By introducing full accountability through catch quotas instead of landing quotas the fisherman's incentive to optimise the value of his catch by discarding less valuable fish would be substituted by his incentive to use selective fishing methods to optimise the value of his total removals from the stocks. The trial aimed at testing whether CQM could provide a reliable accounting for all catches of cod, give better scientific data and encourage fishermen to fish more selectively and reduce accidental catches. The main feature of the trial is that all catches count against the vessel quota and that the fishing vessels are monitored from port to port using sensors and CCTV technology.