Archives par mot-clé : Bears

Arctic Sea Ice Still Quite Abundant for Early Summer

by S. Crockford, Jul 15, 2022 in WUWT/PolarbearScience


Despite rhetoric to the contrary, there is still plenty of sea ice over Arctic regions this summer, supplying feeding platforms for polar bears, ice-dependent seals, and walrus cows nursing their young calves. Forget about whether the numbers are below or above some short-term average, there is no catastrophe in the making for marine mammals in the Arctic at this time.

Remember, by early summer, young seals have left the surface of the ice and are in the water feeding; predator-savvy adults and subadults are hauled out on broken chunks of ice moulting their hair-coat. They may look like sitting ducks but polar bears have a hard time catching them because the seals are vigilant and have many escape routes available (due to all the open water). Most polar bears in Hudson Bay are still on the ice (you’ll see why below): the live cams near Churchill set up to watch polar bears are presently showing images of ravens with sea ice in the background, not bears.

This post is predominantly sea ice charts for mid-July, what we in the science field call observational evidence, aka ‘facts’. Keep in mind that satellites used to produce these images have an especially hard time distinguishing ice topped with melt water from open water, which means much more ice useful to these marine mammals is almost certainly present than is shown in the charts (as much as 20% more in some regions).

Arctic-wide levels, NSIDC Masie

 

Polar Bears’ Arctic Sea Ice Ecosystem Not In Danger Of Melting Away

by S.J. Crockford, October 31, 2018 in ClimateChangeDispatch


What’s a good analogy for sea ice as essential polar bear habitat? Biologist Andrew Derocher claims that the soil in a forest is appropriate because without the soil you can’t have the forest ecosystem.

However, that’s a specious comparison because the amount of soil in a forest does not change markedly with the seasons the way that Arctic sea ice does.

A much better analogy is a big pond that dries up a bit every summer. The amount of habitat available to sustain aquatic plants, amphibians and insects is reduced in the dry season but many species have special adaptations for surviving reduced water availability.