FishWatch

Harvesting Pacific Bigeye Tuna

Bigeye tuna are an important part of the tuna fisheries throughout the Pacific Ocean and are caught by both surface and deeper longline gears. There are two stocks of bigeye in the Pacific – the western and central Pacific stock and the eastern Pacific stock. In the western and central Pacific, large distant-water longline fleets from Japan and Korea and smaller, fresh sashimi longline fleets based in several Pacific Island countries harvest the majority of bigeye tuna. In the eastern Pacific, the commercially important tropical tuna species (yellowfin, bigeye, and skipjack) are mainly harvested by vessels from the Central and South American fishing fleets.

U.S. commercial fishermen harvest bigeye tuna incidentally in the purse seine fishery and with deep-set pelagic longlines on the high seas. Other domestic fisheries harvest smaller amounts of bigeye tuna. Although none of these fishing gears typically impact habitat, purse seines and longlines sometimes incidentally catch other marine species. Many purse seine fishermen use fish aggregating devices (FADs) to target tunas. FADs are natural floating or man-made objects that are found or placed on or near the ocean surface and used to attract schooling fish underneath. However, FADs can also attract non-target and bycatch species, including juvenile tunas, sharks, other fish, and occasionally protected species. Bycatch of juvenile yellowfin and bigeye tuna is the most significant issue in the purse seine fishery. In the eastern Pacific and western and central Pacific, purse seiners are prohibited from fishing in certain areas and with FADs at certain times of the year to regulate fishing effort and reduce bycatch of juvenile tunas. Fishermen are also required to retain all tuna caught in the purse seine fishery. This measure is partly intended to encourage fishermen to target larger, more profitable adult tunas, rather than juvenile tunas (they are prohibited from discarding juvenile tunas to make room in their fish holds).

Interactions with protected species such as sea turtles, marine mammals, and seabirds in these fisheries are rare and survival rates are estimated to be high. Management restricts the type of fishing gear that can be used and prohibits fishing in certain areas to minimize impacts on protected species. In addition, longline fishermen are trained in safe handling and release techniques for sea turtles, seabirds, and marine mammals and carry and use specific equipment for handling and releasing these animals. Scientists and managers continue to monitor bycatch in these fisheries through logbooks and fishery observer programs.

Management

Although NOAA Fisheries and the fishery management councils manage our bigeye tuna fisheries domestically, fisheries for highly migratory species such as bigeye require cooperative international management to ensure they are sustainable.

Who’s in charge? The United States is a member of the Inter-American Tropical Tuna Commission (IATTC) and the Western and Central Pacific Fisheries Commission (WCPFC), both of which are responsible for the international conservation and management of tuna and tuna-like species in the Pacific Ocean. NOAA Fisheries and the Pacific and Western Pacific Fishery Management Councils collaborate in the management of our domestic bigeye fisheries. Domestic management is guided by our participation in the Commissions. Terms of the South Pacific Tuna Treaty also apply to U.S. purse seine vessels operating throughout the central and western Pacific.

Current management: Highly Migratory Species Fishery Management Plan.

• Permitting, logbook, and monitoring requirements.
• Gear restrictions and operational requirements to minimize bycatch.
• Longline vessels and large purse seine vessels on the U.S. West Coast require 100 percent observer coverage. All other purse seine vessels must carry a fishery observer, if requested by NOAA Fisheries.
• Longline fishing prohibited within 200 miles of the U.S. West Coast.
• Mandatory annual protected species workshops for all longline vessel owners and operators.

Fishery Ecosystem Plan for Pelagic Fisheries of the Western Pacific

• Permitting, logbook, and monitoring requirements.
• Gear restrictions and operational requirements to minimize bycatch.
• Limited entry permit program for Hawaii and American Samoa longline fisheries to control the number of vessels fishing.
• Longline fishing prohibited areas around the Main Hawaiian Islands, Northwestern Hawaiian Islands, Guam, the Northern Mariana Islands, and American Samoa to protect endangered Hawaiian monk seals, and reduce potential gear conflicts and localized stock depletion (when a large quantity of fish are removed from an area). These zones are enforced through NOAA Fisheries vessel monitoring system (VMS). Longline boats must be equipped with a satellite transponder that provides real-time position updates and tracks vessel movements.
• Hawaii and American Samoa–based longline vessels must carry onboard observers when requested by NOAA Fisheries, in part to record any interactions with sea turtles, seabirds, and marine mammals. Tuna longline vessels are required to have 20 percent observer coverage. Purse seine vessels operating under the South Pacific Tuna Treaty (i.e., most of the U.S. purse seiners operating in the Pacific Ocean) are required to have 100 percent observer coverage.
• Mandatory annual protected species workshops for all longline vessel owners and operators.

The United States has implemented management measures recommended by the IATTC to address concerns about the condition of eastern Pacific bigeye tuna, including:

• Purse seine closures in the eastern Pacific.
• Required retention of tuna caught in the purse seine fishery.
• Annual catch limit for bigeye tuna caught in the eastern Pacific by U.S. longline vessels.

The United States has also implemented measures as recommended by the WCPFC to address concerns about the western and central bigeye stock, including:

• Annual bigeye tuna catch limits in the Hawaii tuna (deep-set) longline fishery.
• Limits on purse seine fishing effort.
• Limits on the number of vessels participating in other fisheries that take bigeye tuna.
• Seasonal closure of the purse seine fishery that uses fish aggregating devices.
• Purse seine requirements to retain catch of tuna species.
• Annual catch quota for the purse seine fishery.

Under conditions of the South Pacific Tuna Treaty, purse seine vessels operating throughout the central and western Pacific must be registered and are monitored through logbooks, cannery landing receipts, national surveillance activities, vessel monitoring systems, observers, and port sampling.

Annual Harvest

In 2010, Hawaii commercial fishermen landed nearly 13 million pounds of bigeye tuna. Nearly 389,000 pounds were landing in American Samoa.

Economy

Bigeye tuna caught in the purse seine fishery is canned along with skipjack and yellowfin and sold as “light” tuna. A small amount of bigeye caught in the Hawaii longline fishery is exported fresh; the remaining fresh supply is sold in U.S. markets, both on the island and mainland.

The United States also imports fresh or frozen bigeye tuna from around the world, mainly from Asia, South America, and Central America.

RECREATIONAL

Anglers also fish for bigeye tuna in the Pacific Ocean. To fish for bigeye off California, private anglers must carry a state-issued saltwater fishing license and charter vessels must obtain highly migratory species permits. U.S. recreational anglers are allowed to possess a maximum of 10 bigeye tuna per day, and charter vessels must keep logbooks documenting their catch. There are no federal regulations for recreational fishing off Hawaii and U.S. Pacific Island territories; however, local rules may apply.