|Ahi, bigeye, thon obese (France), mabachi (Japan)|
Bigeye tuna is a worst choice tuna. A better alternative is albacore or skipjack tuna.
Bigeye tuna is a highly migratory species that is deeper swimming than other tuna, found off the coast of the North Island for much of the year. Longline fisheries for this tuna occur mainly in the West and East Coast of the North Island from the Bay of Plenty north. New Zealand represents only 0.5 % of the Pacific catch, which is managed by the Western and Central Pacific Fisheries Commission (WCPFC).
Bigeye tuna is caught mainly by surface longlines. There are concerns over the uncertainty about the state of the stocks, declining stock trend, lack of effective action by WCPFC and absence of overall management plan. There is a high bycatch of sharks, seabirds, turtles and New Zealand fur seals. The bigeye target tuna longline fishery captures an estimated 40 turtles a year including the vulnerable threatened leatherback. It is also estimated to capture 593 seabirds a year including vulnerable threatened Gibson’s and Antipodean albatross, and near-threatened southern Buller’s albatross. Bigeye tuna is listed as a vulnerable threatened species on the IUCN Red List.
Not certified under any scheme.
Over 90% of bigeye is exported to Japan and worth $1.16m in 2015. The export value of all tuna and swordfish species combined was $42.3 million in 2015.
No regional or fishing method difference.
|Population size:||South Pacific migratory population|
|Annual catch limit:||New Zealand limit set at 714 tonnes since 2004.|
|Recorded catch:||Latest reported annual landings of 116 tonnes in 2013-14 within the EEZ and 235 tonnes outside by New Zealand vessels, out of a total 154,601 tonnes in Western and Central Pacific.|
|Stock trends:||Declining, and overfishing is very likely to be happening.|
|MSY Status:||Catch levels are nearly 50% above the estimated MSY of 108,520 tonnes and “spawning biomass is below the level that will support the BMSY” and below 20%Bo at 16%Bo in 2012.|
|The Ministry of Primary Industries assessment plenary report includes:||“Recent levels of spawning biomass (either the 2008-11 average or the 2012 estimate) are Very Unlikely to be at or above 40-60% SB0” and “Very Unlikely that F < FMSY.” “Overfishing is Very Likely to be occurring.” (MPI, 2015, p89-90).|
|Distribution:||Bigeye tuna are caught mainly on the east and west coast of the North Island, mainly in the Bay of Plenty.|
|Maximum age (years):||11+|
|Age at sexual maturity:||3-6|
|Ability to recover:||Moderate|
|Fishing method(s):||Longlining around the North Island|
|Habitat damage:||No seabed impact|
|Habitat of particular significance:||Hasn’t been defined in New Zealand.|
|Bycatch:||Sharks species are caught in the longline fishery, including blue sharks, porbeagle shark, mako shark, deepwater dogfish and thresher shark. Blue sharks represent over 80% of the bycatch and sharks combined make up over 90% of the bycatch by number. Porbeagle, mako and thresher sharks are listed as vulnerable threatened species by the IUCN.|
|Ecological effects:||Excess removal of this and other large predatory species has knock-on effects on the wider food web and can have considerable ecological implications.|
|Bycatch:||Seabirds, turtles and New Zealand fur seals are caught in the surface longline fishery. The fishery also catches turtles (including leatherback turtle) at an observed rate of about one per year but, given level of observer coverage, actual numbers could be 10-40 times this. Estimated captures of about 593 seabirds a year in the bigeye longline target fishery, including vulnerable threatened Gibson’s and Antipodean albatross, and near-threatened southern Buller’s albatross (includes cryptic mortality). It is estimated that four New Zealand fur seal captures occur per year (based on the last 5 years).|
|Management component:||Single species – could be a Pacific wide stock, which is different from assessments involving Western and Central Pacific fish and Eastern Pacific Ocean fish.|
|Quota Management Species:||Yes from 2004.|
|Management plan:||Highly Migratory Species management plan for 2010-15 is out of date, and has yet to be reviewed and replaced. There is no operational plan and the old management plan lacks key environmental standards. The National Plans of Action on Seabirds and Sharks are more relevant but they are slow to be implemented. There is no international management plan and the WCPFC has yet to apply effective measures to prevent over-fishing.|
|Stock assessment:||No New Zealand quantitative assessment but a 2014 assessment for the Western and Central Pacific Fisheries Convention is used.|
|Research:||There is little directed research on this fishery in New Zealand.|
|Observer coverage:||Observer coverage of 4.7% annually over last 5 years but it is not spatially or temporally representative of the fishing effort.|
Overview of the Western and Central Pacific Ocean Tuna Fisheries, 2000, A Lewis and P Williams, Oceanic Fisheries Programme, Secretariat of the Pacific Community, New Caledonia, August 2001; National Tuna Fishery Report 2001 – New Zealand, T Murray and L Griggs, NIWA; Report from the Fishery Assessment plenary, November 2015: stock assessments and stock status – Volume 1: Introductory Sections to Ray’s Bream. Science Group, Ministry for Primary Industries; Ministry for Primary Industries (2016) Aquatic Environment and Biodiversity Annual Review 2015. Compiled by the Fisheries Management Science Team, Ministry for Primary Industries. 682p. The Guidebook to New Zealand Commercial Fish Species, 2007 Revised Edition, The New Zealand Seafood Industry Council Ltd. Seafood NZ, 2016. New Zealand Seafood Exports to December 2015. 133p. Ministry of Fisheries (2010) Operational Management Plan for Large Pelagic Species. 27p.