Last updated on 13 January 2016

SUMMARY

SUMMARY

IDENTIFICATION

SCIENTIFIC NAME(s)

Thunnus obesus

SPECIES NAME(s)

Bigeye tuna

At this point in time it is assumed there is a single Atlantic-wide population of bigeye tuna. This is based on a lack of identified genetic heterogenity, time/area distribution of fish and movement patterns of tagged fish {ICCAT 2012}.

This fishery was withdrawing from the full assessment by the Marine Stewardship Council system in June 2014.For more information click here.


ANALYSIS

Strengths

There is a total allowable catch (TAC) in place, a limit on the number of longline vessels and a time area closure for surface gears.  The TAC was lowered to levels (85,000 t) suggested by the scientific committee in 2009 and 2015 (65,000 t) and total catches have been below TAC levels since 2005.  There is a time/area closure in place for the purse seine fishery to protect juvenile bigeye tuna.  There is a multi-year conservation and management program in place through ICCAT for bigeye.

Weaknesses

Bigeye tuna in the Atlantic are overfished and undergoing overfishing. Due to unreported and mis-identified bigeye tuna, there was a large degree of uncertainty surrounding the assessment results.  There is no harvest control rule in place and no target or limit reference point. There is the need to monitor individual countries not included in the total allowable catch (TAC) allocation to ensure that catches do not exceed TAC levels. Mandated observer coverage (5%) is low and there are incidental interactions in both the longline and purse seine fisheries with protected, endangered and threatened species and sharks.

FISHSOURCE SCORES

Management Quality:

Management Strategy:

≥ 6

Managers Compliance:

≥ 8

Fishers Compliance:

10

Stock Health:

Current
Health:

6.7

Future Health:

7.2


RECOMMENDATIONS

CATCHERS & REGULATORS

1. Comply with all of the International Commission for the Conservation of Atlantic Tunas (ICCAT’s) conservation and management measures (CMMs), including measures aimed at both target and incidental market and non-market species, and all other obligations. Through your delegation to ICCAT, encourage the compliance committee to make information on non-compliance by individual members and cooperating non-members publicly available in order to increase the incentive for compliance by all ICCAT members and cooperating non-members.
2. Promote the adoption by the International Commission for the Conservation of Atlantic Tunas (ICCAT) and member countries of precautionary and ecosystem-based management measures, including biological reference points, harvest control rules, increased observer coverage, national management measures and monitoring efforts adequate to ensure harvest strategy objectives are being met. Adopt domestic laws and regulation to implement ICCAT measures and provide monitoring and surveillance adequate for compliance. Encourage ICCAT and parties to comply with current required onboard observer coverage rates.
3. Encourage the ICCAT to monitor catches to ensure they do not go over the total allowable catch limit (TAC) and re-structure the TAC in a way that does not allow for permissible overages by countries not included in the TAC allocation. Encourage ICCAT to continue monitoring bigeye weight as an indicator of the effects of surface gear closures. Improve data collection and reporting to ensure complete data sets (i.e. catches, effort, size), which are needed for robust stock assessments. Encourage ICCAT to expand the current data collection system to investigate whether significant catches have been under-reported. Conduct studies, increase monitoring and publish information to assess longline and purse seine interactions with protected, endangered and threatened (PET) and other bycatch species. Identify and mandate best practices bycatch mitigation techniques for both gear types. Comply with ICCAT management measures prohibiting the retention of silky, hammerhead, oceanic whitetip and thresher sharks and promote the use of non-entangling fish aggregating devices (FADs).

RETAILERS & SUPPLY CHAIN

1. Ask the International Commission for the Conservation of Atlantic Tunas (ICCAT) and individual member countries to adopt precautionary and ecosystem-based management measures including formal reference points harvest control rules and increased observer coverage.
2. Require that your suppliers source only from fisheries that comply with all ICCAT’s Conservation and Management Measures, and request that ICCAT make information on compliance by members and cooperating non-members publicly available. An example of how this might be achieved is a control document that ensures recording and reporting interactions, and prohibition on retaining thresher, silky, hammerhead and oceanic whitetip sharks.
3. Source from vessels registered on the International Seafood Sustainability Foundation (ISSF) Proactive Vessel Register (PVR) and in full compliance with all measures relevant to their gear type as demonstrated by annual independent audit reports that are made publicly available.


FIPS

No related FIPs

CERTIFICATIONS

  • Southeast US North Atlantic big eye tuna and yellowfin tuna:

    Withdrawn

Fisheries

Within FishSource, the term "fishery" is used to indicate each unique combination of a flag country with a fishing gear, operating within a particular management unit, upon a resource. That resource may have a known biological stock structure and/or may be assessed at another level for practical or jurisdictional reasons. A fishery is the finest scale of resolution captured in FishSource profiles, as it is generally the scale at which sustainability can most fairly and practically be evaluated.

ASSESSMENT UNIT MANAGEMENT UNIT FLAG COUNTRY FISHING GEAR
Atlantic Ocean Cameroon Cameroon Associated purse seining
Unassociated purse seining
ICCAT Canada Drifting longlines
Longlines
Equatorial Guinea Associated purse seining
Unassociated purse seining
France Associated purse seining
Unassociated purse seining
Gabon Associated purse seining
Longlines
Unassociated purse seining
Ghana Associated purse seining
Longlines
Unassociated purse seining
Guatemala Associated purse seining
Unassociated purse seining
South Africa Longlines
Spain Longlines
Purse seines
Unassociated purse seining
United States Longlines
Saint Helena Saint Helena Hooks and lines

Analysis

OVERVIEW

Last updated on 13 December 2013

Strengths

There is a total allowable catch (TAC) in place, a limit on the number of longline vessels and a time area closure for surface gears.  The TAC was lowered to levels (85,000 t) suggested by the scientific committee in 2009 and 2015 (65,000 t) and total catches have been below TAC levels since 2005.  There is a time/area closure in place for the purse seine fishery to protect juvenile bigeye tuna.  There is a multi-year conservation and management program in place through ICCAT for bigeye.

Weaknesses

Bigeye tuna in the Atlantic are overfished and undergoing overfishing. Due to unreported and mis-identified bigeye tuna, there was a large degree of uncertainty surrounding the assessment results.  There is no harvest control rule in place and no target or limit reference point. There is the need to monitor individual countries not included in the total allowable catch (TAC) allocation to ensure that catches do not exceed TAC levels. Mandated observer coverage (5%) is low and there are incidental interactions in both the longline and purse seine fisheries with protected, endangered and threatened species and sharks.

RECOMMENDATIONS

Last updated on 28 June 2016

Improvement Recommendations to Catchers & Regulators

1. Comply with all of the International Commission for the Conservation of Atlantic Tunas (ICCAT’s) conservation and management measures (CMMs), including measures aimed at both target and incidental market and non-market species, and all other obligations. Through your delegation to ICCAT, encourage the compliance committee to make information on non-compliance by individual members and cooperating non-members publicly available in order to increase the incentive for compliance by all ICCAT members and cooperating non-members.
2. Promote the adoption by the International Commission for the Conservation of Atlantic Tunas (ICCAT) and member countries of precautionary and ecosystem-based management measures, including biological reference points, harvest control rules, increased observer coverage, national management measures and monitoring efforts adequate to ensure harvest strategy objectives are being met. Adopt domestic laws and regulation to implement ICCAT measures and provide monitoring and surveillance adequate for compliance. Encourage ICCAT and parties to comply with current required onboard observer coverage rates.
3. Encourage the ICCAT to monitor catches to ensure they do not go over the total allowable catch limit (TAC) and re-structure the TAC in a way that does not allow for permissible overages by countries not included in the TAC allocation. Encourage ICCAT to continue monitoring bigeye weight as an indicator of the effects of surface gear closures. Improve data collection and reporting to ensure complete data sets (i.e. catches, effort, size), which are needed for robust stock assessments. Encourage ICCAT to expand the current data collection system to investigate whether significant catches have been under-reported. Conduct studies, increase monitoring and publish information to assess longline and purse seine interactions with protected, endangered and threatened (PET) and other bycatch species. Identify and mandate best practices bycatch mitigation techniques for both gear types. Comply with ICCAT management measures prohibiting the retention of silky, hammerhead, oceanic whitetip and thresher sharks and promote the use of non-entangling fish aggregating devices (FADs).

Recommendations to Retailers & Supply Chain

1. Ask the International Commission for the Conservation of Atlantic Tunas (ICCAT) and individual member countries to adopt precautionary and ecosystem-based management measures including formal reference points harvest control rules and increased observer coverage.
2. Require that your suppliers source only from fisheries that comply with all ICCAT’s Conservation and Management Measures, and request that ICCAT make information on compliance by members and cooperating non-members publicly available. An example of how this might be achieved is a control document that ensures recording and reporting interactions, and prohibition on retaining thresher, silky, hammerhead and oceanic whitetip sharks.
3. Source from vessels registered on the International Seafood Sustainability Foundation (ISSF) Proactive Vessel Register (PVR) and in full compliance with all measures relevant to their gear type as demonstrated by annual independent audit reports that are made publicly available.

1.STOCK STATUS

STOCK ASSESSMENT

An updated stock assessment was conducted in 2015. Catch and effort data from 1950-2014 was included in the assessment. Several models including non-equilibrium and statistical assessment models were used {ICCAT 2015}.

SCIENTIFIC ADVICE

Last updated on 9 December 2009

The advice from the 2015 assessment was that the current total allowable catch (TAC) of 85,000 t should be reduced to allow the population to recover. The current TAC would result in a 30% probability of recovering by 2028. A TAC of 65,000 t would have a 49% probability and catches of 60,000 T a 58% probability of recovery by 2028 {ICCAT 2015}.

Reference Points

Last updated on 09 Dec 2009

ICCAT uses two reference points to determine the status of bigeye tuna populations in the Atlantic, Bcurrent/BMSY and Fcurrent/FMSY.

Parameter                Value

Fcurrent/FMSY         0.776-1.635

Bcurrent/BMSY        0.435-0.917

MSY                       67,727-85,009 mt


 

 
CURRENT STATUS

Last updated on 9 December 2009

Median estimates of biomass and fishing reference points, indicate the population is overfished and undergoing overfishing {ICCAT 2015}..

Trends

Last updated on 09 Dec 2009

Fishing mortality rates have been increasing since the start of the fishery. Rapid increases were seen through the end of the 1990's after which mortality rates were right around sustainable levels. At the end of the 2000's mortality rates increased sharply, which a good indication that mortality rates were higher than sustainable levels in 2014. Biomass has been decreasing since the start of the time series and has remained below sustainable levels since 201o {ICCAT 2015}.

2.MANAGEMENT QUALITY

MANAGEMENT

Last updated on 9 December 2009

Bigeye tuna are managed through a total allowable catch (TAC), limits on the number of fishing vessels, limits on the number of longline and purse seine vessels.  In addition, no fishing with natural or artificial floating objects is allowed during January and February off a specified area of the African coast. There is a limit on the number of instrumental buoys that can be used {ICCAT 2015b}.

Recovery Plans

Last updated on 09 Dec 2009

Bigeye tuna are included in the Multi-Annual Conservation and Management Program for Tropical Tunas. This management measure was last updated in 2015 {ICCAT 2015b}.

COMPLIANCE

Last updated on 9 December 2009

Catches of bigeye tuna have been below the total allowable catch (TAC) levels since 2005 {ICCAT 2015}.

3.ENVIRONMENT AND BIODIVERSITY

BYCATCH
ETP Species
ICCAT
United States
Longlines

Last updated on 23 June 2010

The pelagic longline gear used in the Atlantic Highly migratory species is classified as Category I fishery for interactions with marine mammals under the
Marine Mammal Protection Act.
NMFS allocates observers in areas with high observed or reported bycatch rates of pilot whales, with a 17.3% observer overage in 2009.
Turtle interactions with PLL fishing vessels and discards of non-target species are monitored through observer coverage.

Other Species
ICCAT
United States
Longlines

Last updated on 23 June 2010

Regional (ICCAT Area)
Juveile Big eye tuna are caught along with skipjack and yellowfin tuna in FADs associated fisheries in EU purse seine and Ghana purse seine fisheries (ICCAT 2010a).

USA
In Gulf of Mexico tuna fishery to minimise bycatch, NMFS regulation prohibit use of livebait (NOAA 2010). Further in the Gulf of Mexico, with the
exception of Northeast Distant Waters (NED), circle hooks (16/0 or larger non-offset and 18/0 or larger with an offset not exceeding 10 degrees) are
required.
To minimise by-catch in the The South Atlantic – Florida East Coast to Cape Hatteras Swordfish Fishery two closures are in place to minimise bycatch
and interaction with protected species:
1) Florida East Coast closed area (year-round closure)
2) Charleston Bump closed area (February through April closure)
Vessels fishing in the NED area, are required to use 18/0 or larger circle hooks with an offset not exceeding 10 degrees and whole mackerel or squid
baits.
All PLL fishing vessel owners and operators are required to be certified and trained in handling and release of sea turtles and protected species.
Data collected from Pelagic longline observer (POP) coverage in 2009 showed, 243 interactions with Loggerhead sea turtles, 286 interactions with Leatherback turtles, and 144 interactions with marine mammals were observed in the U.S. Atlantic Pelagic Longline Fishery (NOAA 2010). Of the 150
interactions with sea birds, 108 birds were found dead, while 42 were released alive (NOAA 2010).

HABITAT
ICCAT
United States
Longlines

Last updated on 23 June 2010

Primary gear used to catch bigeye tuna, including purse seine, pelagic longline and pole-and-line gear, do not come in direct contact with the seafloor. Lost and discarded gear can damage coastal habitats.

Marine Reserves

Last updated on 23 Jun 2010

Area / Time closures in place to protect non-target species and reduce mortality of juvenile tuna and swordfish species.
1) Northeastern US Closure (closed to PLL fishing vessels in June)
2) Cape Hatteras Special Research Area (CHSRA) – PLL Special observer coverage.
3) Northeast Distant PLL gear restricted area
4) Charleston Bump (Closed from Feb 1 to April 30, every year)
5) Florida East Coast (Closed to PLL throughout the year)
6) De Sote Canyon (Closed to PLL all year)

FishSource Scores

Last updated on 14 August 2018

MANAGEMENT QUALITY

As calculated for 2014 data.

The score is ≥ 6.

There are some management measures for bigeye tuna in the Atlantic but no formal target or limit reference points and no harvest control rule.

As calculated for 2014 data.

The score is ≥ 8.

ICCAT reduced the TAC to 65,000 t (starting in 2016). This coincides with scientific advice that the TAC should be reduced from 85,000 t to increase probability of rebuilding.

As calculated for 2014 data.

The score is 10.0.

This measures the Landings as a percentage of the Set TAC.

The Landings is 72.6 ('000 t). The Set TAC is 85.0 ('000 t) .

The underlying Landings/Set TAC for this index is 85.4%.

STOCK HEALTH:

As calculated for 2014 data.

The score is 6.7.

This measures the Ratio SSB/SSBmsy as a percentage of the SSB=SSBmsy.

The Ratio SSB/SSBmsy is 0.676 . The SSB=SSBmsy is 1.00 .

The underlying Ratio SSB/SSBmsy/SSB=SSBmsy for this index is 67.6%.

As calculated for 2014 data.

The score is 7.2.

This measures the Ratio F/Fmsy as a percentage of the F management target.

The Ratio F/Fmsy is 1.20 . The F management target is 1.00 .

The underlying Ratio F/Fmsy/F management target for this index is 120%.

To see data for biomass, please view this site on a desktop.
To see data for catch and tac, please view this site on a desktop.
To see data for fishing mortality, please view this site on a desktop.
No data available for recruitment
No data available for recruitment
To see data for management quality, please view this site on a desktop.
To see data for stock status, please view this site on a desktop.
DATA NOTES

1). The time series of F and SSB are provided relative to MSY (F/FMSY, B/BMSY); the thresholds have been set accordingly. 2). There is no Blrp in place thus score 1 cannot be computed. Hence, qualitative score has been given for this aspect. Catches and TAC levels have been updated through 2013 {ICCAT 2014}.

Download Source Data

Registered users can download the original data file for calculating the scores after logging in. If you wish, you can Register now.

Fishery Improvement Projects (FIPs)

No related FIPs

Certifications

Marine Stewardship Council (MSC)

SELECT MSC

NAME

Southeast US North Atlantic big eye tuna and yellowfin tuna

STATUS

Withdrawn on 18 June 2014

SCORES

Certification Type:

Sources

Credits
  1. ICCAT, 2004. 04-01 Recommendation by ICCAT on a multi-year conservation and management program for bigeye tuna. 3 p. http://www.iccat.int/Documents%5CRecs%5Ccompendiopdf-e%5C2004-01-e.pdf
  2. ICCAT, 2007. Report of the 2007 ICCAT bigeye tuna stock assessment session. 143 p.http://www.iccat.int/Documents/SCRS/DetRep/DET_bet.pdf
  3. ICCAT, 2008. 08-01 Recommendation by ICCAT to amend the recommendation by ICCAT on a multi-year conservation and management program for bigeye tuna. 4 p.http://www.iccat.int/Documents%5CRecs%5Ccompendiopdf-e%5C2008-01-e.pdf
  4. ICCAT, 2009a. Biennial Reports on management measures adopted and scientific advice provided by the SCRS. 275 p.http://www.iccat.int/Documents/BienRep/REP_EN_08-09_I_2.pdf
  5. ICCAT, 2009b. 09-01 Recommendation by ICCAT to amend the recommendation by iccat on multi-year conservation and management program for bigeye tuna. 1 p.http://www.iccat.int/Documents%5CRecs%5Ccompendiopdf-e%5C2009-01-e.pdf
  6. ICCAT. 2015. REport of the 2010 ICCAT bigeye tuna stock assessment session. Pasaia, Gipuzkoa, Spain, July 5-9 2010. http://www.iccat.int/Documents/Meetings/Docs/2010_BET_Assessment_REP_ENG.pdf

    ICCAT. 2015b. Recommendation by ICCAT on a multi-annual conservation and management program for tropical tunas. CMM 15-01.http://www.iccat.int/Documents/Recs/compendiopdf-e/2015-01-e.pdf

References

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