Last updated on 18 February 2016

SUMMARY

SUMMARY

IDENTIFICATION

SCIENTIFIC NAME(s)

Katsuwonus pelamis

SPECIES NAME(s)

Skipjack tuna

It is likely that skipjack are distributed throughout the Pacific as a single population. Exchange of fish between the eastern and western region is not common. The majority of catches occur in the eastern and western regions. Therefore assessments are conducted for both the eastern and western regions (Maunder 2015).


ANALYSIS

Strengths
  • Fishing mortality rates and biomass are currently thought to be sustainable.
  • Discarding of tunas is prohibited.
  • There is a multi-year conservation plan in place, which has just been extended, for skipjack tuna (and other tuna species).
  • A harvest control rule has been adopted.
  • There is 100% observer coverage on large purse seine vessels operating on the high seas.

At the national level, there are adequate regulations for protecting PET species (ban on sea turtle and whale fishing); closed season for lesser pelagics while fishing in territorial waters; required use of special screen on purse seiners for safe release of marine mammals; Ecuador is signatory to the International Dolphin Conservation Program (AIDCP) under the IATTC; Ecuador implements the IATTC resolution which bans transshipment of tuna on the high seas; Mandatory use of excluder screen on class six tuna vessels to prevent capture of juvenile fish (Prieto 2009). Fishing mortality rates are sustainable and the biomass is healthy. Interim limit reference points have been defined and FMSY and BMSY are used as informal reference points. There are time/area closures in place for the purse seine fleet fishing in high seas waters and all tuna must be landed. There is a multi-year conservation plan in place under IATTC, which has just been extended, for skipjack tuna (and other tuna species).There is 100% observer coverage for purse seine vessels operating in the high seas.

Weaknesses
  • There are no MSY based reference points used for skipjack tuna in the EPO.
  • There are time/area closures in place for the purse seine fleet but these measures are not sufficient to manage the fish aggregating device (FAD) fishery.
  • Purse seine fisheries can interact with ETP species..

The stock structure is uncertain for skipjack tuna in the Eastern Pacific Ocean in comparison to the Western and Central Pacific stocks (IATTC 2012). Tuna monitoring is poor in artisanal fisheries, especially for catch records; enforcement of artisanal fleet is difficult due to large number of small vessels that target tuna and other pelagic fish (Prieto 2009). There is shortage of information on catches of skipjack tuna in other surface fisheries prior to 1970. There was no observer scheme prior to 1993 and hence no discards are assumed before this period (Maunder 2012). Formal reference points and harvest control rules have not been adopted at the international RFMO level.

FISHSOURCE SCORES

Management Quality:

Management Strategy:

≥ 6

Managers Compliance:

≥ 6

Fishers Compliance:

≥ 6

Stock Health:

Current
Health:

≥ 8

Future Health:

≥ 8


RECOMMENDATIONS

CATCHERS & REGULATORS

1. Ensure member countries comply with all Inter-American Tropical Tuna Commission’s (IATTC) 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 IATTC, encourage the compliance committee to make information on non-compliance by individual members and cooperating non-members publicly available and transparent.
2. A) Regulators -Promote the adoption by the Inter-American Tropical Tuna Commission’s (IATTC) and member countries of precautionary and ecosystem-based management measures, including MSY based biological reference points, harvest control rules (interim plan is currently being used), national management measures and monitoring efforts adequate to ensure harvest strategy objectives are being met.
B) Catchers – Inform relevant delegations to the Inter-American Tropical Tuna Commission’s (IATTC), those being Member and Cooperating Non-Members in countries where your company is incorporated and where your company conducts operations, to have IATTC adopt a formal MSY based target reference point for EPO skipjack tuna, a harvest strategy responsive to the state of the stock and designed to achieve the limit and target reference points, and management measure and tools consistent with the harvest strategy that reduces fishing mortality, as a limit reference point is approached. Comply with current required onboard observer coverage rates.
3. Encourage IATTC to conduct a feasibility study for routine sampling (i.e. length data) of adult tunas from canneries and to continue monitoring the average weight of skipjack tuna. Improved tagging data is also needed for skipjack tuna in the EPO region to properly define populations. Encourage IATTC to implement additional management measures to reduce fish aggregating device (FAD) fishing mortality, such as limiting the number of FAD sets allowed each year.
4. Conduct studies, increase monitoring and publish information to assess longline and purse seine interactions with endangered, threatened and protected (ETP) and other bycatch species. Identify and mandate best practice bycatch mitigation techniques. Central American countries should work with IATTC to provide various information on shark catches (http://www.iattc.org/Meetings/Meetings2015/6SAC/PDFs/SAC-06-08c-FAO-GEF-shark-project.pdf). Demand compliance with recently implemented IATTC management measures prohibiting the retention of oceanic whitetip sharks. Encourage IATTC to adopt similar measures to those adopted by the Western and Central Pacific Fisheries Commission for silky shark; including prohibited retention by purse seine vessels.

RETAILERS & SUPPLY CHAIN

1. Encourage both the Inter-American Tropical Tuna Commission’s (IATTC) and individual member and cooperating non-members to adopt precautionary and ecosystem-based management measures. Demand that member countries comply with all IATTC’s Conservation and Management Measures, and request the IATTC make information on monitoring and compliance publicly available.
2. Explore implementation of control documents to ensure supplier compliance with IATTC conservation and management measures (CMMs) (e.g. around bycatch). 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. Encourage ISSF to expand the ecological sustainability criteria against which tuna vessels on the PVR are assessed.
3. Encourage the IATTC and member countries to conduct studies, increase monitoring and publish information with protected, endangered and threatened (PET) and other bycatch species. Explore opportunities to support studies and data gathering.
4. Contact SFP to learn more about fishery improvement projects (FIPs) and the Eastern Pacific Large Pelagic Supplier Roundtable.


FIPS

  • Eastern Pacific Ocean tropical tuna - purse seine (TUNACONS):

    Stage 4, Progress Rating A

CERTIFICATIONS

No related MSC fisheries

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
Eastern Pacific Ocean IATTC Ecuador Dolphin set purse seining
Purse seines
Unassociated purse seining
Mexico Dolphin set purse seining
Pole-lines hand operated
Purse seines
Unassociated purse seining
Nicaragua Associated purse seining
Unassociated purse seining
Panama Associated purse seining
Unassociated purse seining
Spain Purse seines
Unassociated purse seining
United States Drifting longlines

Analysis

OVERVIEW

Last updated on 12 December 2013

Strengths
  • Fishing mortality rates and biomass are currently thought to be sustainable.
  • Discarding of tunas is prohibited.
  • There is a multi-year conservation plan in place, which has just been extended, for skipjack tuna (and other tuna species).
  • A harvest control rule has been adopted.
  • There is 100% observer coverage on large purse seine vessels operating on the high seas.
IATTC
Ecuador
Purse seines

Last updated on 12 December 2013

At the national level, there are adequate regulations for protecting PET species (ban on sea turtle and whale fishing); closed season for lesser pelagics while fishing in territorial waters; required use of special screen on purse seiners for safe release of marine mammals; Ecuador is signatory to the International Dolphin Conservation Program (AIDCP) under the IATTC; Ecuador implements the IATTC resolution which bans transshipment of tuna on the high seas; Mandatory use of excluder screen on class six tuna vessels to prevent capture of juvenile fish (Prieto 2009). Fishing mortality rates are sustainable and the biomass is healthy. Interim limit reference points have been defined and FMSY and BMSY are used as informal reference points. There are time/area closures in place for the purse seine fleet fishing in high seas waters and all tuna must be landed. There is a multi-year conservation plan in place under IATTC, which has just been extended, for skipjack tuna (and other tuna species).There is 100% observer coverage for purse seine vessels operating in the high seas.

Weaknesses
  • There are no MSY based reference points used for skipjack tuna in the EPO.
  • There are time/area closures in place for the purse seine fleet but these measures are not sufficient to manage the fish aggregating device (FAD) fishery.
  • Purse seine fisheries can interact with ETP species..
IATTC
Ecuador
Purse seines

Last updated on 12 December 2013

The stock structure is uncertain for skipjack tuna in the Eastern Pacific Ocean in comparison to the Western and Central Pacific stocks (IATTC 2012). Tuna monitoring is poor in artisanal fisheries, especially for catch records; enforcement of artisanal fleet is difficult due to large number of small vessels that target tuna and other pelagic fish (Prieto 2009). There is shortage of information on catches of skipjack tuna in other surface fisheries prior to 1970. There was no observer scheme prior to 1993 and hence no discards are assumed before this period (Maunder 2012). Formal reference points and harvest control rules have not been adopted at the international RFMO level.

RECOMMENDATIONS

Last updated on 28 June 2016

Improvement Recommendations to Catchers & Regulators

1. Ensure member countries comply with all Inter-American Tropical Tuna Commission’s (IATTC) 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 IATTC, encourage the compliance committee to make information on non-compliance by individual members and cooperating non-members publicly available and transparent.
2. A) Regulators -Promote the adoption by the Inter-American Tropical Tuna Commission’s (IATTC) and member countries of precautionary and ecosystem-based management measures, including MSY based biological reference points, harvest control rules (interim plan is currently being used), national management measures and monitoring efforts adequate to ensure harvest strategy objectives are being met.
B) Catchers – Inform relevant delegations to the Inter-American Tropical Tuna Commission’s (IATTC), those being Member and Cooperating Non-Members in countries where your company is incorporated and where your company conducts operations, to have IATTC adopt a formal MSY based target reference point for EPO skipjack tuna, a harvest strategy responsive to the state of the stock and designed to achieve the limit and target reference points, and management measure and tools consistent with the harvest strategy that reduces fishing mortality, as a limit reference point is approached. Comply with current required onboard observer coverage rates.
3. Encourage IATTC to conduct a feasibility study for routine sampling (i.e. length data) of adult tunas from canneries and to continue monitoring the average weight of skipjack tuna. Improved tagging data is also needed for skipjack tuna in the EPO region to properly define populations. Encourage IATTC to implement additional management measures to reduce fish aggregating device (FAD) fishing mortality, such as limiting the number of FAD sets allowed each year.
4. Conduct studies, increase monitoring and publish information to assess longline and purse seine interactions with endangered, threatened and protected (ETP) and other bycatch species. Identify and mandate best practice bycatch mitigation techniques. Central American countries should work with IATTC to provide various information on shark catches (http://www.iattc.org/Meetings/Meetings2015/6SAC/PDFs/SAC-06-08c-FAO-GEF-shark-project.pdf). Demand compliance with recently implemented IATTC management measures prohibiting the retention of oceanic whitetip sharks. Encourage IATTC to adopt similar measures to those adopted by the Western and Central Pacific Fisheries Commission for silky shark; including prohibited retention by purse seine vessels.

Recommendations to Retailers & Supply Chain

1. Encourage both the Inter-American Tropical Tuna Commission’s (IATTC) and individual member and cooperating non-members to adopt precautionary and ecosystem-based management measures. Demand that member countries comply with all IATTC’s Conservation and Management Measures, and request the IATTC make information on monitoring and compliance publicly available.
2. Explore implementation of control documents to ensure supplier compliance with IATTC conservation and management measures (CMMs) (e.g. around bycatch). 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. Encourage ISSF to expand the ecological sustainability criteria against which tuna vessels on the PVR are assessed.
3. Encourage the IATTC and member countries to conduct studies, increase monitoring and publish information with protected, endangered and threatened (PET) and other bycatch species. Explore opportunities to support studies and data gathering.
4. Contact SFP to learn more about fishery improvement projects (FIPs) and the Eastern Pacific Large Pelagic Supplier Roundtable.

1.STOCK STATUS

STOCK ASSESSMENT

Last updated on 16 August 2018

Stock assessments are difficult to conduct on skipjack tuna due to their high and variable productivity. These characteristics make it difficult to determine the effect of fishing using typical stock assessment techniques. The Inter-American Tropical Tuna Commission (IATTC) conducts assessments of skipjack tuna using various indicators instead of traditional reference points. The most recent assessment conducted in 2018 used eight data and model based indicators 1) catch, 2) CPDF NOA, 3) average weight, 4) relative recruitment, 5) CPDF OBJ, 6) standardized effort, 7) relative biomass, and 8) exploitation rate (Maunder 2018).

SCIENTIFIC ADVICE

Last updated on 16 August 2018

The latest scientific advice, based on the 2015 assessment, is that there is no concern over the status of the stock and no additional management measures beyond those adopted for other tropical tuna species are needed (IATTC 2018)(Maunder 2018).

Reference Points

 

There are no MSY based reference points used to define the status of skipjack tuna in the eastern Pacific Ocean (Maunder 2018).

Fcurrent/FMSY <1

Bcurrent/BMSY >1  

CURRENT STATUS

Last updated on 16 August 2018

It is most likely that skipjack tuna are not overfished or undergoing overfishing (Maunder 2018).

Trends

The biomass, recruitment and exploitation rates have been variable over time. In recent years the biomass has been above average levels but this varies among regions of the eastern Pacific Ocean. Fishing mortality rates were higher during the 1970’s and early 1980’s and has fluctuated around average levels since the mid-1990's (Maunder 2018).

2.MANAGEMENT QUALITY

MANAGEMENT

Last updated on 16 August 2018

The Inter-American Tropical Tuna Commission (IATTC) currently has a multi-year conservation plan in place for bigeye, skipjack and yellowfin tuna caught in the eastern Pacific Ocean. Management measures specific to the purse seine fisheries include a mandatory closure for 72 days during one of two predefined time periods and there is an additional purse seine closure between October 9th and November 8th in the area of 960 and 1100W and between 40N and 30S (IATTC 2017). If a fisheries observer is onboard from the On-Board Observer Program of the Agreement on the International Dolphin Conservation Program (AIDCP), the vessels (182-272 metric tons carrying capacity) can make one 30 day trip during the specified closures dates. An additional time/area closure off the coast of Central and South America for purse seine vessels is also in place (IATTC 2017). Discarding bigeye, skipjack and yellowfin tuna is prohibited {IATTC 2013}. Purse seine vessels are also prohibited from setting on data buoys {IATTC 2010}.

Recovery Plans

Last updated on 31 Oct 2014

IATTC has a multi-annual conservation program in place to monitor tuna populations. The plan was last updated in 2017 for the 2018-2020 fishing seasons (IATTC 2017).

COMPLIANCE

Last updated on 16 August 2018

There is no TAC in place for skipjack tuna.

IATTC
Ecuador
Purse seines

Last updated on 22 September 2012

In Ecuador waters, compliance is relatively good in the industrial fishing sector with vessels monitored through VMS and onboard observers for compliance with national and IATTC regulations. However, there are huge gaps in monitoring landings from small-scale landing centres, and IUU landings from this sector remain largely unaccounted in catch statistics.

3.ENVIRONMENT AND BIODIVERSITY

BYCATCH
ETP Species

Last updated on 16 August 2018

Purse seine fisheries have some interactions with sea turtles, but far less than in the longline fisheries and marine mammal interactions are minimal. The troll and pole fisheries for bigeye tuna do not incidentally capture any of these species.The Inter-American Tropical Tuna Commission (IATTC) has put several management measures aimed at bycatch species into place. Shark finning is banned (5% rule) and oceanic whitetip sharks are prohibited from being retained (IATTC 2011b)(IATTC 2011c)(IATTC 2005)(IAC 2012). Purse seine fisheries fishing on fish aggregating devices (FADs) must use specific methods designed to avoid entangling sea turtles or other bycatch species. Any interactions must be reported and sea turtles are to be released (IATTC 2012)(IATTC 2007).

Other Species

Last updated on 1 November 2014

In the purse seine fishery (floating object), yellowtail, mahimahi, rainbow runner and wahoo are common bycatch species. Mahimahi and rainbow runner are also caught in the unassociated fisheries. Assessments have not been conducted on these species, so their status is unknown. Silky and oceanic white tips sharks, along with manta rays (unassociated) are also incidentally caught (Hall and Rowman 2013). No assessments of oceanic whitetip sharks or manta rays have been conducted. Oceanic whitetip sharks are prohibited from being retained and shark finning (5% rule) is prohibited (IATTC 2011c).

IATTC
Ecuador
Purse seines

Last updated on 23 September 2012

In the Eastern Pacific Ocean, by-catch for tuna purse seiners >363 MT, is available in page 139, (IATTC (2012) report. By-catch reported in the fishery include Billfishes (Makaira indica, Makaira nigricans, Kajikia audax, Istiophorus platypterus ), Dolphins ( Stenella attenuata, Stenella longirostris, Delphinus delphis ), Olive ridley turtles (Lepidochelys olivacea) and large pelagic fish (Common Dolphin fish, Pompano dolphin fish, Wahoo, Rainbow runner, Bigeye trevally, Yellowtail amberjack, Ocean Sunfish),Rays (Giant Manta, Spinetail Manta, Smoothtail Manta), sharks (Silky sharks, Oceanic whitetip sharks, Bigeye thresher sharks, Scalloped hammerhead sharks, Great Hammerhead sharks, Smooth hammerhead sharks, shortfin mako sharks), andsmaller fish like Ocean trigger fish, Bluestriped chub, Scrawled filefish, etc. (IATTC 2012).

The Skipjack tuna purse seine fishery off Ecuador, Galapagos islands and high seas areas of Eastern Pacific Ocean has reported problematic by-catch of sharks such as Carcharhinus falciformis, C. limbatus, C. longimanus, Sphyrna zygaena, Sphrna lewini (Roman-Verdesto and Orozco-Zöller 2006; Watson et al., 2009; Román-Verdesoto et al., 2010), mahi mahi, and other pelagic fish.

By-catch species commonly reported in the purse seine fisheries include small tunas, billfishes, rainbow runner, yellowtail, wahoo, sharks , rays, sea turtles, dolphinfish, trigger fishes and carangids (Hall 1998). For recording non-mammal by-catch, the observer coverage has witnessed an increase from 40% in 1993 to 100% by 2009 (IATTC 2011b).

HABITAT

Last updated on 23 September 2012

The gears used to capture tuna have no impact on bottom habitats.

Marine Reserves

Last updated on 23 Sep 2012

All tuna purse seiners operating in the Eastern Pacific Ocean were required to stop fishing for a period of 62 days in 2011 and 2012 (IATTC 2012). The closures were in effect for the following time periods.

2011 – 29 July to 28 September, or from 18 November to 18 January 2012.
2012 – 29 July to 28 September, or from 18 November to 18 January 2013.
2013 – 29 July to 28 September, or from 18 November to 18 January 2014.

IATTC
Ecuador
Purse seines

Last updated on 21 September 2012

Pelagic fishing gear like purse seines have nominal adverse effects on coastal and marine habitats.

Marine Reserves

Last updated on 21 Sep 2012

All tuna purse seiners operating in the Eastern Pacific Ocean were required to stop fishing for a period of62 days in 2011 and 2012 (IATTC 2012). The closures were in effect for the following time periods.

2011 – 29 July to 28 September, or from 18 November to 18 January 2012.
2012 – 29 July to 28 September, or from 18 November to 18 January 2013.
2013 – 29 July to 28 September, or from 18 November to 18 January 2014.

FishSource Scores

Last updated on 13 July 2018

MANAGEMENT QUALITY

As calculated for 2018 data.

The score is ≥ 6.

There are no specific management plans in place, but harvest control rules have been officially adopted. There are no MSY based reference points for skipjack tuna in the EPO.

As calculated for 2018 data.

The score is ≥ 6.

Managers have followed scientific advice by carrying over the current management plan into 2014 but have not adopted harvest control rules or reference points as of the 2014 Commission meeting.

As calculated for 2018 data.

The score is ≥ 6.

There is no TAC in place for skipjack tuna.

STOCK HEALTH:

As calculated for 2018 data.

The score is ≥ 8.

The biomass is likely above MSY levels

As calculated for 2018 data.

The score is ≥ 8.

Fishing mortality rates are likely below MSY levels

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. We are aware of no advised or set quotas/TAC thus qualitative scores have been computed for 1, 2 and 3. 2. Indicators are currently used instead of traditional MSY based reference points. Thus the qualitative score for #’s 4 and 5. 3. Catches for 2017 from IATTC Fishery Status report for tuna, 2016 (IATTC 2017).

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Fishery Improvement Projects (FIPs)

SELECT FIP

Access FIP Public Report

Progress Rating: A
Evaluation Start Date: 2 Jan 2017
Type: Comprehensive

Comments:

FIP progress ratiing remains at A. Last stage 4 results during past 12 months

1.
FIP Development
Feb 16
2.
FIP Launch
Jan 17
Aug 16
3.
FIP Implementation
Dec 17
4.
Improvements in Fishing Practices and Fishery Management
Dec 17
5.
Improvements on the Water
Verifiable improvement on the water
6.
MSC certification (optional)
MSC certificate made public

Certifications

Marine Stewardship Council (MSC)

No related MSC certifications

Sources

Credits

IATTC. 2015. Recommendations by the staff for conservation measures in the eastern Pacific Ocean, 2015. Document SAC-06-11.

IATTC. 2017. Conservation of tuna in the Eastern Pacific Ocean during 2017. Resolution C-17-01. http://www.iattc.org/PDFFiles2/Resolutions/C-17-01-Tuna-conservation-2017.pdf

Lehodey, P., Senina, I., Calmettes, B., Hampton, J., Nicol, S., Williams, P., Jurado Molina, J., Ogura, M., Kiyofuji, H., and Okamoto, S. 2011. SEAPODYM working progress and applications to Pacific skipjack tuna population and fisheries. WCPFC-SC7-2011/EB-WP 06 rev. 1.

Maunder, M.N. 2016. Status of skipjack tuna in the eastern Pacific Ocean in 2016. IATTC Document SAC-07-05c.

References

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