Ecosystem assessment of the Central Arctic Ocean: Description of human activities, its pressures, and vulnerability of the ecosystem

Report, 2025

The Central Arctic Ocean (CAO) is a fast-changing region due to global warming. In addition, it is affected by pressures that are the result of both local human activities, such as research and ship traffic from tourism and the military, and distant global sources that arrive via air, rivers, and ocean currents.

Contaminants, non-indigenous species, marine litter (including microplastics), artificial noise pollution, nutrient and organic enrichment, extraction of species, extraction of non-living resources, physical seabed and sea ice disturbance, artificial light pollution, unintended injury and mortality in open water, and human presence on ice are the 11 local, direct human-induced pressures recognized as relevant for the CAO. Pressures from global sources include contaminants, litter, and non‑indigenous species that enter the ocean from outside the CAO. Both categories of pressure are included in this report. The impact of climate change originating from human activity (the pressure heating) is included as climate-related effects on the ecosystem.

Ice prokaryotes and viruses, water column and seabed prokaryotes and viruses, ice algae, phytoplankton, ice invertebrates, zooplankton, pelagic squid, soft-bottom and hard-bottom benthos, sympagic-, mesopelagic-, and demersal/bentho-pelagic fishes, polar bear, ringed seal, bowhead whale, narwhal, beluga whale, transient-, seasonal resident- and ice obligate-sea birds were identified as groups or species that represent relevant ecosystem components of the CAO. Most of these taxonomic groups have populations that are widely distributed across the entire CAO, while a few groups have limited distributions on the seabed (hard-bottom benthos), in the water column (whales), or along the ice edge (ice-obligate seabirds and ringed seal). While most ecosystem components are present inside the CAO year-round, some few components (whales and migratory and seasonally resident seabirds) are only present for a few months each year.

Some of the relevant pressures introduced by local sources in the CAO are anticipated to have impacts on all (e.g. contaminants), some (e.g. artificial noise pollution), or only a few (e.g. nutrient and organic enrichment) ecosystem components in the CAO.

This report is part II to CRR Vol. 355 - Ecosystem assessment of the Central Arctic Ocean: Description of the ecosystem.