The Parties to the Nauru Agreement (PNA) controls the world’s largest sustainable tuna purse-seine fishery. PNA countries provide around 50% of the global supply of skipjack tuna, the most commonly canned tuna.

The PNA members are: Federated States of Micronesia, Kiribati, Marshall Islands, Nauru, Palau, Papua New Guinea, Solomon Islands and Tuvalu.

Article 4 of the Parties to the Nauru Agreement (signed in 1982 and amended in 2010) states that the member states need to establish particular procedures and administrative arrangements. These are for the exchange and analysis of:

  • statistical data about the catch and effort of fishing vessels in the fisheries zones
  • information about vessels and fleets.

The Vessel Day Scheme – cornerstone of the PNA

The Palau Arrangement for the operation of the Purse Seine Vessel Day Scheme (amended in October 2016) details how the PNA members manage tuna stocks sustainably while maximising local incomes. The arrangement sets out the operating rules for these two types of fishing vessels. Under the rules, the PNA members sell a limited number of fishing days in the exclusive economic zones of the PNA states.

The VDS applies to vessels:

  • operating under a valid licence issued under the Federated States of Micronesia (FSM) arrangement, adopted in 1995
  • fishing in waters outside of their own exclusive economic zone (EEZ).

Vessels operating under the VDS are allocated a maximum number of fishing days in a management year. Once this maximum has been reached, a vessel must immediately stop fishing outside its EEZ.

A “fishing day” is calculated according to how long a vessel is in the area, its fishing activity, and the size of the vessel:

  • if a vessel is in an area outside its EEZ for 24 hours and undertakes any fishing activity for any length of time = 1 day
  • if a vessel is outside its EEZ for only part of a day and fishes for only part of a day = part day
  • if a vessel is in an area outside its EEZ for 24 hours and undertakes no fishing activity = 0 day
  • for vessels smaller than 50 metres, 1 fishing day = 0.5 fishing days
  • for vessels 50–80 metres long, 1 fishing day = 1 fishing day
  • for vessels longer than 80 metres, 1 fishing day = 1.5 fishing days.

The Longline Vessel Day Scheme (amended October 2016) operates similarly to the Purse Seine VDS. For longline fishing, a fishing day is calculated according to:

  • the actual time spent fishing in the waters of any of the Parties (but not at port)
  • if a vessel is 40 metres or shorter, 1 fishing day = 0.8 fishing days
  • if a vessel is longer than 40 metres, 1 fishing day = 1.6 days.


The third arrangement for implementing the Nauru Agreement states that all bigeye, skipjack and yellowfin tuna taken by purse-seine vessels need to be kept on board until they are landed and transhipped, except for fish that are clearly unfit for human consumption, or excess fish caught in the last set of the trip that cannot fit on the ship.

The same arrangement states that no vessels are to deploy or service fish-aggregating devices (FADs) and associated equipment, or to fish by purse-seining vessels on floating objects, between 0001 GMT on 1 July and 2359 GMT on 30 September each year. The only exceptions are when there is deemed to be an unfair burden on a Party and or its domestic fleet.

It also defines the areas of the high seas that are closed to fishing as being:

  • the area bounded by the national waters of the Federated States of Micronesia (FSM), Indonesia, Palau and Papua New Guinea (PNG)
  • the area bounded by the national waters of FSM, Fiji, Kiribati, Marshall Islands, Nauru, PNG, Solomon Islands and Tuvalu
  • the area located within 10°N and 20°S latitude and 170°E and 150°W longitude.
The vessel day scheme is to control catch and harvest in PNA fisheries zones. Photo: Francisco Blaha.