Port State measures have been identified as a desirable and cost-effective tool in the fight against illegal, unreported and unregulated (IUU) fishing. In the past decade, national, regional and international initiatives have focused on increasingly stringent port and market State measures to deter, prevent and eliminate IUU fishing. This culminated in the negotiation of a Port State Measures Agreement, hosted by the U.N. Food and Agriculture Organization (FAO) during 2008 and 2009. Once it enters into force, it will be legally binding.

A conservation management measure (CMM) adopted by most of the high seas Regional Fisheries Management Organisations (RFMOs) is the maintenance of a list of vessels that have been found to be participating in or supporting IUU fishing. This measure aims to increase the costs and reduce the value of the vessels involved in such activities as contracting parties to the RFMO are asked to deny these vessels landing, transshipment of fish and provision of port services. Some RFMOs go further. In the case of the Northwest Atlantic Fisheries Organization (NAFO), North East Atlantic Fisheries Commission (NEAFC), Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) and the International Commission for the Conservation of Atlantic Tunas (ICCAT), this extends to denying them access to port.

Paragraph 56 of the FAO International Plan of Action on IUU fishing, adopted in 2001, and Paragraphs 2.6 and 2.7 of the FAO Model Scheme on Port State Measures, adopted in 2005, encourage States to limit access to their ports when they have clear grounds to believe that a vessel has engaged in or supported IUU fishing activity, and to assist other countries in their efforts to combat illegal fishing.
This study aims to investigate the port visits of vessels on the IUU vessel lists of four high seas RFMOs (CCAMLR, NAFO, NEAFC and the South East Atlantic Fisheries Organization) and four tuna RFMOs (Indian Ocean Tuna Commission, Inter-American Tropical Tuna Commission and Western and Central Pacific Fisheries Commission) over the past five years.

While vessels on the IUU vessel list represent only a small fraction of those operating illegally, they are a good indicator of the willingness or capacity of port States to implement the most basic port State measures.

This research also strives to use the data collected to identify the reasons for failures of compliance or lack of cooperation, as well as developing recommendations and tools to assist in the effort to deter, prevent and eliminate IUU fishing.