Regional Fisheries Management Organizations are mandated to manage and conserve the living resources of the ocean. In this undertaking, their efforts have not been entirely successful. One of the reasons for this failure revolves around the conflicting interests between coastal states, and distant water fishing states, flag states. At the heart of this conflict is the reluctance of flag states to exercise enforcement measures against fishing vessels flying their flag on the high seas, thereby undermining the conservation efforts. The recent international instruments make it quite clear that jurisdiction over fishing vessels on the high seas is no longer exclusively a matter for the flag state. They create competing jurisdictions on the high seas between flag and non-flag states. This work focuses on recent developments in the law of the sea with regard to the jurisdiction of coastal states to arrest fishing vessels that are deemed to be breaching fisheries law. The main issue considered is whether the arrest by a non-flag state of a fishing vessel engaged in illegal fishing on the high seas is permissible, and how this enforcement jurisdiction can be legitimately exercised.