Exploring the Possible Impacts of WTO Rules on Fisheries Subsidies: The Case of the Southern Longline Tuna Fishery in the Western and Central Pacific

The report examines how WTO rules targeting illegal, unreported and unregulated (IUU) fishing, overfished stocks, and overcapacity would affect the Southern Longline (SLL) tuna fishery. While target stocks like South Pacific albacore are healthy, the fishery suffers from 'economic overfishing' characterized by falling catch per unit effort (CPUE). Analysis suggests that vessels from China and Chinese Taipei may be heavily dependent on subsidies to remain viable, whereas Fijian-flagged vessels appear marginally profitable without them. The report argues that while subsidy prohibitions could reduce overall effort and improve CPUE, they must be balanced with the development aspirations of Pacific Island countries (PICs), who rely on tuna for GDP and employment.

• The Southern Longline (SLL) fishery is experiencing 'economic overfishing,' where catch per unit effort (CPUE) has been falling since around 2000, meaning fewer fish are caught for the same operational cost despite target stocks remaining biologically healthy.
• Estimated cost and revenue structures suggest that larger vessels (>24m) from China and Chinese Taipei may be unable to cover operating costs without financial assistance, making them highly vulnerable to subsidy prohibitions.
• In contrast to distant water fleets, Fijian-flagged longliners appear to be marginally profitable on their own, with tax concessions for fuel and bait having a negligible impact on their overall viability.
• IUU fishing in the SLL fishery is primarily driven by misreporting (57%) and illegal transshipment (36%) rather than unlicensed fishing, which is considered negligible.
• A WTO subsidy prohibition based on the fishing of overfished stocks would likely trigger for all fleets in the fishery because the oceanic whitetip shark, a common bycatch species, is assessed as overfished.
• The impact of an IUU-triggered subsidy prohibition would be limited if based solely on the WCPFC IUU Vessel List, which contained only three vessels in 2019.
• Prohibiting subsidies for operating costs (including fuel) or for fishing beyond national jurisdictions could reduce overall effort in the fishery, potentially improving CPUE for remaining vessels.
• Subsidy prohibitions on capital costs or vessel importation could disproportionately harm Pacific Island countries (PICs) by hindering their ability to modernize aging fleets or develop domestic industries.

APA

Sen, S., & Cartwright, I. (2019). Exploring the Possible Impacts of WTO Rules on Fisheries Subsidies: The Case of the Southern Longline Tuna Fishery in the Western and Central Pacific. International Institute for Sustainable Development. https://www.iisd.org/system/files/publications/fisheries-subsidies-tuna-pacific-en.pdf

Chicago

Sen, Sevaly, and Ian Cartwright. Exploring the Possible Impacts of WTO Rules on Fisheries Subsidies: The Case of the Southern Longline Tuna Fishery in the Western and Central Pacific. International Institute for Sustainable Development, 2019. https://www.iisd.org/system/files/publications/fisheries-subsidies-tuna-pacific-en.pdf.

Wikipedia

{{cite report |last1=Sen |first1=Sevaly |last2=Cartwright |first2=Ian |title=Exploring the Possible Impacts of WTO Rules on Fisheries Subsidies: The Case of the Southern Longline Tuna Fishery in the Western and Central Pacific |publisher=International Institute for Sustainable Development |date=December 2019 |url=https://www.iisd.org/system/files/publications/fisheries-subsidies-tuna-pacific-en.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{sen2019exploring, author = {Sen, Sevaly and Cartwright, Ian}, title = {{Exploring the Possible Impacts of WTO Rules on Fisheries Subsidies: The Case of the Southern Longline Tuna Fishery in the Western and Central Pacific}}, institution = {International Institute for Sustainable Development}, year = {2019}, month = dec, url = {https://www.iisd.org/system/files/publications/fisheries-subsidies-tuna-pacific-en.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }