A Legal Consideration on Port State Jurisdiction and Port State Control in respect of the Prevention of Vessel-Source Marine Pollution

Traditionally, the responsibility for securing the ships’ safety and the protection of the marine environment falls under a flag state flying its flag under international law. However, with the introduction of FOC regime, flag state control has weakened over the last few decades and this circumstance had resulted in severe maritime accidents and pollution incidents. Thus, the international community have been tried to contribute to the protection of the marine environment through the port states’ regulation under the recognition of that the flag state could be difficult to solve the issue of comprehensive regulation for the prevention and reduction of marine pollution. Under the LOSC, a port state may exercise legislative and enforcement jurisdiction over the ship that violated international rule and standards in their maritime zone and may institute proceedings over a foreign vessel that violated international rules and standards and IMO conventions relevant to marine pollution in the high sea or EEZ of another state. Port state control allows a port state to take proper measures over foreign vessels (e.g. ships’ detention or a port embargo) by verifying as to whether the ships comply with international rules and standards in respect of the safety of ships, certification and training of seafarers, crew competence and working conditions, in order to ensure maritime safety and protect the marine environment in their maritime zone. As a naturally acknowledged coastal states’ jurisdiction or sovereignty in the territorial sea under customary international law, besides, port state control enables a port state to fundamentally control vessel-source marine pollution by targeting ships’ physical defect or human defect as a prior measure. In contrast, port state jurisdiction based on Article 218 of the LOSC is not concerned with ships’ construction, equipment and design, but the violation of discharge standards referred in ’generally accepted international rules and standards’. Such port state jurisdiction seems to have a different viewpoint from traditional rule for maritime jurisdiction. In practice, port state control can be more effective measure than port state jurisdiction because port state control has low disturbance for international shipping and can play a role as a priori measure in preventing marine pollution. However, it should be kept in mind that a port state should actively exercise port state jurisdiction of the post-regulation level along with the exercise of port state control of a precautionary level to protect the marine environment of the global ocean and regional sea areas by preventing accidental discharges or operational discharges from ships beforehand. This study looks at in-depth the legal basis for port state jurisdiction and port state control as well as contents related to them. Further, this study wishes to refer to the contribution of port state jurisdiction and port state control to combat vessel-source marine pollution.