Eastern boundary upwelling systems (EBUS) are located along the west coasts of the Americas and Africa, where strong equatorward winds promote cold and nutrient rich waters to be brought to the surface - a process called upwelling. The injection of nutrients to the sunlit surface layer enables proliferation of phytoplankton and makes upwelling regions some of the ocean’s most biologically productive regimes. They constitute less than 1% of the total ocean area, but account for nearly 20% of global fish catch. EBUS are hotspots of global climate change. Regional and more localized changes are expected in wind forcing, temperature as well as stratification. Deoxygenation and acidification will be additional sources of stress for EBUS ecosystems. However, fine-scale “chaotic” details of the oceanic circulation, with horizontal sizes between ~ 1 and 100 km arising from the turbulent nature of ocean flows can modulate biogeochemical changes in ways that are poorly understood until today. In addition, the effects of fine-scale ocean turbulence may be different in each EBUS.
West African (WA) societies such as Senegal, Mauritania and Guinea depend heavily on a healthy ocean which provides food and employment. For example in Senegal, small fish mainly caught close to the shores by artisanal fisherman is the most important source of animal protein for the population. In a perspective of adaptive management, it is key to understand how climate change is impacting these resources and ecosystem services. To provide robust and reliable projections of the future states of the WA coastal ocean, the interactions between fine-scale ocean turbulence and biogeochemistry has to be understood and accounted for.
WACO aims to clarify the role of fine-scale physical processes in the present-day functioning and future evolutions of the WA coastal ocean, including its biogeochemical cycles.
