Losing our breath: The causes and consequences of aquatic deoxygenation

Dissolved oxygen losses are occurring in many waterbodies globally, including rivers, lakes and reservoirs, and marine ecosystems. Despite a large variation in deoxygenation rates among waterbodies, the causes of deoxygenation can be grouped into just a few categories, including reductions in solubility associated with warming temperatures, stronger and longer stratification that reduces deep-water ventilation, and increases in biological and chemical oxygen demand. Among these drivers, warming temperatures and stratification changes are global drivers affecting most regions, while changes in oxygen demand are often associated with local waterbody and landscape drivers. This talk will also briefly discuss some examples of research and monitoring programs actively seeking to understand the causes and consequences of aquatic deoxygenation. SCALE, A Survey of Climate and Adirondack Lake Ecosystems, is an example program focused on waterbodies in the Adirondack Park, New York State, USA. Deoxygenation impacts are diverse and can include the initiation of regime shifts resulting in a rapid transition to a less desirable state associated with lower water quality including the presence of harmful algal blooms. The loss of dissolved oxygen can harm biodiversity, contribute to release of phosphorus and dissolved organic matter from lake sediments, and regulate other processes such as mercury methylation and methane production. Given its global pervasiveness and widespread impacts aquatic deoxygenation can arguably be considered a Planetary Boundary process.

Presentation Preference: No Preference

Primary Presenter: Kevin Rose, Rensselaer Polytechnic Institute (rosek4@rpi.edu)

Authors:

Stephen Jane, Department of Applied and Computational Mathematics and Statistics, University of Notre Dame  (sjane@nd.edu)