Context

Offshore fishing in the Western and Central Pacific Ocean (WCPO) predominantly targets high-value tuna species such as albacore, bigeye, and yellowfin. These fisheries operate under established management frameworks, seeking to optimise yield while maintaining sustainability. However, this fishing activity often results in the incidental capture of non-target species, commonly referred to as bycatch, which includes finfish, billfish, sharks and rays (elasmobranchs), marine mammals, and sea turtles. While some bycatch species are discarded at sea, others, such as juvenile tuna or non-exportable species, may be retained and sold domestically as byproduct.[1]

The unintentional capture and mortality of these non-target species can impact marine biodiversity. Globally, bycatch is recognised as a critical risk to approximately half of all marine mammal and seabird species, the majority of elasmobranchs,[2] and all seven sea turtle species.[3] Given the ecological importance and vulnerability of many bycatch species, ongoing monitoring and impact assessments are essential. In the WCPO region, bycatch assessments involve detailed analyses of longline and purse seine observer data to estimate species composition, frequency, and mortality trends, so that region-specific issues can be identified.[4]

These assessments contribute to regional stock assessments and enable countries to implement responsive management measures as needed. At the regional level, the Western and Central Pacific Fisheries Commission (WCPFC), through its Scientific Services Provider (SSP), the Pacific Community (SPC), conducts stock assessments and provides scientific advice to member countries. These scientific outputs support national bycatch reporting and inform the development of domestic fisheries legislation, policies, and regulatory frameworks.

Change process

In support of national-level monitoring and reporting, countries collaborate with the SPC to generate tailored bycatch reports. These reports provide national estimates using country-specific observer datasets and methodologies aligned with regional analyses.

In the case of the Cook Islands, a draft National Bycatch Report was developed as part of broader support provided to Pacific-European Union Marine Partnership (PEUMP) programme member countries. The report was prepared by SPC using national longline observer data and was co-authored by SPC’s long-time fisheries consultant, Tom Peatman. It drew upon established methodologies, including those used in regional analyses presented to the WCPFC’s Scientific Committee (SC18 report, WCPFC, 2022).

The draft report was reviewed by Cook Islands officials and national stakeholders during 2022–2023. Based on their feedback, SPC adjusted the final version in 2023–2024. This iterative process enhanced national ownership and alignment with domestic data priorities.

Results and Impact

The completion of the Cook Islands' draft National Bycatch Report marked a significant step forward in strengthening the country’s capacity to assess and manage non-target species interactions in its longline fishery. The final draft report:

• Enhanced national understanding of bycatch composition and trends within the Cook Islands’ Exclusive Economic Zone (EEZ);
• Strengthened national evidence-based policymaking by providing science-based estimates of bycatch rates by species group;
• Increased data availability to inform ecosystem-based fisheries management (EBFM) approaches and international reporting obligations;
• Supported the Cook Islands in meeting its WCPFC reporting responsibilities on bycatch and ecosystem impacts.

In response to the insights gained from the longline bycatch report, the Cook Islands formally requested the development of a similar assessment for its purse seine fishery. This follow-up initiative reflects the country’s increasing commitment to adopting an ecosystem approach to fisheries management (EAFM)—an approach that recognizes and addresses the broader ecological impacts of fishing beyond the sustainability of target stocks.

The national bycatch report played a crucial role in informing the Cook Islands’ national fisheries planning, particularly in guiding consultations related to sustainable tuna development strategies under the Tuna Management and Development Plan (TMDP). The scientific evidence and ecological insights derived from the assessment enhanced national understanding of non-target species interactions and provided a stronger foundation for integrated and forward-looking fisheries governance.

As a direct outcome of this work, the process has fostered a national commitment to expand bycatch assessments to additional gear types, including purse seine operations. This marks a significant step toward further strengthening the Cook Islands’ ecosystem-based management framework and underscores the country’s dedication to responsible, evidence-based, and transparent fisheries management.

Lesson Learned:

Based on the responses received from stakeholders that were contacted for this story, the following are some actionable lessons learned:

• • While high-level engagement with senior officials is important, the operational staff play a key role in interpreting data, providing field insights, and implementing actions. The limited engagement with technical staff during the development of the Cook Islands report suggests the need for more inclusive and structured communication throughout the reporting process to enhance ownership and utility of the findings.
  • The report's use of well-organized graphs and explanations was noted as a strength. This reinforces the value of clear data visualization and structured narratives in scientific reporting, which helps facilitate better decision-making.
  • The draft bycatch report directly informed the revision of the Cook Islands’ TMDP. This demonstrates the benefit of aligning scientific outputs with national policy development cycles, increasing the practical impact and uptake of technical work.
  • Competing priorities often delay national review of technical documents. Providing dedicated time during regional meetings for face-to-face discussions can help resolve this and ensure timely feedback. This approach fosters stronger collaboration, faster resolution of issues, and clearer understanding of member needs.

[1] World Wide Fund for Nature Pacific. (n.d.). (Pacific Islands species factsheet). Pacific Islands Forum Fisheries Agency. Retrieved from bycatch_fs_1.pdf.

[2] Zydelis, R., Wallace, B.P., Gilman, E.L., & Werner, T.B. (2009). Conservation of marine megafauna through minimization of fisheries bycatch. Conservation Biology, 23(3), 608-616. Retrieved from Conservation of Marine Megafauna through Minimization of Fisheries Bycatch.

[3] Wallace, B.P, Lewison, R.L., McDonald, R.K., Kot, C.Y., Kelez, S., Bkorkland, R.K., Finkbeiner, E.M., Helmbrecht, S., & Crowder, L.B. (2010). Global patterns of marine turtle bycatch. Conservation Letters, 3(3), 131-142. Retrieved from The Society for Conservation Biology.

[4] Peatman, T., & Nicol, S. (2023). Summary of bycatch in WCPFC longline fisheries at a regional scale, 2003-2021 (WCPFC Scientific Paper 2023/ST-WP-02). Western and Central Pacific Fisheries Commission. Retrieved from Summary of bycatch in WCPFC longline fisheries at a regional scale, 2003–2021 | WCPFC Meetings.