INTRODUCTION: Naturally occurring hydroxylated polybrominated diphenyl ethers (OH-PBDEs), their methoxylated counterparts (MeO-PBDEs), and polybrominated dibenzo-p-dioxins (PBDDs), together with their potential precursors polybrominated phenols (PBPs) and polybrominated anisoles (PBAs), were analyzed in blue mussels (Mytilus edulis) gathered along the east coast (bordering the Baltic Sea) and west coast of Sweden (bordering the North Sea). Brown algae (Dictyosiphon foenicolaceus) and cyanobacteria (Nodularia spumigena) from the Baltic Sea, considered to be among the primary producers of these compounds, were also analyzed for comparison. MATERIALS AND METHODS: The samples were liquid–liquid extracted, separated into a phenolic and a neutral fraction, and subsequently analyzed by gas chromatography–mass spectrometry (GS-MS). RESULTS AND DISCUSSION: The levels of OH-PBDEs, MeO-PBDEs and PBDDs were significantly higher in Baltic Sea mussels than in those from the west coast, whereas the levels of PBPs and PBAs displayed the opposite pattern. The blue mussels from the Baltic Sea contained high levels of all analyzed substances, much higher than the levels of, e.g., polybrominated diphenyl ethers. In addition, the GC-MS chromatogram of the phenolic fraction of the west coast samples was dominated by four unknown peak clusters, three of which were tentatively identified as dihydroxy-PBDEs and the other as a hydroxylated-methyl-tetraBDE. CONCLUSIONS: Clearly, all of the compounds analyzed are natural products, both in the Baltic and the North Sea. However, the geographical differences in composition may indicate different origin, e.g., due to differences in the occurrence and/or abundance of various algae species along these two coasts or possibly a more extensive dilution on the west coast.

Purpose As one component of the German ecological environment observation, the Environmental Specimen Bank program was initiated in the mid-1980s. Under the program, representative specimens of marine, fresh water, and terrestrial ecosystems are sampled regularly and archived under chemically stable conditions. An initial characterization of the samples provides data regarding the status quo of the respective ecosystems. The aim of the present publication is to give insight into these real-time monitoring data, which have been generated for the last 10 to 20 years. This is done exemplarily for the heavy metals cadmium (Cd), mercury (Hg), and lead (Pb) in marine specimens of the Baltic and the North Sea. Methods Bladder wrack (Fucus vesiculosus), blue mussel (Mytilus edulis), eelpout (Zoarces viviparus), and eggs of herring gulls (Larus argentatus) were sampled at one location in the Baltic Sea and at two sites in the North Sea (Schleswig-Holstein Wadden Sea and Lower Saxony Wadden Sea). Annual samples were pooled, homogenized, and analyzed for a set of elements. Cd and Pb were quantified after freeze-drying and microwave digestion using inductively coupled plasma-mass spectrometry. Total Hg in freeze-dried samples was determined by atomic absorption spectrometry using a direct mercury analyzer. Results Time series data covering up to two decades revealed comparable cadmium levels at all three locations. Concentrations in bladder wrack ranged between 0.10 and 0.37 µg/g on a wet weight basis (ww). Respective values for blue mussel and eelpout liver were 0.07-0.29 and 0.01-0.10 µg/g ww. Herring gull eggs were not included in cadmium analyses. Declining trends were observed in North Sea bladder wrack and mussels, eelpout from the Lower Saxony site, and mussels from the Baltic Sea. Upward trends were apparent in eelpout from the Schleswig-Holstein location. Mercury concentrations in Baltic Sea specimens ranged from 1.1-2.7 ng/g ww in bladder wrack to 2.6-5.1, 26-52, and 86-226 ng/g ww in blue mussel, eelpout muscle, and herring gull eggs, respectively. No temporal trends were observed. North Sea bladder wrack had accumulated 5.4-24 ng/g ww Hg. The respective Hg values for blue mussel and eelpout muscle were 19-64 and 73-187 ng/g ww. Highest Hg contents were detected in herring gull eggs (90-1,100 ng/g ww). Declining trends of Hg were observed in herring gull eggs at both North Sea locations and in blue mussels at the Lower Saxony site. Lead concentrations in Baltic Sea specimens were 48-222 ng/g ww in bladder wrack, 85-189 ng/g ww in blue mussel, 2.0-9.5 and 10-42 ng/g ww in eelpout muscle and liver, and 2.7-26 ng/g ww in herring gull eggs. In the North Sea, Pb concentrations were as follows: 68-397 ng/g ww in bladder wrack, 101-507 ng/g ww in blue mussels, 2.6-35 and 5.9-158 ng/g ww in eelpout muscle and liver, and 3.5-55 ng/g ww in herring gull eggs. Highest Pb-levels were found at the Lower Saxony site. Declining Pb-trends were observed in bladder wrack from the Baltic Sea; in bladder wrack and mussel at the Schleswig-Holstein location; and in bladder wrack, mussels, eelpout liver, and herring gull eggs at the Lower Saxony site. Conclusions During the 10 to 20 years of monitoring, reliable data were obtained which allow a good insight into metal contamination of marine biota. Assessment of the data according to OSPAR criteria (OSPAR 2005) revealed cadmium levels above the derived background concentrations in mussels of all three sites. Mercury levels above background concentrations were found at both North Sea locations, whereas only mussels at the Lower Saxony site had Pb concentrations above the reference value. Archived specimens are available for further analyses and questions which may arise in the future (speciation of elements, metallomics).