The FAO Port State Measures Agreement sets minimum standards for port access by foreign flagged fishing vessels and related support vessels.
Port State Measures (PSM) are requirements established or interventions undertaken by port states which a foreign fishing vessel must comply with or is subjected to as a condition for use of ports within the port state. National PSM would typically include requirements related to prior notification of port entry, use of designated ports, restrictions on port entry and landing/transhipment of fish, restrictions on supplies and services, documentation requirements and port inspections, as well as related measures, such as IUU vessel listing, trade-related measures and sanctions.
The PSM hence, is a key tool to support mesures design to fight illegal, unregulated and unreported (IUU) fishing.
This video illustrates the topic:
More on PSM here