ROCCH, the french monitoring network carried out by Ifremer,  surveys chemical contaminants levels in coastal areas through two programmes, mussel watch programme and  sediment watch programme. In 1996, 2006, 2012 and 2017, samples were collected in different french mediterranean lagoons for metallic contamination evaluation. In 2017, organic pollutants  from the WFD and MSD european directives were analysed too. Data were completed by additional elements of diagnosis like organic matter, total nitrogen and phosphorus concentrations. Chemical contaminant are analysed in whole sediment and co - factors like aluminium and organic carbon are simultaneously measured for normalisation procedures.