Albacore tuna, Bigeye tuna, Pacific Bluefin tuna, Southern Bluefin tuna, Swordfish, Yellowfin tuna

Transcription

1 Albacore tuna, Bigeye tuna, Pacific Bluefin tuna, Southern Bluefin tuna, Swordfish, Yellowfin tuna Thunnus alalunga, Thunnus obesus, Thunnus orientalis, Thunnus maccoyii, Xiphias gladius and Thunnus albacares Monterey Bay Aquarium North, South, and Western and Central Pacific Drifting longline March 12, 2015 (updated January 8, 2018) Seafood Watch 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. Seafood Watch Standard used in this assessment: Standard for Fisheries vf2

2 Table of Contents About Seafood Watch Guiding Principles Summary Final Seafood Recommendations Introduction Assessment Criterion 1: Impacts on the species under assessment Criterion 2: Impacts on other species Criterion 3: Management Effectiveness Criterion 4: Impacts on the habitat and ecosystem Acknowledgements References Appendix A: Extra By Catch Species Appendix B: Updated January 8,

3 About Seafood Watch Monterey Bay Aquarium s Seafood Watch program evaluates the ecological sustainability of wild-caught 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 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

4 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

5 Summary Albacore, bigeye, Pacific bluefin, southern bluefin and yellowfin tuna and swordfish are caught by a variety of gears in the Western and Central Pacific Ocean (WCPO), including the North and South Pacific regions. This report focuses on the longline fisheries within the WCPO region that target these six species. There are several broadly defined categories of longline fisheries. These include: 1. South Pacific albacore fishery, which is made up of domestic vessels from Pacific Island countries that operate in subtropical waters targeting albacore and distant water vessels from Chinese-Taipei, China and Vanuatu, that fish south of 20 degrees S and supply albacore to canneries. 2. South Pacific distant water swordfish fishery, which is mostly made up of vessels from Spain. 3. Tropical offshore and distant water bigeye and yellowfin tuna targeted fisheries. The offshore fishery includes vessels from Chinese-Taipei and China that are based in the Pacific Island countries and the distant water fleet is made up of Japanese, Korean, Chinese-Taipei, China and Vanuatu vessels. The offshore fishery supplies tuna to the sashimi market and the distant water to the frozen sashimi market. 4. North Pacific distant water albacore and swordfish fisheries, made up of vessels from Japan, Chinese-Taipei and Vanuatu. Pacific bluefin tuna are targeted by Japanese and Chinese-Taipei longliners and southern bluefin tuna are caught in longline fisheries operating in the South Pacific Ocean. In addition to these fisheries, there are a number of domestic tuna fisheries operating in the sub-tropical and temperate areas of the WCPO (SPC 2014). We have included in this report the North and South Pacific fisheries targeting albacore and swordfish, the North Pacific fishery for Pacific bluefin tuna and the south Pacific fishery for southern bluefin tuna. In addition, the tropical tuna fishery, which targets yellowfin and bigeye tuna is included in this report. Populations of swordfish, albacore, and yellowfin tuna are healthy and fishing mortality rates are currently sustainable, although swordfish in the South Pacific may be undergoing overfishing. Bigeye tuna populations have increased in recent years and they are no longer considered overfished. However, populations of Pacific bluefin tuna in the North Pacific ocean have been greatly reduced, as much as 96% over time and fishing mortality rates are currently too high. The Western and Central Pacific Fisheries Commission (WCPFC) manages bigeye, and yellowfin tuna in the WCPO and albacore tuna in the South Pacific, while the WCPFC and Inter-American Tropical Tuna Commission manage swordfish, albacore and Pacific bluefin tuna throughout the North Pacific Ocean. Both organizations have provided few management measures specific to these species and have been only moderately effective in enforcing them. Management of bluefin tuna has not been effective to date at maintaining population abundance. Pelagic longline gears typically have little to no contact with bottom habitats but do interact with ecologically important species, which could cause negative effects to the ecosystem. 5

6 Final Seafood Recommendations SPECIES/FISHERY CRITERION 1: IMPACTS ON THE SPECIES CRITERION 2: IMPACTS ON OTHER SPECIES CRITERION 3: MANAGEMENT EFFECTIVENESS CRITERION 4: HABITAT AND ECOSYSTEM OVERALL RECOMMENDATION Albacore South Pacific, Drifting longline Southern bluefin tuna South Pacific, Drifting longline Bigeye tuna Western and Central Pacific, Drifting longline Yellow fin tuna Western and Central Pacific, Drifting longline Pacific bluefin tuna North Pacific, Drifting longline Sw ordfish North Pacific, Drifting longline Albacore North Pacific, Drifting longline Sw ordfish South Pacific, Drifting longline Green (4.47) Red (1.00) Red (1.00) Green (3.87) Avoid (2.04) Red (1.92) Red (1.00) Red (1.00) Green (3.87) Avoid (1.65) Green (3.83) Red (1.00) Red (1.73) Green (3.87) Avoid (2.25) Green (5.00) Red (1.00) Red (1.73) Green (3.87) Avoid (2.41) Red (1.41) Red (0.95) Red (1.00) Green (3.87) Avoid (1.51) Green (5.00) Red (0.95) Red (1.00) Green (3.87) Avoid (2.07) Green (3.83) Red (0.95) Red (1.00) Green (3.87) Avoid (1.94) Yellow (3.05) Red (1.00) Red (1.00) Green (3.87) Avoid (1.85) Summary The overall recommendation for longline caught albacore, bigeye, yellowfin and Pacific bluefin tuna along with swordfish caught in the western and central, north and south Pacific Ocean is 'Avoid'. This is due to a combination of factors including the current status of Pacific bluefin tuna, bycatch associated with these fisheries and a lack of well focuses management plans. 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). 6

7 Best Choice/Green = Final Score >3.2, and no Red Criteria, and no Critical scores Good Alternative/Yellow = Final score > , 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 Avoid/Red = Final Score 2.2, or either Harvest Strategy (Factor 3.1) or Bycatch Management Strategy (Factor 3.2) is Very High 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). 7

8 Introduction Scope of the analysis and ensuing recommendation This report is on the tropical tuna pelagic longline fisheries for Western and Central Pacific populations of bigeye tuna (Thunnus obesus) and and yellowfin tuna (Thunnus albacares), the northern and southern Pacific longline fisheries for swordfish (Xiphias gladius) and albacore tuna (Thunnus alalunga), the north Pacific longline fishery for Pacific bluefin (Thunnus orientalis) and the south Pacific longline fishery for southern bluefin (Thunnus maccoyii) tunas. Species Overview 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 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 ocean. There are six managed populations of albacore tuna, North and South Pacific Ocean, North and South Atlantic Ocean, Indian Ocean and Mediterranean Sea (ISCAWG 2014). Bigeye, 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 tuna: Western and Central Pacific Ocean, Eastern Pacific Ocean, Atlantic and Indian Ocean. Pacific bluefin tuna are a single stock found throughout the North Pacific Ocean. Southern bluefin tuna are only found in the southern hemisphere, primarily in the Indian, Atlantic and Western Pacific Ocean and are uncommonly found in the Eastern Pacific Ocean. This species migrates from the south coast of Australia and the central Indian Ocean as juvenile and remain in offshore waters as adults. There is only one known spawning location, south-east of Java, Indonesia in the Indian Ocean (IOTC 2013). 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 Pacific bluefin and yellowfin tuna. The Western and Central Pacific Fisheries Commission is in charge of management of swordfish, albacore, bigeye, and yellowfin tuna in the Western and Central Pacific Ocean. The Inter-American Tropical Tuna Commission is also in charge of management of swordfish, Pacific bluefin and albacore tuna in the North and south (swordfish) Pacific Ocean. The Commission for the Conservation of Southern Bluefin Tuna manages that species throughout their range. Production Statistics Catches of swordfish in the western and central north Pacific Ocean have varied over time, peaking during the late 1950's and again during the early to mid 1990's. The majority of swordfish are caught by longlines. Catches in recent years have declined to below 13,000 t (ISCBWG 2014) In the South Pacific Ocean, the majority of swordfish are captured by longline fisheries. Total catches in this region have been increasing over time, fluctuating around 6,000 t in recent years (Davies et al. 2013). 8

9 Figure 1 Swordfish landings (mt) in the western and central north Pacific Ocean ( ) (ISC 2014) Figure 2 Annual catches (t) of swordfish in the south Pacific ( ). 9

10 Longline fisheries for albacore tuna in the North Pacific caught 40% of all albacore in the region during 2013 (ISSF 2014). 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). Annual catches between averaged around 78,000 t (IATTC 2014). The major fisheries for albacore tuna in the South Pacific are several distant water longline fleets (Japan, Chinese Taipei and China) along with some Pacific Island country domestic longline fleets. Longline fishing has increased since the mid-1990 s due to the development and expansion of small-scale fisheries in the Pacific Island countries (American Samoa, Cook Islands, Fiji, French Polynesia, New Caledonia, Samoa, Tonga and Vanuatu). Since 2000, catches of albacore in the South Pacific have increased to more than 80,000 mt, with the majority being caught by the longline fishery (Hoyle et al. 2012). Figure 3 Catches of north Pacific albacore by major gear types, The Other gear category includes catches with purse seine, recreational gear, hand lines, and harpoons (ISCAWG 2014). 10

11 Figure 4 Catches of albacore tuna in the south Pacific between 1950 and 2011 by gear type (Hoyle et al. 2012). Total catches of bigeye tuna in the western and central Pacific Ocean have increased over time, peaking in the mid 2000's at just under 200,000 mt. Longline catches of bigeye tuna in the Western and Central Pacific Ocean (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). 11

12 Figure 5 Total annual catch (1000s mt) of bigeye tuna from the WCPO by fishing method from (Harley et al. 2014) Total catches of yellowfin tuna in the WCPO have increased over time from a low of under 50,000 t during the mid 1950's to over 600,000 t in 2008 and Annual catches of yellowfin tuna by longliners in the WCPO have been around 70,000 to 80,000 t since the mid 1980's (Davies et al. 2014b). Figure 6 Annual catches (1000 t) of yellowfin tuna in the WCPO from by fishing gear (Davies et al. 2014) 12

13 Purse seines catch the majority of Pacific bluefin tuna, followed by troll, longline and set nets in recent years. Information on historical Pacific bluefin catches (total) is limited, although data sets since 1804 and the early 1900 s are available from Japan and the US respectively. Catches were high from 1929 to 1940, peaking at 59,000 mt in In 1949, as the Japanese fleet moved across the North Pacific Ocean, catches increased significantly. Since 1952 (when catch reporting improved), the majority of Pacific bluefin tuna have been caught by Japan. Historically the United States was the second most important fishing nation for Pacific bluefin tuna. The United States began targeting Pacific bluefin tuna during the early part of the 20th century, with catches throughout the region peaking between 1929 and However, since the late 1990's Mexico has replaced the United States and is now the second largest fishing nation. Annual catches have been under 20,000 t during the past few years (ISCPBWG 2014). Figure 7 Annual catch of Pacific bluefin tuna by gear ( ) (ISWPBWG 2014) Only a small proportion of southern bluefin tuna (16%) are caught in the Pacific Ocean. Total catches of southern bluefin tuna peaked in the 1960's at around 82,000 t, with just under 80,000 t coming from the longline fishery. Catches have declined significantly since then, being only around 10,000 t in 2012, with around 13

14 half of that coming from the longline fleet. Catches in the Pacific Ocean have ranged from 800 t to 19,000 t since 1968, with an average catch of 5,500 t(iotc 2013). Figure 8 Southern Bluefin tuna catches (IOTC 2013). 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). Figure 9 Major contributors to US albacore tuna imports (%) all countries and region (counry of origin) (NMFS 14

15 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 10 Major contributors to US bigeye tuna imports (%) all countries and regions (counry 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). 15

16 Figure 11 Major contributors to US yellowfin tuna imports (%) all countries and regions (counry of origin) (NMFS 2014) During 2013, swordfish imports into the United States were primarily from Ecuador (23%), Canada (14%) and Costa Rica and Singapore (11%). Figure 12 Major contributors to US swordfish imports (%) all countries (counry of origin) (NMFS 2014) 16

17 During 2013, the United States imported the majority (36%) of Pacific bluefin tuna from Spain, followed by Japan (23%) and Mexico (15%). Total imports during 2012 were t. Export data is for Atlantic and Pacific bluefin tuna combined. During 2012, to t of fresh and t of frozen bluefin tuna were exported, primarily to Japan (NMFS 2014). Figure 13 Pacific bluefin tuna imports (percentage), 2013, for all countries and regions (counry of origin) (NMFS 2014) The US imports the majority of southern bluefin tuna from New Zealand (47%), followed by Japan (33%) (NMFS 2014). Figure 14 Southern bluefin tuna imports (percentage), 2013, for all countries and regions (counry of origin) (NMFS 2014) 17

18 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. In Hawaii, albacore tuna is known as tombo ahi, bigeye and yellwofin tuna are known as Ahi, skipjack as Aku and swordfish as mekajiki. Bluefin tuna are also known as giant bluefin, northern bluefin tuna, tunny and oriental tuna. Southern bluefin tuna are also known as southern tunny or tunny. Primary product forms Swordfish, albacore, bigeye, and yellowfin tuna are sold in fresh and frozen forms. Albacore tuna is sold in primarily in canned form but also in fresh and frozen form. 18

19 Assessment This section assesses the sustainability of the fishery(s) relative to the Seafood Watch Criteria for Fisheries, available at Criterion 1: Impacts on the species under assessment 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 Region Method Country Custom Group South Pacific Drifting longline North Pacific Drifting longline Inherent Vulnerability Abundance Fishing Mortality Score 2.00: Medium 4.00: Low 5.00: Very Low Green (4.47) 2.00: Medium 4.00: Low 3.67: Low Green (3.83) BIGEYE TUNA Region Method Country Custom Group Western and Central Pacific Drifting longline Inherent Vulnerability Abundance Fishing Mortality Score 2.00: Medium 4.00: Low 3.67: Low Green (3.83) PACIFIC BLUEFIN TUNA Region Method Country Custom Group North Pacific Drifting longline Inherent Vulnerability Abundance Fishing Mortality Score 2.00: Medium 2.00: High 1.00: High Red (1.41) 19

20 SOUTHERN BLUEFIN TUNA Region Method Country Custom Group South Pacific Drifting longline Inherent Vulnerability Abundance Fishing Mortality Score 1.00: High 1.00: Very High 3.67: Low Red (1.92) SWORDFISH Region Method Country Custom Group North Pacific Drifting longline Inherent Vulnerability Abundance Fishing Mortality Score 2.00: Medium 5.00: Very Low 5.00: Very Low Green (5.00) South Pacific Drifting longline 2.00: Medium 4.00: Low 2.33: Moderate Yellow (3.05) YELLOWFIN TUNA Region Method Country Custom Group Western and Central Pacific Drifting longline Inherent Vulnerability Abundance Fishing Mortality Score 2.00: Medium 5.00: Very Low 5.00: Very Low Green (5.00) Populations of albacore tuna and swordfish in the North and South Pacific Ocean are healthy and fishing mortality rates appear sustainable, although there is the possability that swordfish in the South Pacific are undergoing overfishing. However, populations of Pacific bluefin tuna in the North Pacific ocean have been greatly reduced, as much as 96% over time and fishing mortality rates are currently too high. Throughout the Western and Central Pacific Ocean, skipjack and yellowfin tuna populations are healthy and fishing mortality rates are low. In recent years the population of bigeye tuna has increased and is no longer considered overfished. Criterion 1 Assessment SCORING GUIDELINES Factor Inherent Vulnerability 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 , 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, 20

21 aggregating for breeding, or consistently returning to the same sites for feeding or reproduction) and geographic range. Factor Abundance 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. Factor Fishing Mortality 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) (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) (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. ALBACORE Factor Inherent Vulnerability 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" vulnerability. Factor Abundance Low 21

22 Albacore tuna in the South Pacific was last assessed in 2012 and the results were very similar to previous assessments (2009 and 2011). According to the assessment, the total biomass of albacore tuna has been reduced to around 82% (62 to 93%) of unfished levels, while the spawning biomass (mature females) has been reduced to 63% (35 to 80%) of unfished levels. Both of these are considered "moderate" levels of depletion. The current ratio of the current total biomass and spawning biomass to that needed to produce the maximum sustainable yield (B CURRENT/B MSY = 1.6 (1.4 to 1.9) and SB CURRENT/SB MSY = 2.6 (1.5 to 5.2) ) are both above 1. However, several issues were addressed during this assessment, chiefly the unrealistic declines in abundance during the early part of the time series and the high uncertainty surrounding increases in recruitment in recent years (Hoyle et al. 2012). We have awarded a score of "low" concern because, while the model suggests a healthy stock, a large amount of uncertainty surrounds these results. Low The most recent stock assessment for albacore tuna in the North Pacific Ocean was conducted in According to this assessment, the spawning stock biomass (SSB) in 2015 (last year of data included in the model) was 132,072 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 because it is likely that albacore tuna in the North Pacific are not overfished; we did not award a score of "very low" concern because no reference points are currently accepted (ISC 2017). Factor Fishing Mortality Very Low According to the most recent stock assessment (2012), the fishing mortality reference point for albacore tuna in the South Pacific, F CURRENT/F MSY, had a median estimate of 0.21 ( ) and there is a low risk that overfishing is occurring. Low The current fishing mortality rate (F ) for albacore tuna in the North Pacific Ocean is below potential F-based reference points (FMSY F0.1 and F10-40% (fishing mortality that gives 10-40% reduction in the spawning potential ratio)) except for 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 (ISC 2017). We have awarded a low and not very low concern score because overfishing is likely not occurring, but there is some uncertainty and potential for increased fishing mortality that would lead to overfishing. BIGEYE TUNA Factor Inherent Vulnerability Medium 22

23 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 to 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 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 tuna is known, this inherent vulnerability score will not affect the overall outcome. We have therefore awarded a "medium" vulnerability based on the productivity table analysis. Factor Abundance Low Bigeye tuna in the Western and Central Pacific Ocean (WCPO) were most recently assessed in According to the base case model, the median ratio of the current average (2011 to 2014) spawning biomass to that needed to produce the maximum sustainable yield (SB RECENT/SB MSY) was 1.21 and the ratio of the latest (2014) spawning biomass (mature fish) to that needed to produce the maximum sustainable yield (SB LATEST/SB MSY) was The median ratio of the recent spawning biomass to that spawning biomass with no fishing is 0.34, which is above the limit reference point of 0.20, indicating that the population is not overfished (McKechnie et al. 2017). This is a significant change and improvement from the 2014 assessment (Harley et al. 2014). We have awarded a score of "low" concern because bigeye tuna are no longer overfished and the spawning stock biomass is above that needed to produce maximum sustainable yield. Factor Fishing Mortality Low The median ratio of current fishing mortality rates to those that produce the maximum sustainable yield (Fcurrent/FMSY) was 0.83, indicating overfishing is not occurring (McKechnie et al. 2017). This is a significant improvement from the last assessment (Harley et al. 2014). We have awarded a low concern score based on the assessment results that overfishing is no longer occurring but not a very low concern because overfishing had previously been occurring for a very long time and there is still some uncertainty with regard to current fishing mortality rates. PACIFIC BLUEFIN TUNA Factor Inherent Vulnerability Medium FishBase assigned a "high" vulnerability score of 60 out of 100 (Froese and Pauly 2013). Pacific bluefin tuna begin reaching sexual maturity around 150 cm in size and reach sexual maturity between 3 to 5 years of age (PBTWG 2012). A maximum size and age of 300 cm and 15 years respectively have been reported. Pacific blueftin tuna are broadcast spawners and have a high trophic level according to Fishbase (Froese and Pauly 2013). According to these life history characteristics, Pacific bluefin tuna have a "moderate" level of 23

24 vulnerability and we have therefore adjusted the score. Factor Abundance High An updated assessment for Pacific bluefin tuna was conducted in Based on the updated analysis, the ratio of the spawning stock biomass in 2014 to that of unfished levels was 2.6%. There are no defined reference points for Pacific bluefin tuna. However, the results were compared to other reference points and based on a reference point of SSB 20%, the population would be considered overfished. In addition, based on this reference point, the population has been overfished for the majority of the assessed time period (1950 to 2014) (ISC 2016). We have therefore awarded a score of "high" concern. Factor Fishing Mortality High Based on the updated 2016 assessment, current fishing mortality rates (2011 to 2013) are higher than all potential biological reference points, except F MED and F LOSS. Because there are no currently defined reference points for Pacific bluefin tuna, the assessment presented two alternative results. Assuming an F MED reference point, the stock would be approaching an overfished status. Assuming an F 20% reference point, overfishing would have been occurring for the majority of the assessed time period (1952 to 2015) (ISC 2016). We have awarded a score of "high" concern because the best available data indicates that overfishing is likely occurring. SOUTHERN BLUEFIN TUNA Factor Inherent Vulnerability High FishBase assigned a "high" to "very high" vulnerability score of 67 out of 100 (Froese and Pauly 2013). Southern bluefin tuna reach sexual maturity after at least 8 years of age and at a size of 155 cm in length, but perhaps not until 15 years of age. They reach a total length of 2 m and can live up to 42 years (IOTC 2013e). Southern bluefin tuna are a top predator and are considered broadcast spawners (Froese and Pauly 2013). We have awarded a score of "high" vulnerability based on the FishBase score. Factor Abundance Very High The International Union for the Conservation of Nature (IUCN) has classified southern bluefin tuna as "Critically Endangered" (Collete et al. 2011e). According to the latest stock assessment, the current spawning biomass of southern bluefin tuna is a small fraction of virgin levels and well below the level needed to produce the maximum sustainable yield (SB CURRENT/SB MSY = [ ]). However, at current catch levels the 24

25 population is expected to increase. Catch rates from the Japanese longline fishery have been increasing since 2007 for some age classes and aerial surveys have indicated a recent increase in abundance in 2013, the second highest in history (IOTC 2013e). We have awarded a score of "very high" concern based on the current low biomass levels and IUCN status. Factor Fishing Mortality Low Fishing mortality rates have decreased for southern bluefin tuna and are now below those needed to produce the maximum sustainable yield (Fcurrent/FMSY = 0.76 ( )). In addition, reported catches are below the maximum sustainable yield (MSY) levels and current exploitation rates are considered moderate (IOTC 2013e). We have awarded a low instead of very low concern score because fishing mortality rates have just decreased to sustainable levels and because current exploitation rates are considered moderate. SWORDFISH Factor Inherent Vulnerability 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. Swordfish are broadcast spawners and are top predators (Froese and Pauly 2013). This is more indicative of a moderate vulnerability to fishing. Factor Abundance Very Low In 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 (B MSY) for most of the time series ( ) and there is a low probability (14%) of the biomass being below B MSY in 2012 (ISCBWG 2014). We have therefore awarded a very low concern score. Low In 2013 and updated assessment of swordfish in the southern region of the Western and Central Pacific Ocean (WCPO) was conducted. This updated stock assessment included both the South-West Pacific (SWP) as well as the South-Central Pacific (SCP). Compared to the 2008 assessment, this updated one was able to determine abundance estimates for both regions. However, considerable uncertainty still surrounded the 25

26 assumptions made with regard to growth, maturity and mortality (age specific). Standardized catch rates for the main fleets declined drastically between 1997 and 2011 and the mean size also decreased in the main fisheries. The total and spawning biomass have declined since the late 1990's and the current levels are 44-68% and 27-55% of virgin levels. The ratios of biomass and spawning biomass (mature fish) levels to those needed to produce the maximum sustainable yield (MSY) range from and respectively, indicating the population is not overfished (Davies et al. 2013). We have awarded a low and not very low concern score due to the high level of uncertainty. Factor Fishing Mortality Very Low In 2014 an assessment for swordfish was in the North Pacific was conducted. Exploitation rates in this region peaked in 1960's and have declined since. The current fishing mortality rate (H ) 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 (ISCBWG 2014). We have therefore awarded a very low concern score. Moderate According to the updated 2013 assessment of swordfish in the Southwest Pacific Ocean, catches are around levels needed to produce the maximum sustainable yield (MSY) (82% -102%). The fishing mortality rate for juvenile swordfish increased in the mid 1990''s and the ratio of current fishing mortality rates to those needed to produce MSY range from 0.33 to This indicates that the population under some assumptions may be undergoing overfishing (Davies et al. 2013). We have therefore awarded a moderate and not low concern score. YELLOWFIN TUNA Factor Inherent Vulnerability Medium FishBase assigned a "moderate" to "high" vulnerability fo 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, and 2 to 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 (Langley et al. 2011) (Froesy and Pauly 2013). Factor Abundance Very Low The biomass based reference points for the reference model used in the 2017 assessment (SB RECENT/SB MSY the ratio of the current (2011 to 2014) spawning (mature fish) biomass to that needed to produce the 26

27 maximum sustainable yield) was The ratio of the latest (2014) spawning biomass to the level needed to produce the maximum sustainable yield (SB CURRENT/SB MSY) was The ratio of the recent spawning biomass to the biomass with no fishing mortality is 0.31, which is higher than the limit reference point (0.20). Therefore, yellowfin tuna are not in an overfished state (Tremblay-Boyer et al. 2017) and biomass is well above appropriate target levels such as SB MSY. We have subsequently awarded a score of "very low" concern. Factor Fishing Mortality Very Low The current fishing mortality rate is below levels needed to produce the maximum sustainable yield (F RECENT/F MSY = 0.79) for the most realistic models. Therefore overfishing is not occurring (Tremblay-Boyer et al. 2017) and we have awarded a very low concern score. 27

28 Criterion 2: Impacts on other species All main retained and bycatch species in the fishery are evaluated in the same way as the species under assessment were evaluated in Criterion 1. Seafood Watch defines bycatch as all fisheries-related mortality or injury to species other than the retained catch. Examples include discards, endangered or threatened species catch, and ghost fishing. To determine the final Criterion 2 score, the score for the lowest scoring retained/bycatch species is multiplied by the discard rate score (ranges from 0-1), which evaluates the amount of non-retained catch (discards) and bait use relative to the retained catch. The Criterion 2 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 2.3 (Fishing Mortality) is Crtitical Criterion 2 Summary Only the lowest scoring main species is/are listed in the table and text in this Criterion 2 section; a full list and assessment of the main species can be found in Appendix A. ALBACORE - NORTH PACIFIC - DRIFTING LONGLINE Subscore: 1.00 Discard Rate: 0.95 C2 Rate: 0.95 Species Inherent Vulnerability Abundance Fishing Mortality Subscore Leatherback turtle 1.00:High 1.00:Very High Loggerhead turtle 1.00:High 1.00:Very High 1.00:High Red (1.00) 1.00:High Red (1.00) Whitetip shark 1.00:High 2.00:High 1.00:High Red (1.41) Pacific bluefin tuna 2.00:Medium 2.00:High 1.00:High Red (1.41) Shortfin mako shark 1.00:High 2.00:High 1.00:High Red (1.41) Silky shark 1.00:High 2.00:High 1.00:High Red (1.41) black-footed albatross 1.00:High 2.00:High 1.00:High Red (1.41) Striped marlin 2.00:Medium 2.00:High 1.00:High Red (1.41) laysan albatross 1.00:High 2.00:High 2.33:Moderate Opah 2.00:Medium 3.00:Moderate 2.33:Moderate Red (2.16) Yellow (2.64) Bigeye tuna 2.00:Medium 4.00:Low 3.67:Low Green (3.83) 28

29 Blue marlin 2.00:Medium 4.00:Low 3.67:Low Green (3.83) Blue shark 1.00:High 4.00:Low 3.67:Low Green (3.83) Swordfish 2.00:Medium 5.00:Very Low Yellowfin tuna 2.00:Medium 5.00:Very Low 5.00:Very Low 5.00:Very Low Green (5.00) Green (5.00) ALBACORE - SOUTH PACIFIC - DRIFTING LONGLINE Subscore: 1.00 Discard Rate: 1.00 C2 Rate: 1.00 Species Inherent Vulnerability Abundance Fishing Mortality Subscore Leatherback turtle 1.00:High 1.00:Very High Loggerhead turtle 1.00:High 1.00:Very High 1.00:High Red (1.00) 1.00:High Red (1.00) Blue shark 1.00:High 2.00:High 1.00:High Red (1.41) Whitetip shark 1.00:High 2.00:High 1.00:High Red (1.41) Shortfin mako shark 1.00:High 2.00:High 1.00:High Red (1.41) Silky shark 1.00:High 2.00:High 1.00:High Red (1.41) Green sea turtle 1.00:High 1.00:Very High Southern bluefin tuna 1.00:High 1.00:Very High 2.33:Moderate grey petrel 1.00:High 2.00:High 2.33:Moderate Olive ridley turtle 1.00:High 2.00:High 2.33:Moderate Salvin's albatross 1.00:High 2.00:High 2.33:Moderate wandering albatross 1.00:High 2.00:High 2.33:Moderate white-chinned petrel 1.00:High 2.00:High 2.33:Moderate Black marlin 2.00:Medium 3.00:Moderate Red (1.53) 3.67:Low Red (1.92) 2.33:Moderate Red (2.16) Red (2.16) Red (2.16) Red (2.16) Red (2.16) Yellow (2.64) 29

30 Opah 2.00:Medium 3.00:Moderate 2.33:Moderate Yellow (2.64) Black-browed albatross 1.00:High 2.00:High 3.67:Low Yellow (2.71) light-mantled albatross 1.00:High 2.00:High 3.67:Low Yellow (2.71) flesh-footed shearwater 1.00:High 4.00:Low 2.33:Moderate Swordfish 2.00:Medium 4.00:Low 2.33:Moderate Striped marlin 2.00:Medium 3.00:Moderate 3.67:Low Yellow (3.05) Yellow (3.05) Green (3.32) Bigeye tuna 2.00:Medium 4.00:Low 3.67:Low Green (3.83) Blue marlin 2.00:Medium 4.00:Low 3.67:Low Green (3.83) Yellowfin tuna 2.00:Medium 5.00:Very Low 5.00:Very Low Green (5.00) BIGEYE TUNA - WESTERN AND CENTRAL PACIFIC - DRIFTING LONGLINE Subscore: 1.00 Discard Rate: 1.00 C2 Rate: 1.00 Species Inherent Vulnerability Abundance Fishing Mortality Subscore Hawksbill turtle 1.00:High 1.00:Very High Leatherback turtle 1.00:High 1.00:Very High Loggerhead turtle 1.00:High 1.00:Very High 1.00:High Red (1.00) 1.00:High Red (1.00) 1.00:High Red (1.00) Whitetip shark 1.00:High 2.00:High 1.00:High Red (1.41) Shortfin mako shark 1.00:High 2.00:High 1.00:High Red (1.41) Silky shark 1.00:High 2.00:High 1.00:High Red (1.41) Striped marlin 2.00:Medium 2.00:High 1.00:High Red (1.41) Green sea turtle 1.00:High 1.00:Very High 2.33:Moderate Red (1.53) 30

31 Olive ridley turtle 1.00:High 2.00:High 2.33:Moderate Red (2.16) Black marlin 2.00:Medium 3.00:Moderate Opah 2.00:Medium 3.00:Moderate 2.33:Moderate 2.33:Moderate Swordfish 2.00:Medium 4.00:Low 2.33:Moderate Yellow (2.64) Yellow (2.64) Yellow (3.05) Blue marlin 2.00:Medium 4.00:Low 3.67:Low Green (3.83) Blue shark 1.00:High 4.00:Low 3.67:Low Green (3.83) Yellowfin tuna 2.00:Medium 5.00:Very Low 5.00:Very Low Green (5.00) PACIFIC BLUEFIN TUNA - NORTH PACIFIC - DRIFTING LONGLINE Subscore: 1.00 Discard Rate: 0.95 C2 Rate: 0.95 Species Inherent Vulnerability Abundance Fishing Mortality Subscore Leatherback turtle 1.00:High 1.00:Very High Loggerhead turtle 1.00:High 1.00:Very High 1.00:High Red (1.00) 1.00:High Red (1.00) Whitetip shark 1.00:High 2.00:High 1.00:High Red (1.41) Shortfin mako shark 1.00:High 2.00:High 1.00:High Red (1.41) Silky shark 1.00:High 2.00:High 1.00:High Red (1.41) black-footed albatross 1.00:High 2.00:High 1.00:High Red (1.41) Striped marlin 2.00:Medium 2.00:High 1.00:High Red (1.41) laysan albatross 1.00:High 2.00:High 2.33:Moderate Opah 2.00:Medium 3.00:Moderate 2.33:Moderate Red (2.16) Yellow (2.64) Albacore 2.00:Medium 4.00:Low 3.67:Low Green (3.83) 31

32 Bigeye tuna 2.00:Medium 4.00:Low 3.67:Low Green (3.83) Blue marlin 2.00:Medium 4.00:Low 3.67:Low Green (3.83) Blue shark 1.00:High 4.00:Low 3.67:Low Green (3.83) Swordfish 2.00:Medium 5.00:Very Low Yellowfin tuna 2.00:Medium 5.00:Very Low 5.00:Very Low 5.00:Very Low Green (5.00) Green (5.00) SOUTHERN BLUEFIN TUNA - SOUTH PACIFIC - DRIFTING LONGLINE Subscore: 1.00 Discard Rate: 1.00 C2 Rate: 1.00 Species Inherent Vulnerability Abundance Fishing Mortality Subscore Leatherback turtle 1.00:High 1.00:Very High Loggerhead turtle 1.00:High 1.00:Very High 1.00:High Red (1.00) 1.00:High Red (1.00) Blue shark 1.00:High 2.00:High 1.00:High Red (1.41) Whitetip shark 1.00:High 2.00:High 1.00:High Red (1.41) Shortfin mako shark 1.00:High 2.00:High 1.00:High Red (1.41) Silky shark 1.00:High 2.00:High 1.00:High Red (1.41) Green sea turtle 1.00:High 1.00:Very High 2.33:Moderate grey petrel 1.00:High 2.00:High 2.33:Moderate Olive ridley turtle 1.00:High 2.00:High 2.33:Moderate Salvin's albatross 1.00:High 2.00:High 2.33:Moderate wandering albatross 1.00:High 2.00:High 2.33:Moderate white-chinned petrel 1.00:High 2.00:High 2.33:Moderate Black marlin 2.00:Medium 3.00:Moderate 2.33:Moderate Red (1.53) Red (2.16) Red (2.16) Red (2.16) Red (2.16) Red (2.16) Yellow (2.64) 32

33 Opah 2.00:Medium 3.00:Moderate 2.33:Moderate Yellow (2.64) Black-browed albatross 1.00:High 2.00:High 3.67:Low Yellow (2.71) light-mantled albatross 1.00:High 2.00:High 3.67:Low Yellow (2.71) flesh-footed shearwater 1.00:High 4.00:Low 2.33:Moderate Swordfish 2.00:Medium 4.00:Low 2.33:Moderate Striped marlin 2.00:Medium 3.00:Moderate 3.67:Low Yellow (3.05) Yellow (3.05) Green (3.32) Bigeye tuna 2.00:Medium 4.00:Low 3.67:Low Green (3.83) Blue marlin 2.00:Medium 4.00:Low 3.67:Low Green (3.83) Albacore 2.00:Medium 4.00:Low 5.00:Very Low Yellowfin tuna 2.00:Medium 5.00:Very Low 5.00:Very Low Green (4.47) Green (5.00) SWORDFISH - NORTH PACIFIC - DRIFTING LONGLINE Subscore: 1.00 Discard Rate: 0.95 C2 Rate: 0.95 Species Inherent Vulnerability Abundance Fishing Mortality Subscore Leatherback turtle 1.00:High 1.00:Very High Loggerhead turtle 1.00:High 1.00:Very High 1.00:High Red (1.00) 1.00:High Red (1.00) Whitetip shark 1.00:High 2.00:High 1.00:High Red (1.41) Pacific bluefin tuna 2.00:Medium 2.00:High 1.00:High Red (1.41) Shortfin mako shark 1.00:High 2.00:High 1.00:High Red (1.41) Silky shark 1.00:High 2.00:High 1.00:High Red (1.41) black-footed albatross 1.00:High 2.00:High 1.00:High Red (1.41) 33