Water Column Monitoring 2012 Troll C platform

The WCM programme was performed at the Troll field where the potential biological effects of operational discharges were investigated. The 2012 WCM programme focused on caged mussels allowing for an increased number of sampling stations and biological effects endpoints to be measured. Therefore, the programme involved 13 mussel stations including 2 reference stations and 11 exposure stations. The positions of the 11 exposure stations at 500 m, 1000 m and 2000 m from the Troll C platform were positioned with respect to the predicted, and later confirmed, plume direction (Fig 1). Mussels (Mytilus spp.) were held at a depth of 15 m at all stations and retrieved after an exposure period of 6 weeks. The current meter data confi1med the expected dominant direction of the PW plume, and the stations selected for the biomarker analysis were in the PW plume axis direction.