Identification of UV filter enrichment areas in the Baltic Sea - Investigation of the transport processes and long-term sinks in water and sediment

• Applicant: Dr. Kathrin Fisch
• Subject Area: Oceanography
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 502554158

Pollution of the marine environment by organic UV filters is of increasing scientific concern. Studies have shown that UV filters can have potential negative effects on organisms. This has already led to bans on the use of some UV filters in sunscreen products in Palau and Hawaii. The Baltic Sea is a popular holiday and leisure region. It is exposed to high anthropogenic pressure from pollution. This pressure is further intensified by the fact that pollutants accumulate in the Baltic Sea. At present, however, there are only a few studies on the occurrence of UV filters in the Baltic Sea. The focus of this project is to gain a better understanding of the behavior and fate of UV filters in the Baltic Sea. So far, they have only been detected in coastal areas (water phase) and few surface sediments (open Baltic Sea). UV filters are mainly introduced into the Baltic Sea via the water phase (directly or indirectly). Currently it is not proven whether these are transported in the water phase from areas close to the coast into the open Baltic Sea or if they accumulate in bays and areas of high spatial pollution exist. The key to a better understanding of possible transport processes is to better understand the UV-filter dynamics between the individual compartments water, sediment and biota. It is well known that pollutants such as persistent organic pollutants are depleted in seawater with the spring and summer bloom and are enriched with the sinking biomass in the sediment. This process can also be of great importance for the transport of UV-filters from seawater into the sediment. It is assumed that UV-filters can adsorb on sediments, which could thus act as sink for them. The function of sediments as long-term sinks has not yet been investigated in detail. The investigation of UV-filters in different sediment layers in connection with age dating of sediments is relevant to study the importance of the sediment sink function and the fate of UV-filters in the marine environment. In addition, the possibility of analyzing the accumulation of UV-filters in the biomass will be opened up in order to investigate the transport process from the seawater into the sediment. Several campaigns are planned to sample the seawater and sediment phase and the biomass (algae blooms) at different seasons. The UV-filter concentrations will be quantified and qualified using modern analytical methods. The results will contribute fundamentally to (i) identifying regionally contaminated areas and (ii) to better understand the transport processes of UV-filters between the different compartments water, sediment, and biota (iii) and to demonstrate the importance of sediments as long-term sinks.

• DFG Programme: Research Grants
• International Connection: USA
• Co-Investigator: Professor Dr. Detlef Eckart Schulz-Bull
• Cooperation Partner: Professor Dr. Lee Blaney