Herring gull eggs as bioindicators for chlorinated hydrocarbons (contribution to the German Federal Environmental Specimen Bank).

From its position in the marine food chain, the herring gull (Larus argentatus) is a suitable indicator for the level of contamination of its habitats with lipophilic chemicals, especially the chlorinated hydrocarbons. The gull's utility as an indicator is demonstrated by investigations performed at Trischen island in the Elbe estuary and Alte Mellum island situated in the Weser estuary, when judged by their ability to reflect variations in pollution levels. The use of the analysis technique developed and standardized for the German Environmental Specimen Bank gives comparable results for both temporal and spatial variations for contamination levels on the different islands in the Wadden Sea area (North Sea coast) of Germany