertheless, the media have been informed that the few hundred sea birds that died this 12 months within the monumental Bering/Chukchi Sea area over the 4 months of summer time in 2022 is a portend of local weather change disaster–though the authors of the NOAA report admit they don’t have any conclusive proof to clarify the phenomenon. Nevertheless, listed below are additionally some trustworthy figures which might be fairly illuminating.
Sea ice
The graph on the backside of this graphic, unfold out relatively than bunched as much as make modifications appear extra dramatic, makes it a lot simpler to see the shortage of a declining development in sea ice extent since 2007, and that winter (March) protection has modified hardly in any respect.
Arctic temperatures
Examine the graph of general Arctic temperature on this composite to the ocean ice graph above: be aware the shortage of correspondence between common temperature and sea ice extent since 2007.
Lack of multiyear ice
The essay by Meier and colleagues additionally contains an attention-grabbing graphic, exhibiting modifications in multiyear ice over time since 1984. Be aware that multiyear ice is unproductive habitat so far as marine organisms are conserved: first 12 months (seasonal) ice over continental cabinets are the the most efficient and thus the place the overwhelming majority of polar bears, seals, fish, whales, and sea birds are discovered. I don’t see a lot cause to mourn the decline of extraordinarily thick multiyear ice (>4 years previous, crimson line within the graph beneath) so far as wildlife is anxious, particularly since 2-3 12 months previous ice that can be utilized as a resting/looking platform for seals and polar bears in summer time has not been declining since 2007.
Sea floor temperature
A graph of sea floor temperatures in August introduced by authors Timmermans and Lab reveals how chilly it has been for the final two years within the Chukchi Sea (the place Pacific walrus spend the summer time), mirrored the truth that sea ice within the area has not melted utterly over the summer time.
Main productiveness
The report by Frey and colleagues this 12 months updates these from the previous couple of experiences and confirms that major productiveness–which implies extra meals for seals, walrus, and polar bears–remains to be excessive in summer time resulting from much less sea ice protection, particularly within the Barents Sea, the Russian Arctic, the Bering/Chukchi Seas. The authors conclude:
All areas proceed to exhibit optimistic traits in major productiveness over the 2003-22 interval, with the strongest traits within the Eurasian Arctic and Barents Sea.
Broad areas of lower-than-average major productiveness throughout 2022, significantly for the Beaufort Sea, East Siberian Sea, Greenland Sea, and Baffin Bay (related to higher-than-average sea ice cowl in these areas)...
Within the graphic from the report beneath, be aware the gradual general enhance in major productiveness in Hudson Bay and the Greenland Sea in comparison with different areas. The report particularly mentions “higher-than-average sea ice cowl” as the reason for the Greenland Sea outcome however not for Hudson Bay (which is in any other case not talked about within the report). I’m wondering why? The Beaufort Sea (information not proven) apparently additionally had decrease than common productiveness resulting from excessive sea ice cowl. These are the 2 areas talked about most frequently as exhibiting sturdy indicators of declines in polar bear well being and survival resulting from lack of summer time sea ice, however I’m positive that’s only a coincidence.
Dying of sea birds
A report on 450 sea birds that died within the Bering and southern Chukchi Seas this 12 months in comparison with earlier years by Kaler and colleagues is a little bit of a head-scratcher. They admit they don’t actually know why massive numbers of birds have died lately however that always, the final word trigger seems to be hunger. They counsel this could possibly be resulting from a decline in major productiveness brought on by sea ice decline, in direct contradiction to the report by Frey and colleagues a couple of pages earlier than:
Seabirds are sentinels of the standing of marine ecosystems and these die-offs are concurrent with a large ecological shift ensuing from the lack of sea ice extent and period within the Bering and Chukchi Seas.…Whereas the precise reason behind why seabird die-offs have elevated in frequency stays largely unknown, the lower in sea ice extent and lipid-rich ice algae together with hotter ocean circumstances are possible concerned.
A brief report by the US Fish & Wildlife Service on the phenomenon in 2016 famous that sea birds can starve to dying in the event that they haven’t eaten in 4 days, which makes them significantly susceptible to any disruption of feeding, together with by storms.
The graphic beneath, supplied within the NOAA essay, reveals that the massive die-off of widespread murres in 2015-2016 (occasion #7) overshadows all current occasions. Solely about 450 birds died this 12 months, a comparatively small quantity in comparison with earlier occasions.
Be aware that the widespread murre is probably on of the commonest sea birds within the area and the Alaska inhabitants alone is estimated at 2.8 million birds in 230 colonies. It isn’t sudden, due to this fact, that many widespread murres die when circumstances are difficult, every time that occurs (e.g. particulars in graphic beneath for 1970).
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