From Overfished to Sustainable Harvests: Pacific Bluefin Tuna Rebound to New Highs


New stock assessment reveals largest recorded biomass since assessments began.

The recovery of Pacific bluefin tuna has achieved a major milestone—the species exceeded international targets a decade ahead of schedule. The rebuilding of Pacific bluefin tuna reflects a fisheries management success. International organizations cooperated across the Pacific to reverse decades of overfishing for the prized species.

The International Scientific Committee for Tuna and Tuna-Like Species in the North Pacific Ocean (ISC), including NOAA Fisheries researchers, provided scientific expertise to inform conservation measures. The Inter-American Tropical Tuna Commission (IATTC) and Western and Central Pacific Fisheries Commission (WCPFC) adopted these measures.

The ISC recently finalized the new stock assessment at the annual meeting in Victoria, Canada. The assessment confirmed that the stock reached the second rebuilding target in 2021. If the current management measures persist, the population growth is expected to continue growing.

“This is an amazingly resilient fish and the new assessment is showing us that. While the population is thriving, ongoing monitoring of data quality is essential to ensure the continued accuracy of the assessment,” said Dr. Huihua Lee, a research mathematical statistician at NOAA Fisheries’ Southwest Fisheries Science Center who led the work on the stock assessment in the United States. “It also demonstrates the success of coordinated scientific efforts taken by the member countries through the ISC.”

Dr. Lee said the stock assessments translate decades of high-quality data on Pacific bluefin and a thorough understanding of the biology of the species into accurate predictions of future trends.

U.S. Harvests Smaller Share

Pacific bluefin tuna are the largest species of tuna in the Pacific with adults reaching nearly 10 feet in length and 990 pounds. The habitat of this Highly Migratory Species mostly spans the temperate waters of the North Pacific—from East Asia to the North American West Coast.