Bigeye Tuna

Bigeye Tuna
Common Name Bigeye Tuna
Market Name ahi
Scientific name Thunnus obesus

Sourcing Summary

Size

20-50 lbs.

While bigeye tuna quality is difficult to determine due to subjective criteria, number 2 quality is usually adequate for the U.S. market while Number 1 quality is primarily exported to Japan. Fresh and frozen bigeye is sold to foodservice operators as loins and steaks. Early fall is a good time to buy fresh bigeye tuna, as demand drops and landings are normally still quite good. Frozen bigeye tuna is commonly treated with carbon monoxide or tasteless smoke to prevent the red color of the fish from going brown. If abused, carbon monoxide can be used to enhance the color of lower grade bigeye. However, fresh bigeye loins and steaks are rarely treated with carbon monoxide to maintain color. Additionally, the quality of pole and handline-caught bigeye can suffer because the fish can "burn" themselves when they struggle as they are landed and will result in the fish having a very short shelf life.

Product Forms

Fresh/Frozen
Fresh
Product Forms
Loins
Whole
Fresh/Frozen
Frozen
Product Forms
Loins
Steaks
Whole

Fresh Seasonal Availability

JanFebMarAprMayJunJulAugSepOctNovDec
nonononononoyesyesyesyesnono

Culinary Composition

Mild

Flavor

Firm

Texture

High

Oil

Cooking Methods

Advisory Concern

Mercury

Health/Nutrition

Nutrition facts

Serving Size: 100g
Amount per serving
Calories 108
Total Fat 1g
Cholesterol 41mg
Sodium 49mg
Carbohydrates 0g
Protein 23g
Omega-3 500mg

Science & Management

Conservation Criteria - Wild

Impact on Stock

Bigeye tuna, also called ahi, reproduces quickly. Fast and highly migratory, bigeye tuna can be found in the Pacific, Atlantic and Indian Oceans. This tuna is also long-lived but growth rates vary by population and ocean. Seafood Watch reports that in the Indian Ocean bigeye populations are healthy and fishing mortality rates are low. In the Atlantic, bigeye tuna populations are fluctuating around healthy levels, but have been below these levels in recent years, according to a Seafood Watch report. Despite their wide distribution and abundance, bigeye tuna in the Pacific declined over the past several decades due to intense fishing pressure. Bigeye are overfished in the eastern Pacific. In the western and central Pacific, bigeye populations are not healthy and fishing pressure is too high.

Habitat impacts (Wild)

Bigeye tuna are caught primarily with longlines, which are set off the bottom so they have minimal habitat impacts. Bigeye are also caught with troll lines, pole-and-lines, gillnets and purse seines. Purse seines usually have little contact with the bottom, although fish aggregating devices can be anchored there. Trolling and pole-and-line fishing also have minimal impact on bottom habitats, according to the Seafood Watch.

Bycatch

The longlines and purse seines targeting bigeye tuna also capture non-targeted fish such as other tunas, billfish and bony fish as well as sharks, seabirds and threatened sea turtles. Longliners in particular result in high bycatch rates. Purse seiners using fish aggregating devices can inadvertently attract non-targeted fish and sometimes protected species. Juvenile and small adult bigeye tuna bycatch is high for the skipjack and yellowfin purse seine fisheries. Bigeye tuna caught by troll or pole-and-line, particularly in the U.S. Atlantic, results in some of the least bycatch.

Management effectiveness

Bigeye tuna’s wide distribution requires effective international management, which has not been successful so far. Despite measures that include reporting requirements, observer programs, bycatch reduction, vessel monitoring, and fishing capacity limits, conservation goals are not being met in every region. 

In the Atlantic, bigeye tuna is managed by International Commission for the Conservation of Atlantic Tunas (ICCAT). The National Marine Fisheries Service, and Fisheries and Oceans Canada manage tuna in U.S. and Canadian waters. The Inter-American Tropical Tuna Commission manages bigeye and other tuna species in the eastern Pacific. 

There is a multi-annual management plan in place for bigeye in the eastern Pacific. However, many of ICCAT’s measures for the longline tuna fisheries do not meet best practice requirements, and scientific advice has not always been followed when setting those measures, according to Seafood Watch. Purse seines have 100% observer coverage but there are no harvest control rules or target reference points. For state waters in the western and central Pacific, the state of Hawaii manages tuna. In U.S. federal waters, the Western Pacific Regional Fishery Management Council (WPRFMC) manages them. Seafood Watch considers measures in this region to be moderately effective. The Western and Central Pacific Fisheries Commission (WCPFC) also manages bigeye. While some purse seine specific management measures have been introduced in that region, the success is not known.

Indian Ocean bigeye tuna are managed by the Indian Ocean Tuna Commission, and by the Ministry of Fisheries and Aquatic Sciences in Sri Lanka. Seafood Watch gave management in that region a red rating.

Conservation Criteria - Farmed

Origin Method Ratings
All Other Origins All Other Fishing Methods  
Atlantic Ocean Purse Seine - Floating Object  
Atlantic Ocean Purse Seine - Unassociated  
Atlantic Ocean Troll/Pole  
Atlantic Ocean - North Pelagic Longline  
Atlantic Ocean - South Pelagic Longline  
Indian Ocean Pelagic Longline  
Indian Ocean Purse Seine - Floating Object  
Indian Ocean Purse Seine - Unassociated  
Indian Ocean Troll/Pole  
Indian Ocean - South Pelagic Longline  
Indian Ocean - Sri Lanka Pelagic Longline  
North Atlantic - Canada Pelagic Longline  
Pacific Ocean - East Pelagic Longline  
Pacific Ocean - East Purse Seine - Floating Object  
Pacific Ocean - East Troll/Pole  
Pacific Ocean - West Central Pelagic Longline  
Pacific Ocean - West Central Purse Seine - Floating Object  
Pacific Ocean - West Central Troll/Pole  
USA - Atlantic Bottom Longline  
USA - Hawaii (Eastern Central Pacific) Deep-Set Longline  
USA - Hawaii (Western Central Pacific) Pelagic Longline  
USA - North Atlantic Greenstick  
Name Country State / Province
Albion Farms & Fisheries Canada British Columbia
Catalina Offshore Products United States California
Cherry Point Seafoods United States South Carolina
Codfathers Seafood Market Canada British Columbia
Daily Seafood Inc. Canada Ontario
Dock-to-Dish United States New York
Empire Fish Company United States Wisconsin
Euclid Fish Company United States Ohio
Export Packers Company Limited Canada Ontario
Global Food Networking Inc. United States Virginia
Harbor Pride Seafood United States California
IndiSea International LLC United States Florida
Lee Fish USA United States California
Norpac Fisheries Export United States Hawaii
Pacific Harvest Seafoods United States California
Red's Best United States Massachusetts
Sam Rust Seafood United States Virginia
Sea to Table, USA United States New York
Seafood Imports Inc. United States California
Stavis Seafoods United States Massachusetts