SUMMARY

SUMMARY

IDENTIFICATION

SCIENTIFIC NAME(s)

Thunnus albacares

SPECIES NAME(s)

Yellowfin tuna

An assessment unit is considered to exist in the Indian Ocean by the Indian Ocean Tuna Commission (IOTC, 2014).


ANALYSIS

Strengths

The stock assessment has been carried out regularly using a range of assessment methods.  The IOTC has recently adopted precautionary management, which includes the use of interim target and limit reference points and calls for the use of harvest control rules and management strategy evaluation. 

  • National level management regulations for Archipelagic and territorial waters (MKDPRI PER 30/MEN/2012) and the EEZ PER.12/MEN/2012 are the tools covering application of shark, turtle, sea mammals and bird measures.
  • Indonesia completed its Shark National Plan of Action and Sea Turtle National Plan of Action in 2016, and there is a moratorium on the export the hammerhead and oceanic white tip shark and fins (Decree 59/PERMEN-KP/2014).
Weaknesses

Yellowfin tuna in the Indian Ocean are overfished and undergoing overfishing.  Catches have been over recommended level since 2011.  Recent advice calls for a 20% reduction but only a 5-15% reduction (depending on the fleet) has been adopted by the Commission (2016). IUU fishing and piracy has been a major issue in the Indian Ocean and there are compliance issues with regard to the quality of reported data {IOTC 2013b}.  The Commission has taken recent action to continue addressing these issues but the success of these measures is not yet known. A number of bycatch species, including sharks, sea turtles and sea birds are incidentally captured in fisheries targeting yellowfin tuna.  Observer coverage rates are low in fisheries targeting yellowfin tuna.

  • Systematic observation and reporting of ETP bycatch in Indonesian handline gear in the Indian Ocean are not available; bycatch information reported by Indonesia to the IOTC is for all longlines combined, including handlines. 
  • This fishery uses FADs, but the number and locations are highly variable and not reported, which prevents assessments of whether they comply with IOTC resolutions on FAD use and what impacts they might have on ETP species and the ecosystem.
  • It is not possible to assess potential impacts of bycatch in Indonesian handline fishery in the Indian Ocean on ETP populations nor the ecosystem with information currently available. 

FISHSOURCE SCORES

Management Quality:

Management Strategy:

≥ 6

Managers Compliance:

≥ 6

Fishers Compliance:

< 6

Stock Health:

Current
Health:

7.6

Future Health:

7.6


RECOMMENDATIONS

RETAILERS & SUPPLY CHAIN
  • Work with IOTC Members and Cooperating Non-Contracting Parties to:
    • Ensure full compliance with Resolution 17/01, the interim rebuilding plan for yellowfin tuna.
    • Improve data collection (i.e. catches, effort, size) for all gear types, for both target and bycatch species, and reporting through measures such as electronic logbooks.
    • 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 IOTC 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.
  • 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

  • Indonesian Indian Ocean yellowfin tuna - handline:

    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
Indian Ocean IOTC France Associated purse seining
FAD-free
India Hooks and lines
Longlines
Indonesia FAD-free
Gillnets and entangling nets
Handlines hand operated
Hooks and lines
Longlines
Mechanized lines
Pole-lines hand operated
Purse seines
Seine nets
Italy Associated purse seining
FAD-free
Korea, Republic of Longlines
Malaysia Handlines hand operated
Longlines
Maldives Pole-lines hand operated
Mauritius FAD-free
Hooks and lines
Longlines
Purse seines
Mozambique Longlines
Oman Handlines hand operated
Seychelles Associated purse seining
FAD-free
Spain FAD-free
Longlines
Purse seines
Sri Lanka Drifting longlines
Thailand Handlines hand operated
Longlines
Mechanized lines

Analysis

OVERVIEW

Last updated on 2 July 2019

Strengths

The stock assessment has been carried out regularly using a range of assessment methods.  The IOTC has recently adopted precautionary management, which includes the use of interim target and limit reference points and calls for the use of harvest control rules and management strategy evaluation. 

IOTC
Indonesia
Handlines hand operated

Last updated on 2 July 2019

  • National level management regulations for Archipelagic and territorial waters (MKDPRI PER 30/MEN/2012) and the EEZ PER.12/MEN/2012 are the tools covering application of shark, turtle, sea mammals and bird measures.
  • Indonesia completed its Shark National Plan of Action and Sea Turtle National Plan of Action in 2016, and there is a moratorium on the export the hammerhead and oceanic white tip shark and fins (Decree 59/PERMEN-KP/2014).
Weaknesses

Yellowfin tuna in the Indian Ocean are overfished and undergoing overfishing.  Catches have been over recommended level since 2011.  Recent advice calls for a 20% reduction but only a 5-15% reduction (depending on the fleet) has been adopted by the Commission (2016). IUU fishing and piracy has been a major issue in the Indian Ocean and there are compliance issues with regard to the quality of reported data {IOTC 2013b}.  The Commission has taken recent action to continue addressing these issues but the success of these measures is not yet known. A number of bycatch species, including sharks, sea turtles and sea birds are incidentally captured in fisheries targeting yellowfin tuna.  Observer coverage rates are low in fisheries targeting yellowfin tuna.

IOTC
Indonesia
Handlines hand operated

Last updated on 2 July 2019

  • Systematic observation and reporting of ETP bycatch in Indonesian handline gear in the Indian Ocean are not available; bycatch information reported by Indonesia to the IOTC is for all longlines combined, including handlines. 
  • This fishery uses FADs, but the number and locations are highly variable and not reported, which prevents assessments of whether they comply with IOTC resolutions on FAD use and what impacts they might have on ETP species and the ecosystem.
  • It is not possible to assess potential impacts of bycatch in Indonesian handline fishery in the Indian Ocean on ETP populations nor the ecosystem with information currently available. 
RECOMMENDATIONS

Last updated on 7 August 2018

Recommendations to Retailers & Supply Chain
  • Work with IOTC Members and Cooperating Non-Contracting Parties to:
    • Ensure full compliance with Resolution 17/01, the interim rebuilding plan for yellowfin tuna.
    • Improve data collection (i.e. catches, effort, size) for all gear types, for both target and bycatch species, and reporting through measures such as electronic logbooks.
    • 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 IOTC 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.
  • 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 16 January 2018

Yellowfin tuna is assumed to be a single stock across Indian Ocean. This is supported by the tag recoveries that provide evidence of large movements of yellowfin tuna. The latest full stock assessment was conducted in 2015 and an updated assessment was conducted in 2016. Three assessment models were used in the 2015 assessment were the, BBPm, SCAA and Stock Synthesis III . This stock assessment included catch data from 1950 through 2014 {IOTC 2015}. The udated 2016 assessment utilized the Biomass Dynamic MOdel (BDM) and Stock Synthesis III and included catch and effort data through 2015 (IOTC 2016).

SCIENTIFIC ADVICE

Last updated on 16 January 2018

In 2015, it was advised that catches of yellowfin tuna should be reduced to a minimum of 80% of current (2014) catch levels to rebuild by 2024 {IOTC 2015}. An intermin rebuilding plan was adopted in 2016, but the success of this plan has yet to be evaluated. No new advice was provided in 2016 as a result of the updated assessment but did indicate there is a risk of continuing to exceed the biomass reference point if catches increase or remain at 2015 levels until 2018 (IOTC 2016).

Reference Points

Last updated on 16 Jan 2018

Reference points for yellowfin tuna in the Indian Ocean Tuna commission Area: Source: IOTC (2016)
2015 catch estimate: 4307,575 tonnes
Average Catches (2011-2015): 390,185 tonnes
MSY: 422,000 tonnes
SB2015/SBMSY = 0.89 (0.79—0.99)
F2015/FMSY = 1.11 (0.86-1.36)
SB2015/SB0 = 0.29 

CURRENT STATUS

Last updated on 16 January 2018

The stock is currently overfished ((B2015<BMSY) and undergoing occurring(F2015>FMSY) (IOTC, 2016).

Trends

Last updated on 16 Jan 2018

Catch per unit effort trends have been decreasing over time for yellowfin tuna in the Indian Ocean {IOTC 2016}.

2.MANAGEMENT QUALITY

MANAGEMENT

Last updated on 17 September 2018

The Indian Ocean Tuna Commission (IOTC) is one of five global tuna-regional fisheries management organizations. IOTC is mandated to manage tuna and tuna-like species in the Indian Ocean and adjacent seas. Its objective is to promote cooperation among its Members with a view to ensuring, through appropriate management, the conservation and optimum utilization of stocks and encouraging sustainable development of fisheries based on such stocks. Members of IOTC include Australia, Belize, China, Comoros, Eritrea, European Community, France, Guinea, India, Indonesia, Republic Islamic of Iran, Japan, Kenya, Republic of Korea, Madagascar, Malaysia, Mauritius, Sultanate of Oman, Pakistan, Philippines, Seychelles, Sierra Leone, Sri Lanka, Sudan, Tanzania, Thailand, United Kingdom, and Vanuatu. The Cooperating Non-Contracting Parties are Senegal, South Africa and Uruguay.

A proposal for adopting a catch limit for yellowfin tuna was introduced in 2009, along with proposed TACs for bigeye tuna and swordfish. The proposal was to introduce catch restrictions on yellowfin tuna (to the levels recommended by the Scientific Committee), including catch allocations for Members (on the basis of the catch figures indicated in the IOTC Scientific Committee report 2008). These proposals were submitted in response to the advice from the Scientific Committee that yellowfin tuna stocks were evaluated to be at levels near or below MSY; and recognizing the importance of applying the precautionary approach for the management of the stock in the Indian Ocean.  However, after considerable debate, no consensus was reached on a formula to distribute the allowable catches between Members, and the proposals for catch limits were dropped from further consideration at the 2009 IOTC meeting. The advice from the 2015 stock assessment called for a reduction in catches of around 20%. The Commission adopted a reduction of 10% for gillnet and longline vessels, 15% for purse seine vessels (with catches higher than 5,000 mt during 2014) and 5% for other gears {IOTC 2016b}. Discarding yellowfin tuna caught by purse seine's is prohibited (IOTC 2017).

Other management measures in place include: required reporting and recording of catches and effort, providing a record of active fishing vessels, limiting fishing capacity to levels from 2007.   Artificial lights and the use of aircraft and/or unmanned aerial vehicles is prohibited in the purse seine fishery {IOTC 2016b}. There are interim limit and target reference points in place for yellowfin tuna in the Indian Ocean (IOTC 2015).


 

Recovery Plans

Yellowfin tuna are currently managed by an interim rebuilding plan (IOTC 2016).

COMPLIANCE

Last updated on 22 January 2015

There is no TAC or other output controls for yellowfin tuna in the Indian Ocean. Therefore, compliance cannot be measured. However, the IOTC Scientific Committee has repeatedly pointed out that fishing levels of yellowfin tuna stock have exceeded recommended amounts (IOTC 2013). In addition, the Compliance Committee indicated that reporting of mandatory statistics is generally poor, due to incomplete and/or poorly documented data, although an improvement was noted in 2012 {IOTC 2013b}. The lack of quality data can negatively impact stock assessments.

IUU fishing in the Indian Ocean and piracy have been major issues, which includes a range of illicit activities: fishing without permission or out of season; harvesting prohibited species; using outlawed types of fishing gear; disregarding catch quotas; or non-reporting or underreporting catch weights. Of particular concern are the western Indian Ocean and the maritime areas along the coast of eastern Africa. There, fishing vessels of various flags have taken advantage of the absence in coastal countries of strong enforcement mechanisms (FAO 2007). The Commission has regularly established a list of vessels presumed to have carried out illegal, unregulated and unreported fishing in the IOTC area. In 2013, the IOTC adopted a new resolution to make a record of vessels authorized to operation in the IOTC area of competence (IOTC 2013c). In 2016, the Commission took further steps to address IUU fishing and compliance with catch reporting and other Conservation and Management Measure requirements {IOTC 2016}.

3.ENVIRONMENT AND BIODIVERSITY

BYCATCH
ETP Species

Last updated on 22 January 2015

Longlines incidentally capture vulnerable species including sea birds and sea turtles. Bycatch of seabirds, sea turtles, marine mammals and sharks in pelagic longline tuna fisheries threatens some populations with extinction. Purse seines can also incidentally capture sea turtles. The Indian Ocean Tuna Commission (IOTC) has implemented several management measures addressing these incidental captures.

Regarding sea birds, a 2010 resolution, superseding previous measures, requires, when south of 25oS, use of at least two seabird mitigation methods selected from two lists of nine alternatives (IOTC, 2010b).

A 2009 resolution requires member countries to report data on sea turtle interactions and for vessels to follow sea turtles handling and release guidelines and posses and use specified turtle release equipment (IOTC, 2009c). Purse seine vessels are not allowed to encircle sea turtles while setting their nets (IOTC 2013).

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).

Required observer coverage rates and compliance with these rates are low in the Indian Ocean. In 2016, the Commission adopted a new resolution to develop a pilot program to promote the regional observer scheme of the IOTC {IOTC 2016}.

IOTC
Indonesia
Handlines hand operated

Last updated on 2 July 2019

Indonesia has been recognized as the highest tuna-producing country in the world, contributing 15 percent of global tuna production in 2009 (FishStat 2006). Approximately 20% of Indonesia’s tuna production comes from the Indian Ocean, and 80% from the Western Central Pacific Ocean (FishStat 2006). Indonesian tuna fisheries are difficult to assess separately, and are often reported altogether because they cumulatively affect target stocks, specifically yellowfin tuna (YFT) and skipjack tuna, as well as other overexploited stocks such as bigeye tuna and baitfish (Moody Marine LTD 2010).

This narrative presents information for Indonesia’s handline fisheries in the Indian Ocean wherever possible; however, the majority of available information is for Indonesia’s tuna fisheries (purse seines not included here), specifically longline fisheries in the Indian Ocean. Thus, unless handline fisheries are specifically referenced, information presented here represents summaries across different tuna fisheries.

Although assumed to be highly selective in terms of catch, there is a high degree of uncertainty about the overall scale and potential impacts of the Indonesian handline fisheries targeting yellowfin tuna (YFT) on ETP species and the ecosystem. In 2010, there were 627 active vessels in the Indonesian handline fishery targeting YFT in the Indian Ocean (Moody Marine LTD 2010). However, Indonesia reported only 217 longline vessels overall in 2017, which presumably included handline vessels but did not specify the actual number (Ruchimat et al. 2018). This number was down from 1,311 vessels reported in 2016 (Ruchimat et al. 2017). There has apparently been a rapid and uncontrolled growth in tuna handliners in Indonesia as vessels convert from other gears (e.g., driftnets); in contrast to the official estimates of permit holders and active vessels described above, perhaps 34,000 small handline vessels targeting tunas regularly or seasonally, which contributes to significant uncertainty about cumulative target catch and bycatch (Moody Marine LTD 2010)). 

The Indian Ocean Tuna Commission (IOTC), of which Indonesia is a member, is responsible for management and conservation measures in international waters of the Indian Ocean. IOTC resolution 10/04 requires at least 5% of the total number of operations/sets for each gear type (including longlines) fishing with vessels ≥ 24 m in the IOTC area of competence, and < 24 m if they fish outside their EEZ (IOTC 2010). However, Indonesia’s country reports to the IOTC are inconsistent with respect to the ETP species reported as well as the ranges of years during which the bycatch was observed, which varied by species ((Ruchimat et al. 2017); (Ruchimat et al. 2018)). Observer coverage of Indonesian handline trips has fluctuated between 0 and 17 trips between 2013-2017 (Ruchimat et al. 2018), but it is unclear what proportional coverage these reported levels represent. Ministerial regulation No. 42/2015 requires all vessels above 30 GT or operating outside the EEZ to be equipped with a VMS transmitter (Ruchimat et al. 2018). RITF maintains a tuna catch monitoring program at Benoa Fishing Port in Bali to verify logbook reports, and has a goal of minimum 30% coverage of landings; Ruchimat et al. (Ruchimat et al. 2018) reported that coverage of port sampling between 2013-2017 was above 50%. These reports include sampling of some shark species (e.g., blue sharks, shortfin makos, oceanic whitetips, and bigeye thresher sharks) as well as billfish (e.g., blue marlin, black marlin, striped marlin, swordfish). 

Though some handline sets occur on free schools or natural objects, Indonesian handline fisheries focus on anchored fish aggregating devices (FADs). In some cases, handliners fish with permission on FADS that are owned and operated by purse seine companies, but most are unlicensed ((Moody Marine LTD 2010); (Hough 2018)). IOTC Resolution 18/08 sets limits on the total number of FADs that can be deployed, specifications of catch reporting, and development of FAD designs to reduce non-target catch, but this applies to purse seine vessels (IOTC 2013). No information was available in country reports about the number or location of FADs, an issue also highlighted by the MSC Pre-assessment (Hough 2018)

Given the current observer coverage and reporting scheme in Indonesian longline fisheries, and handlines in particularly, estimates of total ETP bycatch by species are not possible. This fishery overlaps with several shark, seabird, marine mammal, and sea turtle populations, some of which are currently low abundance and declining, which means that numerically low bycatch interactions can still have significant population impacts (Lewison et al. 2014)

Previous reports suggest limited interactions with ETP species which are unlikely to hinder recovery ETP species; large handline vessels are most likely to have any interactions with ETP species ((Poseidon Aquatic Resource Management Ltd 2016); (Hough 2018)). However, this assertion was based on anecdotal information and inference from other handline fisheries; direct observation and reporting of ETP bycatch for this fishery is unavailable ((Hough 2018)). 

Recent ecological risk assessments for shark species caught in IOTC reported uncertain stock status determinations for oceanic whitetip, shortfin mako, scalloped hammerheads, bigeye and pelagic thresher sharks, and silky sharks, and concluded that blue sharks were not overfished (IOTC 2019).

Despite conservation measures in place, Indonesia is one of the world’s top shark producers ((Lack et al. 2006); (Blaber et al., 2009)), and most shark products come from bycatch (72%) ((Zainudin 2011); cited in (Zainudin et al. 2017)). Shark bycatch from tuna fleets comprised approximately 11% of shark landings in Indonesia between 2011 and 2005 (Blaber et al., 2009). In addition, shark finning on Indonesian vessels is prohibited in some parts of the longline fishery (under AP2HI, for example) but finning is unlikely to be prevented on these vessels (Poseidon Aquatic Resource Management Ltd 2016). Many shark and ray species in Indonesia are overfished and effective management strategies likely need to include gear restrictions and catch limits, as well as controls on the fin trade (Blaber et al., 2009).

Indonesia established a National Plan of Action (NPOA) for sharks and rays for 2015-2019. The Minister of Marine and Fisheries issued regulations (No. 34/PERMEN-KP/2015 and amendment No. 59/PERMEN-KP/2014) that prohibits export of oceanic whitetip sharks and hammerhead sharks and fins from Indonesian territory (Ruchimat et al. 2018). Blue sharks (mostly retained) and crocodile sharks (typically discarded dead) comprised the majority of shark bycatch during 2013-2017 according to Research Institute for Tuna Fisheries (RITF) observer data (Ruchimat et al. 2018).

IOTC has established several conservation measures targeting ETP species, including cetaceans (IOTC 2013), multiple shark species ((IOTC 2016); (IOTC 2017)), billfish (IOTC 2015), seabirds (IOTC 2012), marine turtles (IOTC 2012).

Other Species

Last updated on 17 December 2018

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). Networks of thousands of artificial drifting and anchored FADs aggregate tunas from surrounding waters and possibly act as ‘ecological traps’ of pelagic species by altering their natural spatial and temporal distributions, habitat associations, migration patterns and residence times (Marsac et al., 2000; Bromhead et al., 2003; Hallier and Gaertner, 2008; WCPFC, 2009; Dagorn et al., 2010).

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).

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).

Between 1995 and 2003, the FAD component of the purse seine fishery represented 48-66% of the sets undertaken (60-80% of the positive sets) and took 36-63 % of the yellowfin catch by weight (59-76% of the total catch).

Preliminary quantitative estimates of the main bycatch species and species groups (billfishes, sharks, rays and fin fishes) were made for the whole purse seine fishery since 2003. Data are from the French and Spanish observer programs from 2003 to 2007, representing a total of 1958 observed sets (4% of the total number of sets during this period). Annual raising factors by fishing mode based on tuna production (tonnes per 1000 tonnes of tuna landed) were estimated for each species group from logbooks and observer information stratified by quarter, fishing area and fishing mode. According to these estimations, total bycatch was estimated at 9,585 tonnes, corresponding to 35.5 tonnes bycatch per 1000 tonnes of tuna landed. Tuna discards represents 54% of the total amount, followed by other fin fish (34%), sharks (10%), billfishes (1.5%) and rays (0.7%) (IOTC, 2009).

These mean ratios were applied to the whole purse seine fishery annual catches from 2003 to 2008 to compute total bycatches by species groups, and then distributed within the groups according to the proportion in weight of the main species or families. The bulk of the bycatch consisted of tuna discards (average annual catch 6,700 tonnes; range 5,100-8,300 tonnes). The annual bycatch of all other groups averaged some 4,000 tonnes (range 2,750-4,400 tonnes). Of this the majority was made up of “fin fishes”, with an annual mean catch close to 2,500 tonnes (range 1550-2,800 tonnes). The main species was rainbow runner (Elagatis bipinnulatus, 37% of the total), followed by triggerfishes (Balistidae, 24%), dolphinfishes (Coryphaena spp., 11%) and carangids (Carangidae, 7%), with the balance (21%) being made up of some 50 other species. Most were caught under FADs (95%). Fin fish species composition between FAD and log schools was rather similar, although there were more dolphinfishes on FADs, and the greatest diversity was from free schools. The next most important bycatch group was “sharks”, with a total average annual catch close to 1,300 tonnes (range 1,000-1,650 tonnes). Shark bycatch was dominated by carcharhinids, the most important being the silky shark (Carcharhinus falciformis, 79%) followed by the oceanic whitetip shark (C. longimanus, 11%). 97% of sharks were caught on FADs. Shark species composition was quite similar between FAD and free schools sets. “Billfish” bycatch was relatively low, with an average annual catch of 180 tonnes (range 140-210 tonnes). The most important species were marlins (70%, mainly M. indica and T. audax) and sailfishes (27%). Most billfishes (72%) were caught on FADs. Billfish species composition was quite similar between FAD and log sets. “Rays” were caught in smaller quantities, with an average annual catch of 50 tonnes (range 40-70 tonnes). 65% of rays were caught on FADs. The most important species group was the Mobulidae (42%), followed by the giant manta (Manta birostris, 37%) and other and unidentified rays (20%). Ray species composition is rather similar between FAD and free schools, but with a larger diversity on free schools. Overall, discards by the purse seine fishery (excluding tuna discards) remains relatively low when compared to many other fisheries, with the large majority coming from FAD sets (IOTC, 2009).

IOTC
Indonesia
Handlines hand operated

Last updated on 17 December 2018

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).

HABITAT

Last updated on 5 July 2011

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

IOTC
Indonesia
Handlines hand operated

Last updated on 2 July 2019

The Indonesian yellowfin tuna handline fishery is a pelagic fishery, which operate in deep oceanic waters and do not interact with the seabed. Negligible habitats impacts would therefore be anticipated (Moody Marine LTD 2010); (Hough 2018)).  However, the fishery uses anchored fishing aggregation devices (FADs), which the MSC recognizes as habitat modifications (Hough 2018). The extent to which this fishery contributes chemical pollution or derelict fishing gear into oceanic pelagic habitats operates is unknown but warrants review.

ECOSYSTEM
IOTC
Indonesia
Handlines hand operated

Last updated on 2 July 2019

Fisheries that target high-level predators such as tunas will have some impact on marine ecosystems. Some research has suggested that exploitation by tuna fisheries can alter both target populations and a diversity of other species in the affected ecosystems ((Hinke et al. 2004); see (Schindler et al. 2002), for review); however, there is little empirical evidence for top-down control in oceanic ecosystems such as the Indian Ocean (Baum and Myers 2009). In addition, the Indonesian yellowfin handline fishery in the Indian Ocean uses fishing aggregation devices (FADs), which the MSC recognizes as habitat modifications and could entrain tuna and other species, including ETP species (Hough 2018). It is unclear what effects these FADs might have on Indian Ocean ecosystems.

In addition, the handline fishery catches its own bait (Hough 2018). Large quantities of baitfish are needed to support productive hook and line tuna fisheries; depending on the type and source of these baitfish, required quantities might not be possible or sustainable (Gillett 2011). Thus, baitfish harvest for longline tuna fishing operations could affect pelagic ecosystems as well.

Although some studies have included the North Central Pacific, Central Pacific, and Eastern Tropical Pacific (Schindler et al. 2002); (Baum and Myers 2009)) and have suggested mesopredator and prey releases when predatory tuna species are overexploited, no studies – either empirically derived or model-based – have examined potential ecosystem effects specifically in the Indian Ocean.

FishSource Scores

Last updated on 17 September 2018

MANAGEMENT QUALITY

As calculated for 2017 data.

The score is ≥ 6.

There are interim target and limit reference points in place. The IOTC adopted a precautionary management approach in 2012 that will utilize reference points, harvest control rules and management strategy evaluation.

As calculated for 2017 data.

The score is ≥ 6.

Managers have adopted measures to reduce catches of yellowfin by 5-15% (depending on the fleet) but this is below the scientifically requested 20%.

As calculated for 2017 data.

The score is < 6.

Yellowfin tuna catches have been increasing since 2012 to unsustainable levels. In addition, there are significant issues with the quality of data reported by some countries to the Commission.

STOCK HEALTH:

As calculated for 2015 data.

The score is 7.6.

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

The Ratio SSB/SSBmsy is 0.890 . The SSB=SSBmsy is 1.00 .

The underlying Ratio SSB/SSBmsy/SSB=SSBmsy for this index is 89.0%.

As calculated for 2015 data.

The score is 7.6.

This measures the Harvest rate as a percentage of the F management target.

The Harvest rate is 1.11 (Y/TSB). The F management target is 1.00 .

The underlying Harvest rate/F management target for this index is 111%.

ECOSYSTEM IMPACTS

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Bycatch Subscores

  • Indoneisa has a logbook program in place for handline fisheries. The observer program was extended to hand line fisheries in 2013.
  • Anecdotal information and inference from other handline fisheries available, but systematic observation and reporting of ETP bycatch in Indonesian handline gear in the Indian Ocean is not available. Bycatch information reported by Indonesia to the IOTC is for all longlines combined, including handlines.

  • Suggestion that interactions between handline vessels and ETP species are likely to be low and thus not expected to hinder recovery of ETP species (Hough 2018). However, lack of information about bycatch makes assessment of outcome impossible.
  • This fishery overlaps with several shark, seabird, marine mammal, and sea turtle populations, some of which are currently low abundance and declining, which means that numerically low bycatch interactions can still have significant population impacts (Lewison et al. 2014).

Handline fisheries have very low bycatch rates (Miller et al. 2017).

Existing IOTC conservation measures to protect ETP species apply to this fishery, but compliance uncertain.

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Habitat Subscores

  • There is some information on the location and timing of fishing (IOTC 2017).
  • The Indonesia tuna handline fishery in the Indian Ocean is a pelagic fishery, which operate in deep oceanic waters and do not interact with the seabed. Negligible habitats impacts would therefore be anticipated (Hough 2018)
  • Number and locations of FADs unknown (Hough 2018)
  • The extent to which this fishery contributes chemical pollution or derelict fishing gear into oceanic pelagic habitats operates is unknown but warrants review.

Some priority habitats have been identified (IOTC 2017)

General map of fishing area for Indonesian longlines (presumably including handlines) available (Ruchimat et al. 2018).

  • The fishery will not reduce the structure and function of the habitat (Chuenpagdee et al. 2003).
  • The Indonesia tuna handline fishery in the Indian Ocean is a pelagic fishery, which operate in deep oceanic waters and do not interact with the seabed. Negligible habitats impacts would therefore be anticipated (Hough 2018)
  • However, potential effects of anchored FADs are unknown and need to be assessed to confirm lack of significant habitat impact.

  • There are no measures in place to manage potential impacts on priority habitats.
  • Controls and management of FADs are variable (Hough 2018).

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Ecosystem Subscores

There is some reliable information to assess the main impacts of the fishery on the ecosystem structure (IOTC 2017)​, but fisheries that target high-level predators such as tuna that also catch overexploited stocks (e.g., baitfish) and ETP species will have some impact on marine ecosystems. However, relatively small scale and pelagic nature make significant impacts less likely.

  • General map of fishing area for Indonesian longlines (presumably including handlines) available (Ruchimat et al. 2018).

Insufficient information available to assess ecosystem effects of this particular fishery—including effects of FADs associated with this fishery on pelagic ecosystems (i.e., depletion of key species such as tunas and baitfish species)—but fisheries that target high-level predators such as tuna that also catch overexploited stocks (e.g., baitfish) and ETP species will have some impact on marine ecosystems. However, relatively small scale and pelagic nature make significant impacts less likely.

No measures are in place to manage the potential impacts of the fishery on the ecosystem. Management of tuna populations, baitfish populations, ETP species, and FADs should be required.

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No data available for recruitment
No data available for recruitment
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To see data for stock status, please view this site on a desktop.
DATA NOTES

F and SSB are provided relative to MSY (F/FMSY, B/BMSY) and reference points have been set accordingly. F to be adopted at low biomass is not defined and there is no set TAC. Therefore, Scores 1, 2 and 3 have been determined qualitatively (please mouse-over for explanation).

 

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Fishery Improvement Projects (FIPs)

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Access FIP Public Report

Progress Rating: C
Evaluation Start Date: 1 Jul 2018
Type: Comprehensive

Comments:

FIP undertaking stage 3 activities - FIP rated C

1.
FIP Development
Jun 18
2.
FIP Launch
Aug 17
Jul 18
3.
FIP Implementation
May 19
4.
Improvements in Fishing Practices and Fishery Management
Verifiable improvement in policy/management and fishing practices
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

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.

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.

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.

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.

FAO. 2008. Fishing Gear Types. Lift nets. Food and Agriculture Organization of the United Nations, Fisheries and Aquaculture Department, Rome.

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.

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.

Gilman, E. 2011. Bycatch governance and best practice mitigation technology in global tuna fisheries. Marine Policy 35: 590-609.

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.

IOTC. 2011a. Report of the Thirteenth Session of the IOTC Working Party on Tropical Tunas, Indian Ocean Tuna Commission, Maldives, 16-23 October 2011, 94 pp.

IOTC. 2010a. Report of the Fourteenth Session of the Indian Ocean Tuna Commission. Indian Ocean Tuna Commission, Mahé, Seychelles.

IOTC. 2010b. Report of the Twelfth Session of the IOTC Working Party on Tropical Tunas. Victoria, Seychelles, 18-25 October 2010.

IOTC. 2010c. Report of the Thirteenth Session of the Scientific Committee. Victoria, Seychelles, 6-10 December 2010. Indian Ocean Tuna Commission, Seychelles.

IOTC. 2009d. Report of the Twelfth Session of the Science Committee, Victoria, Seychelles, 30 November – 4 December 2009. Indian Ocean Tuna Commission, Mahé, Seychelles.

IOTC. 2002. Resolution 02/08 on the Conservation of Bigeye and Yellowfin Tuna in the Indian Ocean. Indian Ocean Tuna Commission, Mahé, Seychelles.

IOTC. 2015. Status of the Indian Ocean yellowfin tuna (YFT: Thunnus albacares) resource. IOTC-2015-SC18-ES04[E].

IOTC. 2013b. Summary report on the level of compliance. IOTC-2013-CoC10-03. Available at: http://www.iotc.org/files/proceedings/2013/coc/IOTC-2013-CoC10-03%5BE%5D.pdf

IOTC. 2013c. Compendium of active and pending conservation and management measures for the Indian Ocean Tuna Commission. September 15, 2013. Available at: http://www.iotc.org/files/CMM/IOTC%20-%20Compendium%20of%20ACTIVE%20CMMs%2015%20September%202013.pdf

IOTC. 2016. Status of the Indian Ocean yellowfin tuna (YFT: Thunnus albacares) resource. IOTC-2016-SC19-ES04


IOTC. 2016b. Conservation and Management Measures adopted by the IOTC at its 20th Session. IOTC Circular 2016-054.

Langley, A. 2010. Stock assessment of Yellowfin Tuna in the Indian Ocean using MULTIFAN-CL. IUTC-2010-WPTT-23.

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.

Murua, H., Arrizabalaga, H., Huang, J., Romanov, E., Bach, P., de Bruyn, P., Chavance, P., de Molina, A., Pianet, R., Ariz, J., Ruiz, J. 2009. Ecological Risk Assessment (ERA) for Species Caught in Fisheries Managed by the Indian Ocean Tuna Commission (IOTC): A First Attempt. IOTC-2009-WPEB-20. Indian Ocean Tuna Commission, Mahé, Seychelles.

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.

Nishida. 2010. IO YFT stock assessment by ASPIC (revised version 3). Indian Ocean Tuna Commission, Victoria, Seychelles.

Romanov, E. 2002. Bycatch in the tuna purse-seine fisheries of the western Indian Ocean. Fish. Bull. 100(1): 90-105

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.

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.

WCPFC. 2009. Conservation and Management Measure for Sharks. Conservation and Management Measre 2009-04. Sixth Regular Session, 7-11 December 2009, Papeete, Tahiti, French Polynesia. Western and Central Pacific Fisheries Commission, Palikir, Federated States of Micronesia.

WCPFC. 2007. Conservation and Management Measure to Mitigate the Impact of Fishing for Highly Migratory Fish Stocks on Seabirds. CMM 2007-04. Western and Central Pacific Fisheries Commission, Palikir, Federated States of Micronesia.

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References

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