Selected Results - Longterm monitoring
A selection of commented investigation results based on sampling data from the Environmental Specimen Bank.
Longterm monitoring
Accumulation patterns of heavy metals in the marine food web
The analysis of organisms from different trophic levels allows the assessment of the accumulation pattern of substances in the food web. Lead is not enriched in the marine food web. Highest levels are found in blue mussels. In contrast, mercury is clearly biomagnified with highest concentrations in herring gull eggs.
Longterm monitoring
Arsenic in environmental specimens
Levels of arsenic are mostly quite low. Continuous concentration trends over time are found only in single cases. During the monitoring period, decreasing arsenic concentrations were detected in spruce shoots from the Saarland conurbation (Warndt). Arsenic also decreased in herring gull eggs from the North Sea island Trischen. In contrast, levels of arsenic increased in bream from the Saale (Wettin).
Longterm monitoring
Cadmium in environmental specimens
Since the mid 1980s cadmium levels in spruce shoots and poplar leaves from the Saarland conurbation remained more or less constant.<br /> In marine samples cadmium levels increased, decreased or remained more or less constant depending on sampling area and specimen.
Longterm monitoring
Comparison between North Sea and Baltic Sea: Differences in levels of metals and arsenic in blue mussels
Blue mussels from the North Sea sampling sites Eckwarderhörne (Jadebay) and Südlich Lister Hafen/Königshafen (Sylt-Römö-Watt) have significantly higher mercury and arsenic contents compared to mussels from the Baltic Sea sampling site Darßer Ort. In contrast, cadmium levels are higher in Baltic Sea mussels. Lead concentrations are more or less the same in blue mussels from the sampling sites Darßer Ort and Eckwarderhörne whereas lower levels are observed in mussels from the Sylt-Römö-Watt. While nearly constant burdens are detected in mussels from Eckwarderhörne and Darßer Ort, concentrations of cadmium, mercury and arsenic have increased in mussels from the Sylt-Römö-Watt since the mid 1980s. <br /> Blue mussels from both North Sea sites exceed the OSPAR background concentrations for cadmium, lead and mercury. Respective background concentrations for Baltic Sea mussels are not available yet.
Longterm monitoring
Mercury contamination of environmental specimens
Since the late 1980s mercury levels in spruce shoots from the Saarland conurbation have declined considerably. A similar trend is apparent for herring gull eggs from the North Sea. In herring gull eggs from the Baltic Sea, however, mercury has increased slightly. Decreasing mercury levels are also detected in bream from Rhine, Elbe and Mulde whereas contamination of breams from the rivers Saar and Saale have increased slightly since the mid 1990s.