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Model Simulations for an improved Eutrophication Assessment in the Baltic Sea

01.08.2023 - 31.12.2025
Project manager:
Dr. Sarah Piehl
UBA - Umweltbundesamt
Focus 4: Coastal seas and society

The inter- and transdisciplinary project UBA-MoSEA utilizes high-resolution simulations with the 3D ecosystem model ERGOM-MOM to improve the assessment of eutrophication in the western Baltic Sea. On the one hand, causes for contradictory assessment results of the eutrophication indicators (nutrients and chlorophyll-a) are to be found in order to propose solutions for more reliable assessments in this area. As eutrophication is currently managed at many different levels, a harmonized approach between nutrient loads at the limnic-marine transfer point and the eutrophication status of the inner (EU-WFD) and outer coastal waters as well as the adjacent deep basins of the open Baltic Sea (EU-MSRL) will be investigated by a case study. In addition, the ability of the model to reproduce other indicators particularly relevant to shallow coastal waters, such as water transparency, will be investigated. Specifically for the proposed HELCOM indicator "shallow water oxygen", the model products are used to provide a better basis for the assessment of the indicator. Here, the provisional target and threshold values of the indicator need to be critically reviewed. The results generated by the model will be regularly discussed with national authorities (UBA, LUNG, LfU) in order to develop application-oriented solutions for improved water quality management in the western Baltic Sea.


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  • Schaub, I., R. Friedland and M. L. Zettler (2024). Good-Moderate boundary setting for the environmental status assessment of the macrozoobenthos communities with the Benthic Quality Index (BQI) in the south-western Baltic Sea. Mar. Poll. Bull. 201: 116150, doi: 10.1016/j.marpolbul.2024.116150
  • Arlinghaus, R., R. Friedland, P. Roser, D. Niessner, W.-C. Lewin, M. Dorow and L. Westphal (2023). Menschgemachte und natürliche Umweltveränderungen an den Bodden. In: Boddenhecht – Ökologie, Nutzung und Schutz von Hechten in den Küstengewässern Mecklenburg-Vorpommerns. Berlin: Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB) im Forschungsverbund Berlin e. V. (Berichte des IGB): 68-97, doi: 10.4126/FRL01-006453300
  • Friedland, R., C. Vock and S. Piehl (2023). Estimation of hypoxic areas in the western Baltic Sea with geostatistical models. Water 15: 3235, doi: 10.3390/w15183235