Memberships international:

International Council for the Exploration of the Sea (ICES)
Working Group on Transfer and Introductions of
Marine Organisms (WGITMO) and
ICES/IOC/IMO Working Group on Ballast and other
Ship Vectors (WGBOSV)
Baltic Marine Biologists (BMB)
Convener of Working Group 30: Non-indigenous Estuarine and Marine organisms (NEMO)
International Maritime Organization (IMO). Advisor of the German Delegation at the Marine Environment Protection Committee (MEPC), Ballast Water Working Group (BWWG)
Issue Group on Sustainable Shipping (IGSS)
IUCN, Invasive Species Specialist Group (ISSG)
Technical Advisory Group (TAG) of Global Ballast Water Programme (GloBallast)
European Research Network on Aquatic Invasive Species (ERNAIS)