EGU21-15806, updated on 04 Mar 2021
https://doi.org/10.5194/egusphere-egu21-15806
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

An inventory of dissolved oxygen conditions along the eastern boundary of tropical and subtropical Atlantic: building oxygen monitoring capacity in West African countries, 2013-2019

Paulo Coelho1, Pedro Tchipalanga1, Marisa Macuéria1, Anja van der Plas2, Benjamin N’Guessan3, Kanga Desiré3, Ahmed Makaoui4, Ismail Bessa4, Mohamed Idrissi4, Omar Ettahiri4, Karim Hilmi4, Issufo Halo5, Sunke Schmidtko6, Marcus Dengler6, Peter Brandt6,7, David Cervantes8, Helene Lødemol9, Melissa Chierici9, Marek Ostrowski8, Mamadou Lamba Bâ10, and the WG TOMSWA - Ad-Hoc Working Group on Transboundary Oxygen Monitoring Status in West Africa*
Paulo Coelho et al.
  • 1Instituto Nacional de Investigação Pesqueira e Marinha, Luanda Angola
  • 2Ministry of Fisheries & Marine Resources, Swakopmund, Namibia
  • 3Centre National de Recherches Océanologiques, Abidjan, Côte d’Ivoire
  • 4Institut National de Recherche Halieutique, Casablanca, Morocco
  • 5Department of Conservation and Marine Science, Cape Peninsula University of Technology, South Africa
  • 6GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
  • 7Kiel University, Kiel, Germany
  • 8Institute of Marine Research, Bergen, Norway
  • 9Institute of Marine Research, Tromsø, Norway
  • 10Institut Mauritanien de Recherches Océanographiques et des Pêches, Nouadhibou, Mauritanie
  • *A full list of authors appears at the end of the abstract
Climate change is expected to result in a reduction of oceanic oxygen concentration and an expansion of oxygen-minimum zones (OMZs) in the tropical ocean. Oxygen is perhaps the principal environmental variable influencing habitat and health of fish populations. In West Africa, where rich fisheries are essential for supporting the livelihood of coastal populations, the prospect of expanding hypoxic conditions into fishable coastal shelf waters is a major concern. A transboundary sharing of information on expanding OMZs could provide valuable operational data for fishers and managers, but the capacity for monitoring oxygen conditions at the trans-regional scale is today limited in many countries of the region. Here, we present an inventory of oxygen content in the coastal fringe off West Africa between 30°N and 30°S. Our aim is to present a unified and fisheries relevant information on oxygen water quality along the entire West African continental boundary. The inventory collates the results of recent international expeditions monitoring trans-regional oxygen data over the shelves of West African countries. The EAF Nansen Programme surveys on board the RV Dr Fridtjof Nansen in 2017 and 2019 provided one source such data. During these surveys, scientists representing regional research fisheries institutes carried out observations on dissolved oxygen conditions within their respective exclusive economic zones (EEZ). These data are complemented by oxygen data collected during different international expeditions particularly including research cruises with RV Meteor covering the EEZ of West African countries during 2013-2019. The Meteor results have long established the baseline for Oxygen Minimum Zone (OMZ) monitoring. Our inventory attempts to extend this baseline to cover the coastal West African waters.  In this presentation, we show the distribution of the mean and extreme oxygen conditions in the coastal fringe along the West African continental boundary, provide insight into the seasonal variability across the region, identify data-poor subregions, and discuss potential impacts of the observed oxygen distributions on local ecosystems and fisheries.
WG TOMSWA - Ad-Hoc Working Group on Transboundary Oxygen Monitoring Status in West Africa:

Coelho,P., Tchipalanga, P.,Macuéria, M., van der Plas, A., N’Guessan, B., Desiré, K.,Makaoui, A., Bessa, I., Idrissi, M., Ettahiri, O., Hilmi, K., Halo, I.,Schmidtko, S., Dengler, M., Brandt, P., Cervantes, D., Lødemol, H., Chierici, M., Ostrowski, M., Bâ, M.L., Sarre, A., S., Faye, S..

How to cite: Coelho, P., Tchipalanga, P., Macuéria, M., van der Plas, A., N’Guessan, B., Desiré, K., Makaoui, A., Bessa, I., Idrissi, M., Ettahiri, O., Hilmi, K., Halo, I., Schmidtko, S., Dengler, M., Brandt, P., Cervantes, D., Lødemol, H., Chierici, M., Ostrowski, M., and Bâ, M. L. and the WG TOMSWA - Ad-Hoc Working Group on Transboundary Oxygen Monitoring Status in West Africa: An inventory of dissolved oxygen conditions along the eastern boundary of tropical and subtropical Atlantic: building oxygen monitoring capacity in West African countries, 2013-2019, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15806, https://doi.org/10.5194/egusphere-egu21-15806, 2021.

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