Benthic macroinvertebrates as reference indicators for monitoring of anthropogenic isotope 137Cs contamination in the marine environment.

Due to the limited studies dealing with isotopes levels in benthic macroinvertebrates other than Mytilus sp. in period 2011-2018, macroinvertebrates and seawater samples from the southern Baltic Sea were collected. Activity of 137Cs was measured in most common benthic macroinvertebrates inhabiting southern Baltic Sea in the context of choosing the best bioindicators. Taking into account the narrow range of CR coefficients, statistically significant correlation between 137Cs activities in seawater and species, a high frequency of occurrence and thus high biomass and the common occurrence, only Limecola balthica could potentially serve as indicators for shallow and deep-sea areas accordingly. Widely spread Mytillus trossulus was characterised by large size variability in samples and shows no significant correlation between activities in species and seawater and appears not so common as L. balthica.

Non-indigenous species refined national baseline inventories: A synthesis in the context of the European Union's Marine Strategy Framework Directive.

Refined baseline inventories of non-indigenous species (NIS) are set per European Union Member State (MS), in the context of the Marine Strategy Framework Directive (MSFD). The inventories are based on the initial assessment of the MSFD (2012) and the updated data of the European Alien Species Information Network, in collaboration with NIS experts appointed by the MSs. The analysis revealed that a large number of NIS was not reported from the initial assessments. Moreover, several NIS initially listed are currently considered as native in Europe or were proven to be historical misreportings. The refined baseline inventories constitute a milestone for the MSFD Descriptor 2 implementation, providing an improved basis for reporting new NIS introductions, facilitating the MSFD D2 assessment. In addition, the inventories can help MSs in the establishment of monitoring systems of targeted NIS, and foster cooperation on monitoring of NIS across or within shared marine subregions.