Rocch, the french "mussel watch", provides chemical data for marine quality management. Once a year, trace metals, organic compounds (chlorinated, PAH, brominated flame retardants, perfluorinated compounds, organotins ...) are analysed in molluscs tissues to check chemical quality according to European Framework Directives and to Regional Seas Convention (OSPAR).

ROCCH, the French Chemical Contaminant Monitoring Network,  regularly provides a new official dataset for assessing the chemical quality status of French coastal waters. Concentrations of trace metal elements and organic compounds were measured in samples of marine surface sediments collected in the English Channel and Bay of Biscay, during 3 campaigns over a period of 6 years. Samples of fine sediment material, from 200 to 250 monitoring stations, were freeze-dried and sieved prior to analysis. The Results were submitted to the international database of ICES (for the OSPAR Convention).