POSTER SESSION 1
15:30–17:30, Monday, September 14
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1316 | POSTER 37
MONITORING CLIMATE-DRIVEN SHIFTS IN PHYTOPLANKTON AND MARINE LIGHTSCAPES IN THE WESTERN BALTIC SEA
The Western Baltic Sea is an optically complex, coastal transition zone where climate-driven changes are influencing phytoplankton phenology, community composition, and underwater light regimes. Observations indicate shifts in bloom timing and increasing occurrence of cyanobacterial and mixotrophic species, associated with warming, freshening, and nutrient feedbacks. These ecological changes occur alongside alterations in marine lightscapes, including coastal darkening, with implications for water quality monitoring and ecosystem assessment. Monitoring these changes remains challenging. The optical complexity of the region poses a particular challenge for ocean colour retrievals, where standard algorithms often exhibit systematic biases. Reliable validation of satellite-derived products is therefore essential to support both scientific applications and operational monitoring. Within the ValWaQua initiative (Validation Workflows for Water Quality Products in the Western Baltic Sea), multispectral and hyperspectral in situ measurements are used to evaluate the performance of Copernicus ocean colour products in the Western Baltic Sea. The analysis focuses on key variables relevant for water quality and ecosystem monitoring, (i.e. chlorophyll-a, Kd(443), turbidity, and remote sensing reflectance). Particular attention is given to identifying conditions under which products perform reliably, as well as sources of uncertainty and systematic bias. Python-based workflows provide standardised validation processing pipelines and facilitate consistent intercomparison of products. Parallel initiatives, SeaGuard (AI-Predictions of Seagrass Growth and Adaptation) and ISOLUME (Indicators of Changing Lightscapes in Underwater Marine Ecosystems) provide complementary frameworks for linking validated ocean colour observations with ecosystem responses, supporting the interpretation of observed variability. Together, these efforts support long-term monitoring and future integration into operational environments.
Bronwyn Cahill, Leibniz Institute for Baltic Sea Research Warnemuende, [email protected], https://orcid.org/0000-0002-3237-706X
Madhusmita Dash, Leibniz Institute for Baltic Sea Research Warnemende, [email protected]
Helena Frazao, Leibniz Institute for Baltic Sea Research Warnemende, [email protected]
Ulf Graewe, Leibniz Institute for Baltic Sea Research Warnemende, [email protected]
Robert Mars, Leibniz Institute for Baltic Sea Research Warnemende, [email protected]
Chandanlal Parida, Leibniz Institute for Baltic Sea Research Warnemende, [email protected]
Eefke van der Lee, German Hydrographic Agency, [email protected]
Thorger Bruening, German Hydrographic Agency, [email protected]
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
