The aim of the project „Identification of Organic Pollutants in the North and Baltic Seas” was to identify and quantify toxic organic substances in the marine environment of the North Sea and Baltic Sea for which environmental data are either insufficient or not available. The selection of compounds is based on the lists of substances identified for priority action by the ⁠OSPAR⁠ and HELCOM Conventions and the European Commissions Water Framework Directive.