From Fallout to Fish: The Irish Sea and the Baltic Sea in Focus

The Irish Sea and the Baltic Sea remain among the most Cs-137 contaminated seas in the world. However, the reasons for this pollution could not be more different. While the Baltic Sea was accidentally contaminated by global fallout after the Chernobyl reactor accident in 1986, the Sellafield reprocessing plant deliberately used the Irish Sea for the discharge of low-level radioactive liquid waste between the 1950s and 1990s. More than 30 years later, these contaminations can still be detected in the fish, water, and sediments of both seas. Monitoring the Cs-137 concentration in fish is essential to assess the potential radiation exposure to humans. In a new study, researchers from the Thünen Institute of Fisheries Ecology and the Federal Maritime and Hydrographic Agency, led by Dr. Pedro Nogueira, show that the Baltic Sea is still the leader in radioactive contamination with Cs-137 in fish: in Baltic Sea fish, the activity is up to 4.6 times higher than in fish from the Irish Sea.

Original publication: Nogueira P, Kammann U, Schmied SAK, Aust M-O (2024) Comparison between the Baltic Sea and Irish Sea level of Cs-137 contamination on benthic, demersal and pelagic fish species. Journal of Environmental Radioactivity 278:107510.