It’s no secret that the habitat of our more Northern creatures is declining due to increases in overall temperature. It is also true that in the history of the earth, there have been closings and openings of waterways and formation and then subsequent retreat of glacial ice sheets; however, it is the rate at which Arctic ecosystems are now changing that is of concern (Root et al. 2003, Overpeck et al. 2005, Walsh 2008). Research is now being done to explore what the effects of melting ice and loss of habitat are on Arctic species populations.
One such paper was written by the Ecological Society of America (Moore and Huntington in 2008, Ecological Applications pp. S157-S165). In this paper, the authors explore how recent changes in Arctic climate may challenge the adaptive capability of more northern adapted species, such as some species of whales, walrus seals and polar bears. The issue is that other species of whales and seals only seasonally occupy the Arctic and subarctic, but are now more easily able to encroach into these northern habitats due to climate change. For example, killer whales can now more easily access northern Arctic habitats and compete with resident northern whale species there for prey and habitat. In the paper, the authors take a two-step approach to examining the impacts and resilience of Arctic marine mammals to climate change: a conceptual model that accounts for ecological scale of the species, and resilience scenarios relative to climate change in four Arctic regions (1 p. S158).
It is interesting to explore what the impact is on more northern species, when species that are less-well adapted to colder areas are able to infringe on these areas due to a warmer climate.
Other issues include the loss of sea ice due to melting, and therefore its loss in ability to serve as 1) platforms, 2) marine ecosystem foundations and 3) barriers to non-ice adapted marine mammals and human commercial activities (1). In the ice-obligate and dependent category, the polar bear provides the clearest example: reductions in sea ice remove their hunting and resting platforms and likely reduce survivorship of ringed seals, which are their primary prey (Derocher et al. 2004, Laidre et al. 2008) (1 pg. S159).
1). Moore, SE, Huntington, HP, Arctic Marine Mammals and Climate Change: Impacts and Resilience. Ecological Applications, 18(2) Supplement (2008), pp. S157-S165