The ghosts of the ocean, the Pacific bluefin tuna, have been depleted by a staggering 97.4%, a haunting statistic that unveils a global crisis where many other tuna species are teetering on the edge of collapse.
Key Takeaways
- The Pacific bluefin tuna spawning stock biomass has declined by 97.4% from unfished levels as of 2019 assessments
- Western Atlantic bluefin tuna population is at only 13% of maximum sustainable yield levels per 2022 ICCAT assessment
- Eastern Atlantic and Mediterranean bluefin tuna biomass increased to 36% of unfished levels by 2021 after strict quotas
- Global tuna catch reached 5.3 million tonnes in 2020 FAO data
- Purse seine catch of skipjack in WCPO hit 2.8 million mt in 2022 WCPFC
- Yellowfin tuna Indian Ocean landings 400,000 mt annually averaging 2015-2022 IOTC
- Bycatch of sharks in tuna purse seines WCPO 200,000 mt annually WCPFC
- Silky sharks 45% of non-tuna catch in tropical purse seines ISSF
- Sea turtles entangled in longlines Pacific 4,000 loggerheads yearly NOAA
- Global tuna market value $42 billion in 2021 with 5% annual growth
- Pacific Island nations lose $500 million/year from tuna access fees mismanagement
- Canned tuna industry employs 1 million people globally ISSF
- ICCAT bluefin tuna TAC set at 36,000 tonnes for 2023-2025 recovering stock
- WCPFC tropical tuna FAD management non-entering limit 2024-2026
- IOTC yellowfin rebuilding plan adopted 2022 with 20% TAC cut over 4 years
Global tuna stocks are critically depleted by severe and widespread overfishing.
Bycatch and Ecosystem Impacts
- Bycatch of sharks in tuna purse seines WCPO 200,000 mt annually WCPFC
- Silky sharks 45% of non-tuna catch in tropical purse seines ISSF
- Sea turtles entangled in longlines Pacific 4,000 loggerheads yearly NOAA
- Billfish discard rates 20-30% in bigeye tuna longline fisheries ICCAT
- Juvenile yellowfin mortality from FADs 50% of catch under 40cm IOTC
- Oceanic whitetip sharks 73% decline linked to tuna fisheries IUCN
- Mahi-mahi bycatch in purse seines EPO 50,000 mt yearly IATTC
- Seabirds hooked in tuna longlines Southern Ocean 10,000 birds/year CCSBT
- Rays and skates discards 15% biomass in Indian Ocean trawls for tuna IOTC
- False killer whales Pacific longline bycatch 60 animals/year NMFS
- Rainbow runner incidental catch 10% in skipjack purse seines WCPO
- Hammerhead sharks finned from tuna vessels 100,000 fins/year est. WWF
- Wahoo bycatch rates 5-10% in tropical longlines IATTC
- Marine mammals total bycatch tuna fisheries 100,000/year global FAO
- Jellyfish blooms increase 20% linked to overfished tuna predator control
- Ecosystem trophic level of catches declined 0.3 since 1950 in tuna areas
- Coral reef fish declines 30% near FAD moorings Pacific islands
- Blue marlin Atlantic bycatch mortality 25% post-release ICCAT
- Mobulid rays fins 20% from tuna IUU catches Pacific
- Squid biomass increase 40% due to tuna predator removal Japan data
- Leatherback turtles EPO longline bycatch halved to 200/year post-circle hooks
- Ecosystem modeling shows 50% forage fish increase from tuna decline
- Tuna overfishing causes 15% biodiversity loss in pelagic zones IUCN
Bycatch and Ecosystem Impacts Interpretation
The ocean is trying to tell us that our tuna sandwich is a tragically inefficient multi-species casserole, where the main ingredient comes garnished with a side of ecological collapse.
Conservation Measures and Recovery Efforts
- ICCAT bluefin tuna TAC set at 36,000 tonnes for 2023-2025 recovering stock
- WCPFC tropical tuna FAD management non-entering limit 2024-2026
- IOTC yellowfin rebuilding plan adopted 2022 with 20% TAC cut over 4 years
- CCSBT Southern bluefin TAC 17,160 mt stable for 2023 with allocation scheme
- IATTC yellowfin reference points adopted Fmsy proxy 2023 assessments
- EU Common Fisheries Policy tuna quotas aligned MSC standards 2022
- Pacific Bluefin ISC management procedure adopted 2021 with harvest control rule
- FAO Port State Measures Agreement ratified by 150 countries combat IUU tuna
- MSC certification covers 20% global tuna catch with 15 labels active
- Circle hook mandates reduced turtle bycatch 60% in Atlantic longlines ICCAT
- RFMOs vessel monitoring systems track 95% large tuna vessels real-time
- Bluefin tuna Mediterranean farms closed 2008-2010 aiding 200% biomass recovery
- WCPFC juvenile bigeye protections limit purse seine 10% under 55cm 2023
- ISSF tuna measure resolutions adopted by all RFMOs FAD tracking 2023
- US Big Island closed area Hawaii longline reduced bycatch 90%
- IOTC ban on shark finning onboard tuna vessels since 2019 compliance 80%
- Parties to Nauru Agreement vessel day scheme limits 45,000 days WCPO tuna
- Albacore ISC harvest strategy interim F based framework 2022
- Greenpeace market pressure led major retailers 100% sustainable tuna pledge 2020
- Blockchain tuna traceability pilots Thailand/EU track 50,000 mt 2023
- Observer coverage mandated 10% purse seine 100% longline RFMOs average
- Bluefin electronic reporting systems ICCAT 100% compliance 2022
- Marine reserves Palau Micronesia protect 20% tuna spawning grounds
- AI satellite monitoring detects 30% IUU incursions Pacific Global Fishing Watch
- Tuna RFMO compliance committees blacklist 50 vessels yearly average
Conservation Measures and Recovery Efforts Interpretation
Global tuna management has reached a precarious peak of bureaucracy and innovation, where regulators are frantically writing rules to save the fish we are still frantically catching.
Economic and Social Consequences
- Global tuna market value $42 billion in 2021 with 5% annual growth
- Pacific Island nations lose $500 million/year from tuna access fees mismanagement
- Canned tuna industry employs 1 million people globally ISSF
- Japan tuna import bill $3 billion annually for sashimi markets
- EU tuna processing sector €5 billion turnover 2022 STECF
- Small-scale fishers Pacific 50,000 livelihoods threatened by industrial overfishing
- Thailand canned tuna exports $2.5 billion 2022 but stocks declining
- US West Coast albacore fishery revenue $50 million/year NOAA
- IUU tuna trade costs $10 billion lost revenue globally yearly
- Seychelles tuna fleet contributes 30% GDP from licenses $100 million/year
- Mexico yellowfin fishery supports 40,000 jobs but overcapacity issues
- Global tuna price premium for MSC certified 20-30% higher
- Food security risk for 60 million people reliant on tuna protein FAO
- China tuna processing industry $15 billion output 2022
- Kiribati tuna revenue 80% government budget $150 million/year
- Overfishing subsidies $4.6 billion to tuna fleets global
- Ecuador purse seine fleet $1 billion revenue but bycatch costs extra $200 million
- Vietnam canned tuna exports $1.2 billion 2022 growth 10%
- Spain Basque tuna fleet economic loss from quotas €100 million/year
- Indonesia artisanal tuna fishers 2 million people income halved since 2010
- Global insurance claims for lost tuna gear $500 million/year FAD damage
- Bluefin tuna ranching Italy revenue €300 million pre-2008 crash
- Projected $20 billion loss by 2030 from tuna stock collapse WWF
- Maldives pole-line fishers income stable at $50 million but competition rises
- ICCAT bluefin TAC reductions cost fleets €1 billion since 2009
Economic and Social Consequences Interpretation
We’re paying billions to catch, can, and trade tuna while simultaneously paying billions more to manage its decline, a paradox as rich in folly as it is poor in future fish.
Fishing Pressure and Catch Volumes
- Global tuna catch reached 5.3 million tonnes in 2020 FAO data
- Purse seine catch of skipjack in WCPO hit 2.8 million mt in 2022 WCPFC
- Yellowfin tuna Indian Ocean landings 400,000 mt annually averaging 2015-2022 IOTC
- Atlantic bluefin purse seine quota utilization 90% of 32,000 t TAC in 2022 ICCAT
- Pacific bigeye longline catch 150,000 mt yearly WCPO 2020s WCPFC
- Albacore North Pacific troll/pole catch 25,000 mt US fleet 2021 NOAA
- FAD-associated purse seine sets WCPO increased 300% since 1995 to 60,000/year
- Southern bluefin tuna total catch quota 17,160 mt for 2023 CCSBT
- Eastern Pacific yellowfin purse seine catch 450,000 mt 2022 IATTC
- Bigeye tuna Atlantic longline catch 60,000 mt annually ICCAT
- Skipjack purse seine EPO 200,000 mt yearly average IATTC
- Bluefin tuna Japanese longline catch reduced to 4,000 mt under quota 2022
- Indian Ocean longline effort doubled to 20,000 sets/year for bigeye since 2010 IOTC
- WCPO tropical tuna FAD fishing 55% of total purse seine effort 2022
- US Bigeye tuna Hawaii longline landings 2,500 mt 2021 NOAA
- Mediterranean bluefin farm transfers 20,000 mt annually pre-quota reforms ICCAT
- Global tuna exports value $40 billion with 4.5 million mt traded 2021 ISSF
- Pole and line skipjack Maldives catch 100,000 mt sustainable claim 2022
- Atlantic yellowfin driftnet illegal catch estimated 10,000 mt yearly Greenpeace
- Pacific albacore surface fishery catch 50,000 mt NZ/Australia 2022
- IUU tuna catch Pacific estimated 20-30% of total or 200,000 mt WWF
- Chinese distant water fleet tuna catch 500,000 mt globally 2020
- EU purse seine fleet WCPO tuna landings 150,000 mt 2022
- Korean longline bigeye catch EPO 15,000 mt average IATTC
- Global FAD deployments estimated 100,000 units yearly ISSF
- Tuna catch per unit effort global longline down 80% since 1950s
Fishing Pressure and Catch Volumes Interpretation
We've reached the point where we're so good at catching tuna that our global success is measured not in thriving populations, but in the startling efficiency of our own depletion, with a side of questionable math and a $40 billion price tag.
Stock Status and Population Decline
- The Pacific bluefin tuna spawning stock biomass has declined by 97.4% from unfished levels as of 2019 assessments
- Western Atlantic bluefin tuna population is at only 13% of maximum sustainable yield levels per 2022 ICCAT assessment
- Eastern Atlantic and Mediterranean bluefin tuna biomass increased to 36% of unfished levels by 2021 after strict quotas
- Yellowfin tuna in the Indian Ocean Indian Ocean Tuna Commission estimates spawning stock at 30-50% below MSY in 2022
- Bigeye tuna Western and Central Pacific stocks depleted to 15% of unfished biomass per 2023 WCPFC
- Albacore tuna North Pacific stock at 40% of unfished spawning biomass in 2021 ISC assessment
- Skipjack tuna in WCPO remains above MSY at 80% biomass but declining trend since 2010
- Southern Bluefin Tuna global stock at critically low 5-10% of unfished levels per CCSBT 2022
- Atlantic bigeye tuna overfished with F/Fmsy ratio of 1.8 in 2021 ICCAT data
- Yellowfin tuna EPO stock biomass at 22% of unfished levels per IATTC 2023
- Longtail tuna Indian Ocean stocks showing 25% decline in CPUE from 2010-2020 IOTC data
- Bluefin tuna Adriatic nursery areas show juvenile abundance down 60% since 2000 per ICCAT
- Pacific bigeye tuna juvenile biomass 70% depleted per 2022 assessment
- North Atlantic swordfish linked to tuna fisheries shows proxy decline of 40% biomass
- Bullet tuna Mediterranean stocks collapsed 80% post-2010 overfishing surge
- Kawakawa Indian Ocean CPUE dropped 35% from 2005-2022 IOTC stats
- Frigate tuna stocks in Gulf of Thailand at 20% historical levels per SEAFDEC
- Little tunny Atlantic coast US surveys show 50% biomass reduction since 1990s NOAA
- Blackfin tuna Caribbean populations estimated 65% depleted per ICCAT
- Striped bonito Pacific stocks down 45% per ISC assessments
- Global tuna stocks overall 60% overfished per FAO SOFIA 2022
- Tropical tunas WCPO 80% of catch from FADs contributing to 50% juvenile mortality
- Bluefin tuna age-1 recruits down 75% in 2020s vs 1980s Japan data
- Yellowfin tuna Indian Ocean SSB at 0.35 Bmsy per 2023 IOTC
- Albacore South Pacific biomass 55% unfished but fishing mortality high at 1.5 Fmsy
- Skipjack Indian Ocean stocks pressured with 20% recent decline IOTC
- Bigeye Atlantic SSB ratio 0.6 to BMSY proxy 2022 ICCAT
- Pacific bluefin age structure skewed with only 10% mature fish in catches 2022
- Eastern Pacific yellowfin F/Fmsy 2.1 indicating overfishing IATTC 2023
- Global longline CPUE for bigeye tuna down 60% since 1990s ISSF data
Stock Status and Population Decline Interpretation
The ocean's tuna, once the silver currency of healthy seas, are now a collection of overdrawn accounts and bounced checks, with the Pacific bluefin nearly bankrupt at 3% of its original value and most others deep in the red.
Sources & References
- Reference 1ISCisc.ac.affrc.go.jpVisit source
- Reference 2ICCATiccat.intVisit source
- Reference 3IOTCiotc.orgVisit source
- Reference 4WCPFCwcpfc.intVisit source
- Reference 5CCSBTccsbt.orgVisit source
- Reference 6IATTCiattc.orgVisit source
- Reference 7FAOfao.orgVisit source
- Reference 8SEAFDECseafdec.orgVisit source
- Reference 9FISHERIESfisheries.noaa.govVisit source
- Reference 10JFAjfa.maff.go.jpVisit source
- Reference 11MEETINGSmeetings.spc.intVisit source
- Reference 12ISS-FOUNDATIONiss-foundation.orgVisit source
- Reference 13IPNLFipnlf.orgVisit source
- Reference 14GREENPEACEgreenpeace.orgVisit source
- Reference 15WWFwwf.panda.orgVisit source
- Reference 16PEWTRUSTSpewtrusts.orgVisit source
- Reference 17STECFstecf.jrc.ec.europa.euVisit source
- Reference 18NATUREnature.comVisit source
- Reference 19IUCNREDLISTiucnredlist.orgVisit source
- Reference 20SCIENCEDIRECTsciencedirect.comVisit source
- Reference 21PORTALSportals.iucn.orgVisit source
- Reference 22WORLDBANKworldbank.orgVisit source
- Reference 23MSCmsc.orgVisit source
- Reference 24SEAFOODSOURCEseafoodsource.comVisit source
- Reference 25FORUMSECforumsec.orgVisit source