Jörn is WorldFish Director for Sustainable Aquatic Food Systems. He began his career in Hannover, Germany, studying biology and conducting research on blood parasites of common carp. His PhD focused on zooplankton and fish larvae interactions. After completing his PhD at GEOMAR in Kiel, Jorn coordinated herring larvae surveys in the North Sea and contributed to the stock assessment of North Sea Herring. He later joined Kiel University's Department of Economics, developing ecological-economic models. In 2014, Jorn expanded his work to West Africa, focusing on community perceptions of environmental and regulatory changes in Senegal, Cabo Verde, and Nigeria. Most recently, he led the Research Group on Marine Food Security at the Center for Ocean and Society (CeOS) at Kiel University and served as Chair of the Science Committee of the International Council for the Exploration of the Sea (ICES), overseeing the science of the organisation and supporting over 3500 scientists in their network.