A new study by Sustainable Fisheries Partnership (SFP) released today measures the historical impact of tuna longline fishing in the Western Central Pacific Ocean (WCPO) on endangered, threatened, and protected (ETP) species. The research finds that tuna buyers can help restore populations of sharks, sea turtles, and seabirds by encouraging the adoption of proven best practices for longline fishing in their supply chains.

“Restoring biodiversity and nature is critical to the long-term sustainability of fisheries,” says Kathryn Novak, global markets director, SFP. “Buyers of longline caught tuna from the WCPO have an exciting opportunity to drive targeted improvements that could rebuild populations of vulnerable marine wildlife, while providing a healthy protein to customers.”

The research identified substantial declines of some species of sharks, seabirds, and sea turtle populations in the WCPO, many of which are listed as Vulnerable, Endangered or Critically Endangered by the International Union for Conservation of Nature (IUCN) Red List. While many different factors caused these declines, bycatch, the unintended catch of non-target species, is currently the key driver of the loss for many of these ETP species. Longlines have one of the highest bycatch rates for these species of gear types used in commercial tuna fisheries.

The study recommends that buyers of longline-caught albacore and fresh/frozen yellowfin, albacore, and bigeye from the WCPO should:

  • Require that bycatch mitigation best practices are implemented in their source fisheries by 2025, such as adoption of fishing techniques like using circle hooks, eliminating wire leaders, and switching bait types; and
  • Require that their source fisheries have 50 percent observer (human observer and electronic monitoring combined) coverage by 2025 and 100 percent by 2030.

The study also outlines data-collection protocols that need to be implemented for electronic monitoring, and best practices for specific wildlife species.

“Bycatch of ETP species in longline fisheries is a well known problem. Thankfully there are proven best practice options which can be adopted by the industry, such as the use of large circle hooks to reduce sea turtle capture, hook shielding devices to reduce seabird interactions and removing wire leaders to help reduce shark interactions,” says Alexia Morgan, ocean wildlife manager, SFP.  “The use of these best practices options offers the supply chain an opportunity to help reduce bycatch mortality of ETP species and subsequently help rebuild their populations to healthier levels.”

The study also calls for better management and compliance by the Western Central Pacific Fisheries Commission (WCPFC), the international management body for highly migratory species in the region, and WCPFC countries. At its most recent meeting in early December, the WCPFC did take action to prohibit the use of wire leaders to protect sharks in certain areas beginning in 2024, but voluntary action can be taken sooner, as recommended in the SFP report.

To help tuna buyers to better understand the ETP bycatch interactions in their source fisheries, SFP launched an ETP Bycatch Audit program earlier this year. SFP also launched the Solve My Bycatch Tool, an online tool to help seafood buyers and suppliers find solutions to specific tuna bycatch problems. Other tools include SFP’s leading guide Best Practices for Reducing Bycatch in Longline Tuna Fisheries, available in English, Japanese, Bahasa, and Spanish.

The study was made possible through funding by the Walmart Foundation. The findings and recommendations presented in these reports are those of Sustainable Fisheries Partnership alone, and do not necessarily reflect the opinions of the Walmart Foundation. The research summary and full technical paper can be found on the SFP website.