The discharge of scrubber water – the water that is used to clean the exhaust gas in ships (see fact box) - will be banned from 1 July 2025. The ban applies in Danish waters that are within 22 km of the coast and is based on DTU research and other international studies.
DTU's research has documented that the scrubber discharge water increases mortality and reduces feeding and reproduction of zooplankton – the microscopic organisms that are the base of the marine food-web. Scrubber discharge water contains several heavy metals and PAHs that can bioaccumulate and are harmful to the entire food chain, from plankton to fish and invertebrates that live on the seabed.
DTU's Provost Christine Nellemann sees the research into scrubber water as an example of DTU delivering on one of the university's core tasks – namely research-based advise. This type of advise is either commissioned directly by the authorities or, as in this case, sought by the authorities due to the specific expertise of DTU Aqua in the field.
"One of DTU's important tasks as a university is to provide research and new knowledge that society can use. DTU researchers were among the first to document the damage caused by scrubber water to the aquatic environment. Since then, researchers have demonstrated the effects on some of the species living in coastal areas in Denmark, thereby creating a solid scientific knowledge base for politicians to legislate in this area," DTU Provost Christine Nellemann says.
