Geochemistry and Ecosystem Research in the Namibian Upwelling System (GENUS)

Summary of the project

The global coastal ocean comprises around 7% of the Earth surface, has a significant role in the sequestration of carbon by hosting 25% of global biological productivity (prominently in upwelling areas) and storing 90% of organic carbon runoff from land in sediments, and yields 90% of global fisheries. While the physical boundary conditions of shelf seas (and upwelling systems in particular) are adjusting to global warming, human society continues to exploit their natural resources (minerals, fossil fuels, fishes) without sufficient understanding and prognostic capabilities to foresee how exactly the interplay of changing physical drivers and continued exploitation will affect ecosystem structures and functioning.

GENUS aims to clarify relationships between climate change, biogeochemical cycles, and ecosystem structure in the large marine ecosystem of the northern Benguela/SW Africa. The coastal upwelling system has high seasonal and interannual variability in atmospheric forcing, in properties of water masses on the shelf offshore the Republic of Namibia, and in oxygen supply and demand on the shelf. In consequence, concentrations and ratios of nutrients in upwelling water and their CO2-content have steep gradients in space and time. In the past, significant and economically severe changes in ecosystem structure have occurred which are in part attributed to changes in physical forcing, translated to the ecosystem by oxygen dynamics.

The coastal upwelling system offers ideal conditions to address four scientific themes of relevance to IMBER goals:

  1. Retrospective analyses of physical boundary conditions and biogeochemical cycles;
  2. Identification of key processes/species and analysis of key rates of physical, biogeochemical and biological ecosystem components;
  3. Quantifying feedback of trophic structures on biogeochemical cycles;
  4. Simulations of interactions between shelf ecosystem – open ocean – atmosphere.

Project tasks, which are designed to build on and develop regional scientific capacity, are empirical and theoretical studies into processes and rates of ocean circulation, biogeochemical cycling of nutrient elements between water column, biota and sediments, and trophic interactions and energy flows. GENUS will employ a hierarchy of numerical models from regional climate, ocean circulation, ecosystems, and energy flows to develop scenarios of possible future developments of the coastal upwelling ecosystem to gauge how the interplay of changing physical drivers and continued exploitation will affect essential ecosystem goods and services.

GENUS II (2013-2015, second funding phase, funded by the German Federal Ministry of Education and Research) continues to study relationships between climate change, biogeochemical cycles of nutrient elements, radiatively active gases, and ecosystem structure in the coastal upwelling system of the northern Benguela/SE Africa.

Area of study

SE Atlantic, Northern Benguela Upwelling System off shore the Republic of Namibia

TimeTable for activities

First project period (GENUS I): April 1, 2009 to March 31, 2012

Second project period (GENUS II): 2013-2015