Blue Ocean Institute


Some problems exist with this species' status or catch methods, or information is insufficient for evaluating. Tuna, Yellowfin – U.S. Longline (Maguro) These fish contain levels of mercury or PCBs that may pose a health risk to adults and children.

Yellowfin Tuna reach sexual maturity at a younger age (about three years) than most other tunas and grow quickly. They produce millions of eggs per spawning, and can live up to nine years. Yellowfin Tuna are found throughout the world’s tropical and sub-tropical oceans, with one population occurring in each of the Indian and Atlantic Oceans and two in the Pacific.

Abundance of Yellowfin Tuna varies among populations, but overall abundance is at a medium level. Globally longline vessels catch 15% of all tuna species including Yellowfin Tuna. Longline tuna fisheries catch large numbers of unwanted species or bycatch, including billfish, sharks, seabirds, sea turtles, and marine mammals. Management of Yellowfin Tuna fisheries in the U.S. is moderately effective.

While longline caught yellowfin tuna in the U.S. is rated yellow, longline caught yellowfin tuna imported from Grenada, Trinidad and Tobago, and Indonesia is now rated red. Yellowfin tuna globally are undergoing reassessment. In the meantime, please refer to the Monterey Bay Aquarium Seafood Watch Guide for longline caught yellowfin tuna ratings for other countries.

Full species report here.

This fish may have high levels of mercury that could pose a health risk to adults and children. More info here about mercury in tuna. Check out our mercury in seafood section.