Outlook on Changes in Bering Sea Oxygen Cycling

The Bering Sea is highly vulnerable to the effects of climate warming, with the threat of low-oxygen waters expected to increase as temperature rises. A regional ocean model was used to estimate and simulate the mechanisms that drive oxygen cycling in the region over a decadal hindcast (2003-2012). Comparison with observed data collected in 2008-2010 indicates that the model successfully simulates oxygen concentrations, particularly in the outer shelf domain. The results indicate that bottom oxygen is highest on the inner shelf domain and decreases in the middle and outer shelves. Interannual oxygen variability was relatively low except in the ice-free region southwest of St Lawrence Island. Intra-year bottom oxygen peaked in early June and reached its lowest level in early October, showing strong seasonal variation linked to biological respiration and remineralization. Future model projections are now being studied in order to better predict future oxygen regimes. Understanding current and future drivers of variability in oxygen cycling will inform commercial and cultural decision making as the region moves into a warmer, less-oxygenated regime.