Impacts on the world’s biomes

6.6.8 Polar regions

Biodiversity in the Arctic and Antarctic regions is under particular stress (Bennett et al. 2015) (see Section 4.3.2). Many native species are in decline; rising temperatures and invasive species, especially in the sub-Antarctic and Antarctic Peninsula, are major pressures (Hughes, Cowan and Wilmotte 2015; Amesbury et al. 2017). Industrial development, pollution and local disturbances present additional pressures (Conservation of Arctic Flora and Fauna [CAFF] 2013), with polar regions acting as a sink for many anthropogenic pollutants such as persistent organic pollutants (POPs) and other synthetic organic chemicals (Alava et al. 2017).

Substantial changes expected to Antarctic ice sheets before the turn of the century may have considerable global consequences (Chown et al. 2017) (see Section 4.3.2). Under most climate scenarios, the Arctic is projected to be ice-free in summer by 2050 (IPCC 2013, p. 1090), although remnants of multi-year ice will remain off the coasts of Canada and Alaska. The retreat of sea ice is likely to result in major ecological shifts linked to:

1. an increase in primary productivity as a result of more open water and greater freshwater flow carrying nutrients;
2. a comparable shift in the source and quality of food for species at higher trophic levels such as krill, fish and marine mammals (Frey et al. 2016; Alsos et al. 2016); and
3. an influx of new species into the polar regions with productivity and food web relationships changing as coastal and sea ice systems of polar regions experience earlier spring bloom and longer growing periods for microalgae (Potts et al. 2016).

Average abundance of Arctic vertebrates increased from 1970 until 1990 and then remained fairly stable through to 2007, as measured by the Arctic Species Trend Index (McRae et al. 2012; CAFF 2013). However, some food resources are being lost in areas of diminishing sea ice, posing health risks to species such as the walrus, ivory gull, polar bear and Barents Sea harp seal (CAFF 2017). Penguins are one of the more regularly monitored species groups in Antarctica, and populations have been changing over the last century with recorded declines in some colonies of macaroni, Adélie and chinstrap penguins (Trathan, Lynch and Fraser 2016).

It is likely that, due to higher productivity, the availability of some natural resources will increase for circumpolar peoples and communities (Arrigo 2014), but changes in hunting conditions will have a detrimental impact on the Inuit and other groups that have relied on seal hunting and other traditional food sources for which sea ice provides access. Some negative impacts are already being felt; for example, a significant die-off of seals and walruses in the Pacific Arctic in 2011 affected food sources for indigenous communities in the United States of America, Canada and Russian Federation (CAFF 2017). Breaks in the dormancy of pathogenic bacteria and viruses in thawing permafrost are a direct threat to human health (Sutherland et al. 2018).

The opening of potential new fishing zones, oil and gas development and shipping may result in future conflicts, especially with regard to economic use, governance, cultural interests and marine protected areas. As the Antarctic has no indigenous people or local communities and is outside the range of the Convention on Biological Diversity’s Nagoya Protocol, the equitable sharing of benefits from biodiversity to people, including those benefits derived from bioprospecting, represents a particular challenge not completely addressed by the Antarctic Treaty System (Chown et al. 2017).