Pollution by plastics has been recognized recently as a serious issue of global concern with substantial risks for marine ecosystems, fisheries, and food supply to people. Plastic particles smaller than 2 mm (microplastics) are found everywhere in the ocean, from tropical to polar regions, frozen in Arctic sea ice and accumulating on the sea floor. Microplastic particles in very high concentrations have been shown to substantially decrease the feeding capacity, growth and reproductive output of marine organisms. The implications for biogeochemical cycles and the risks for marine ecosystems are not understood. Given that plastic inputs to the ocean are predicted to double in the next 25 years, an assessment of the potential risk is urgently needed. The candidate will develop and implemen