The Humboldt Current System is one of the four large upwelling areas on the eastern oceans boundaries, which are characterised by a wealth of fish. These ecosystems have a high economic value for the neighbouring coastal states. Their fishery yields contribute about 20% to global fishery production, although the upwelling areas cover only about 1% of the ocean surface.
The reason for the high productivity of these areas is a continuous supply of nutrients from the deep water. The relatively constant trade wind in these shelf areas drives a current regime that pumps nutrient-rich water from deeper ocean layers into the light-flooded surface layer, where it stimulates a high productivity.
Because of the direct coupling of the current regime to the intensity and spatial extent of the trade wind, the upwelling areas at the eastern edges of the oceans react very sensitively to changes in atmospheric circulation, as is to be expected as a result of climate change. In order to be able to detect these changes in time, the team of scientists wants to investigate the effect of changing wind forcing on the dynamics of the Peruvian upwelling region. The following questions will be investigated:

• How do varying structures of the wind drive affect the upwelling?
• How is the upwelling intensity in the Peruvian ecosystem related to the growth of phytoplankton,
• and how do changes in the wind field caused by climate change affect the effectiveness of the food chain and thus the sustainably achievable catch quantities of anchovies.

The scientists plan to conduct an interdisciplinary expedition to obtain the decisive data to answer these questions. The intensive analysis of satellite data will be used to investigate the variability of the wind fields that cause upwelling and to determine changes on longer time scales. In addition, the further development of theoretical approaches and models plays an important role in improving the fundamental understanding of the processes in upwelling systems.
The CUSCO research project fits into the existing research priorities of the Leibniz Institute for Baltic Sea Research. In this way, the knowledge gained contributes to an understanding of the ecosystem dynamics of shelf areas and marginal seas. Thus the project contribute to the IOW's research objective to perform interdisciplinary research in coastal areas with the aim of better understanding their functionality. Measures for capacity development on site in the form of the integration of scientists and students from the region into the data collection and analysis will accompany the research project.
The German project consortium of scientists from leading German marine research institutions will be coordinated by Prof. Ulf Riebesell of the Helmholtz Centre for Ocean Research GEOMAR.