||Characterising nitrous oxide release into the atmosphere related to coastal hypoxia
Seasonal hypoxia in the waters due to human activity creates dead zones in the summer months. Increasing in severity with global warming, it not only affects sea life but stimulates nitrous oxide (N2O) emissions, further increasing global warming and ozone depletion. With the support of the Marie Sklodowska-Curie Actions programme, the DYNOX project will investigate the role of seasonal hypoxia in N2O exchange across the sediment-water-air interfaces. An innovative observational paradigm will enable unprecedented analysis of N2O fluxes, their natural variability related to seasonal hypoxia and potential changes with further ocean warming and deoxygenation, and microbial responses. Outcomes will help local authorities prioritise locations for environmental monitoring.
The DYNOX project will elucidate the role of seasonal hypoxia as a driving mechanism for the exchange of the potent greenhouse gas (GHG) nitrous oxide (N2O) across the sediment-water-air interfaces in anthropogenically impacted coastal regions. To this end, the applicants propose to employ a comprehensive and innovative observational approach in Lake Grevelingen (Netherlands), which is a saline coastal reservoir that experiences seasonal hypoxia as a result of limited water exchange after two dams were built in the 60s-70s. The measurement strategy will consist of novel shipboard measurements, laboratory-based incubation experiments and analysis of archived samples. This comprehensive approach will allow an unprecedented analysis of the fluxes of N2O from a shallow coastal ecosystem, their natural variability in response to the onset of seasonal hypoxia as well as potential changes with further ocean warming and deoxygenation, and the underlying microbial responses. DYNOX will not only close gaps in data and fundamental understanding in the field of Earth and Environmental Sciences, but will also provide valuable data to the Essential Ocean Variables Framework of the Global Ocean Observing System, and serve as a scientific basis for issuing recommendations to local authorities on priority locations for cost-effective environmental monitoring. Hence, the project will contribute to the research and innovation framework programme “Horizon Europe”, within the mission area “Healthy oceans, seas, coastal and inland waters”, as well as to the UN Sustainable Development Goals (SDG) by addressing SDG 13 “Climate Action” and SDG 14 “Life Below Water”. The project will be carried out during a fellowship at the Department of Earth Sciences at Utrecht University under the supervision of Professor Caroline Slomp, and is expected to promote substantial progress in the scientific career of Dr. Arévalo-Martínez, who aims to establish himself as an independent research group leader.