Bigeye Tuna

NOAA Fisheries and NOAA Fisheries’ Atlantic Highly Migratory Species (HMS) Division are responsible for managing the US Atlantic bigeye tuna fishery under the Consolidated Atlantic Highly Migratory Species Fishery Management Plan. Amongst measures outlined in the plan include: permit requirements, gear restrictions, time and area closures, and minimum size limits. All federal management measures for Atlantic tunas apply to US state waters (except in Maine, Connecticut, and Mississippi). The US harvest of bigeye makes up a small proportion of the total worldwide catch (less than one percent). 

Like other tunas, bigeye are highly migratory and cross international boarders and the high seas. As such, their management requires international cooperation. The United Nations Law of the Sea indicates that the management of HMS be carried out through Regional Fishery Management Organizations (RFMOs). RFMOs are the only legally mandated fishery management body on the high seas. The RFMO responsible for the management of Atlantic tunas, as well as other Atlantic HMS, is the International Commission for the Conservation of Atlantic Tunas (ICCAT). ICCAT is made up of 51 contracting parties including the United States, Canada, Japan, China, Russia, and the United Kingdom. Among management measures ICCAT outlines are: 

• A total allowable catch (currently set at 65,000 tonnes) allocated between members as well as sharing arrangements for other countries;
• Time and area closures; 
• Size limits;
• Effort controls; and, 
• Monitoring, reporting, and inspection programs.

Between 2011 and 2015 bigeye tuna account for roughly 16 percent of the total tuna catch in the Atlantic. In 2015, purse seine and pole-and-line vessels accounted for about 37 and 15 percent of the total Atlantic bigeye tuna catch respectively. According to the last stock assessment conducted by the ICCAT Standing Committee on Research and Statistics in 2015, the stock is estimated to be overfished and overfishing is occurring. NOAA Fisheries uses conservation and management measures adopted by ICCAT, along with their own research, to set regulations for the US Atlantic skipjack fishery. 

NOAA Fisheries and the Pacific Fishery Management Council manage the skipjack tuna fishery on the US West Coast under the Fishery Management Plan (FMP) for US West Coast Fisheries for Highly Migratory Species. Management measures outlined within the FMP include: permit requirements, catch recording, gear restrictions (no longlines are allowed within 200 miles of the coast, etc.), and observer coverage (100 percent for longline vessels and large purse seine vessels). In Hawaii and Pacific Island territories, NOAA Fisheries and the Western Pacific Fishery Management Council manage the skipjack tuna fishery in the US Pacific under the Fishery Ecosystem Plan for Pelagic Fisheries of the Western Pacific. Management measures outlined in this FMP include: permit requirements and limits, gear restrictions, area closures (to protect endangered Hawaiian monk seals), and a vessel monitoring system and observer coverage (100 percent for longline vessels operating in Hawaii and America Samoa and purse seine vessels operating under the South Pacific Tuna Treaty).

The Inter-American Tropical Tuna Commission (IATTC) is the RFMO in charge of managing international bigeye tuna stocks in the Eastern Pacific Ocean (EPO). Composed of over 20 different nations including the United States, Canada, China, Belize, Costa Rica, and Mexico, IATTC sets management measures that all member nations must adhere to. As of 2015, the majority of bigeye tuna in the EPO are caught using purse seine (62 percent of the total catch) and longline gear (38 percent of the total catch). In the EPO, IATTC has set management measures for the purse seine and longline fisheries which include time and area closures, 100 percent observer coverage on large vessels, annual catch limits, and requirements that all vessels in the purse seine fishery retain all tuna caught. Any purse seine vessel operating in the EPO must also operate in accordance to the International Dolphin Conservation Program, which works reduce bycatch of dolphins and undersized tuna. Between 2011 and 2015 bigeye account for 16 percent of the total average tuna catch in the EPO. According to the updated 2016 stock assessment EPO bigeye are currently overfished; however, overfishing is not taking place.

The Western and Central Pacific Fisheries Commission (WCPFC) is the RFMO in charge of managing international bigeye stocks in the Western and Central Pacific Ocean (WCPO). WCPFC is composed of over 25 member countries including Australia, China, New Zealand, Indonesia, Japan, France, the United States, and the Republic of Korea. Among measures member nations adhere to are:

• A three-month prohibition on setting fish aggregating devices (FADs) in exclusive economic zones (EEZs) and high seas between 20 degrees north and 20 degrees south (additionally each member must choose between extending the FAD closure to a total of four months or limit the annual number of FAD sets made by its vessels as outlined in specified reference period);
• Coastal states must reduce purse seine effort to 2010 levels (if they are a member country of the Parties to the Nauru Agreement (PNA);
• If they are not a participant in the PNA they must reduce purse seine effort to average levels between 2001 and 2004;
• Purse seine vessels for other countries cannot increase;
• A FAD management plan to reduce capture of juvenile tunas and prepare for FAD closures; 
• Annual compliance monitoring requirements and 100 percent observer coverage for purse seine vessels on the high seas, in waters under the jurisdiction of one or more coastal States, or for vessels operating between 20 degrees north and 20 degrees south (unless operating exclusively in their EEZ) ; and,
• Prohibition of discarding any tuna catch between 20 degrees north and 20 degrees south.

PNA member countries have also agreed to additional management measures including: a regional fishing vessel register, high seas pocket area closures, FAD prohibitions during set times, and a vessel day scheme.

The majority of the WCPO bigeye catch is caught using purse seine and longline gears. From 2011 to 2015 bigeye tuna accounted for an average of six percent of the total tuna catch from the WCPO. Despite management measures, the WCPO bigeye stock is considered to be overfished and measures in place are considered to be insufficient to end overfishing. 

The Indian Ocean Tuna Commission (IOTC) is the RFMO charged with managing bigeye tuna in the Indian Ocean. There are currently 31 members (majority are nation states) in the IOTC. There are no species-specific conservation measures established by the IOTC for IO bigeye tuna; however, member countries must have: reference points and harvest control limits, bycatch mitigation strategies (particularly with sea turtles, juvenile tunas, and sharks), and observer coverage (IOTC requires at least five percent of vessels have an observer). Additionally, IOTC members must have a FAD management plan that includes information on the fleet, number of drifting FADs, logbooks, and monitoring and review plans. IOTC member nations require all tuna caught by purse seiners be retained and landed, and encourages retention of other non-targeted finfish. Member countries are also required to record and report catch and effort data by species and gear type. From 2011 to 2015 bigeye tuna accounted for roughly 11 percent of the total tuna catch in the IO. According to a 2016 stock assessment, overfishing is not occurring and the stock is not overfished.