Reference organisms for assessing the impact of ionizing radiation on the environment of the southern Baltic Sea

Assessing the impact of ionizing radiation on the marine environment requires a well-defined methodology, which includes, among other elements, the analysis of exposure and effects. One of the most important components of the assessment system is the choice of reference organisms specific for the assessed area that fulfill requirements such as radioecological sensitivity, widespread distribution, and amenability to research and monitoring. The following species specific to the southern Baltic Sea that represent diversified ecological niches were proposed as reference organisms. Polysiphonia fucoides was proposed as a representative of macroalgae. Pelagic and benthic fauna were represented by Crangon crangon (crustacean), Saduria entomon (crustacean), Hediste diversicolor (polychaete), and Mytilus trossulus (mollusc). Fish were represented by Clupea harengus (pelagic planctotrophic fish), Gadus morhua (pelagic carnivorous fish), and Platichthys flesus (benthic fish). Activity concentrations of 137Cs were determined in reference biota as well as in seawater, as required for the total dose-rate evaluation, and relevant concentration factors were calculated.