Profile updated on 26 July 2019

SUMMARY

SUMMARY

IDENTIFICATION

SCIENTIFIC NAME(s)

Thunnus obesus

SPECIES NAME(s)

Bigeye tuna

It is likely there is one stock of bigeye tuna across the Pacific Ocean. The assessment in the EPO is conducted assuming there is a single population for management purposes {Aires-da-Silve and Maunder 2014}.


ANALYSIS

Strengths

The biomass is considered healthy.

There is a catch limit for bigeye tuna caught in the longline fisheries for some countries (China, Japan, Korea, Chinese Taipei).

There is a multi-year conservation plan in place, which has just been extended, for bigeye tuna (and other tuna species).

There is 100% observer coverage on large purse seine vessels operating on the high seas.

Weaknesses

Fishing mortality rates are above sustainable levels.

Formal reference points and harvest control rules (only interim) have not been adopted. 

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.

Observer coverage (required) in the longline fishery is too low (5%).

There continues to be uncertainty surrounding the stock assessment results.

The longline and purse seine fisheries can interact with ETP species

FISHSOURCE SCORES

Management Quality:

Management Strategy:

≥ 6 to ≥ 8

Managers Compliance:

≥ 6

Fishers Compliance:

≥ 6

Stock Health:

Current
Health:

8.1

Future Health:

7.4


RECOMMENDATIONS

RETAILERS & SUPPLY CHAIN
  • Work with IATTC Members and Cooperating Non-Members to: 
    • Develop and implement comprehensive, precautionary harvest strategies with specific timelines for all tuna stocks, including the adoption and implementation of limit and target reference points, harvest control rules, monitoring strategies, operational objectives, performance indicators, and management strategy evaluation.
    • Strengthen compliance processes and make information on non-compliance public and continue to provide evidence of compliance with all IATTC Conservation and Management Measures in a timely manner.
    • Implement a 100% observer coverage requirement for at-sea transshipment activities, as well as other measures that ensure transshipment activity is transparent and well-managed, and that all required data are collected and transmitted to the appropriate bodies in a timely manner.
    • Increase compliance with the mandatory minimum 5% longline observer coverage rates by identifying and correcting non-compliance.
    • Implement a 100% observer coverage requirement – human and/or electronic – within five years for longline fisheries.  Adopt a 100% observer coverage requirement for purse seine vessels where it is not already required and require the use of the best-available observer safety equipment, communications and procedures.
    • Adopt effective measures for the use of non-entangling FAD designs as a precautionary measure to minimize the entanglement of sharks and other non-target species, and support research on biodegradable materials and transition to their use to mitigate marine debris. 
    • More effectively implement, and ensure compliance with, existing RFMO bycatch requirements and take additional mitigation action, such as improving monitoring at sea, collecting and sharing operational-level, species-specific data, and adopting stronger compliance measures, including consequences for non-compliance for all gear types.
  • Monitor IATTC progress on assessing alternative indicators and improving the stock assessment model to determine the status of bigeye tuna in the EPO and to develop management advice.
  • 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 in compliance with best practices.

FIPS

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

    Stage 4, Progress Rating A

  • Eastern Pacific Ocean tuna - longline (Transmarina):

    Stage 3, Progress Rating C

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 IATTC Colombia Associated purse seining
FAD-free
Ecuador Associated purse seining
Drifting longlines
FAD-free
Spain FAD-free
Purse seines
United States Associated purse seining
Longlines

Analysis

OVERVIEW

Last updated on 14 August 2018

Strengths

The biomass is considered healthy.

There is a catch limit for bigeye tuna caught in the longline fisheries for some countries (China, Japan, Korea, Chinese Taipei).

There is a multi-year conservation plan in place, which has just been extended, for bigeye tuna (and other tuna species).

There is 100% observer coverage on large purse seine vessels operating on the high seas.

Weaknesses

Fishing mortality rates are above sustainable levels.

Formal reference points and harvest control rules (only interim) have not been adopted. 

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.

Observer coverage (required) in the longline fishery is too low (5%).

There continues to be uncertainty surrounding the stock assessment results.

The longline and purse seine fisheries can interact with ETP species

RECOMMENDATIONS

Last updated on 15 October 2018

Recommendations to Retailers & Supply Chain
  • Work with IATTC Members and Cooperating Non-Members to: 
    • Develop and implement comprehensive, precautionary harvest strategies with specific timelines for all tuna stocks, including the adoption and implementation of limit and target reference points, harvest control rules, monitoring strategies, operational objectives, performance indicators, and management strategy evaluation.
    • Strengthen compliance processes and make information on non-compliance public and continue to provide evidence of compliance with all IATTC Conservation and Management Measures in a timely manner.
    • Implement a 100% observer coverage requirement for at-sea transshipment activities, as well as other measures that ensure transshipment activity is transparent and well-managed, and that all required data are collected and transmitted to the appropriate bodies in a timely manner.
    • Increase compliance with the mandatory minimum 5% longline observer coverage rates by identifying and correcting non-compliance.
    • Implement a 100% observer coverage requirement – human and/or electronic – within five years for longline fisheries.  Adopt a 100% observer coverage requirement for purse seine vessels where it is not already required and require the use of the best-available observer safety equipment, communications and procedures.
    • Adopt effective measures for the use of non-entangling FAD designs as a precautionary measure to minimize the entanglement of sharks and other non-target species, and support research on biodegradable materials and transition to their use to mitigate marine debris. 
    • More effectively implement, and ensure compliance with, existing RFMO bycatch requirements and take additional mitigation action, such as improving monitoring at sea, collecting and sharing operational-level, species-specific data, and adopting stronger compliance measures, including consequences for non-compliance for all gear types.
  • Monitor IATTC progress on assessing alternative indicators and improving the stock assessment model to determine the status of bigeye tuna in the EPO and to develop management advice.
  • 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 in compliance with best practices.

1.STOCK STATUS

STOCK ASSESSMENT

Last updated on 11 June 2019

A updated stock assessment of bigeye tuna in the Eastern Pacific Ocean (EPO) was conducted during 2018. The assessment was conducted using an age structured model called Stock Synthesis, which has been used in previous assessments.  Because this is an 'updated' assessment, the same base case model from the 2016 assessment was used and only data was updated. Data includes information on catch, discards, catch per unit effort and size composition. New or updated longline data for this assessment were availalbe from China, Japan, Korea, Chinese Taipei, the US, French Polynesia and Vanuatu. The assessment assumes a single stock of bigeye tuna in the EPO, with minimal net movement between the EPO and western and central Pacific Ocean (Xu et al. 2018)

SCIENTIFIC ADVICE

Last updated on 11 June 2019

In 2013 the Inter-American Tropical Tuna Commission (IATTC) Scientific Committee made the following recommendations to the Commission in 2013 for tunas and sharks: 1. The current tuna management plan should be continued through 2014 because there is evidence that fishing mortality for bigeye tuna may still be too high. 2. A harvest control rule that requires effort to be reduced once fishing mortality exceeds the maximum sustainable yield should be adopted {IATTC 2013a}.

In 2014, the Scientific Committee made several additional recommendations including conducting a feasibility study for sampling lengths from adult tuna on a regular basis, combining observer data into a central database, and analyze movement patterns of bigeye tuna (IATTC 2014). In 2016, the Scientific Committee indicated that the current tuna conservation and management plan should be maintained with the addition of additional purse seine closure days (87 instead of 62)  (IATTC 2016).

The Scientific Committee was unable to provide new management advice for bigeye tuna in 2018 due to considerable uncertainty in the updated stock assessment results (Xu et al. 2018). Instead they suggested a limit on the number of purse seine sets be adopted for the entire fishery (IATTC 2018)

In 2019, due to issues with the yellowfin tuna stock assessment, the IATTC scientific staff was unable to make any management recommendations specific to yellowfin tuna. They instead provided a similar recommendation to that from 2018 to maintain the current management resolution and limit the total number of purse seine (associated and unassociated) sets in 2020 to 15,723  (IATTC 2019). The IATTC Scientific Advisory Committee did not endorse this recommendation from the IATTC staff and provided no additional management advice for yellowfin tuna in 2019 (final report not published yet, personal communication from the meeting).

 
CURRENT STATUS

Last updated on 11 June 2019

The 2017 updated assessment indicated a recovering trend for bigeye tuna in the EPO between 2005-2009 but the rebuilding trend was not sustained between 2010-2013. The spawning biomass ratio (SBR) declined gradually to a historically low value of 0.15 at the start of 2013. The SBR has increased since to 0.23 at the start of 2016. Bigeye tuna are not currently considered overfished in the eastern Pacific Ocean (Xu et al. 2018).

Fishing mortality rates are above the level corresponding to the maximum sustainable yield (MSY). Bigeye tuna in the eastern Pacific Ocean are undergoing overfishing based on this increased fishing mortality rate (Xu et al. 2018)

2.MANAGEMENT QUALITY

MANAGEMENT

Last updated on 14 August 2018

Management measures specific to pelagic longline fisheries operating in the Eastern Pacific Ocean include catch limits (combined) for bigeye and yellowfin tuna by set type for large purse seine vessels. There are additional catch limits for longline caught bigeye by China, Japan, Korea and Taiwan. IATTC currently uses an interim limit reference point for bigeye tuna but target reference points and harvest control rules are not used. 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 2013b}. 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

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

Ecuador
Drifting longlines

Last updated on 6 September 2019

There is not enough information available to determine whether bigeye tuna in the Pacific Ocean constitutes a single stock or several stocks (Deriso et al. 1998). Within Ecuador, the Instituto Nacional de Pesca is the scientific body in charge of assessing the marine resources and then for advising and providing the recommended management measures to the Viceministerio de Acuacultura y Pesca,  The Inter-American Tropical Tuna Commission (IATTC or CIAT in Spanish: Comisión Interamericana del Atún Tropical) is the entity which assesses, regulates and manages the tuna fishery in the Eastern Pacific Ocean, Ecuador is part of this Regional Fisheries Management Organization and responds to the resolutions adopted by this body.

The current IATTC management plan for the period 2018-2020 has been established by the resolution C-17-02 (IATTC 2017). The measures developed here, apply to all longline vessels over 24 meters length overall that fish for yellowfin tuna, bigeye tuna, and skipjack tuna. These vessels are considered an industrial large-scale fleet (known as LSTLFVs) and according to the IATTC vessel database (available at: https://www.iattc.org/VesselDataBaseENG.htm), there are currently 20 Ecuadorian flag vessels registered to operate in the Convention area with a fish-holding capacity that ranges from 57 m³ up to 589 m³.  Ecuador submits an annual report to IATTC which contains information from this longline fleet such as the total capture and its composition, interaction with other species (non-target and ETP species) and fishing effort; in the period between January 2017 to September 2017 the coverage of observers in the fleet was about 10% of the total effort estimated in fishing days. It is important to mention that the IATTC has calculated that the minimum and sufficient level of coverage on longline vessels to produce reliable estimates of the species caught is 20% although its resolution C-11-08 (IATTC 2011) establishes a mandatory coverage of 5% of the fishing effort by a scientific observer.

Bigeye tuna catch limits are clearly set in the multiannual conservation plan for all the IATTC members and cooperating non-members jointly with a transfer of quota requirements.

Ecuador, through the Acuerdo Ministerial N° 407 (Ministerio de Agricultura, Ganadería, Acuacultura y Pesca 2011) defines a ‘nodriza’ as a vessel that tows up to ten smaller artisanal longline vessels or ‘fibras’ towards far fishing grounds and its purpose is to supply water, fuel, food, bait and other supplies for fishing, and also to receive the catch from the small vessels. Amongst the requirements needed for the fishing, there is an ‘official agreement’ grant by the Subsecretaría de Recursos Pesqueros, a fishing permit which has to be annually renovated, certificates of the ship, a vessel monitoring system and a sanitary permit.

Within the Ecuadorian framework, seasonal closures have not been found for its longline fleet, probably due to the fact that neither the IATTC apply them. The Acuerdo Ministerial N° 407 (Ministerio de Agricultura, Ganadería, Acuacultura y Pesca 2011) states that the Subsecretaría de Recursos Pesqueros has the responsibility of setting an observer program covering 10% of the artisanal ‘nodriza’ fleet.  Nevertheless, specific and technical aspects like the fishing gear interaction with other species and catch per unit of effort in longlines is not being taken, this generates a void in data and potential management. Another measure taking in Ecuador by some tuna companies is the implementation of a Fisheries Improvement Project (FIP) aimed at getting the sustainability standard of the Marine Stewardship Council (MSC), and as result of this, there is a current process to design the National Plan of Action for the sustainable management of the industrial fishery for the Ecuadorian Tuna (PAN-Atún) FIP, led by the Viceministerio de Acuacultura y Pesca through a participatory process that involves key players in the value chain of this fishery.

COMPLIANCE

Last updated on 14 August 2018

Individual countries that have been given a catch limit for longline caught bigeye tuna, China, Japan, Korea and Chinese Taipei, have abided by those limits. Other countries have kept their catches below 500 t or at 2001 levels (Xu et al. 2018).

Ecuador
Drifting longlines

Last updated on 6 September 2019

Through the publication of the Acuerdo Ministerial No. MAGAP-MAGAP-2015-001-A,(Ministerio de Agricultura, Ganadería, Acuacultura y Pesca 2015) the national action plan to prevent, discourage and eliminate illegal, unreported and unregulated fishing came into effect (PAN-INDNR, in Spanish). The Control and Monitoring System (SCM, in Spanish), set by the Subsecretaría de Recursos Pesqueros of Ecuador, gathers data from the Ecuadorian artisanal fleet in the main artisanal landing ports. This artisanal fleet comprises an artisanal-oceanic component that consists in large vessels called ‘nodrizas’ which tow smaller fiberglass vessels (called ‘fibras’) which operate mainly with pelagic longlines off 200 miles from the coast. It has been estimated that ‘Nodrizas’ represent up to 80% of the total artisanal capture (Martínez-Ortiz et al. 2015).

The IATTC registers the information of all the vessels authorized to operate in the Eastern Pacific Ocean, but it is recognized that this list is incomplete (IATTC 2018) particularly regarding the large longline fleet and small vessels. Ecuador through the INP gathers and presents some biological data from the large-scale longline fleet. Information about capture and characterization of artisanal longline fleets have been shown in studies conducted by INP staff. In addition, it should be mentioned that regarding the longline capture, the IATTC maintains data about the spatial and temporal distribution of longline captures by countries. Data from the industrial longline fleet is taken by IATTC observers in collaboration with the INP with a coverage of approximately 10% of the fishing effort, in comparison with the minimum 5% set by the IATTC resolution C-11-08 (IATTC 2011). Discarding cannot be estimated with accuracy for the artisanal longline fleet, one reason might be the coverage of the observer program onboard in port, inspectors monitor the landing and assess the reliability of the data recorded in the captain’s logbook. A monitoring certificate is generated and delivered during the landing (Martínez-Ortiz et al. 2015) Such verified logbook records provide trip-by-trip catch composition data ( in numbers of fish and weight), as well as effort information (number of hooks per set, days fished, numbers of individual smaller boats operating from the mother-ship) (Martínez-Ortiz et al. 2015).

According to the IATTC, the longline fleet operating in the eastern Pacific Ocean captures roughly 31 thousand tons of bigeye tuna, reaching 28 814 and 36 095 tons registered in 2017 and 2016, respectively. Twenty large-scale longline vessels (larger than 24 meters length) flying the Ecuadorian flag were found in the IATTC's Regional Register of Vessel. From 1985 to 1993 longlines caught an average of 95% of the bigeye tuna in the eastern Pacific Ocean, during  2002-2016 this average dropped to 38% (IATTC 2018).

3.ENVIRONMENT AND BIODIVERSITY

BYCATCH
ETP Species

Last updated on 14 August 2018

The longline fisheries operating in the eastern Pacific Ocean (EPO) that capture bigeye tuna can also incidentally catch several species of sea turtles currently listed under CITES Appendix I. Purse seine fisheries have some interactions with sea turtles, but far less than in the longline fisheries. The troll and pole fisheries for bigeye tuna do not incidentally capture any of these species.

Green, hawksbill, leatherback, loggerhead and olive ridley sea turtles have been reported as incidentally captures in longline fisheries operating in the EPO. The International Union for the Conservation of Nature (IUCN) classifies green, leatherback and loggerhead turtles as Endangered, hawksbill as Critically Endangered, and olive ridley as Vulnerable (www.iucn.org).

Marine mammal interactions are not common in this fishery.

Several species of seabirds, including black-footed, laysan and waved albatross. Black-footed, laysan albatross are considered Near Threatened by the IUCN and waved albatross as Critically Endangered.

Purse seine (associated) fisheries also incidentally capture a variety of bycatch species including some sea turtles and shark species. Unassociated purse seine fisheries typically have less bycatch associated with them.

The Inter-American Tropical Tuna Commission (IATTC) has put several management measures aimed at bycatch species into place. IATTC member countries are to implement an International Plan of Action for Seabirds. Two seabird mitigation methods are required on vessels larger than 20 m fishing in specific areas. A 3 year program to reduce the impact of fishing on sea turtles has been put into place. This plan requires reporting of any interaction and carrying of proper handling and release gears. 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).

The dolphin set fishery has historically had interactions with spinner and pan tropical dolphins. The Agreement of the International Dolphin Conservation Program (AIDCP) was put into place to track this fishery and any dolphin moralities (IATTC 2003).

Ecuador
Drifting longlines

Last updated on 6 September 2019

There are few estimations regarding the incidental catch of marine turtles by longlines in Ecuador. The incidental catch of turtles associated with the industrial longline fleet in the Eastern Pacific Ocean targeting Bigeye tuna is probably lesser at greater depths (200-300m) (IATTC 2018) and occurs when they take the bait on the hooks, when they accidentally get hooked or entangled in lines (IATTC 2018)(IATTC 2018). Mortality data on the interactions between the longline fishery and turtles is deficient in the Eastern Pacific Ocean (IATTC 2018). For Ecuadorian longline fisheries participatory programs have been developed which involve the voluntary testing of circle hooks to reduce the mortality of sea turtles  (Andraka et al. 2013)(Gilman et al. 2006) and other activities such as training of fishers in on-board sea turtle handling techniques to improve the survival of the turtles released after hooking or entanglement (Andraka et al. 2013). Loggerhead and leatherback turtles are the primary species caught in the pelagic longline gear and olive ridley, hawksbill (Eretmochelys imbricata) and Kemp's ridley (Lepidochelys kempii) turtles are also captured (Gilman et al. 2006). According to the observers program in the large-scale longline fleet, in 2017 Ecuador reported to the IATTC  incidental captures of green turtle (Chelonia mydas) and olive ridley turtle( Lepidochelys olivacea) Andraka et. al (2013) described the interaction of the olive ridley turtle (Lepidochelys olivacea) with the artisanal longline fleet in the eastern Pacific Ocean.

Regarding shark and rays species, IATTC (IATTC 2018)(IATTC 2018) registered interactions of longlines with the silky shark (Carcharhinus falciformis), the oceanic whitetip shark (Carcharhinus longimanus), hammerheads (Sphyrna spp.), threshers (Alopias spp.) and mako (Isurus spp) sharks. Further information regarding shark interactions with the Ecuadorian longline fleet targeting tuna is scarce but two studies do exist. The first one conducted by the INP (Pacheco 2010) on a Spanish longline fleet associated with Ecuador targeting tuna and other species, which registered the capture of shortfin mako (Isurus oxyrinchus), smooth hammerhead (Sphyrna zygaena), blue shark (Prionace glauca) and bigeye thresher (Alopias superciliosus) and leatherback turtle (Dermochelys coriacea). The second one, conducted by Martínez-Ortiz et al. (Martínez-Ortiz et al. 2015), states that sharks caught by longline gear are largely dominated by the thresher shark group, then the pelagic thresher and blue and silky sharks make up the second dominant group. Furthermore, IATTC (IATTC 2018) states that sharks are captured as incidental catch in the longline fishery within the Eastern Pacific Ocean. Ecuadorian national framework has established measures to reduce the impact of longlines on sharks, which are contained in the Decreto N° 486, the N° 902 and the Plan Acción de Tiburones (PAT-Ec), which establish the conservation and management of sharks as national priority, forbidding the target of sharks and specialized fishing gear adaptations.

On the other hand, there were no interactions with birds or mammals. Some endemic bird species are of special concern like the Albatross de Galápagos (Phoesbastria irrorata) but any registers of the albatross interaction with the Ecuadorian longline fleet has not been found.

Other Species

Last updated on 14 August 2018

Eastern Pacific Ocean (EPO) longlines fisheries that capture bigeye tuna also catch a number of other species of fish, including billfish and other tuna species, and sharks. Purse seine fisheries also catch a number of fish and shark species. The troll fishery catches small amounts of other tuna species and fish.

Other common bycatch species in the longline fishery include blue and silky sharks, indo-Pacific sailfish, dolphinfish and swordfish. Blue shark populations are currently healthy in the north Pacific region of the EPO but populations in the south Pacific appear to be in much worse condition. The current status of silky sharks, despite an assessment being conducted, is unknown in this region. The status of indo-Pacific sailfish is also uncertain. Swordfish populations are healthy in both the northern and southern region of the EPO {ISCSWG 2014}{IATTC 2013c}{IATTC 2014b}.

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).

Ecuador
Drifting longlines

Last updated on 6 September 2019

With respect to the Scombridae family, longline catches by the artisanal fleet are dominated by yellowfin tuna (Thunnus albacares), bigeye tuna (Thunnus obesus) and also the swordfish (Xiphias gladus) represents an important amount of the catches (Martínez-Ortiz et al. 2015). Andraka et al. (Andraka et al. 2013) points to important bycatch species for this fishery being: yellowfiun tuna (Thunnus albacares), mahi mahi (Coryphaena hippurus), skipjack tuna (Katsuwonus pelamis), swordfish (Xiphias gladus), sailfish (Istiophorus platypterus) and black marlin (Istiompax indica). Regarding the sailfish and swordfish, the structure of their population is well-known in the Pacific Ocean and even genetic data analyses have been conducted to unveil whether there are differences in its geographical distribution (IATTC 2018). Despite this, it not has been possible to determine the current condition of the population of sailfish in the eastern Pacific Ocean with respect to specific management parameters as the maximum sustainable yield (MSY) (IATTC 2018). It is suggested that there exist captures that are not reported, so it is unlikely a reliable assessment of this resource can be conducted without more real catch estimations. On the other hand, IATTC assessments in the northern and south-eastern areas of the eastern Pacific Ocean suggest that the swordfish is not undergoing overfishing (IATTC 2018). Finally, in the case of the black marlin, no stock assessments have been conducted (IATTC 2018) The current stock status and impact of the fishery on species like. Mahi mahi or black marlin is still difficult to predict in some cases because of the lack of reliable data. Probably one important boost in the long-term for one of this species (mahi mahi), is the current assessment of its fishery in Ecuador against the Marine Stewardship Council standard which could help at some extent to quantify properly the accumulated impact on this species.

Estimated target reference points or regulations focused on controlling the capture and landings of the other bycatch species have not been defined and a relative population analysis should be conducted with more accurate and reliable capture and effort data.

HABITAT

Last updated on 30 October 2014

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

Ecuador
Drifting longlines

Last updated on 6 September 2019

Juvenile and adult bigeye tuna are distributed throughout the Pacific Ocean from about 40°N to 40°S and the larvae are widely dispersed from about 20°N to 0° in the eastern Pacific (Deriso et al. 1998). Unlike other species of tuna, the depth distribution of bigeye tuna appears to be directly related to ambient temperature preference and minimum dissolved oxygen requirements (Bigelow et al. 2002); Suda et al. (1969, in Deriso et al. 1998) reported that bigeye prefer waters in or just below the thermocline, a hypothesis of these same authors states the bigeye prefer temperatures of about 20°C, but tolerates as low as 11° or 12°C, and this range occurs mainly between the surface and 100 meters in temperate regions, but in much deeper waters in the equatorial zone. Nakamura (1969, in (Deriso et al. 1998) suggested that bigeye and other species of tuna stay with a particular water mass or current systems during each phase of life, that is, they may be in one current system as immature fish and in another as spawners. Thus, bigeye tuna is more likely to be caught by deep longlines, high CPUE values were found for longline fleet targeting bigeye tuna off Ecuador (Deriso et al. 1998)

Some research has been conducted in order to know more about priority habitats. Kikawa (1962, in (Deriso et al. 1998) found in the Eastern Pacific a peak of the spawning to occur in January through March in the area between the equator and 10°S and concluded that the portion of mature fish increases from west to east in the tropical Pacific. In the area among 10°N and 15°S from 120°W to 130°W mature bigeye were found to occur throughout the year. Suda and Schaefer (1956, in Bayliff 1980) noted the development of a concentration of bigeye in the fourth quarter and possibly first quarter of the year in the area to the north and east of the Galapagos Island and the catch of bigeye by nighttime longlines which fish shallower than do daytime longlines, may indicate a migration toward the surface during darkness (Kume and Morita 1966, in Deriso et al. 1998)

Bigeye tuna is an oceanic species (FishBase, 2019), it is considered that a negative interaction between the seafloor and longlines are not likely to happen, due to the passive nature of the fishing gear and small size of the fishing fleet. Unlike some other gear types, pelagic longlines do not touch the seafloor and do not directly damage the habitat (Gilman et al. 2006).  Nonetheless, it is also necessary to conduct further research to know the real impact of deep longlines. There is not considered to be robust information to identify location, timing, and severity of the longline fleet in the habitats due to the coverage of the surveillance and monitoring system and therefore whether there is an impact is still unclear.

ECOSYSTEM
Ecuador
Drifting longlines

Last updated on 6 September 2019

Small bigeye tuna are frequently found in association with yellowfin, skipjack, kawakana (Euthynnus affinis) and frigate tuna (Auxis thazard) (Miyabe, 1994 in Deriso et al. 1998). Also, Calkins et al. (1993) (Deriso et al. 1998), reported that bigeye are caught in association with yellowfin and skipjack in the eastern Pacific, giving evidence of the need to quantify the juvenile structure in similar fisheries to measure any possible impact to the bigeye stock. Moreover, since the surface fisheries exploit small to medium fish and the longline fishery exploits medium to large fish, the surface fishery might have a direct negative effect on the longline fishery, but the reverse is not the case: the longline fishery could have an indirect negative effect on the surface fishery if it reduces that spawning stock sufficiently to reduce recruitment, however, there is no evidence indicating that this is the case (Tomlinson, 1998 in Deriso et al. 1998). It is important to note that historically, nearly all the catches of bigeye have been taken by longlines, but during the 1990s the catches of bigeye by surface gear fisheries began to increase. Research on the interaction between the surface and longline fisheries is continuing and probably, one of the greatest needs, from the standpoint of evaluation of the effect of the surface fishery on the longline fishery is obtaining more precise estimates of age-specific mortality (Deriso et al. 1998)

The IATTC (IATTC 2018) has conducted research on the eastern Pacific Ocean ecosystem using trophic levels (TL) to characterize the energy fluxes through the different communities. In this case, the average trophic level of capture (MTLc) can be a useful metric of change and sustainability of the ecosystem integrating a variety of biological data regarding the components of the system and several MTL are calculated in relation to the TL  It's also an indicator of whether fisheries are changing their fishing practices These indicators point to the fact that ecosystem structure has probably changed, however, if this is a direct result from fisheries, they are not considered ecologically harmful (IATTC 2018). No studies about the ecosystem state of reference, the effect of fishing and its dynamics has been done by the Ecuadorian scientific advisory body, mostly this analysis falls on the IATTC.

FishSource Scores

Last updated on 9 September 2019

SELECT SCORES

MANAGEMENT QUALITY

Different components of this assessment unit score differently at the fishery level. Please look at the individual fisheries using the selection drop down above.

As calculated for 2018 data.

The score is ≥ 8.

The regional fisheries management organization has adopted a harvest control rule, and interim reference points are in place. There is a tuna conservation and management plan in place that includes bigeye tuna.

Different components of this assessment unit score differently at the fishery level. Please look at the individual fisheries using the selection drop down above.

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.

Different components of this assessment unit score differently at the fishery level. Please look at the individual fisheries using the selection drop down above.

As calculated for 2018 data.

The score is ≥ 6.

The TAC is only in place for the longline fleet and for four countries. China has exceeded their TAC in recent years, while the other countries catches have remained within their alloted TAC.

STOCK HEALTH:

As calculated for 2017 data.

The score is 8.1.

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

The Ratio SSB/SSBmsy is 1.02 . The SSB=SSBmsy is 1.00 .

The underlying Ratio SSB/SSBmsy/SSB=SSBmsy for this index is 102%.

As calculated for 2017 data.

The score is 7.4.

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

The Ratio F/Fmsy is 1.15 . The F management target is 1.00 .

The underlying Ratio F/Fmsy/F management target for this index is 115%.

ECOSYSTEM IMPACTS

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×

Bycatch Subscores

Different components has different justification at the fishery level. Please look at the individual fisheries using the selection drop down above.

Different components has different justification at the fishery level. Please look at the individual fisheries using the selection drop down above.

Different components has different justification at the fishery level. Please look at the individual fisheries using the selection drop down above.

There are generic measures tailored for avoiding sharks capture (gear and hook restrictions) (Correa 2008) and marine turtles.

×

Habitat Subscores

There is general information regarding the impact of longlines in marine habitats.

There is some information available regarding the location and timing of the fishing.

Since longlines are set near the surface or mid-waters, impacts on the bottom are minimal.

The species distribution and some environmental requirements in the eastern Pacific have been mapped (Deriso et al. 1998; Hu et al. 2018)

Since this fishing gear interacts passively with the marine environment, it is unlikely that longlines would interact negatively or hinder the structure and function of the habitat.

No measures in place to avoid the potential damage of longlines in habitats were found within the Ecuadorian framework.

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Ecosystem Subscores

There is biological information used by RFMOs to describe the impact of the tuna species fishery.

There is comprehensive information about the distribution, behavior and interaction of this species within the ecosystem which permits to set state references (Deriso et al. 1998; IATTC 2018; IATTC 2018)

Some impact is measurable through the use of trophic indicators and a comprehensive data gathering by the IATTC.

No measures in place were found.

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) There are country TAC longline limits for China, Japan), Korea  and Taiwan  and other countries must keep catches below 500 t or catch levels from 2001. 3) The time series of F and B is provided relative to MSY (F/FMSY)(B/B[~MSY`]); the thresholds have been set accordingly. 4) Catches are from IATTC Fishery for tunas and billfishes in the 2017 report (IATTC 2017).

Ecuador

Last updated on 9 September 2019

The catch data is for purse seine vessels only.

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Fishery Improvement Projects (FIPs)

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Access FIP Public Report

Progress Rating: A
Evaluation Start Date: 30 Sep 2016
Type: Comprehensive

Comments:

Stage 4 progress related to non-entangling FADs. FIP rating is A

1.
FIP Development
Sep 15
2.
FIP Launch
Jan 16
Jan 18
3.
FIP Implementation
May 19
4.
Improvements in Fishing Practices and Fishery Management
May 19
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

SFP is grateful to the Global Sustainable Supply Chains for Marine Commodities (GMC) project for contributing to the development and update of this profile at several node levels. GMC is an interregional initiative implemented by Ministries and Bureaus of Fisheries and Planning of Costa Rica, Ecuador, Indonesia, and the Philippines, with technical support of the United Nations Development Programme (UNDP), facilitated by Sustainable Fisheries Partnership (SFP) and funded by the Global Environment Facility (GEF).

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  2. Aires-da-Silva, A., and Maunder, M. 2015. Status of bigeye tuna in the eastern Pacific Ocean in 2014 and outlook for the future. IATTC Document SAC-06-05.
  3. Aires-da-Silva, A., Minte-Vera, C. and Maunder, M.N. 2016. Status of bigeye tuna in the eastern Pacific Ocean in 2015 and outlook for the future. Document SAC-07-05a.
  4. An H-H, Kwon Y-J, Kim DN, Moon DY, Hwang SJ. 2009. Effects of set type on catch of small-sized tuna by the Korean tuna purse seine fishery in the WCPO. Western and Central Pacific Fisheries Commission Scientific Committee Fifth Regular Session, 10-21 August 2009, Port Vila, Vanuatu. Information Paper Number WCPFC-SC5-2009/FT-WP-02. Western and Central Pacific Fisheries Commission, Palikir, Pohnpei, Federated States of Micronesia.
  5. Bromhead D, Foster J, Attard R, Findlay J, Kalish J. 2003.. A review of the impacts of fish aggregating devices (FADs) on tuna fisheries. Final Report to the Fisheries Resources Research Fund. Bureau of Rural Sciences, Canberra, ACT, Australia.
  6. Cramer, J. 2003. Distribution of juvenile swordfish (Xiphias gladius) caught by pelagic longline in the Atlantic Ocean. Col. Vol. Sci. Pap. ICCAT 55(4): 1587-1596.
  7. Dagorn, L., Holland, K.N., Filmalter, J., Are drifting FADs essential for testing the ecological trap hypothesis? Fisheries Research (2010), doi:10.1016/j.fishres.2010.07.002.
  8. FAO. 1997. A Study of the Options for Utilization of Bycatch and Discards from Marine Capture Fisheries. FAO Fisheries Circular C928. Food and Agriculture Organization of the United Nations, Rome, Italy.
  9. FAO. 2008. Fishing Gear Types. Lift nets. Food and Agriculture Organization of the United Nations, Fisheries and Aquaculture Department, Rome.
  10. Fonteneau A, Pallares P, Pianet R. 2000. A worldwide review of purse seine fisheries on FADs. In: Le Gall JY, Cayré P, Taquet M (eds) Pêche thonière et dispositifs de concentration de poissons. Actes Colloques‐IFREMER 28:15–35.
  11. Gillett, R. 2010. Replacing Purse Seining with Pole-and-Line Fishing in the Western Pacific: Some Aspects of the Baitfish Requirements. International Seafood Sustainability Foundation, Washington, D.C., USA.
  12. Gilman, E., Lundin, C. 2010. Minimizing Bycatch of Sensitive Species Groups in Marine Capture Fisheries: Lessons from Commercial Tuna Fisheries. Pp. 150-164 IN: Grafton, Q., Hillborn, R., Squires, D., Tait, M., Williams, M. (Eds.). Handbook of Marine Fisheries Conservation and Management. Oxford University Press.
  13. Hall, M. and Roman M. 2013. Bycatch and non-tuna catch in the tropical tuna purse seine fisheries of the world. FAO Fisheries and Aquaculture Technical Paper 568.
  14. Hallier, J.P., Gaertner, D., 2008. Drifting fish aggregation devices could act as an ecological trap for tropical tuna species. Mar. Ecol. Prog. Ser. 353, 255-264.
  15. Inter-American Convention for the Protection and Conservation of Sea Turtles (IAC). 2012. Conservation status and habitat use of sea turtles in the Eastern Pacific Ocean. 3rd Meeting of the Scientific Advisory Committee, 15-18 May, 2012, La Jolla, CA
  16. IATTC. 2005. Resolution on the conservation of sharks caught in association with fisheries in the Eastern Pacific Ocean. Resolution C-05-03.
  17. IATTC. 2007. Resolution to mitigate the impact of tuna fishing vessels on sea turtles. Resolution C-07-03.
  18. IATTC. 2010. Recommendation prohibiting fishing on data buoys. Recommendation C-10-03.
  19. IATTC. 2011a. Resolution on the conservation of oceanic whitetip sharks caught in association with fisheries in the Antigua Convention Area. Resolution C-11-10.
  20. IATTC. 2011b. Resolution to mitigate the impact on seabirds of fishing for species covered by the IATTC. Resolution C-11-02.
  21. IATTC. 2011c. Resolution on the conservation of oceanic whitetip sharks caught in association with fisheries in the Antigua Convention Area. Resolution C-11-10.
  22. IATTC. 2012. Bycatch issues. 2nd Meeting of the Scientific Advisory Committee 9-14 May 2011, La Jolla, CA
  23. IATTC. 2013a. Meeting report. Scientific Meeting, La Jolla, CA, 29 April – 3 May 2013.
  24. IATTC. 2013b. Multiannual program for the conservation of tuna in the Eastern Pacific Ocean during 2014-2016. Resolution C-13-01.
  25. IATTC. 2013c. Status of sailfish in the Eastern Pacific Ocean in 2011 and outlook for the future. Document SAC-04-07c.
  26. IATTC. 2013d. Collection and analyses of data on fish-aggregating devices. Resolution C-13-04.
  27. IATTC. 2014. Fishery status report No. 12. IATTA, La Jolla, CA.
  28. IATTC. 2014b. Scientific Advisory Committee Fifth Meeting. La Jolla, California 12-16 May 2014. Available at:http://www.iattc.org/Meetings/Meetings2014/MAYSAC/PDFs/SAC-05-May-2014-Meeting-report.pdf
  29. IATTC. 2015. Recommendations by the staff for conservation measures in the eastern Pacific Ocean, 2015. Document SAC-06-11.
  30.  
  31. IATTC. 2016. Recommendations by the staff for conservation measures in the eastern Pacific Ocean, 2016. Document SAC-07-08.
  32. 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
  33. IOTC. 2002. Resolution 02/08 on the Conservation of Bigeye and Yellowfin Tuna in the Indian Ocean. Indian Ocean Tuna Commission, Mahé, Seychelles.
  34. ISCSWG. 2014. Stock assessment and future projections of blue shark in the North Pacific Ocean. Report of the Shark Working Group. International Scientific Committee for Tuna and Tuna-like species in the North Pacific Ocean. 16-21 July 2014 Taipei, Chinese-Taipei.
  35. Marsac, F., Fonteneau A., Ménard, F., 2000. Drifting FADs used in tuna fisheries: and ecological trap? In: Le Gall, J.Y., Cayré, P., Taquet, M. (Eds.), Pêche thonière et dispositifs de concentration de poisons. Actes Colloques-IFREMER. 28, 537-552.
  36. Nicol S., Lawson T., Briand K., Kirby D., Molony B., Bromhead D., Williams P., Schneiter E., Kumoru L., Hampton J. 2009. Characterisation of the tuna purse seine fishery in Papua New Guinea. Australian Centre for International Agricultural Research, Canberra, Australia. ISBN 978 1 921531 77 4.
  37. PNA. 2008. A Third Arrangement Implementing the Nauru Agreement Setting Forth Additional Terms and Conditions of Access to the Fisheries Zones of the Parties. Parties to the Nauru Agreement Concerning Cooperation in the Management of Fisheries of Common Interest, 16 May 2008, Koror, Palau.
  38. Romanov, E. 2002. Bycatch in the tuna purse-seine fisheries of the western Indian Ocean. Fish. Bull. 100(1): 90-105.
  39. Secretariat of the Pacific Community. 2006. Preliminary Review of the Western and Central Pacific Ocean Purse Seine Fishery. Prepared for the Internal Meeting of Pacific Island Parties to the South Pacific Regional U.S. Multilateral Treaty, March 6-8, Honolulu, Hawaii. Oceanic Fisheries Programme, Secretariat of the Pacific Community, Noumea, New Caledonia. 18 pp.
  40. Ward, P., Porter, J., Elscot, S. 2008. Broadbill swordfish: status of established fisheries and lessons for developing fisheries. Fish and Fisheries 1(4): 317-336.
  41.  
References

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    Bigeye tuna - Eastern Pacific

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