Denaturing gradient gel electrophoresis (DGGE) and fluorescence in situ hybridisation (FISH) were applied to biofilm and water samples collected from a number of North Sea seawater injection systems and a laboratory mesocosm model system.  The data were compared to determine common findings and gross differences between locations and the occurrence of MIC.  The results are discussed with regard to the potential of using DGGE and FISH protocols to develop a common routine monitoring tool applicable to the measurement of MIC mitigation controls.