SUMMARY

SUMMARY

IDENTIFICATION

SCIENTIFIC NAME(s)

Katsuwonus pelamis

SPECIES NAME(s)

Skipjack tuna

Skipjack tuna in the western and central Pacific Ocean are considered a single stock for assessment purposes {Rice et al. 2014}.


ANALYSIS

Strengths

Skipjack tuna in the western and central Pacific Ocean are managed at the international level by the Western and Central Pacific Fisheries Commission (WCPFC). Regular assessments of target tuna and tuna-like species are conducted. Therefore the status of the stocks is known and regularly monitored.The Parties to the Nauru Agreement (PNA)(EEZ’s of Papua New Guinea, Kiribati, FS Micronesia, Marshall Islands, Nauru, Palau, Solomon Islands and Tuvalu) purse seine (unassociated or free school sets) fishery is MSC certified for skipjack tuna. Skipjack tuna have a healthy population size and fishing mortality rates are sustainable. There are several management measures specific to skipjack tuna purse seine fisheries currently in place through the WCPFC.

Regular assessments of target tuna and tuna-like species are conducted. Therefore the status of the stocks is known and regularly monitored. Skipjack tuna have a healthy population size and fishing mortality rates are sustainable. The National Tuna Management Plan of Indonesia has been developed as a product of a joint cooperation between the Directorate General of Capture Fisheries, Ministry of Marine Affairs and Fisheries of Indonesia and the Western Central Pacific Fisheries Commission (WCPFC). The aims of the management plan are to support the effective implementation of the tuna fisheries management in a sustainable way (MMAF and WCPFC, 2012). Indonesia has also launched a National Plan of Action for tuna, skipjack and neritic tuna in November of 2014 (MMAF 2014).

Weaknesses

There is no formally adopted harvest control rule or target reference points. Information on compliance and monitoring by member countries has historically not been available. In recent years, there has been an increased lack of transparency with regard to the WCPFC decision making process.Skipjack tuna are difficult to assess because of their high and variable productivity. Timely submissions and data accuracy from some member countries is a problem which mainly contributes to the significant uncertainties in the stock assessment results. The Japanese pole and line fishery, which represents less than 4% of the total catch in this region is the only long term abundance data set. Calculating an index of abundance for the purse seine fishery, which dominates the equatorial catches, is difficult. The impact of fish aggregating device (FAD) purse seine fishing on ecologically important species, continues to be an issue. The WCPFC has yet to formally adopt management measures that require the use of non-entanglement FAD designs. The WCPFC Scientific Committee management advice included concerns over high catches of skipjack in equatorial waters. The Scientific Committee suggested that there should be management of total effort in the WCPO, including stricter rules surrounding purse seine fishing. In 2012, the WCPFC adopted a measure prohibiting the discard of skipjack (bigeye and yellowfin) tuna caught in purse seine fisheries, but it is too early to determine if this had reduced fishing pressure.

There is no formally adopted harvest control rule or target reference points. Skipjack tuna are difficult to assess because of their high and variable productivity. Effort data from Indonesia has been unavailable for stock assessment purposes. Indonesia has an observer program in place but coverage is very low.

FISHSOURCE SCORES

Management Quality:

Management Strategy:

≥ 6

Managers Compliance:

≥ 6

Fishers Compliance:

≥ 6

Stock Health:

Current
Health:

10

Future Health:

10


RECOMMENDATIONS

RETAILERS & SUPPLY CHAIN

Stock-wide recommendations

  • Conduct outreach to the Western and Central Pacific Fisheries Commission (WCPFC) requesting continued work on the development and adoption of a harvest control rule, and encourage the WCPFC to take demonstrably effective actions to keep the spawning biomass near the adopted target reference point.
  • Request improved transparency of and by the WCPFC, especially regarding the Compliance Committee and issues of non-compliance by individual members (nations). Press individual members to provide evidence of compliance with all WCPFC Conservation and Management Measures in a timely manner.
  • Ensure all products are traceable back to legal sources. Verify source information and full chain traceability through traceability desk audits or third party traceability certification. For fisheries without robust traceability systems in place, invest in meaningful improvements to bring the fisheries and supply chain into compliance with best practices.
  • Encourage the supply chain to adopt voluntary shark fins naturally attached regulations and promote the adoption of this rule by the WCPFC.
  • Improve data collection (i.e. catches, effort, size), on both target and bycatch species, and reporting through measures such as electronic logbooks (e-reporting). 
  • Identify and mandate the use of best practice bycatch mitigation techniques.
  • Contact SFP to learn how to initiate your own fishery improvement project (FIP), engage in an ongoing FIP, and/or SFP’s Supply Chain Roundtables.

FIPS

No related FIPs

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.

Fisheries
ASSESSMENT UNIT MANAGEMENT UNIT FLAG COUNTRY FISHING GEAR
Western and Central Pacific Ocean Parties to the Nauru Agreement (PNA) China Associated purse seining
FAD-free
Japan FAD-free
Hooks and lines
Pole-lines mechanized
Purse seines
Kiribati FAD-free
Purse seines
Korea, Republic of FAD-free
Purse seines
Marshall Islands FAD-free
Purse seines
Micronesia, Federated States of FAD-free
Purse seines
Nauru FAD-free
Purse seines
New Zealand FAD-free
Purse seines
Palau FAD-free
Purse seines
Papua New Guinea FAD-free
Purse seines
Philippines FAD-free
Purse seines
Solomon Islands FAD-free
Pole-lines hand operated
Purse seines
Spain FAD-free
Purse seines
Taiwan, Province of China FAD-free
Purse seines
Tuvalu FAD-free
Purse seines
United States FAD-free
Purse seines
Vanuatu FAD-free
Purse seines
Viet Nam Viet Nam Purse seines
WCPFC China FAD-free
Purse seines
Indonesia FAD-free
Gillnets and entangling nets
Hooks and lines
Pole-lines hand operated
Purse seines
Trolling lines
Japan FAD-free
Mechanized lines
Pole-lines hand operated
Purse seines
Kiribati FAD-free
Purse seines
Korea, Republic of FAD-free
Purse seines
Marshall Islands FAD-free
Purse seines
Micronesia, Federated States of FAD-free
Purse seines
Nauru FAD-free
Purse seines
New Zealand FAD-free
Purse seines
Palau FAD-free
Purse seines
Papua New Guinea FAD-free
Purse seines
Philippines FAD-free
Pole-lines hand operated
Purse seines
Solomon Islands FAD-free
Purse seines
Spain FAD-free
Purse seines
Taiwan, Province of China FAD-free
Purse seines
Thailand FAD-free
Pole-lines mechanized
Purse seines
Tuvalu FAD-free
Purse seines
United States FAD-free
Longlines
Purse seines
Seine nets

Analysis

OVERVIEW

Last updated on 17 October 2014

Strengths

Skipjack tuna in the western and central Pacific Ocean are managed at the international level by the Western and Central Pacific Fisheries Commission (WCPFC). Regular assessments of target tuna and tuna-like species are conducted. Therefore the status of the stocks is known and regularly monitored.The Parties to the Nauru Agreement (PNA)(EEZ’s of Papua New Guinea, Kiribati, FS Micronesia, Marshall Islands, Nauru, Palau, Solomon Islands and Tuvalu) purse seine (unassociated or free school sets) fishery is MSC certified for skipjack tuna. Skipjack tuna have a healthy population size and fishing mortality rates are sustainable. There are several management measures specific to skipjack tuna purse seine fisheries currently in place through the WCPFC.

WCPFC
Indonesia

Regular assessments of target tuna and tuna-like species are conducted. Therefore the status of the stocks is known and regularly monitored. Skipjack tuna have a healthy population size and fishing mortality rates are sustainable. The National Tuna Management Plan of Indonesia has been developed as a product of a joint cooperation between the Directorate General of Capture Fisheries, Ministry of Marine Affairs and Fisheries of Indonesia and the Western Central Pacific Fisheries Commission (WCPFC). The aims of the management plan are to support the effective implementation of the tuna fisheries management in a sustainable way (MMAF and WCPFC, 2012). Indonesia has also launched a National Plan of Action for tuna, skipjack and neritic tuna in November of 2014 (MMAF 2014).

Weaknesses

There is no formally adopted harvest control rule or target reference points. Information on compliance and monitoring by member countries has historically not been available. In recent years, there has been an increased lack of transparency with regard to the WCPFC decision making process.Skipjack tuna are difficult to assess because of their high and variable productivity. Timely submissions and data accuracy from some member countries is a problem which mainly contributes to the significant uncertainties in the stock assessment results. The Japanese pole and line fishery, which represents less than 4% of the total catch in this region is the only long term abundance data set. Calculating an index of abundance for the purse seine fishery, which dominates the equatorial catches, is difficult. The impact of fish aggregating device (FAD) purse seine fishing on ecologically important species, continues to be an issue. The WCPFC has yet to formally adopt management measures that require the use of non-entanglement FAD designs. The WCPFC Scientific Committee management advice included concerns over high catches of skipjack in equatorial waters. The Scientific Committee suggested that there should be management of total effort in the WCPO, including stricter rules surrounding purse seine fishing. In 2012, the WCPFC adopted a measure prohibiting the discard of skipjack (bigeye and yellowfin) tuna caught in purse seine fisheries, but it is too early to determine if this had reduced fishing pressure.

WCPFC
Indonesia
Hooks and lines

Last updated on 8 July 2015

There is no formally adopted harvest control rule or target reference points. Skipjack tuna are difficult to assess because of their high and variable productivity. Effort data from Indonesia has been unavailable for stock assessment purposes. Indonesia has an observer program in place but coverage is very low.

RECOMMENDATIONS

Last updated on 31 July 2019

Recommendations to Retailers & Supply Chain

Stock-wide recommendations

  • Conduct outreach to the Western and Central Pacific Fisheries Commission (WCPFC) requesting continued work on the development and adoption of a harvest control rule, and encourage the WCPFC to take demonstrably effective actions to keep the spawning biomass near the adopted target reference point.
  • Request improved transparency of and by the WCPFC, especially regarding the Compliance Committee and issues of non-compliance by individual members (nations). Press individual members to provide evidence of compliance with all WCPFC Conservation and Management Measures in a timely manner.
  • Ensure all products are traceable back to legal sources. Verify source information and full chain traceability through traceability desk audits or third party traceability certification. For fisheries without robust traceability systems in place, invest in meaningful improvements to bring the fisheries and supply chain into compliance with best practices.
  • Encourage the supply chain to adopt voluntary shark fins naturally attached regulations and promote the adoption of this rule by the WCPFC.
  • Improve data collection (i.e. catches, effort, size), on both target and bycatch species, and reporting through measures such as electronic logbooks (e-reporting). 
  • Identify and mandate the use of best practice bycatch mitigation techniques.
  • Contact SFP to learn how to initiate your own fishery improvement project (FIP), engage in an ongoing FIP, and/or SFP’s Supply Chain Roundtables.

1.STOCK STATUS

STOCK ASSESSMENT

Last updated on 16 January 2018

The skipjack tuna population in the western and central Pacific Ocean is assessed using the MULTIFAN-CL software, which has been used since 2000. The last assessment was conduced in 2016. The model is age (16 quarterly age classes) and spatially structured for quarterly time periods from 1972-2014 and includes catch, effort, size composition and tagging data. This new assessment included a modified tagging input file, changes to the relative weighting of the CPUE, legnth composition and tagging data and modifications to some model parameters {McKechnie et al. 2016}.

SCIENTIFIC ADVICE

Last updated on 16 January 2018

The Scientific Committee advised the Commission in 2016 that managers should be aware of the total effort in the WCPO region and should take action to keep the spawning biomass near the target reference point (McKechnie et al. 2016).

Reference Points

Last updated on 16 Jan 2018

ParameterValue
Frecent/FMSY0.45 (0.40-0.62)
SBrecent/SBMSY2.31 (1.80 - 2.63)
SBlatest/SBMSY2.56 (1.81-2.93)
MSY1.891 million mt (1.591 million mt – 2.076 million mt)

*current represents 2011-2014 and latest represents 2014
(Rice et al. 2014)

CURRENT STATUS

Last updated on 16 January 2018

The current biomass is above levels needed to produce the maximum sustainable yield (MSY) and fishing mortality rates are below MSY levels. The population of skipjack tuna in the WCPO is neither overfished nor undergoing overfishing (McKechnie et al. 2016).

Trends

Last updated on 16 Jan 2018

Skipjack tuna populations are strongly linked to environmental factors such as El Niño. This is especially true in the eastern equatorial region (region 3), where the performance of the fishery is strongly influenced by environmental conditions.

The population of skipjack tuna is currently moderately exploited and fishing levels are sustainable. Fishing levels have been increasing through time but are still below levels needed to produce the maximum sustainable yield (MSY) {McKechnie et al. 2016}.

2.MANAGEMENT QUALITY

MANAGEMENT

Last updated on 13 September 2018

Tuna fisheries in the Central and Western Pacific are managed through the recently established Western and Central Fisheries Commission (WCPFC), which is headquartered in Micronesia. The members of the Commission have agreed that only vessels flying the flag of the members of the Commission may be authorized to fish in the Western and Central Pacific. The Commission is tasked with managing the largest industrial tuna fishery in the world.

The most recent management measures for this species were adopted in 2017 (WCPFC 2017). These measures apply to the longline, purse seine and other surface fisheries.  The WCPFC has implemented several management measures specific to the purse seine fisheries. For purse seine fisheries, there is a three month prohibition (July, August and September) on setting on fish aggregating devices (FAD’s) for all purse seine vessels in EEZ’s and the high seas in the area between 200 N and 200 S. In addition, member nations (except Kiribati and Philippines) must iprohibit FAD fishing (deployement and service as well) during an additional two sequential months, either April-May or November-December (WCPFC 2017). Coastal CCM's must also adhere to purse seine effort limits in their EEZs (WCPFC 2017). Other CCMs (non Small Islands Developing States and Indonesia) must limit the number of purse seine vessels larger than 24 m operaring between 200 N and 200 S to the level required under CCM 2013-01 (WCPFC 2017)Member nations must have a FAD management plan in place to help reduce the capture of small bigeye and yellowfin tuans, and implementing FAD closures and discarding bigeye, skipjack or yellowfin tuna is prohibited {WCPFC 2012a}{WCPFC 2013b}{WCPFC 2016b}. In addition, member countries of the Parties to the Nauru Agreement have agreed to use a regional fishing vessel register, abide by a high seas pocket area closures, are prohibited from fishing on FAD’s, utilize a Vessel Day Scheme and retain all catch {PNA 2013}{PNA 2012} [PNA 2010}{WCPFC 2016b}{WCPFC 2016c}. 

In addition, biomass based limit and target reference points have been adopted by the WCPFC for skipjack tuna and are used to determine the status of tuna populations (WCPFC 2015). However, there are no harvest control rules (WCPFC 2017). The WCPFC does have a working group that is working on identifying potential target reference points {WCPFC 2013c}.

Recovery Plans

Skipjack tuna populations are healthy in the western and central Pacific Ocean, so no recovery plans are needed. However, they are covered under the current Conservation and Management Measures adopted by the Western and Central Pacific Ocean for bigeye, yellowfin and skipjack tuna (WCPFC 2017).

WCPFC
Indonesia

Indonesian Law Number 31/2004 of Fisheries in Article 5 (2) stipulates that fishery management outside the Fishery Management Zones of the Republic of Indonesia shall be carried out in conformity with the laws and regulations, prerequisites, and/or generally accepted international standards. It is conducted to achieve the optimum and sustainable benefits while ensuring sustainable fishery resources (Article 6 (1)). Furthermore, Article 10 stipulated that the Government shall participate actively in the membership of any body/institution/ organization at the regional or international levels with respect to the cooperation for regional and international fishery management.

Indonesia has created a National Plan of Action for the management of tuna and there is a draft National Tuna Management Plan. The plan includes ways to improve monitoring, identifying catch limits, and aiding in enforcement and compliance measures {MMAF 2012}{MMAF 2014a}. Indonesia also has a National Plan of Action, tuna skipjack and neritic tuna in place {MMAF 2014b}. Indonesia is also a cooperating member of the Western and Central Pacific Fisheries Commission (WCPFC) and is required to abide by the measures but compliance is not yet 100% {MMAF 2012}. Indonesia does have a port sampling program and observer program in place {Indonesia 2013}.

Hooks and lines

Last updated on 9 February 2015

Recovery Plans

Last updated on 09 Feb 2015

There is no recovery plan for skipjack tuna in place. However, their populations are currently healthy.

COMPLIANCE

Last updated on 2 June 2008

Although some compliance, monitoring and enforcement measures have been put into place by the Western and Central Pacific Fisheries Commission, it is often difficult to determine their success.

The Western and Central Pacific Fisheries Commission (WCPFC) has a compliance monitoring scheme in place that assess’s members compliance with obligations, identifies areas of conservation and management that may need refinement, responds to non-compliance and monitors and resolves non-compliance issues.The Commission evaluates compliance by members annually with respect to: catch and effort limits and reporting for target species, spatial and temporal closures, observer and Vessel Monitoring Systems (VMS) coverage and provision of scientific data {WCPFC 2012b}.

There are specific reporting requirements in place to monitor compliance with the FAD set limiting options {WCPFC 2013a}. Vessel Monitoring Systems are required on all vessels fishing for highly migratory species in the Western and Central Pacific Ocean south of 20N and east of 175E.The area north of 20N and west of 175W will have an activation date for VMS’s set at a later time {WCPFC 2012d}.There are measures in place allowing for the boarding and inspection of vessels in the Convention Area {WCPFC 2006b} and the WCPFC maintains a list of illegal, unreported and unregulated vessels {WCPFC 2010b}.

WCPFC
Indonesia
Hooks and lines

Last updated on 6 February 2015

There is no TAC in place for skipjack tuna in the western and central Pacific Ocean. The Western and Central Pacific Fisheries Commission has noted Indonesia as being non-compliant with some management measures including aspects of the regional observer program, sea turtle, shark and cetacean regulations, transshipment, vessel monitoring systems, reporting deadlines for tuna catches and other aspects of the tropical tuna management measures, and estimation of annual catches (WCPFC 2014).

3.ENVIRONMENT AND BIODIVERSITY

BYCATCH
ETP Species

Last updated on 28 June 2013

Purse seine fisheries do incidentally capture non-target species.Bycatch rates are much lower in unassociated compared to associated fisheries. Bycatch ratios in associated sets in the western and central Pacific Ocean (WCPO) region are 1.7% and for unassociated 0.3% {Dagorn et al. 2012}. In associated fisheries, marine mammals are most often caught during sets made in the western section of the tropical western and central Pacific Ocean, specifically near Papua New Guinea (north-east of EEZ) and the Solomon Islands (north-western EEZ).Sets made on floating objects (logs, dFADs, FADs, whales and whale sharks) caught the most marine mammals.In most instances it was not recorded whether marine mammals were alive or dead when returned, but when it was recorded, the majority were alive.Based on the catch per unit effort of incidental catches, less than 3,500 marine mammals are caught per year in the entire purse seine fleet and the mortality rate is estimated to be less than 10% {Molony 2005}.The purse seine fishery is thought to have little impact on the sustainability of marine mammals in this region. Observer records from the tropical region of the WCPO suggest most interactions between marine mammals and purse seines occurred during sets made on floating objects {Molony 2005}. Sea turtle interactions with the purse seine fishery in the western and central Pacific Ocean are not common, with an estimated encounter frequency (1995-2007) of 0.1% on FAD and 0.8% on log sets {Hall and Roman 2013}. The most commonly caught sea turtles, in descending order, are olive ridley, hawksbill and green {Hall and Roman 2013}.Sea turtle interactions in animal associated sets are the highest, 1.6%, resulting in around 105 captures per year. However the majority are released alive {Hall and Molony 2013}. It is estimated that total turtle captures in the purse seine fishery are 200 per year, with fewer than 20 moralities {Molony 2005}.

Observer records from the tropical region of the WCPO for unassociated purse seine fisheries suggest most interactions between marine mammals and purse seines occurred during sets made on floating objects.In addition, observer records from the same region suggests a very low incidence rate, 0.36%, of sea turtles and purse seine fisheries {Molony 2005}.

The Western and Central Pacific Fisheries Commission (WCPFC)has adopted several management measures to protect vulnerable bycatch species incidentally captured in purse seine fisheries. For example, purse seine vessels in the Western and Central Pacific Ocean are prohibited from setting on a school of tuna with a whale shark, although members that fish north of 30N can implement this measure or a comparable measure.If a whale shark is incidentally encircled, the vessel must take reasonable steps to ensure its safe release and report the incident.However, these measures did not become mandatory until January 1, 2014 {WCPFC 2012e}.In addition, vessels are restricted from making a set on a school of tuna associated with a cetacean or encircle sea turtles and if this does occur they must take measures to ensure its safe release and to report the incident {WCPFC 2012f}{WCPFC 2008b}.

WCPFC
Indonesia
Hooks and lines

Last updated on 19 February 2015

Several species of sea turtles have been reported as incidentally captured in Indonesian longline fisheries. These include olive ridley, leatherbacks, hawksbill, green and loggerhead sea turtles .Observer records have indicated a catch rate of 0.225 turtles per 1000 hooks {Zainudin et al. 2007}.A survey conducted by the WWF (2005) estimated that Indonesian tuna longline bycatch rate in the Pacific is estimated to be 256 to 768 animals per year for leatherback turtles and 768 to 2,304 animals per year for loggerhead turtles. Leatherback and hawksbill sea turtles are listed as Critically Endangered by the IUCN {Martinez 2000}{Mortimer and Donnelly 2008}, loggerhead and green sea turtles are listed as Endangered and olive ridley as Vulnerable by the IUCN {MTSG 1996}{Seminorff 2004}{Abreu-Grobois and Plotkin 2008}.Interactions with sea birds are likely minimal in this fishery because due to low overlap {Filippi 2010}.

Indonesia is a members of the WCPFC and must comply with their measures. The Western and Central Pacific Fisheries Commission (WCPFC)has adopted several management measures to protect vulnerable bycatch species.For example, WCPFCmembers are asked to implement the International Plan of Action for Reducing Incidental Catches of Seabirds in Longline Fisheries.Vessels fishing north of 23N in the western and central Pacific Ocean (WCPO) and eastern Pacific Ocean and purse seine fisheries are not allowed to encircle sea turtles (EPO) are required to use at least two mitigation measures including at least one of the following: side setting, night setting, tori line or weighted branch line.Members must submit annual reports detailing the mitigation measures used and are encouraged to undertake additional mitigation research {WCPFC 2012a}.Members of the WCPFC are also to implement the FAO Guidelines to Reduce Sea Turtle Mortality in Fishing Operations. Proper handling and release guidelines should be used when hard-shell turtles are incidentally captured and longline vessels must carry line cutters and de-hookers to allow for the safe handling and release of turtles.Longline fisheries are also urged to research mitigation techniques such as the use of circle hooks and purse seine fisheries are prohibited from encircling sea turtles {WCPFC 2008b}.In addition, fisheries observers record and report interactions with seabirds and turtles {WCPFC 2012a}{WCPFC 2008b}.It appears Indonesia complies with seabird regulations but it is unclear if sea turtle measures are followed {WCPFC 2013b}.Indonesia has recently created the Indonesia National Tuna Management Plan that indicates fishers must utilize proper handling and release measures for bycatch. This plan is planned for implementation during 2014 {MMAF 2012}.

Purse seine fisheries do incidentally capture non-target species.Bycatch rates are much lower in unassociated compared to associated fisheries. Bycatch ratios in associated sets in the WCPO region are 1.7% and for unassociated 0.3% {Dagorn et al. 2012}. In associated fisheries, marine mammals are most often caught during sets made in the western section of the tropical western and central Pacific Ocean.Sets made on floating objects (logs, dFADs, FADs, whales and whale sharks) catch the most marine mammals.Based on the catch per unit effort of incidental catches, less than 3,500 marine mammals are caught per year in the entire purse seine fleet (all countries operating in the western and central Pacific Ocean (WCPO) and the mortality rate is estimated to be less than 10% {Molony 2005}.Purse seine fisheries are thought to have little impact on the sustainability of marine mammals in this region {Molony 2005}. Sea turtle interactions with the purse seine fishery in the WCPO are not common.Between 1980 and 2009 the incidence rate was about 0.36%, with most interactions occurring during associated sets (>70%) {Molony 2005}It is estimated that total turtle captures in the purse seine fishery are 200 per year, with fewer than 20 moralities {Molony 2005}.

The WCPFC has some management measures in place specific to purse seine fisheries.For example, purse seine vessels in the Western and Central Pacific Ocean are prohibited from setting on a school of tuna with a whale shark, although members that fish north of 30N can implement this measure or a comparable measure.If a whale shark is incidentally encircled, the vessel must take reasonable steps to ensure its safe release and report the incident.However, these measures did not become mandatory until January 1, 2014 {WCPFC 2012e}.In addition, vessels are restricted from making a set on a school of tuna associated with a cetacean or encircle sea turtles and if this does occur they must take measures to ensure its safe release and to report the incident {WCPFC 2012f}{WCPFC 2008b}.

Handline and hook and line fisheries traditionally have low bycatch levels.

Other Species

Last updated on 2 June 2008

Purse seine fisheries, primarily associated fisheries, do capture additional non-target species, including other tunas, billfish, sharks and bony fish. Within the western and central Pacific Ocean, silky sharks are the most commonly caught shark species, followed by whales sharks – which are incidentally captured in unassociated fisheries. Oceanic whitetips are also commonly captured in purse seine fisheries. Both silkyand oceanic whitetip sharks are overfished and undergoing overfishing in this region {Rice and Harley 2012a,b}. Recently the Western and Central Pacific Ocean banned the retention of both silky and oceanic whitetip sharks {WCPFC 2012g}{WCPFC 2013f} and setting around whale sharks is now prohibited {WCPFC 2012e}. Starting on 1 January 2010, WCPFC coverage of purse seine vessels is intended to be 100% within the area bounded by 20oN and 20oS, and has adopted a target of 5% coverage by 30 June 2012 of all trips by longline and other vessels (WCPFC 2008). Blue and black marlin are reported as the most common billfish bycatch species, but they are caught in very low numbers. The most common bonny fish bycatch species in this region is the rainbow runner, followed by mahi-mahi and wahoo {Hall and Roman 2013}.

WCPFC
Indonesia
Hooks and lines

Last updated on 19 February 2015

Large longline vessels generally catch older age classes of bigeye tuna (Thunnus obesus) and bluefin tunas (T. maccoyii [southern], _T. orientalis _[Pacific] and T. thynnus [Atlantic]) for the sashimi market and some longline fleets target albacore (T. alalunga_) for canning.Purse seine vessels target younger age classes of skipjack (Katsuwonus pelamis_) and yellowfin (T. albacares) tuna for canning with incidental catch of bigeye tuna.

Purse seine sets on anchored and drifting Fish Aggregating Devices (FADs) and natural floating objects (logs, flotsam) is widespread, with about half of tropical tuna catches coming from FAD sets (Fonteneau et al., 2000).FAD sets have high catch rates of small and juvenile bigeye and yellowfin tunas and unmarketable species and sizes of other fish species, as well as high sea turtle and shark bycatch rates, relative to unassociated sets (Fonteneau et al., 2000; IOTC, 2002; Romanov, 2002; Bromhead et al., 2003; Secretariat of the Pacific Community, 2006; WCPFC, 2007; An et al., 2009; Nicol et al., 2009).

Smaller swordfish are often discarded in pelagic longline tuna fisheries due to minimum size requirements or low market value (Cramer, 2003; Ward et al., 2008).

Members of the WCPFC are prohibited from retaining, transshipping, storing or landing oceanic whitetip sharks and any incidentally caught sharks should be released, the incident recorded and reported {WCPFC 2012f}. Members are also to implement the FAO International Plan of Action for the Conservation and Management of Sharks and National Plans of Action should have policies in place to reduce waste and discarding of sharks.Information on catch and effort for key species is to be reported and shark finning is banned (5% ratio) {WCPFC 2010b}.In the South Pacific, the WCPFC limited the number of vessels targeting swordfish and catches to levels from any year between 2000 and 2005 and required this information to be reported to the Commission {WCPFC 2009}. Starting on 1 January 2010, WCPFC coverage of purse seine vessels is intended to be 100% within the area bounded by 20oN and 20oS, and has adopted a target of 5% coverage by 30 June 2012 of all trips by longline and other vessels (WCPFC 2008).

There are extremely low bycatch levels in pole-and-line fisheries, where bycatch that does occur generally consists of juvenile kawakawa tuna (Euthynnus affinis), frigate mackerel (Auxis rochei), mahimahi (Coryphaena hippurus), and rainbow runner (Elagatis bupinnulata).Discards are believed to have high post release survival rates due to the use of barbless hooks and flick-off practices (FAO, 1997).However, concern over bycatch of reef fish and juvenile classes of target species in baitfish fisheries that supply live bait to pole-and-line fisheries has been raised, as have other ecological issues (ecosystem effects of removal of baitfish species, overexploitation of target baitfish species, habitat degradation) and socioeconomic issues (food security impacts with coastal communities) (FAO, 2008; Gillett, 2010).

Information specific to Indonesian fisheries is limited.Handline fisheries typically have low bycatch rates of other species. Although, other tuna species and sharks can be incidentally captured in low amounts.

HABITAT

Last updated on 2 June 2008

The major gears used to capture skipjack tuna in the western and central Pacific Ocean do not typically come in contact with bottom habitats.

Marine Reserves

Last updated on 02 Jun 2008

There are some areas in the western and central Pacific Ocean where some types of purse seine fishing are prohibited.

FishSource Scores

Last updated on 10 August 2017

MANAGEMENT QUALITY

As calculated for 2015 data.

The score is ≥ 6.

Management strategy is not precautionary because no formal target reference points have been adopted and there is no formal harvest control rule to ensure that fishing mortality rates will be reduced as limit reference points are reached. The 2014 tropical tuna CMM is very similar to previous CMM's.

As calculated for 2015 data.

The score is ≥ 6.

The stock is NOT managed through quotas or TACs; Some but not all of the key recommendations made by the scientific organization responsible for the stock assessments are being taken into account by the management bodies via tangibly implemented conservation measures.

As calculated for 2015 data.

The score is ≥ 6.

The Scientific Committee has noted that the Commission consider stricter control rules for purse seine fisheries.

STOCK HEALTH:

As calculated for 2015 data.

The score is 10.0.

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

The Ratio SSB/SSBmsy is 2.56 . The SSB=SSBmsy is 1.00 .

The underlying Ratio SSB/SSBmsy/SSB=SSBmsy for this index is 256%.

As calculated for 2015 data.

The score is 10.0.

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

The Ratio F/Fmsy is 0.450 . The F management target is 1.00 .

The underlying Ratio F/Fmsy/F management target for this index is 45.0%.

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; SB/SBMSY); 2) Skipjack is not managed as a quota management / TAC species, therefore, qualitative scores have been computed for scores 2 and 3. The most recent updates for reference points Fcurrent/Fmsy and SBlatest/SBmsy were done using last WCPFC stock assessment for this stock in 2016 (McKechnie et al. 2016) and catches came from the WCPFC annual catch report presented at the 2016 Scientific Committee meeting.


 

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Fishery Improvement Projects (FIPs)

No related FIPs

Certifications

Marine Stewardship Council (MSC)

No related MSC certifications

Sources

Credits

Hoyle, S., Kleiber, P., Davies, N., Langley, A., Hampton, J. 2011. Stock assessment of Skipjack tuna in the Western and Central Pacific Ocean, WCPFC-SC7-2011/SA-WP-04, Scientific Committee, Seventh Regular Session, 9-17 August 2011, 134 pages.

Harley, S,J., Berger, A.M., Pilling, G.M., Davies, N., Hampton, J. 2012. Evaluation of stock status of south Pacific albacore, bigeye, skipjack, and yellowfin tunas and southwest Pacific striped marlin against potential limit reference points, Scientific Committee, Eighth Regular Session, 7-15 August 2012, WCPFC-SC8-2012/MI-WP-01_rev1, 22 pages.

Harley, S. J., Williams, P., Nicol, S. and Hampton, J., 2011. The western and central Pacific tuna fishery: 2010 overview and status of stocks. Tuna Fisheries Assessment Report 11. Noumea, New Caledonia: Secretariat of the Pacific Community, 38 pages.

IOTC. 2014. Status of Indian Ocean skipjack tuna (SKJ: Katsuwonus pelamis) resource. IOTC-2014-SC17-ES03.

McKechnie, S., Hampton, J., Pillling, G.M. and Davies, N. 2016. Stock assessment of skipjack tuna in the Western and Central Pacific Ocean. WCPFC-SC12-2016/SA-WP-04. Available at: https://www.wcpfc.int/system/files/SC12-SA-WP-04%20skj%20assessment.pdf

Pilling, G.M., Harley, S.J., Berger, A.M., Davies, N., Hampton, J. 2012. Consideration of target reference points for WCPO stocks with an emphasis on skipjack tuna, Scientific Committee, Eight Regular Session, 7-15 August 2012, WCPFC-SC8-2012/ MI-WP-02, 27 pages.

Rice, J., Harley, S., Davies, N. and Hampton, J. 2014. Stock assessment of skipjack tuna in the western and central Pacific Ocean. Scientific Committee Ninth Regular Session, Majuro, Republic of the Marshall Islands. WCPFC-SC10-2014/SA-WP-05.

WCPFC. 2014. Scientific Committee Tenth Regular Session, summary report. Majuro, Republic of the Marshall Islands 6-14, August 2014. https://www.wcpfc.int/system/files/0_SC10%20Summary%20Report%20-%20Adopted%20Version%20-%2021Aug2014%20%28Rev.3.5%2C%20t-c%29_1.pdf

WCPFC. 2015. Conservation and Management Measuer on a target reference point for WCPO skipjack tuna. CMM 2015-06. Availalbe at: http://www.wcpfc.int/doc/cmm-2015-06/conservation-and-management-measure-target-reference-point-wcpo-skipjack-tuna

WCPFC. 2016. WCPFC 13 Outcomes Document. Circular No. 2016/73. Decebmer 21, 2016. http://www.wcpfc.int/system/files/WCPFC%20Circular%202016-73%20WCPFC13%20Outcomes%20document.%2021%20December%202016.pdf

WCPFC. 2016b. Conservation and Management Measure for bigeye, yellowfin and skipjack tuna in the Western adn Central Pacific Ocean. Conservation and Management Measure 2016-01. http://www.wcpfc.int/system/files/Att%20O_CMM%202016-01%20CMM%20for%20Bigeye%20Yellowfin%20and%20Skipjack%20Tuna_p_1.pdf

WCPFC. 2016c. Conservation and Management Measure for the Eastern High Seas Pocket Special Management Area. Conservation and Management Measure 2016-02. http://www.wcpfc.int/system/files/Att%20K_CMM%202016-02%20CMM%20for%20EHSP-SMA_p.pdf

WCPFC. 2016d. Reference document for the development of harvest strategies under CMM 2014-06. WCPFC13-2016-11A. http://www.wcpfc.int/system/files/WCPFC13-2016-11A%20%5BReference%20document%20for%20Harvest%20Strategy%5D.pdf

Williams, P., Terawasi, P. 2012. Overview of tuna fisheries in the Western and Central Pacific Ocean, including economic conditions – 2011, Scientific Committee, Eighth Regular Session, 7-15 August 2012, WCPFC-SC8-2012/GN WP-1, 53 pages.

References

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