The Central Arctic Ocean ecoregion mostly comprises high seas areas remote from any landmass, including deep basins and slopes up to depths of approximately 500 m, as well as some shallower shelf areas of the bordering Beaufort/Chukchi and East Siberian/Laptev seas. The boundary of the ecoregion follows the outer slopes on the Eurasian side from the Chukchi Sea to the Barents Sea, the shelf edge of north Greenland and the Canadian High Arctic, and runs along the 76°N parallel or the 200-mile Exclusive Economic Zones (EEZs) in the Beaufort/Chukchi seas.
The ecoregion is largely understudied. Thus, information from adjacent seas and nearby areas is used to inform the overview of this ecosystem.
Key signals
- Climate change is the dominant and overarching driver in the ecoregion. Observed climate-related changes include decreases in sea ice extent and thickness, changes in salinity and freshwater content that affect water column stratification, the relative contributions/mixing of North Atlantic and North Pacific water masses in the ecoregion, and subregional increases in seawater temperature.
- The summer minimum sea ice extent decreased by a third in 2007–2020 relative to the 1979–2000 period. Old sea ice (> five years) decreased from 30% to 2% between 1979 and 2018. Mean sea ice thickness declined by 65% between 1975 and 2012.
- Receding sea ice has led to changes in both the range and abundance of species from primary producers to top predators. Examples include an increase in phytoplankton biomass, a reduction in the diversity and biomass of ice-associated algae and the expansion of the feeding migration of young ringed seals (Pusa hispida) into the ecoregion.
- Climate-related changes in both the ecoregion and adjacent seas are playing a key role in facilitating long-distance species exchange, population mixing, and pathogen transfer between the Pacific and Atlantic oceans.
- Ice-dependent fish and marine mammals are experiencing increased competition with boreal species for habitat and food throughout the ecoregion.
- The ecoregion has fewer human activities than other ecoregions and is a sink for contaminants and litter transported from global sources via ocean currents, rivers, and air.
- Climate change is affecting contaminant pathways and loading to the ecoregion and adjacent seas.
- Future perspective: sea ice loss is creating opportunities for the development and expansion of human activities in the ecoregion. However, the potential fish abundance is expected to remain far below levels that can sustain a viable fishery because of the low productivity of the ecoregion.
