IUU Fishing in the Pacific: Where Enforcement Breaks Down
The best available estimate puts IUU fishing in Pacific Islands tuna fisheries at about 192,000 tonnes a year, worth about US$333 million at the boat. Most of it is not pirate vessels. The study commissioned by the Pacific Islands Forum Fisheries Agency found that misreporting by licensed vessels made up 89 per cent of the volume. Regional surveillance is strong and getting more targeted, but enforcement still breaks down in the longline fleet, on the high seas, at the edges of the region and in the slow step from detection to prosecution.
What IUU fishing means in the Pacific
IUU stands for illegal, unreported and unregulated fishing. In the Pacific Islands region the main concern is tuna, the resource that funds many island budgets through licence fees. The Pacific Islands Forum Fisheries Agency (FFA) coordinates monitoring, control and surveillance for its 17 members from its Regional Fisheries Surveillance Centre in Honiara, Solomon Islands (FFA, October 2026). On the high seas between national zones, the Western and Central Pacific Fisheries Commission (WCPFC) sets the rules. Its convention was adopted in Honolulu on Sept. 5, 2000 (WCPFC, CMM 2006-08).
The most detailed public estimate of the problem is a study by MRAG Asia Pacific for FFA, published as a 2020 update covering 2017 to 2019 (MRAG Asia Pacific for FFA, 2021). It sorted IUU risks into four groups: unlicensed or unauthorised fishing, misreporting, breaking other licence conditions such as shark finning, and post-harvest offences such as illegal transhipping.
What the numbers say
The 2020 update's best estimate is 192,186 tonnes a year of tuna product harvested or transhipped with some IUU element, with 90 per cent confidence that the figure lies between 183,809 and 200,884 tonnes. Its ex-vessel value is estimated at US$333.49 million. The authors put the volume at around 6.5 per cent of the total 2019 catch in the WCPFC Convention Area (MRAG Asia Pacific for FFA, 2021).
That is well below the first estimate in 2016, which put the figure at 306,440 tonnes and US$616.11 million. FFA's own committee paper cautions that much of the drop came from better and different information, not only from less illegal fishing, and that uncertainty remains high (FFA Fisheries Committee paper FFC120-WP.02). The study period also ended before COVID-19 disrupted monitoring (MRAG Asia Pacific for FFA, 2021).
| Category | Share of estimated IUU volume |
|---|---|
| Misreporting (catch under-reported, over-reported or misidentified) | 89% |
| Unlicensed or unauthorised fishing | 5% |
| Breaking other licence conditions | 3% |
| Post-harvest offences, such as illegal transhipping | 3% |
Source: MRAG Asia Pacific for FFA, 2021. By sector, the purse seine fishery accounted for 72 per cent of estimated volume, tropical longline for 21 per cent and southern longline for 7 per cent. Because longline-caught tuna is worth more, the tropical longline sector made up 40 per cent of estimated value. The study also estimated that IUU volume of bigeye tuna equalled around 24.3 per cent of the reported bigeye catch in the Convention Area in 2019 (MRAG Asia Pacific for FFA, 2021).
What regional surveillance found in 2026
FFA runs several coordinated operations each year. The 2026 results it has published show a system that is busy and increasingly driven by intelligence and satellite data:
| Operation (dates) | Inspections | Vessels of interest | Apprehensions |
|---|---|---|---|
| Rai Balang (Feb. 26 to Mar. 13) (FFA, March 2026) | 74 | 7 | 3 |
| Tui Moana (May 4 to 22) (FFA, May 2026) | 61 | 4 | 2 |
| Island Chief (Aug. 3 to 14) (FFA, August 2026) | 133 | 16 | 4 |
| KURUKURU (Oct. 5 to 16) (FFA, October 2026) | 82 | 13 | 1 |
KURUKURU covered about 30.5 million square kilometres and logged more than 27,000 satellite detections and 149 vessel sightings (FFA, October 2026). Island Chief analysed 10,884 satellite detections while monitoring more than 3,000 fishing vessels (FFA, August 2026). Tui Moana's suspected offences included vessel monitoring system (VMS) non-reporting, unauthorised bunkering and transhipment, and logsheet reporting (FFA, May 2026). The MRAG study credits regional tools such as the FFA Vessel Register, shared minimum licence terms, the FFA VMS, observer standards and the Niue Treaty for keeping IUU fishing in the region relatively low compared with many other parts of the world (MRAG Asia Pacific for FFA, 2021).
Where enforcement breaks down
The points below are ISPI's analysis, drawn from the sources cited. They show where the system is still weakest.
1. The problem is mostly inside the licensed fleet
Unlicensed fishing was only 5 per cent of estimated volume, and the study found no confirmed unlicensed fishing during regional operations by vessels on the FFA or WCPFC registers (MRAG Asia Pacific for FFA, 2021). Most of the risk sits with vessels that are allowed to fish but report their catch wrongly. That makes IUU fishing an accounting, verification and evidence problem as much as a patrol problem. A patrol boat can count vessels. It cannot easily check whether a logsheet matches what is in the hold.
2. The longline fleet and the high seas are harder to watch
The purse seine fleet operates under 100 per cent observer coverage, must tranship in port and fishes mostly inside national zones. The longline fleet has lower observer coverage, does far more of its fishing on the high seas, and tranships more of its catch at sea, which limits port checks. The study names longline catch monitoring and validation as the priority (MRAG Asia Pacific for FFA, 2021). WCPFC already bans purse seine vessels from transhipping on the high seas (WCPFC, CMM 2009-06 para. 32), while much longline catch is still transhipped at sea (MRAG Asia Pacific for FFA, 2021). High-seas boarding depends on WCPFC's boarding and inspection procedures, which were replaced by a new measure, CMM 2025-07, on Feb. 3, 2026 (WCPFC, CMM 2006-08).
3. Dark vessels and the edges of the region
The study found stronger evidence of regular incursions on the region's fringes, especially the western edge near Southeast Asian domestic fleets (MRAG Asia Pacific for FFA, 2021). Globally, a 2024 study in Nature found that 72 to 76 per cent of the world's industrial fishing vessels were not publicly tracked between 2017 and 2021 (Paolo et al., Nature, 2024). That is why the 2026 operations lean on satellite radar, radio-frequency and optical detection rather than ship transponders alone (FFA, October 2026). Public tools such as the Global Fishing Watch map help researchers and journalists see the same picture.
4. Detection does not equal prosecution
In 2026 the four operations listed above identified 40 vessels of interest and led to 10 apprehensions. Vessels of interest are referred to national authorities and flag states for follow-up under their own processes (FFA, March 2026; FFA, August 2026). Each case then needs evidence that holds up, trained prosecutors, courts and, often, cooperation from a distant flag state. In ISPI's view this is where small administrations are most stretched, because the work is legal and administrative rather than operational.
5. Coverage depends on partners
Aircraft and ships from Australia, France, New Zealand and the United States support every major FFA operation (FFA, October 2026). The United States has shiprider agreements with twelve Pacific Island countries that let local officers board vessels from U.S. Coast Guard cutters, and its expanded agreements with Palau and the Federated States of Micronesia allow some enforcement without an officer physically aboard (Foreign Policy Research Institute, Feb. 2025). On one 46-day patrol from Honolulu in 2025, the cutter William Hart carried out seven boardings with Pacific Island partners and two high-seas WCPFC boardings (U.S. Coast Guard, May 31, 2025). That help is real. It also means much of the region's at-sea coverage rests on outside navies and coast guards, which ties fisheries enforcement into great-power competition. ISPI's Operation Irensia 2026 analysis and the Solomon Islands call for a new fisheries surveillance centre look at that gap, and CM-14 and WP-01 cover how outside security interests play out in island communities.
What can close the gaps
Based on the sources above, ISPI sees five practical priorities for island governments and their partners:
- Catch validation for longliners, including electronic monitoring and checks as catch moves through the supply chain, which the MRAG study names as the top priority (MRAG Asia Pacific for FFA, 2021).
- Port controls. The FAO Agreement on Port State Measures is the first binding international agreement aimed specifically at IUU fishing (FAO). Ports are where catch can be inspected and refused.
- Prosecution capacity, so that vessels of interest become cases that are investigated, charged and resolved, with evidence standards built into how inspections are done.
- Shared intelligence, using the regional surveillance picture and satellite services so that small patrol fleets go where the risk is.
- Clear terms with partners, so that shiprider and patrol support strengthens island control of island waters rather than replacing it. ISPI's PB-03: Public Safety Policy for U.S. Pacific Territories and Compacts of Free Association explainer discuss how this plays out for U.S.-affiliated islands.
Fisheries enforcement also overlaps with other maritime threats. ISPI's CM-13 covers drug trafficking networks in the region, and the deep-sea mining explainer explains why monitoring at sea will only get harder as new ocean industries arrive.
What to watch next
- November 2026: FFA plans the official launch of its Pacific Guardian Surveillance System (PacGuard), which was trialled during KURUKURU (FFA, October 2026).
- 2026 onward: how WCPFC members apply the new high-seas boarding and inspection measure, CMM 2025-07 (WCPFC, CMM 2006-08).
- Follow-up on 2026 cases: whether the vessels of interest referred to national authorities and flag states lead to penalties (FFA, August 2026).
- A new IUU estimate: the last published figures cover 2017 to 2019, before COVID-19 affected monitoring (MRAG Asia Pacific for FFA, 2021).
Frequently asked questions
How much IUU fishing happens in the Pacific?
The FFA-commissioned 2020 update estimated about 192,186 tonnes a year of tuna product involving IUU activity in 2017 to 2019, worth about US$333.49 million ex-vessel, or around 6.5 per cent of the 2019 WCPFC Convention Area catch (MRAG Asia Pacific for FFA, 2021).
Is most IUU fishing in the Pacific done by unlicensed vessels?
No. Misreporting by licensed vessels made up 89 per cent of estimated volume, and unlicensed fishing about 5 per cent (MRAG Asia Pacific for FFA, 2021).
Who enforces fishing rules in Pacific waters?
Each country enforces its own laws in its exclusive economic zone. FFA coordinates regional surveillance for its 17 members (FFA, October 2026), WCPFC sets high-seas measures including boarding and inspection (WCPFC, CMM 2006-08), and partners such as the U.S. Coast Guard support patrols under shiprider agreements (Foreign Policy Research Institute, Feb. 2025).
What is a vessel of interest?
It is a vessel that surveillance and intelligence work flags for further investigation. FFA refers these vessels to the relevant national authorities and flag states for follow-up (FFA, March 2026; FFA, August 2026).
ISPI publishes its research free under CC BY 4.0. If your government, agency or organization needs a briefing on fisheries enforcement, maritime domain awareness or partner arrangements, you can commission research from ISPI. ISPI is a nonprofit organization; its application for 501(c)(3) tax-exempt status is pending. Contributions are not tax-deductible until IRS recognition is granted.
Sources
- MRAG Asia Pacific, “The Quantification of Illegal, Unreported and Unregulated (IUU) Fishing in the Pacific Islands Region – a 2020 Update,” report for FFA
- FFA Fisheries Committee, FFC120-WP.02, “Updated IUU Quantification Study Report”
- FFA, “Operation Rai Balang delivers strong start to 2026 Pacific fisheries surveillance,” March 2026
- FFA, “Pacific nations unite to strengthen fisheries surveillance through Operation Tui Moana 2026,” May 2026
- FFA, “Operation Island Chief identifies 16 vessels of interest,” August 2026
- FFA, “Operation KURUKURU: FFA wraps largest surveillance operation of 2026,” October 2026
- Paolo, F.S. et al., “Satellite mapping reveals extensive industrial activity at sea,” Nature 625 (2024)
- WCPFC, CMM 2006-08, Boarding and Inspection Procedures (superseded by CMM 2025-07 from Feb. 3, 2026)
- WCPFC, CMM 2009-06, paragraph 32 (purse seine high-seas transhipment prohibition)
- Foreign Policy Research Institute, “Strengthening Pacific Security: US Shiprider Agreements,” Feb. 2025
- U.S. Coast Guard, “Coast Guard Cutter William Hart returns home following 46-day Operation Blue Pacific patrol in Oceania,” May 31, 2025
- FAO, Agreement on Port State Measures (PSMA)
- Global Fishing Watch, public map
- ISPI papers: PB-03, CM-13, CM-14, WP-01
