To assess the effects, levels and trends of hazardous substances in marine sediment and biota. The indicator organisms include blue mussel, dogwhelk, cod and plaice. The monitoring sites are mostly coastal and the frequency of sampling is mostly annually for biota and every 10-15 years for sediment. Main gaps: Protected areas and offshore monitoring are generally not included under the CEMP but offshore monitoring is somewhat covered by. IMR/NIFES programmes. Not all substances under EU’s Water Frame Work Directive and Marine Strategy Directive are monitored regularly. Biological effects monitoring is lacking except for IMPOSEX investigations.