Century-scale trends and seasonality in pH and temperature for shallow zones of the Bering Sea

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Fietzke, Jan, Ragazzola, Federica, Halfar, Jochen, Dietze, Heiner, Foster, Laura C., Hansteen, Thor Henrik, Eisenhauer, Anton, Steneck, Robert S.
• Format: Text
• Language: English
• Published: National Academy of Sciences 2015
• Subjects: Physical Sciences; Bering Sea
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4364235/; http://www.ncbi.nlm.nih.gov/pubmed/25713385; https://doi.org/10.1073/pnas.1419216112

Increasing atmospheric CO2 concentrations are potentially affecting marine ecosystems twofold, by warming and acidification. The rising amount of CO2 taken up by the ocean lowers the saturation state of calcium carbonate, complicating the formation of this key biomineral used by many marine organisms to build hard parts like skeletons or shells. Reliable time-series data of seawater pH are needed to evaluate the ongoing change and compare long-term trends and natural variability. For the high-latitude ocean, the region facing the strongest CO2 uptake, such time-series data are so far entirely lacking. Our study provides, to our knowledge, the first reconstruction of seasonal cycle and long-term trend in pH for a high-latitude ocean obtained from 2D images of stable boron isotopes from a coralline alga.