15th April 2011.
A Royal Society workshop on the topic of seawater deoxygenation, organised and led by Anthony Cohen and Neil Edwards (both at the Department of Earth and Environmental Sciences, The Open University), took place at Chicheley Hall, the Kavli Royal Society International Centre, on 11-12 April. The meeting had additional financial support from MethaneNet and The Open University
Twenty international experts in the field gathered to review current knowledge and to exchange ideas on the oxygen status of oceans and coastal waters in times past, present and future. The context of the meeting is the evidence that seawater deoxygenation is currently increasing, amid concerns about the impact of this increase on ecosystem services provided by the world’s oceans.
When asked to consider the key questions and uncertainties facing researchers in this field, the participants drew up a long and diverse list of issues. These included the relationships between nutrient availability, oxygen, other biogeochemical cycles and feedback processes, the difficulty of representing the oxygen state in models, the lack of understanding of the trigger mechanisms and the reasons for apparent slow state of recovery from anoxia. The palaeo-community was well represented at the meeting and emphasised the contribution provided by studies of past Oceanic Anoxic Events, in which large-scale destabilisation of methane hydrate has been implicated.
The interaction between seawater oxygen and the present day methane cycle was also noted as an issue. Whilst it was not the focus of attention at this meeting, the question of how changes in the oxygen status of seawater might affect methane flux from the oceans is one that will concern many scientists seeking to understand and predict greenhouse gas emissions.