Volker Mohrholz - Fields of activity

The Benguela upwelling system off south-western Africa is among the most productive marine ecosystems on our planet. In contrast to other major upwelling systems the Benguela comprises large hypoxic and anoxic shelf areas, which have strong influences on the recruitment strategies of many species inhabiting these areas. Annual fish catches in Benguela are an order of magnitude smaller than that of the Humboldt system despite the similar high levels of primary production in both systems. The oxygen poor environment on the shelf has been sustained for millenniums. This requires balanced oxygen and nutrient budgets, which are generally believed to be controlled primarily by large-scale circulation. These basin scale dynamics is overlayed with the mesoscale upwelling dynamics, forced by the local wind fields. The upwelling process lifts large amounts of nutrients into the euphotic layer and feeds the primary production. 

The focus of our work is on:

• the interaction between remote and local forcing
• the exchange between the shelf area and the adjacent ocean
• and on small scale processes (turbulence, internal waves) that have a major impact on vertical fluxes.