An experimental approach in studying the influence of mercury on a North Sea coastal plankton community

The development of North Sea coastal plankton communities in four simultaneously filled plastic bags was followed for one month. To obtain a concentration of 5 ppb in the water phase a single dose of mercuric chloride was added to two of the bags. This addition had a close impact on the development of the phytoplankton, while that on the zooplankton and the decomposers was less clear. In the course of the experiment, methylation of the added mercury proceeded in the sediment in the bags. The plastic bag method seems to be a suitable tool in toxicological research.