The marine carbonate system is changing as uptake of CO2 from the atmosphere causes ocean acidification. Now, analysis of repeat observations demonstrates that the rate and extent of Arctic Ocean acidification is enhanced through increased transport from the North Pacific.
The oceans are providing a great service in moderating the rate of climate change through the uptake of CO2 from the atmosphere. However, the accumulation of CO2 comes at a cost; ocean acidification. The Arctic Ocean is considered highly sensitive to ocean acidification and is projected to be the first to undergo basin-scale acidification.
Emissions of carbon to the atmosphere continue to grow, promoting the transfer of CO2 into the ocean. Subsequent accumulation and reorganization of CO2 in seawater results in an increase in dissolved inorganic carbon, and reductions in both seawater pH and the mineral saturation state of calcium carbonate. The cold waters of the Arctic Ocean have a lower capacity to buffer CO2 increases and, consequently, undergo greater ocean acidification per unit CO2 increase than their temperate and tropical cousins. Ocean acidification will affect the survival of important Arctic species and, thus, the production, function and diversity of marine ecosystems: some species will be promoted and others relegated, even to the point of local extinctio.
The Arctic Ocean is home to productive fisheries and to organisms and ecosystems with high cultural and subsistence importance. To project, and thus capably manage, change in these services requires an intimate knowledge of the rate and variability of ecosystem-specific ocean acidification.
The Arctic Ocean is one of the most poorly studied regions, reflecting a lack of historical focus, high costs, poor accessibility due to challenges with ice cover, and a closed-door policy to some regions. It is imperative that Arctic Ocean research be coordinated at an international scale to support and harmonize sustained observations of ocean acidification. Only then will we realize informed regional management implementation, promoting the optimal provision and security of ecosystem and cultural services.
A conceptual view of the Arctic Ocean carbon cycle. Arctic Ocean acidification is responding to changes in the marine carbon and hydrological cycles. Increases in carbon are sourced from the atmosphere, land, and advection from other oceans. Ocean acidification can be further regulated or enhanced by internal, physical, biological, and geochemical processes. (Figure: From the publication, adapted from AMAP).