The Benguela System under climate change - Effects of Variability in physical forcing on carbon and oxygen budgets

11.01.2022 – Our first day on board the "Merian"

Today, organisational points were mainly on the agenda. First of all, of course, the obligatory safety briefing. Afterwards, the lab places were divided up according to need and we could already start unpacking the containers. Everyone was busy getting their measuring instruments and experimental set-ups ready for use and setting up their workstations for the coming weeks. So, the first day quickly came to an end. In the evening, there was a first scientific meeting with an overview of the programme for the coming days.

But first, some information about who "we" actually are and why we are participating in this expedition:
We are a team of 22 scientists from different fields of natural sciences. Besides oceanographers, our team also includes (geo)microbiologists, ecologists, trace gas chemists and geologists from the IOW in Rostock and the MARUM in Bremen. This expedition is the second in the framework of the BMBF-funded research project EVAR: "The Benguela Upwelling System under climate change - Effects of variability in physical forcing on carbon and oxygen budgets". The Benguela upwelling system is one of the most biologically productive marine areas on our planet. It extends from southern Angola along the coast of Namibia to the Atlantic coast of South Africa. The regular upwelling of nutrient-rich deep water into the light-flooded, warmer surface layers creates ideal growth conditions for phytoplankton and microorganisms, and consequently for fish and other marine life. In return, however, the bacterial decomposition of the organic material sinking from the surface leads to a strong oxygen depletion in deeper water layers and thus to the microbial formation of climate-relevant gases such as nitrogen oxide and methane, as well as the toxic gas hydrogen sulphide.

So far, little is known about how climatic changes influence ocean currents and upwelling intensity in the Benguela region. Within the EVAR project we want to investigate the complex interactions between upwelling intensity and microbial processes in the water and sediment, as well as the ecology of macrobenthic communities in the area. In the coming days, we will introduce you to the different projects on board in more detail.

 

Text: Fabian J., Braun P. (both IOW)