This document describes a method to expose test organisms (amphipods), directly on the field by a caging methodology, with the aim to measure bioaccumulation of chemical substances on a monitoring station, i.e. either the concentrations of metals or organic compounds, or both, accumulated in the organisms.

This document also describes the specifications for test organism selection and conditioning, in situ exposure, and finally sorting and conditioning of the surviving organisms after exposure.

This document does not apply to organism preparation methods (freeze-drying, extraction, mineralization) and quantification of the chemical substances.