Albacore Tuna, Bigeye Tuna, Skipjack Tuna, Swordfish, Yellowfin Tuna Thunnus alalunga, Thunnus obesus, Katsuwonus pelamis, Xiphias gladius, Thunnus albacares Image Monterey Bay Aquarium Hawaii Longline October 21, 2014 Alexia Morgan, Consulting Researcher Disclaimer Seafood Watch strives to have all Seafood Reports reviewed for accuracy and completeness by external scientists with expertise in ecology, fisheries science and aquaculture. Scientific review, however, does not constitute an endorsement of the Seafood Watch program or its recommendations on the part of the reviewing scientists. Seafood Watch is solely responsible for the conclusions reached in this report.
2 About Seafood Watch Monterey Bay Aquarium s Seafood Watch program evaluates the ecological sustainability of wildcaught and farmed seafood commonly found in the United States marketplace. Seafood Watch defines sustainable seafood as originating from sources, whether wild-caught or farmed, which can maintain or increase production in the long-term without jeopardizing the structure or function of affected ecosystems. Seafood Watch makes its science-based recommendations available to the public in the form of regional pocket guides that can be downloaded from www.seafoodwatch.org. The program s goals are to raise awareness of important ocean conservation issues and empower seafood consumers and businesses to make choices for healthy oceans. Each sustainability recommendation on the regional pocket guides is supported by a Seafood Report. Each report synthesizes and analyzes the most current ecological, fisheries and ecosystem science on a species, then evaluates this information against the program s conservation ethic to arrive at a recommendation of Best Choices, Good Alternatives or Avoid. The detailed evaluation methodology is available upon request. In producing the Seafood Reports, Seafood Watch seeks out research published in academic, peer-reviewed journals whenever possible. Other sources of information include government technical publications, fishery management plans and supporting documents, and other scientific reviews of ecological sustainability. Seafood Watch Research Analysts also communicate regularly with ecologists, fisheries and aquaculture scientists, and members of industry and conservation organizations when evaluating fisheries and aquaculture practices. Capture fisheries and aquaculture practices are highly dynamic; as the scientific information on each species changes, Seafood Watch s sustainability recommendations and the underlying Seafood Reports will be updated to reflect these changes. Parties interested in capture fisheries, aquaculture practices and the sustainability of ocean ecosystems are welcome to use Seafood Reports in any way they find useful. For more information about Seafood Watch and Seafood Reports, please contact the Seafood Watch program at Monterey Bay Aquarium by calling 1-877-229-9990.
3 Guiding Principles Seafood Watch defines sustainable seafood as originating from sources, whether fished 1 or farmed, that can maintain or increase production in the long-term without jeopardizing the structure or function of affected ecosystems. Based on this principle, Seafood Watch had developed four sustainability criteria for evaluating wildcatch fisheries for consumers and businesses. These criteria are: How does fishing affect the species under assessment? How does the fishing affect other, target and non-target species? How effective is the fishery s management? How does the fishing affect habitats and the stability of the ecosystem? Each criterion includes: Factors to evaluate and score Guidelines for integrating these factors to produce a numerical score and rating Once a rating has been assigned to each criterion, we develop an overall recommendation. Criteria ratings and the overall recommendation are color-coded to correspond to the categories on the Seafood Watch pocket guide and online guide: Best Choice/Green: Are well managed and caught in ways that cause little harm to habitats or other wildlife. Good Alternative/Yellow: Buy, but be aware there are concerns with how they re caught. Avoid/Red: Take a pass on these for now. These items are overfished or caught in ways that harm other marine life or the environment. 1 Fish is used throughout this document to refer to finfish, shellfish and other invertebrates.
4 Summary Swordfish and tuna are caught in longline fisheries throughout the world s oceans. This report focuses on the two, shallow-set and deep-set, pelagic longline fisheries that operate in and around Hawaii (~85%) primarily in the western and central Pacific Ocean, but also in the eastern Pacific Ocean (~15% of the total catch). Swordfish are targeted by the Hawaii shallow-set pelagic longline fishery. Abundance levels are high and fishing mortality rates appear low enough to maintain the population at a healthy level. High incidental capture of sea turtles lead to the closure of this fishery between 2001 and 2004. The fishery was reopened in 2005 with several new management measures aimed at reducing sea turtle and sea bird bycatch, including 100% observer coverage, which appears to have successfully reduced bycatch levels. The deep-set pelagic longline fishery targets bigeye tuna. Bigeye tuna are approaching an overfished state and are experiencing overfishing. Several species of sharks and fish are also caught in these fisheries and the status of their population varies from unknown, to overfished, to healthy. In state waters, the state of Hawaii manages tuna, in US federal waters, the Western Pacific Regional Fishery Management Council (WPRFMC) manages swordfish and tuna. In addition, the US is a member of two regional fishery management organizations, the Western and Central Pacific Fisheries Commission (WCPFC) and the Inter-American Tropical Tuna Commission (IATTC), both of which manage these species throughout their range in the Pacific Ocean. Management measures for swordfish and tuna are moderately effective. Pelagic longline gear has minimal impact on bottom habitats because it fishes at or near the surface and improvements such as gear modifications are typically not necessary. Table of Conservation s and Overall Recommendations Stock / Fishery Bigeye Tuna Hawaii Western Central Pacific - Longline, Deep-Set Swordfish Hawaii Western Central Pacific - Longline, Shallow- Set Skipjack Tuna Hawaii Western Central Pacific - Longline, Deep-Set Impacts on the Stock Impacts on Other Spp. Management Habitat and Ecosystem Overall Recommendation Red (1.41) Red (1.34) Green (3.87) Green (3.87) Avoid (2.310) Green (5.00) Red (1.34) Green (5.00) Red (1.34) Green (3.87) Green (3.87) Good Alternative (3.168) Green (3.87) Green (3.87) Good Alternative (3.168)
5 Yellowfin Tuna Hawaii Western Central Pacific - Longline, Deep-Set Albacore Tuna Hawaii Western Central Pacific - Longline, Deep-Set Albacore Tuna Hawaii Eastern Central Pacific - Longline, Deep-Set Bigeye Tuna Hawaii Eastern Central Pacific - Longline, Deep-Set Skipjack Tuna Hawaii Eastern Central Pacific - Longline, Deep-Set Yellowfin Tuna Hawaii Eastern Central Pacific - Longline, Deep-Set Swordfish Hawaii Eastern Central Pacific - Longline, Shallow- Set Green (5.00) Red (1.34) Green (3.83) Red (1.34) Green (3.83) Red (1.34) Yellow (2.71) Red (1.34) Green (3.83) Red (1.34) Yellow (2.71) Red (1.34) Green (5.00) Red (1.34) Green (3.87) Green (3.87) Good Alternative (3.168) Green (3.87) Green (3.87) Good Alternative (2.964) Green (3.87) Green (3.87) Good Alternative (2.964) Green (3.87) Green (3.87) Good Alternative (2.718) Green (3.87) Green (3.87) Good Alternative (2.964) Green (3.87) Green (3.87) Good Alternative (2.718) Green (3.87) Green (3.87) Good Alternative (3.168) Scoring Guide Scores range from zero to five where zero indicates very poor performance and five indicates the fishing operations have no significant impact. Final Score = geometric mean of the four Scores (Criterion 1, Criterion 2, Criterion 3, Criterion 4). Best Choice/Green = Final Score >3.2, and no Red Criteria, and no Critical scores Good Alternative/Yellow = Final score >2.2, and neither Harvest Strategy (Factor 3.1) nor Bycatch Management Strategy (Factor 3.2) are Very High, 2 and no more than one Red Criterion, and no Critical scores, and does not meet the criteria for Best Choice (above) Avoid/Red = Final Score <=2.2, or either Harvest Strategy (Factor 3.1) or Bycatch Management Strategy (Factor 3.2) is Very High, 2 or two or more Red Criteria, or one or more Critical scores. 2 Because effective management is an essential component of sustainable fisheries, Seafood Watch issues an Avoid recommendation for any fishery scored as a Very High for either factor under Management (Criterion 3).
6 Table of Contents About Seafood Watch... 2 Guiding Principles... 3 Summary... 4 Introduction... 7 Assessment... 19 Criterion 1: Stock for which you want a recommendation... 19 Criterion 2: Impacts on Other Species... 35 Criterion 3: Management effectiveness... 64 Criterion 4: Impacts on the habitat and ecosystem... 78 Acknowledgements... 82 References... 83 Appendix A... 91
7 Introduction Scope of the analysis and ensuing recommendation This report is on the Hawaii pelagic longline fisheries for swordfish (Xiphias gladius), albacore tuna (Thunnus alalunga), bigeye tuna (Thunnus obesus), skipjack tuna (Katsuwonus pelamis) and yellowfin tuna (Thunnus albacares) in the western and central Pacific Ocean (WCPO) and eastern Pacific Ocean (EPO). Overview of the species and management bodies Swordfish are a widely distributed billfish species, found globally from 50N to 50S and at all longitudes in the Pacific Ocean. Swordfish are assessed as two populations in the North Pacific (Western and Central Pacific, and Eastern Pacific), a single population in the Southwest Pacific, two populations in the Atlantic (South and North), and a single population in both the Indian Ocean and Mediterranean Sea. Albacore tuna are widely distributed in temperate and tropical waters in all oceans. There are six populations of albacore tuna living in various oceans North and South Pacific Ocean, North and South Atlantic Ocean, Indian Ocean and Mediterranean Sea (ISCAWG 2014). Bigeye, skipjack and yellowfin tuna are found in tropical and subtropical waters of the Pacific Ocean (Davies et al. 2014)(Rice et al. 2014)(Davies et al. 2014b). There are four populations of bigeye and yellowfin and five of skipjack populating the western and central Pacific Ocean, eastern Pacific Ocean, Atlantic (eastern and western skipjack) and Indian Ocean. Globally, longlines are the most common method used to capture swordfish, albacore and bigeye tuna, and purse seines are the primary gear used to capture skipjack and yellowfin tuna. Albacore catches have increased since the 1950s, remaining around 400,000 t over the past decade. Bigeye, skipjack and yellowfin tuna catches have all increased substantially over time, peaking in the early 2000s for bigeye and yellowfin tuna and around 2009 for skipjack tuna (ISSF 2013b). The Western Pacific Regional Fishery Management Council manages these species in Hawaiian waters while the Western and Central Pacific Fisheries Commission, of which the United States is a participating member, is in charge of management in western and central Pacific Ocean. The Inter-American Tropical Tuna Commission is in charge in the eastern Pacific Ocean. Production Statistics In Hawaii, the pelagic longline fishery caught 84% of all pelagic species during 2010. Bigeye tuna makes up the majority of the tuna landings in Hawaii (75% in 2010), and swordfish made up 18% of total landings in 2010 (WPRFMC 2013b).
8 Catches of swordfish in the western and central North Pacific Ocean have varied over time, peaking during the late 1950s and again during the early to mid-1990s. Catches in recent years have declined to below 13,000 t (ISCBWG 2014). Longline catches of swordfish in the northern region of the eastern Pacific Ocean (WPO) have varied over time with peaks occurring during the late 1960s and early 2000s (~6,000 t). In 2012, catches were around 3,000 t, and less than in previous years (~2008-2011) (IATTC 2014). In Hawaii, longline landings of swordfish have varied greatly over time, peaking in 1992 and 1993 at 12,566,000 lbs. (5,702 t) and 13,027,000 lbs. (5,910 t) respectively. Average landings by the longline fishery over time (1987-2010) were 4,648,000 lbs. (2,108 t), with landings ranging from 2,573,000 lbs. (1,167 t) to 4,299,000 lbs. (1,950 t) since the longline fishery reopened in 2005(WPRFMC 2013b). Catches of swordfish in the Hawaii shallow-set longline fishery have been somewhat stable since the fishery was reopened in 2005, but have not returned to levels prior to the closure and have remained below the long-term average of 4,648,300 lbs. since 2001 (WPRFMC 2013b). Figure 1: Swordfish landings (MT) in the western and central North Pacific Ocean (1951-2012) (ISC 2014)
9 Figure 2: Annual landings (1000 lbs.) of swordfish in Hawaii between 1987 and 2010 (WCPRFMC 2012) Longline fisheries for albacore tuna in the North Pacific catch less than half of all albacore in the region. The total catches of albacore in the North Pacific have ranged from a low of 37,000 t in 1991 to a high of 125,000 and 126,000 t in 1999 and 1976 respectively (ISCAWG 2014). From 2006-2012, annual catches averaged around 78,000 t (IATTC 2014). In Hawaii, longline landings of albacore tuna peaked during the mid- to late 1990s and early 2000s and have since declined. Peak landings were 3,626,000 lbs. (1,645 t) in 1997 and in 2010 only 916,000 lbs. (415.5 t) were landed (WPRFMC 2013b).
10 Figure 3: Catches of North Pacific albacore by major gear types, 1966-2012. The Other gear category includes catches with purse seine, recreational gear, hand lines, and harpoons (ISCAWG 2014) Figure 4: Annual landings (1000 lbs.) of albacore tuna in Hawaii between 1987 and 2010 (WCPRFMC 2012) Total catches of bigeye tuna in the western and central Pacific Ocean have increased over time, peaking in the mid-2000s at just under 200,000 MT. Longline catches of bigeye tuna in the WCPO ranged from 44,000 to 62,000 t between 1980 and 1993 and, since 2004, have ranged from 67,000 t to 77,000 t (Davies et al. 2014). The majority of bigeye catches occur within equatorial regions of the western and central Pacific Ocean (Williams and Terewasi 2014). Total
11 catches of bigeye tuna in the eastern Pacific Ocean have varied over time, peaking during the early 1990s and reaching the highest level (148,557 t) in 2000. Since the mid-2000s, catches have been around 100,000 t, but declined to around 80,000 t in 2013 (IATTC 2014). The majority of bigeye tuna in the region are caught with surface fishing gear and not longlines. Historically, longlines were the predominate gear used until the mid-1990s (IATTC 2014). In Hawaii, longline landings of bigeye tuna have increased over time from a low of 1,796,000 lbs. (815 t) in 1987 to a high of 12,909,000 lbs. (5,856 t) in 2008 with average landings of 6,448,000 lbs. (2,925 t) between 1987 and 2010 (WPRFMC 2013b). Figure 5: Total annual catch (1000s MT) of bigeye tuna from the WCPO by fishing method from 1952-2012 (Harley et al. 2014)
12 Figure 6: Annual landings (1000 lbs.) of bigeye tuna in Hawaii between 1987 and 2010 (WCPRFMC 2012) Skipjack make up the majority of the tuna in tuna fisheries within the western and central Pacific (WCPO), but only a small portion of Hawaii tuna catches. Catches of skipjack tuna in the WCPO have increased over time, reaching 1.6 million t in 2009, although longline catches represent only a small portion of these catches (Rice et al. 2014). Catches of skipjack tuna in the eastern Pacific Ocean (EPO) are significantly less than those from the western and central Pacific Ocean. However, catches in the EPO have been increasing over time, peaking in 2006 at over 300,000 t. Catches have since declined to slightly under 300,000 t. The majority of these catches come from the purse seine fisheries (IATTC 2014). Longline landings of skipjack tuna in Hawaii are much lower than for other tuna species, averaging only 178,000 lbs. (80 t) (between 1987 and 2010), although they have increased over time. For example, in 1987 only 3,000 lbs. (1 t) of skipjack tuna were landed in the Hawaiian longline fishery, but 330,000 lbs. (150 t) were landed in 2010 (WPRFMC 2013b).
13 Figure 7: Skipjack catches, 1972-2012, in the WCPO by fishing gear (Rice et al. 2014) Figure 8: Annual landings (1000 lbs.) of skipjack tuna in Hawaii between 1987 and 2010 (WCPRFMC 2012)
14 Total catches of yellowfin tuna in the WCPO have increased over time from a low of less than 50,000 t during the mid-1950s to over 600,000 t in 2008 and 2012. Annual catches of yellowfin tuna by longliners in the WCPO have been around 70,000 to 80,000 t since the mid-1980s (Davies et al. 2014b). Yellowfin tuna catches in the eastern Pacific Ocean peaked in 2002 at 443,458 t and have since decreased to just over 200,000 t in 2013. Over the years, catches have been variable. Longline catches have remained under 40,000 t since the 1970s and have been below 10,000 t since 2010. Peak longline catches occurred during the early and mid- 1990s and the early 2000s (IATTC 2014). Hawaii longline landings of yellowfin tuna have varied to some degree over time, averaging 1,675,000 lbs. (760 t) between 1987 and 2010. For example, longline landings ranged from a low of 575,000 lbs. (261 t) in 1987 to a high of 2,656,000 lbs. (1,205 t) in 2000. During 2010, 1,254,000 lbs. (569 t) were landed (WPRFMC 2013b). Figure 9: Annual landings (1000 lbs.) of yellowfin tuna in Hawaii between 1987 and 2010 {WCPRFMC 2012}
15 Figure 10: Annual catches (1000 t) of yellowfin tuna in the WCPO from 1952-2012 by fishing gear {Davies et al. 2014} Importance to the US/North American market During 2013, the United States imported the most (39%) albacore tuna from Thailand. Other countries the United States imports large amounts of albacore from include Vietnam (20%) and Indonesia (16%) (NMFS 2014).
16 Figure 11: Major contributors to US albacore tuna imports (%) all countries and region (country of origin) (NMFS 2014) The United States imported around 19% of bigeye tuna from Ecuador, 16% from the Marshall Islands and 14% from Sri Lanka during 2013 (NMFS 2014). Figure 12: Major contributors to US bigeye tuna imports (%) all countries and regions (country of origin) (NMFS 2014)
17 The United States imported over half of all skipjack tuna from Panama (55%) during 2013. Other important countries included the Philippines (15%) and Mexico (13%). Figure 13: Major contributors to US skipjack tuna imports (%) all countries and regions (country of origin) (NMFS 2014) The majority of yellowfin tuna were imported from Trinidad and Tobago in 2013 (49%). Smaller amounts were imported from the Philippines (7%), Vietnam (6%) and Indonesia (5%) (NMFS 2014). Figure 14: Major contributors to US yellowfin tuna imports (%) all countries and regions (country of origin) (NMFS 2014)
18 During 2013, swordfish imports into the United States were primarily from Ecuador (23%), Canada (14%) and Costa Rica and Singapore (11%). Figure 15: Major contributors to US swordfish imports (%) all countries (country of origin) (NMFS 2014) Albacore tuna was the most commonly exported tuna species by the United States in 2011 and 2012 (10,205 t in and 11,023 t respectively). Around 200 t of bigeye and skipjack and 300 t of yellowfin were exported in 2011. Exports of bigeye tuna and yellowfin tuna were higher in 2012 (679 t and 843 t respectively). Skipjack tuna exports during 2012 were 339 t. Swordfish exports in 2011 and 2012 were fairly low too, 206 t and 152 t respectively (NMFS 2014). Common and market names Swordfish are also known broadbilled swordfish, broadbill, espada and emperado. Albacore tuna is also known as germon, longfinned tuna, albecore and T. germo. Skipjack tuna are also known as ocean bonito and lesser tuna. In Hawaii, albacore tuna is known as tombo ahi, bigeye and yellowfin tuna are known as ahi, skipjack as aku and swordfish as mekajiki. Primary product forms In Hawaii, swordfish, albacore, bigeye, skipjack and yellowfin tuna are typically landed and sold fresh for both cooking and for sushi and sashimi.
19 Assessment This section assesses the sustainability of the fishery(s) relative to the Seafood Watch Criteria for Fisheries, available at http://www.seafoodwatch.org. Criterion 1: Stock for which you want a recommendation This criterion evaluates the impact of fishing mortality on the species, given its current abundance. The inherent vulnerability to fishing rating influences how abundance is scored, when abundance is unknown. The final Criterion 1 score is determined by taking the geometric mean of the abundance and fishing mortality scores. The Criterion 1 rating is determined as follows: Score >3.2=Green or Low Score >2.2 and <=3.2=Yellow or Moderate Score <=2.2=Red or High Rating is Critical if Factor 1.3 (Fishing Mortality) is Critical. Criterion 1 Summary ALBACORE TUNA Region / Method Hawaii Eastern Central Pacific Longline, Deep-Set Hawaii Western Central Pacific Longline, Deep-Set Inherent Abundance Vulnerability 2.00:Medium 4.00:Low 2.00:Medium 4.00:Low Fishing Mortality 3.67:Low 3.67:Low Subscore Green (3.831) Green (3.831) BIGEYE TUNA Region / Method Hawaii Eastern Central Pacific Longline, Deep-Set Hawaii Western Central Pacific Longline, Deep-Set Inherent Abundance Vulnerability 2.00:Medium 2.00:High 2.00:Medium 2.00:High Fishing Mortality 3.67:Low 1.00:High Subscore Yellow (2.709) Red (1.414) SKIPJACK TUNA Region / Method Hawaii Eastern Central Pacific Longline, Deep-Set Hawaii Western Central Pacific Longline, Deep-Set Inherent Vulnerability Abundance Fishing Mortality Subscore 2.00:Medium 4.00:Low 3.67:Low Green (3.831) 2.00:Medium 5.00:Very Low 5.00:Very Low Green (5.000)
20 SWORDFISH Region / Method Hawaii Eastern Central Pacific Longline, Shallow-Set Hawaii Western Central Pacific Longline, Shallow-Set Inherent Vulnerability Abundance Fishing Mortality Subscore 2.00:Medium 5.00:Very Low 5.00:Very Low Green (5.000) 2.00:Medium 5.00:Very Low 5.00:Very Low Green (5.000) YELLOWFIN TUNA Region / Method Hawaii Eastern Central Pacific Longline, Deep-Set Hawaii Western Central Pacific Longline, Deep-Set Inherent Vulnerability Abundance Fishing Mortality 2.00:Medium 2.00:High 3.67:Low 2.00:Medium 5.00:Very Low 5.00:Very Low Subscore Yellow (2.709) Green (5.000) Abundance levels of albacore skipjack and swordfish are high and fishing mortality rates are sustainable. However, bigeye tuna are approaching an overfished state and are undergoing overfishing in the western and central Pacific, but are not undergoing overfishing in the EPO. Yellowfin tuna are healthy in the western and central Pacific Ocean but are overfished in the EPO. Criterion 1 Assessment ALBACORE TUNA Factor 1.1 - Inherent Vulnerability Scoring Guidelines Low The FishBase vulnerability score for species is 0-35, OR species exhibits life history characteristics that make it resilient to fishing, (e.g., early maturing). Medium The FishBase vulnerability score for species is 36-55, OR species exhibits life history characteristics that make it neither particularly vulnerable nor resilient to fishing, (e.g., moderate age at sexual maturity (5-15 years), moderate maximum age (10-25 years), moderate maximum size, and middle of food chain). High The FishBase vulnerability score for species is 56-100, OR species exhibits life history characteristics that make is particularly vulnerable to fishing, (e.g., long-lived (>25 years), late maturing (>15 years), low reproduction rate, large body size, and top predator).
21 Note: The FishBase vulnerability scores is an index of the inherent vulnerability of marine fishes to fishing based on life history parameters: maximum length, age at first maturity, longevity, growth rate, natural mortality rate, fecundity, spatial behaviors (e.g., schooling, aggregating for breeding, or consistently returning to the same sites for feeding or reproduction) and geographic range. Medium FishBase assigned a high vulnerability score of 58 out of 100 (Froese and Pauly 2013). However, the life history characteristics of albacore suggest only a medium vulnerability to fishing. For example, albacore reach sexual maturity between 5 and 6 years of age and reach a maximum age of 15 years (ISCAWG 2011). They are broadcast spawners and top predators (Froese and Pauly 2013). Based on these life history characteristics we have awarded a score of medium. Medium FishBase assigned a high vulnerability score of 58 out of 100 (Froese and Pauly 2013). However, the life history characteristics of albacore suggest only a medium vulnerability to fishing. For example, albacore reach sexual maturity between 5 and 6 years of age and reach a maximum age of 15 years (ISCAWG 2011). They are broadcast spawners, and top predators (Froese and Pauly 2013). Based on these life history characteristics we have awarded a score of medium. Factor 1.2 - Abundance Scoring Guidelines 5 (Very Low ) Strong evidence exists that the population is above target abundance level (e.g., biomass at maximum sustainable yield, BMSY) or near virgin biomass. 4 (Low ) Population may be below target abundance level, but it is considered not overfished. 3 (Moderate ) Abundance level is unknown and the species has a low or medium inherent vulnerability to fishing. 2 (High ) Population is overfished, depleted, or a species of concern, OR abundance is unknown and the species has a high inherent vulnerability to fishing. 1 (Very High ) Population is listed as threatened or endangered.
22 Low The most recent stock assessment for albacore tuna in the north Pacific Ocean was conducted in 2014. According to this assessment, the spawning stock biomass (SSB) in 2012 (last year of data included in the model) was 110,101 t, with stock depletion estimated to be 35.8% of the unfished SSB. No biomass-based reference points are in place, but the assessment concluded that there was little indication that the SSB was below any candidate biomass-based reference points. We have therefore awarded a score of low concern and not very low concern because it is likely that albacore tuna in the North Pacific are not overfished, and because no reference points are currently accepted (ISCAWG 2014). Factor 1.3 - Fishing Mortality Scoring Guidelines 5 (Very Low ) Highly likely that fishing mortality is below a sustainable level (e.g., below fishing mortality at maximum sustainable yield, FMSY), OR fishery does not target species and its contribution to the mortality of species is negligible ( 5% of a sustainable level of fishing mortality). 3.67 (Low ) Probable (>50%) chance that fishing mortality is at or below a sustainable level, but some uncertainty exists, OR fishery does not target species and does not adversely affect species, but its contribution to mortality is not negligible, OR fishing mortality is unknown, but the population is healthy and the species has a low susceptibility to the fishery (low chance of being caught). 2.33 (Moderate ) Fishing mortality is fluctuating around sustainable levels, OR fishing mortality is unknown and species has a moderate-high susceptibility to the fishery and, if species is depleted, reasonable management is in place. 1 (High ) Overfishing is occurring, but management is in place to curtail overfishing, OR fishing mortality is unknown, species is depleted, and no management is in place. 0 (Critical) Overfishing is known to be occurring and no reasonable management is in place to curtail overfishing.
23 Low The current fishing mortality rate (F2010-2012) for albacore tuna in the north Pacific Ocean is around 72% of the interim reference point (FSSB-ATHL50%= the fishing mortality rate that would lead to future minimum SSB falling below the SSB-ATHL threshold level at least once during a 25 year projection period). In addition, the current fishing mortality rates (F2010-2012) is below other F-based reference points (FMSY F0.1 and F10-40% (fishing mortality that gives 10% 50% reduction in the spawning potential ratio)) except FMED and F50%. Albacore tuna in the north Pacific Ocean are therefore not currently undergoing overfishing; however, increases in fishing mortality rates will significantly reduce the spawning biomass (ISCAWG 2014). We have awarded a score of low concern and not very low concern. BIGEYE TUNA Factor 1.1 - Inherent Vulnerability Scoring Guidelines Low The FishBase vulnerability score for species is 0-35, OR species exhibits life history characteristics that make it resilient to fishing, (e.g., early maturing). Medium The FishBase vulnerability score for species is 36-55, OR species exhibits life history characteristics that make it neither particularly vulnerable nor resilient to fishing, (e.g., moderate age at sexual maturity (5-15 years), moderate maximum age (10-25 years), moderate maximum size, and middle of food chain). High The FishBase vulnerability score for species is 56-100, OR species exhibits life history characteristics that make is particularly vulnerable to fishing, (e.g., long-lived (>25 years), late maturing (>15 years), low reproduction rate, large body size, and top predator). Note: The FishBase vulnerability scores is an index of the inherent vulnerability of marine fishes to fishing based on life history parameters: maximum length, age at first maturity, longevity, growth rate, natural mortality rate, fecundity, spatial behaviors (e.g., schooling, aggregating for breeding, or consistently returning to the same sites for feeding or reproduction) and geographic range. Medium FishBase assigned a high to very high vulnerability of 72 out of 100 (Froese and Pauly 2013). However, bigeye tuna's life history characteristics suggest a medium vulnerability to fishing. For example, bigeye tuna reach sexual maturity around 100-125 cm, reach a maximum size of 200 cm and live around 11 years (Davies et al. 2014)(Froese et al. 2013). They are broadcast spawners and top predators (Froese
24 and Pauly 2013). Based on the Seafood Watch productivity analysis table, these life history characteristics suggest a medium level of vulnerability. We acknowledge that other methods may suggest a different vulnerability rating. However, because the stock status of bigeye tuna is known, this inherent vulnerability score will not affect the overall outcome. We have therefore awarded a score of medium vulnerability based on the productivity table analysis. Medium FishBase assigned a high to very high vulnerability of 72 out of 100 (Froese and Pauly 2013). However, bigeye tuna's life history characteristics suggest a medium vulnerability to fishing. For example, bigeye tuna reach sexual maturity around 100-125 cm, reach a maximum size of 200 cm and live around 11 years (Davies et al. 2014)(Froese et al. 2013). They are broadcast spawners and top predators (Froese and Pauly 2013). Based on these life history characteristics, we have awarded a score of medium. Factor 1.2 - Abundance Scoring Guidelines 5 (Very Low ) Strong evidence exists that the population is above target abundance level (e.g., biomass at maximum sustainable yield, BMSY) or near virgin biomass. 4 (Low ) Population may be below target abundance level, but it is considered not overfished. 3 (Moderate ) Abundance level is unknown and the species has a low or medium inherent vulnerability to fishing. 2 (High ) Population is overfished, depleted, or a species of concern, OR abundance is unknown and the species has a high inherent vulnerability to fishing. 1 (Very High ) Population is listed as threatened or endangered. High Bigeye tuna in the WCPO were last assessed in 2014. According to the base case model, the ratio of the current (2008-2011) spawning biomass to that needed to produce the maximum sustainable yield (SB current /SB MSY) was 0.94 and the ratio of the latest (2012) spawning biomass (mature fish) to that needed to produce the maximum sustainable yield (SB latest /SB MSY) was 0.77, indicating that the population is overfished (Harley et al. 2014). We have therefore awarded a score of high concern.
25 Hawaii Eastern Central Pacific, Longline, Deep-S High According to the last assessment of bigeye tuna in the eastern Pacific Ocean (2014), the spawning biomass (amount of fish capable of reproducing) had decreased to a record low level of 19% of an its unfished abundance level at the beginning of 2014. The spawning biomass (SB) was 5% below the level needed to produce the maximum sustainable yield (SBMSY) and so the population is slightly overfished, which is a change from the previous assessment results. We have therefore awarded a score of high concern (IATTC 2014b). Factor 1.3 - Fishing Mortality Scoring Guidelines 5 (Very Low ) Highly likely that fishing mortality is below a sustainable level (e.g., below fishing mortality at maximum sustainable yield, FMSY), OR fishery does not target species and its contribution to the mortality of species is negligible ( 5% of a sustainable level of fishing mortality). 3.67 (Low ) Probable (>50%) chance that fishing mortality is at or below a sustainable level, but some uncertainty exists, OR fishery does not target species and does not adversely affect species, but its contribution to mortality is not negligible, OR fishing mortality is unknown, but the population is healthy and the species has a low susceptibility to the fishery (low chance of being caught). 2.33 (Moderate ) Fishing mortality is fluctuating around sustainable levels, OR fishing mortality is unknown and species has a moderate-high susceptibility to the fishery and, if species is depleted, reasonable management is in place. 1 (High ) Overfishing is occurring, but management is in place to curtail overfishing, OR fishing mortality is unknown, species is depleted, and no management is in place. 0 (Critical) Overfishing is known to be occurring and no reasonable management is in place to curtail overfishing. High The ratio of current fishing mortality rates to those that produce the maximum sustainable yield (Fcurrent/FMSY) for all model runs were much higher than 1, with the ratio from all runs estimated at 1.57, indicating overfishing is occurring. Based on this estimate, fishing mortality needs to be reduced by more than 30% from 2008-2011 levels to become sustainable. This assessment did note that the impact of fishing on bigeye tuna varies by area and that areas with the largest impacts (equatorial regions) are
26 far from the areas predominately fished by the Hawaii fleet (Harley et al. 2014). However, we have awarded a score of high concern based on the assessment stating that overfishing is occurring and has been for some time. Low Current fishing mortality rates (F) are slightly below levels that would produce the maximum sustainable yield (FMSY), and therefore overfishing is not occurring. However, these estimates are highly uncertain due to assumptions made while conducting the last assessment (IATTC 2014). We have therefore awarded a score of low concern. SKIPJACK TUNA Factor 1.1 - Inherent Vulnerability Scoring Guidelines Low The FishBase vulnerability score for species is 0-35, OR species exhibits life history characteristics that make it resilient to fishing, (e.g., early maturing). Medium The FishBase vulnerability score for species is 36-55, OR species exhibits life history characteristics that make it neither particularly vulnerable nor resilient to fishing, (e.g., moderate age at sexual maturity (5-15 years), moderate maximum age (10-25 years), moderate maximum size, and middle of food chain). High The FishBase vulnerability score for species is 56-100, OR species exhibits life history characteristics that make is particularly vulnerable to fishing, (e.g., long-lived (>25 years), late maturing (>15 years), low reproduction rate, large body size, and top predator). Note: The FishBase vulnerability scores is an index of the inherent vulnerability of marine fishes to fishing based on life history parameters: maximum length, age at first maturity, longevity, growth rate, natural mortality rate, fecundity, spatial behaviors (e.g., schooling, aggregating for breeding, or consistently returning to the same sites for feeding or reproduction) and geographic range. Medium
27 FishBase assigned a moderate vulnerability of 39 out of 100 for skipjack (Froese and Pauly 2013). Their life history characteristics support this score. Sexual maturity is reached around 45 cm or 2 years of age and they can reach a maximum size of 110 cm and age of 12 years. They are broadcast spawners and have a high trophic level (Froese and Pauly 2013). Factor 1.2 - Abundance Scoring Guidelines 5 (Very Low ) Strong evidence exists that the population is above target abundance level (e.g., biomass at maximum sustainable yield, BMSY) or near virgin biomass. 4 (Low ) Population may be below target abundance level, but it is considered not overfished. 3 (Moderate ) Abundance level is unknown and the species has a low or medium inherent vulnerability to fishing. 2 (High ) Population is overfished, depleted, or a species of concern, OR abundance is unknown and the species has a high inherent vulnerability to fishing. 1 (Very High ) Population is listed as threatened or endangered. Very Low Skipjack tuna in the western and central Pacific Ocean were last assessed in 2014. According to the assessment, the total biomass has been higher than the reference point (B MSY - the biomass needed to produce the maximum sustainable yield) over the entire time period (1972-2010). The current total biomass is around 52% of virgin levels (B 0 ) and the ratio of the current spawning biomass to that needed to produce the maximum sustainable yield is well above 1 (SBcurrent/SBMSY = 1.94) (Rice et al. 2014). Therefore, skipjack tuna is not overfished and is above target levels. We have, therefore, awarded a score of very low concern. Low Due to the complexity associated with skipjack tuna stock assessments, the latest assessment used indicators, instead of the typical reference points based on the maximum sustainable yield, to determine the biomass. According to these indicators, biomass appears to have been increasing over the past 20 years and has been at high levels since 2003. There does not appear to be any indication the population is overfished, and so we have awarded a score of low concern (IATTC 2014). We did not
28 award a score of very low concern due to the lack of reference points. Factor 1.3 - Fishing Mortality Scoring Guidelines 5 (Very Low ) Highly likely that fishing mortality is below a sustainable level (e.g., below fishing mortality at maximum sustainable yield, FMSY), OR fishery does not target species and its contribution to the mortality of species is negligible ( 5% of a sustainable level of fishing mortality). 3.67 (Low ) Probable (>50%) chance that fishing mortality is at or below a sustainable level, but some uncertainty exists, OR fishery does not target species and does not adversely affect species, but its contribution to mortality is not negligible, OR fishing mortality is unknown, but the population is healthy and the species has a low susceptibility to the fishery (low chance of being caught). 2.33 (Moderate ) Fishing mortality is fluctuating around sustainable levels, OR fishing mortality is unknown and species has a moderate-high susceptibility to the fishery and, if species is depleted, reasonable management is in place. 1 (High ) Overfishing is occurring, but management is in place to curtail overfishing, OR fishing mortality is unknown, species is depleted, and no management is in place. 0 (Critical) Overfishing is known to be occurring and no reasonable management is in place to curtail overfishing. Very Low The current level of exploitation of skipjack tuna is below that needed to provide the maximum sustainable yield (MSY). Although fishing mortality rates have been increasing over time, the current fishing mortality rate is below that needed to produce MSY (F current /F MSY =0.62) (Rice et al. 2014). Therefore, overfishing of skipjack tuna is not occurring and we have awarded a score of very low concern. Low Fishing mortality rates have been increasing for skipjack tuna since the early 1990s, although decreases were seen in both 2009 and 2010. Increasing fishing mortality rates are a concern for skipjack tuna but
29 they appear to have leveled off in recent years. The indicators used to determine the status of skipjack tuna in the eastern Pacific Ocean have not indicated any negative effects to the population from increased fishing (IATTC 2014). We have therefore awarded a score of low concern. SWORDFISH Factor 1.1 - Inherent Vulnerability Scoring Guidelines Low The FishBase vulnerability score for species is 0-35, OR species exhibits life history characteristics that make it resilient to fishing, (e.g., early maturing). Medium The FishBase vulnerability score for species is 36-55, OR species exhibits life history characteristics that make it neither particularly vulnerable nor resilient to fishing, (e.g., moderate age at sexual maturity (5-15 years), moderate maximum age (10-25 years), moderate maximum size, and middle of food chain). High The FishBase vulnerability score for species is 56-100, OR species exhibits life history characteristics that make is particularly vulnerable to fishing, (e.g., long-lived (>25 years), late maturing (>15 years), low reproduction rate, large body size, and top predator). Note: The FishBase vulnerability scores is an index of the inherent vulnerability of marine fishes to fishing based on life history parameters: maximum length, age at first maturity, longevity, growth rate, natural mortality rate, fecundity, spatial behaviors (e.g., schooling, aggregating for breeding, or consistently returning to the same sites for feeding or reproduction) and geographic range. Hawaii Eastern Central Pacific, Longline, Shallow-Set Hawaii Western Central Pacific, Longline, Shallow-Set Medium FishBase assigned a high to very high vulnerability of 72 out of 100 (Froese and Pauly 2013). However, the life history characteristics of swordfish indicate a lower vulnerability to fishing. For example, swordfish reach sexual maturity is around 180 cm in size and around 5 years of age and they reach a maximum length of 455 cm and live more than 10 years. Also, swordfish are broadcast spawners and are top predators (Froese and Pauly 2013). This is more indicative of a moderate vulnerability to fishing. Factor 1.2 - Abundance Scoring Guidelines
30 5 (Very Low ) Strong evidence exists that the population is above target abundance level (e.g., biomass at maximum sustainable yield, BMSY) or near virgin biomass. 4 (Low ) Population may be below target abundance level, but it is considered not overfished. 3 (Moderate ) Abundance level is unknown and the species has a low or medium inherent vulnerability to fishing. 2 (High ) Population is overfished, depleted, or a species of concern, OR abundance is unknown and the species has a high inherent vulnerability to fishing. 1 (Very High ) Population is listed as threatened or endangered. Hawaii Western Central Pacific, Longline, Shallow-Set Very Low In 20014, an assessment for swordfish in the North Pacific was conducted. This assessment considered two populations; one in the western and central Pacific (WCPO) and one in the eastern Pacific Ocean. According to this model, the exploitable biomass for the population in the WCPO region fluctuated at or above the level needed to produce the maximum sustainable yield (BMSY) for most of the time series (1951-2012) and there is a low probability (14%) of the biomass being below BMSY in 2012 (ISCBWG 2014). We have therefore awarded a score of very low concern. Hawaii Eastern Central Pacific, Longline, Shallow-Set Very Low An assessment conducted on North Pacific swordfish (north of 100N and west of 1400W) indicates that the population is stable and biomass is over 50% above unexploited levels (IATTC 2014). Therefore, swordfish in this region are not overfished and we have awarded a score of very low concern. Factor 1.3 - Fishing Mortality Scoring Guidelines 5 (Very Low ) Highly likely that fishing mortality is below a sustainable level (e.g., below fishing mortality at maximum sustainable yield, FMSY), OR fishery does not target species and its contribution to the mortality of species is negligible ( 5% of a sustainable level of fishing mortality). 3.67 (Low ) Probable (>50%) chance that fishing mortality is at or below a sustainable level, but some uncertainty exists, OR fishery does not target species and does not adversely affect species, but its contribution to mortality is not negligible, OR fishing
31 mortality is unknown, but the population is healthy and the species has a low susceptibility to the fishery (low chance of being caught). 2.33 (Moderate ) Fishing mortality is fluctuating around sustainable levels, OR fishing mortality is unknown and species has a moderate-high susceptibility to the fishery and, if species is depleted, reasonable management is in place. 1 (High ) Overfishing is occurring, but management is in place to curtail overfishing, OR fishing mortality is unknown, species is depleted, and no management is in place. 0 (Critical) Overfishing is known to be occurring and no reasonable management is in place to curtail overfishing. Hawaii Western Central Pacific, Longline, Shallow-Set Very Low In 2014, an assessment was conducted for swordfish in the North Pacific. Exploitation rates in this region peaked in 1960s and have declined since. The current fishing mortality rate (H 2010-2012 ) is 15%, which is lower than the level necessary to produce the maximum sustainable yield (H MSY =25%). It is very unlikely (<1%) that fishing mortality rates (H) are unsustainable and, therefore, overfishing is not occurring (ISC 2014). We have therefore awarded a score of very low concern. Hawaii Eastern Central Pacific, Longline, Shallow-Set Very Low A recent assessment of swordfish in the North Pacific region indicated that current fishing mortality levels are sustainable and unlikely to reduce the spawning biomass to unsustainable levels (IATTC 2014). We have therefore awarded a score of very low concern. YELLOWFIN TUNA Factor 1.1 - Inherent Vulnerability Scoring Guidelines Low The FishBase vulnerability score for species is 0-35, OR species exhibits life history characteristics that make it resilient to fishing, (e.g., early maturing). Medium The FishBase vulnerability score for species is 36-55, OR species exhibits life history characteristics that make it neither particularly vulnerable nor resilient to fishing, (e.g., moderate age at sexual maturity (5-15 years), moderate maximum age (10-25 years), moderate maximum size, and middle of food chain).
32 High The FishBase vulnerability score for species is 56-100, OR species exhibits life history characteristics that make is particularly vulnerable to fishing, (e.g., long-lived (>25 years), late maturing (>15 years), low reproduction rate, large body size, and top predator). Note: The FishBase vulnerability scores is an index of the inherent vulnerability of marine fishes to fishing based on life history parameters: maximum length, age at first maturity, longevity, growth rate, natural mortality rate, fecundity, spatial behaviors (e.g., schooling, aggregating for breeding, or consistently returning to the same sites for feeding or reproduction) and geographic range. Medium FishBase assigned a moderate to high vulnerability of 46 out of 100 (Frose and Pauly 2013). Their life history characteristics support a moderate vulnerability score. Yellowfin tuna reach sexual maturity by 100 cm in length, although growth rates vary by location, usually between 2-3 years of age. They can attain a maximum size of 180 cm and live to at least four years of age and perhaps as much as nine years. They are broadcast spawners and important predators in the ecosystem (Davies et al. 2014b)(Froesy and Pauly 2013). Factor 1.2 - Abundance Scoring Guidelines 5 (Very Low ) Strong evidence exists that the population is above target abundance level (e.g., biomass at maximum sustainable yield, BMSY) or near virgin biomass. 4 (Low ) Population may be below target abundance level, but it is considered not overfished. 3 (Moderate ) Abundance level is unknown and the species has a low or medium inherent vulnerability to fishing. 2 (High ) Population is overfished, depleted, or a species of concern, OR abundance is unknown and the species has a high inherent vulnerability to fishing. 1 (Very High ) Population is listed as threatened or endangered. Very Low The biomass-based reference points for the reference model used in the 2014 assessment (SBcurrent/SB MSY - the ratio of the current (2008-2011) spawning (mature fish) biomass to that needed
33 to produce the maximum sustainable yield) was 1.37. The ratio of the latest (2012) spawning biomass to the level needed to produce the maximum sustainable yield (SBcurrent/SB MSY ) was 1.24. Therefore, yellowfin tuna are above target biomass and not overfished (Davies et al. 2014b). We have therefore awarded a score of very low concern. High According to the 2014 assessment, the spawning biomass ratio was 0.26 (ratio of the spawning biomass to the unfished population) (SBP) at the start of 2014, which is below the maximum sustainable yield (MSY) of 0.27, indicating the population is overfished. The current spawning biomass to the biomass that produces maximum sustainable yield ratio (S/SMSY) is 0.98. The results are complicated due to the uncertainty surrounding the productivity of yellowfin tuna, recruitment levels, and maximum sustainable yield levels, which may have changed over time (IATTC 2014). We have awarded a score of high concern because yellowfin tuna are overfished. Factor 1.3 - Fishing Mortality Scoring Guidelines 5 (Very Low ) Highly likely that fishing mortality is below a sustainable level (e.g., below fishing mortality at maximum sustainable yield, FMSY), OR fishery does not target species and its contribution to the mortality of species is negligible ( 5% of a sustainable level of fishing mortality). 3.67 (Low ) Probable (>50%) chance that fishing mortality is at or below a sustainable level, but some uncertainty exists, OR fishery does not target species and does not adversely affect species, but its contribution to mortality is not negligible, OR fishing mortality is unknown, but the population is healthy and the species has a low susceptibility to the fishery (low chance of being caught). 2.33 (Moderate ) Fishing mortality is fluctuating around sustainable levels, OR fishing mortality is unknown and species has a moderate-high susceptibility to the fishery and, if species is depleted, reasonable management is in place. 1 (High ) Overfishing is occurring, but management is in place to curtail overfishing, OR fishing mortality is unknown, species is depleted, and no management is in place. 0 (Critical) Overfishing is known to be occurring and no reasonable management is in place to curtail overfishing.