In an article published in Science of the Total Environment Ramon et al. presents a comprehensive temporal analysis of the eutrophication status of the Oslofjord, Norway, spanning the period from 1960 to 2023. Using an updated version of the HELCOM Eutrophication Assessment Tool (HEAT), the study consistently identifies “eutrophication problem areas” — particularly in the inner fjord and regions downstream of large catchments and urban centers.
These findings, grounded in well-established assessment criteria, provide a robust foundation for developing evidence-based nutrient management strategies. Without targeted intervention to reduce nutrient inputs, the Oslofjord will remain classified as a “problem area.”

You can find the article by following the link: https://www.sciencedirect.com/science/article/pii/S004896972501099X?dgcid=author