Coastal Upwelling System in a Changing Ocean
|Eastern Boundary Upwelling Systems (EBUS), which support the ocean’s most productive ecosystems and are of major importance to global food security, will be impacted by climate change in multiple ways. While upwelling-favourable winds are projected to increase in poleward regions of the EBUS, weakening wind and upwelling strengths are expected in equatorward regions. Stronger upwelling-favourable winds will be counteracted by increased thermal stratification due to surface ocean warming, the net result of which is still uncertain and likely to differ regionally and seasonally. Among the four EBUS the Humboldt Upwelling System (HUS) stands out in several ways. It is not only the largest and, in terms of fish harvest, most productive of the four EBUS, implying exceptionally high trophic transfer efficiency. It also displays a counterintuitive relationship between upwelling intensity and phytoplankton productivity. In view of its dominant role in global fisheries, there is an urgent need to explore the mechanistic links between upwelling intensity and ecosystem productivity and their sensitivity to climate change in the HUS. The CUSCO project will employ observational, experimental and modelling approaches to better understand the linkages between upwelling intensity, community productivity, food web structure, export and trophic transfer efficiency leading up to fish recruitment. CUSCO will be closely linked with complementary projects investigating other aspects of climate change in the HUS and their social and economic implications.