Deoxygenation: Open Ocean and coastal water

Background and Rationale

Oxygen is critical to the health of the planet. It impacts the biogeochemical cycling of carbon, nitrogen and other key elements, it structures aquatic ecosystems, and is a fundamental requirement for aerobic life from the intertidal to the greatest depths of the ocean. Over geological timescales, recurring changes in the oxygenation status of the ocean have resulted in multiple biotic crises with concomitant changes in marine ecosystems and climate balance (Wright et al., 2012). Most ocean organisms larger than a single cell, and even many microbes, require an adequate supply of oxygen for survival. They depend on oxygen in the water in the same way that animals on land depend on oxygen in the air. A reduction in ambient oxygen below that adequate level causes physiological stress and behavioral changes, and if conditions are sufficiently severe, eventually leads to death. Available monitoring data show that Low Oxygen Zones expansion in the modern ocean is occurring at a rate higher than previously estimated under the combined effect of eutrophication and global warming. The consequences of this expansion are already observed globally, including: reduced biodiversity of higher trophic level and a diversion of the food web towards microbes, collapse of marine resources and modification of the cycling of essential elements. Low Oxygen Zones expansion is expected to have significant impacts on the production and transport of radiative active trace gases, and the earth’s biogeochemical balance in general. Global and regional coupled climate-marine biogeochemical models project that deoxygenation of marine waters will further worsen with continued increases in global temperatures and human population size, leading to widespread consequences for ocean health and ultimately human wellbeing.

The Go2Ne network

The IOC-UNESCO (Intergovernmental Oceanographic Commission from UNESCO) Global Ocean Oxygen NEtwork (GO2NE) is a sustained interdisciplinary network focusing on ocean oxygen and the risks related to its changing concentration. GO2NE has the aim to connect scientists from a wide variety of disciplines and geographic research foci (e.g. open ocean and coastal areas) and is expected to increase the awareness of the potential negative impacts of deoxygenation on the marine environment, to improve the communication and cooperation among experts and decision makers to discuss potential mitigation and adaptation measures, to highlight the importance for sustainable management of ocean resources and to encourage and support capacity building for research and development.



  • Denise Breitburg (Smithsonian Environmental, Research Center; USA)
  • Francisco Chavez (Monterey Bay Aquarium Research Institute; USA)
  • Daniel Conley (GeoBiosphere Science Centre, Department of Geology, Lund University; Sweden)
  • Véronique Garçon (CNRS, LEGOS, France)
  • Denis Gilbert (DFO; Canada)
  • Dimitri Gutierrez (Instituto del Mar del Peru; Peru)
  • Marilaure Grégoire (MAST, University of Liège, Belgium)
  • Nicolas Gruber (Eidgenösische Technische Hochschule Zürich; Switzerland)
  • Tatjana Ilyina (Max-Planck-Institut; Germany)
  • Gil S. Jacinto (University of the Philippines; Philippines)
  • Lisa Levin (Scripps Institution of Oceanography; USA)
  • Karin Limburg (Environmental, Science & Forestry, SUNY; USA)
  • S.W. Naqvi (National Institute of Oceanography, India)
  • Andreas Oschlies (GEOMAR; Germany)
  • Grant Pitcher (Department of Agriculture, Forestry and Fisheries and the University of Cape Town; South Africa)
  • Nancy Rabalais (Louisiana Universities Marine Consortium; USA)
  • Mike Roman (University of Maryland, Center for Environmental Science, USA)
  • Kenneth Rose (Louisiana State University; USA)
  • Brad Seibel (University of Rhode Island; USA)
  • Maciej Telzewski (IOCCP; Poland)
  • Moriaki Yasuhara (University of Hong Kong, School of Biological Sciences, Swire Institute of Marine science, and Department of Earth Sciences ; Hong Kong)
  • Jing Zhang (East China Normal University; China)
  • Ivonne Montes (Ministry of Environment; Peru)


  • Kirsten Isensee (IOC-UNESCO)
  • Henrik Enevoldsen (IOC-UNESCO)