The report summarises the monitoring activities within the National Swedish Contaminant Programme in marine biota. In this report, we present time series and maps of most contaminants in various species but we only comment results that shows large differences compared to the previous year. Results show that herring from Holmöarna had elevated concentrations during the last two years of the time series for approximately half of the analysed metals, most chlorinated pesticides, polychlorinated biphenyls (PCBs) and brominated flame retardants (BFRs). The last two years’ Herring is on average one year older than the previous years’, heavier and the last years’ fat percentage is ca. 2 % higher compared to the year before. These differences in biological variables may have had an influence on the elevated contaminant concentrations. Also, herring from Väderöarna shows increasing concentrations for several chlorinated pesticides, PCBs, dioxins, and BFRs during the ten most recent years. A reason for this might be that the included fish were older during the seven most recent years, although their size was similar or smaller than previous years. Additionally, the fat percentage of the tissue has also decreased over time and might influence the results.

This year’s report is also the first to show PFAS concentrations in Cod, Perch and Eelpout where Perch has the highest concentrations of most PFASs within the Baltic Proper sampling sites.

This report is also the first report within the Swedish National Monitoring Programme of Contaminants in marine biota presenting environmental contaminant data in eggs of Common tern and Eurasian oystercatcher. In general, many of the compounds could be detected in Common tern and Eurasian oystercatcher.

Concentrations of several of the contaminants are similar in the two species, but there are exceptions among each contaminant class and even opposing time trends for some contaminants. There are clear differences in contaminant concentrations between species for PCDD/Fs and BFRs; for most PCDD/Fs, concentrations are higher in Eurasian oystercatcher compared to Common tern, while for the BFRs concentrations are higher in Common tern, with the exception of HBCDD.