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ISSF Releases Interactive “Status of the Stocks Tool”

Written by svanouse on . Posted in News, Press Releases.

The International Seafood Sustainability Foundation (ISSF) has developed a new data-visualization tool based on its long-running and widely followed Status of the Stocks report. The “Status of the Stocks Tool” is located on the ISSF website and accessible through the Status of the Stocks overview page; users can easily toggle through tuna stock health indicators and filter by location, species and other key stock health and catch factors.

The tool, which requires no additional applications or access to use, offers fisheries managers, fishers, RFMOs, scientists, and other stakeholders a convenient and intuitive resource for visualizing the state of tuna stocks worldwide, covering 23 tuna stocks — including ones that have been or are overfished, as well as those at healthy levels. Offering the most current data available, it also pulls information from previous years of ISSF Status of the Stocks reports, which compile key stock health and catch data from the Regional Fisheries Management Organizations (RFMOs).  

Use our new interactive tool to visualize trends in #tuna stock health. Share on X

“As part of our ongoing efforts to bring improved technology into understanding fisheries management, we developed this resource to offer a clearer picture of trends in global tuna stock health over time,” said ISSF President Susan Jackson. “Not only does a data visualization tool such as this allow users a customized look at the tuna stocks they are most interested in, it also offers a meaningful understanding of the impact of changes in RFMO management on those tuna stocks over time.”

For example, the number of stocks well-managed in terms of fishing mortality has increased from 8 (35%) in 2012 to 15 (65%) in 2018, demonstrating the improvement of management measures put in place by the RFMOs. Improved management measures lead to stock rebuilding, as in the case of bluefin tuna stocks, where 100% of the catch came from overfished stocks in 2013, versus just 26.5% of the catch in 2018. The tool can also be used to monitor those stocks for which management has been effective and, therefore, resulted in maintained healthy levels of abundance over time (e.g., skipjack stocks).

The tool was developed by ISSF’s science and communications teams and was reviewed by the scientists on the ISSF Scientific Advisory Committee.

Interactive Tool Design

The tool, built using Tableau technology, features two tabs — one for visualizing tuna stock health trends since 2011, and another for visualizing the recent tuna catch by fishing method.

Users can generate a variety of customized and exportable graphics within the tool based on the parameters they choose in the checkboxes (such as “ocean location”) or buttons. By hovering or clicking on the graphics, users can see percentages and other details.

On the Stock Health tab, data can be filtered first by tuna species and ocean region. The user can choose between visualizing data relative to total catch or to number of stocks, and between ratings on stock abundance or on fishing mortality. As a result, the corresponding area graph is generated.

Like the Status of the Stocks reports, the tool uses a color rating system: green (“healthy”), yellow (“intermediate”), and orange (“needs improvement”).

The Catch tab currently features data from 2016, the most recent year for which complete catch data are available. Gear type data can be filtered by ocean location to generate a bar chart.

ISSF’s “Status of the Stocks Tool” will be updated as new iterations of the Status of the Stocks Report are released. To access the most recent Status of the Stocks report in full, click here.

About the ISSF Status of the Stocks Report

There are 23 stocks of major commercial tuna species worldwide – 6 albacore, 4 bigeye, 4 bluefin, 5 skipjack, and 4 yellowfin stocks. The Status of the Stocks summarizes the results of the most recent scientific assessments of these stocks, as well as the current management measures adopted by the RFMOs. This report ranks the status and management of the 23 stocks using a consistent methodology based on three factors: Abundance, Exploitation/Management (fishing mortality) and Environmental Impact (bycatch).

ISSF also produces a complementary report, the Evaluation of the Sustainability of Global Tuna Stocks Relative to Marine Stewardship Council Criteria (MSC) which provides scores for the stocks and RFMOs based on MSC assessment criteria. The MSC-certified fisheries list (Appendix 2) in Status of the Stocks complements the Evaluation report.

Together, these tools help to define the continuous improvement achieved, as well as the areas and issues that require more attention. Access the newly updated ISSF stock status ratings here.

ISSF Skipper Workshops Reached Record-High Number of Tuna Fishers in 2017

Written by svanouse on . Posted in News, Press Releases.

The International Seafood Sustainability Foundation (ISSF) Skippers’ Workshop program marked its most successful year on record in 2017, reaching 794 participants, with tuna purse-seine skippers (457) and crew (238) comprising the majority (88 percent) of attendees. Other workshop participants included vessel owners and officials.

Since 2009, ISSF has been conducting workshops worldwide that unite fishers from tropical tuna fleets with scientists and other stakeholders to discuss methods for reducing shark and other bycatch, especially during Fish Aggregating Device (FAD) fishing. ISSF partners with AZTI, a Spanish technological research center for marine and food innovation, to conduct its skippers workshops.

#Tuna #fishers in ISSF workshops are increasingly accepting of more #sustainable methods. Share on X

Last year, ISSF added new workshop locations, including Zhoushan, China and Ambon, Makassar, and Manado, Indonesia. Eighteen skippers workshops were conducted across 10 different countries, covering fleets in the Western and Central Pacific Ocean, Atlantic Ocean, Indian Ocean, and Eastern Pacific Ocean. Since their inception, ISSF workshops have attracted more than 3,000 participants — including more than 1,700 skippers, enough to put nearly two ISSF-trained fishers on each large purse seine vessel operating today. 

Notable activities in and findings from 2017 workshops include:

  • Rising acceptance of biodegradable FADs to reduce marine debris, with initiatives like the one in the Indian Ocean, Project BIOFAD, with participation from Spanish and French fleets
  • Continued success in advancing the use of lower-entanglement-risk FADs and non-entangling FADs by fleets in three out of the four major tuna fishing regions
  • Wide acceptance of best bycatch release methods, with some fleets applying them daily
  • Fisher support for technology to remotely identify the presence of small bigeye and yellowfin tuna at FADs
  • Discussion of options to reduce FAD impacts, including limiting FAD numbers, FAD closures, or prohibiting supply vessels

Now in its second year, ISSF’s “Train-the-Trainer” program in Indonesia reached small-vessel tuna purse-seine captains in seven workshops. These local trainers will enable the program to reach more skippers in remote locations across the archipelago.

“Our skippers workshops continue to be the best method for ensuring that our research findings on FAD management and bycatch reduction result in positive shifts on the water,” said ISSF President Susan Jackson. “Not only are we able to share best practices as we gain more scientific knowledge, but we are also able to gain valuable insight directly from the fishers who spend their working hours fishing for tuna. It’s education that goes both ways.”

All 2017 successes are outlined in the recently published ISSF Technical Report ISSF Skippers’ Workshops Round 7. The report includes details on each 2017 workshop, photos, and graphs showing fisher participation and acceptance of best practices. It also features a “Novel ideas and improvements for mitigation activities” section.

Skippers’ workshop attendance fulfills the requirement for ISSF conservation measure 3.4.

State of Tuna Stocks Worldwide Assessed in Comprehensive ISSF Report

Written by svanouse on . Posted in News, Press Releases.

Of the total tuna catch in 2016, 78% came from stocks at “healthy” levels, unchanged since last reported, according to a February 2018 International Seafood Sustainability Foundation (ISSF) Status of the Stocks report. Skipjack tuna stocks — at healthy levels in all ocean regions — constituted more than one-half of the 2016 total catch.

One notable change in stock status in the February 2018 Status report is for Southern bluefin tuna, a stock that has moved from orange to yellow in abundance ratings. Stock abundance is low, about 13% of the unfished level. However, the stock is rebuilding continuously as a result of the implementation of a robust Management Procedure (a Harvest Strategy) by the Commission for the Conservation of Southern Bluefin Tuna, the regional organization in charge of managing the stock.

In contrast, the Pacific bluefin stock, along with the Indian Ocean yellowfin stock and the Atlantic Ocean bigeye stock, remains overfished. See Tables 1 and 2 in the report for specific rating changes.

Southern #bluefin #tuna is rebuilding as a result of #CCSBT's robust Management Procedure. Share on X

There were no dramatic changes in tuna stock status since the previous November 2017 Status report; the updated report reflects new data made available at late 2017 tuna Regional Fisheries Management Organization (RFMO) meetings.

Updated several times per year, Status of the Stocks assigns color ratings (green, yellow or orange) on stock heath, stock management, and ecosystem impact. The report ranks the 23 stocks of major commercial tunas around the world using a consistent methodology.

Key Statistics in the Report

  • Total catch: In 2016, the total major commercial tuna catch was 4.9 million tonnes, a 2% increase from 2015. More than half of the total catch (57%) was skipjack tuna, followed by yellowfin (30%), bigeye (8%) and albacore (4%). Bluefin tunas (3 species) accounted for only 1% of the global catch. These percentages changed only slightly from the Nov. 2017 reporting period.
  • Abundance or “spawning biomass” levels: Globally, 57% of the 23 stocks are at a healthy level of abundance, 13% are overfished, and 30% are at an intermediate level.
    • Stocks receiving orange scores, indicating overfished status, include Atlantic Ocean bigeye, Pacific Ocean bluefin and Indian Ocean yellowfin.
  • Fishing mortality levels: 65% of the 23 stocks are experiencing a well-managed fishing mortality rate, and 13% are experiencing overfishing (with no change from the previous report).
  • Largest catches by stock: The three largest catches in tonnes are Western Pacific Ocean skipjack, Western Pacific Ocean yellowfin, and Indian Ocean skipjack.
  • Tuna production by ocean region: Most (53%) of the world’s tuna is harvested from the Western and Central Pacific Ocean, followed by the Indian Ocean (20%), Eastern Pacific Ocean (13%), and Atlantic Ocean (10%).
  • Tuna production by fishing gear: 65% of the catch is made by purse seining, followed by longline (12%), pole-and-line (8%), gillnets (3%) and miscellaneous gears (12%). These percentages changed only slightly from the Nov. 2017 reporting period.

About the Report

There are 23 stocks of major commercial tuna species worldwide – 6 albacore, 4 bigeye, 4 bluefin, 5 skipjack, and 4 yellowfin stocks. The Status of the Stocks summarizes the results of the most recent scientific assessments of these stocks, as well as the current management measures adopted by the RFMOs. This report ranks the status and management of the 23 stocks using a consistent methodology based on three factors: Abundance, Exploitation/Management (fishing mortality) and Environmental Impact (bycatch).

ISSF produces two reports annually that seek to provide clarity about where we stand — and how much more needs to be done — to ensure the long-term sustainability of tuna stocks: the Status of the Stocks provides a comprehensive analysis of tuna stocks by species, and the Evaluation of the Sustainability of Global Tuna Stocks Relative to Marine Stewardship Council Criteria (MSC) provides scores for the stocks and RFMOs based on MSC assessment criteria. The MSC-certified fisheries list (Appendix 2) in Status of the Stocks complements the Evaluation report.

Together, these tools help to define the continuous improvement achieved, as well as the areas and issues that require more attention. Access the newly updated ISSF stock status ratings here.

Advancing Sustainable Tuna Fisheries

Written by svanouse on . Posted in News, Press Releases.

 The International Seafood Sustainability Foundation (ISSF) released its Strategic Plan for 2018-2022, Advancing Sustainable Tuna Fisheries: A Five-Year Plan, which lays out the research and advocacy organization’s mission and approach to meeting sustainability objectives over the next five years.

The new strategic plan is activated through three core pillars of science, influence, and verification — encompassing tuna stock health and fisheries bycatch, outreach to Regional Fisheries Management Organizations (RFMOs) and vessels, partnerships with tuna companies, fishery improvement support, and more. ISSF’s ultimate objective remains to improve the sustainability of global tuna fisheries so they are capable of meeting the Marine Stewardship Council (MSC) certification standard without conditions.

Read about ISSF's #sustainability goals for the next 5 years in its new strategic plan. Share on X

“Since ISSF began its work in 2009, tuna fisheries have changed, the industry has changed, and sustainability challenges have strengthened stakeholder cooperation,” said ISSF President Susan Jackson. “As progress is made and priorities evolve, it is essential to recalibrate our strategies to continue to drive the industry towards a more sustainable future. That’s what Advancing Sustainable Tuna Fisheries allows us to do.”

Objective Strategies, Evolved Approaches

While ISSF tools and resources — because they help reach the organization’s objective regarding MSC certification — are complementary to fisheries improvement work, a formalized focus on Fisheries Improvement Projects (FIPs) is new to Advancing Sustainable Tuna Fisheries.

“ISSF has a reputation for taking the scientific route — identifying and advocating for approaches based on the best data available,” said Bill Fox, ISSF Board member of Vice President, Fisheries, WWF-U.S. “We look forward to the Foundation bringing this rigorous focus to bear on the fisheries improvement work progressing across global tuna fisheries.”

In the plan, the Foundation also pledges to monitor emerging labor and social standards for tuna fishing activities, and to consider how ISSF and its nearly 30 participating tuna companies can support standards for best labor practices.

Progress to Date, Goals to Prioritize

ISSF has launched a related, infographic-rich microsite that explores five focus areas of the strategic plan: bycatch mitigation, FADs and FAD management, illegal fishing, industry commitment, and harvest strategies. For all focus areas, which have evolved from the organization’s previous five-year plan, ISSF cites outcomes to date as a result of its model of scientific research, knowledge sharing, and advocacy.

Additional Strategic Plan goals laid out in the microsite include:

  • Harvest control rules for all commercial tuna stocks
  • All RFMOs require biodegradable Fish Aggregating Devices (FADs)
  • 100% observer coverage across all gears and tuna fisheries
  • Additional tuna vessels of all gear types on ISSF’s ProActive Vessel Register
  • More companies across the tuna supply chain committing to ISSF conservation measures
  • ISSF participating companies maintaining full conformance with ISSF conservation measures

The microsite also highlights benchmarking tools and summarizes ISSF resources for FIPs and MSC certification efforts.

The 2018-2022 strategic plan was developed with input from ISSF partners representing more than a dozen external stakeholder groups and organizations — including those from the scientific, charitable foundation, and NGO communities. The plan was developed over a ten-month period and approved by ISSF’s Board of Directors. The plan PDF can be downloaded from the microsite.

 

ISSF’s Impact on Tuna Sustainability

Written by svanouse on . Posted in News, Videos.

This video, which features interviews with ISSF scientist-consultants and Scientific Advisory Committee members, explores ISSF’s unique approach to tuna and fisheries management as well as ocean conservation.

ISSF Report Shows Management of Many Tuna Stocks Not Meeting Criteria for Marine Stewardship Council (MSC) Sustainability Standards

Written by svanouse on . Posted in News, Press Releases.

Only six out of 19 major commercial tuna stocks are being managed to avoid overfishing and restore depleted fish populations because the majority of the stocks are not protected by well-defined harvest control rules (HCRs) from Regional Fishing Management Organizations (RFMOs), according to independent scientists in a report published by the International Seafood Sustainability Foundation (ISSF).

ISSF 2017-09: An Evaluation of the Sustainability of Global Tuna Stocks Relative to Marine Stewardship Council Criteria finds that, while there has been progress by RFMOs towards developing harvest strategies and implementing well-defined harvest control rules, failure to implement controls for stocks before rebuilding is required has led to an inability to meet the MSC standard’s minimum requirements on harvest control rules.

Only 6 of 19 commercial #tuna stocks are being managed to avoid #overfishing. Share on X

In the December 2016 version of the report, almost twice as many stocks — 11 of 19 — were found to be well managed. This variance can be attributed in part to refinements made in 2017 regarding how the MSC standard assesses harvest control rules. The authors note, “Scoring guideposts were changed and additional guidance was provided to interpret the scoring guidepost text. The objective of these changes was not to alter the standard, but to continue to improve consistency in its definition and application across the wide variety of fisheries that are seeking certification.”

The report also notes an improvement in stock status scores (PI 1.1.1). For a visual summary of changes over time in the report’s scores, please see related infographics on the ISSF website: Summary of Sustainable Tuna Stocks (MSC Principle 1) and RFMO Performance (MSC Principle 3 Averages).

About the Report
An Evaluation of the Sustainability of Global Tuna Stocks takes a consistent, comprehensive approach to scoring stocks against certain components of the Marine Stewardship Council (MSC) standard. The MSC is a global certification program for fisheries.

The report — updated three times since first published in 2013, and organized by individual tuna stock and tuna RFMO — is designed to:

  • Provide a basis for comparing between stock scores and tuna RFMO scores as assessed by the same experts
  • Become a useful source document for future tuna certifications or in the establishment of tuna Fishery Improvement Projects (FIPs)
  • Prioritize ISSF projects and advocacy efforts against initiatives that will improve low performance indicator scores

The scores in the report focus on stock status (MSC Principle 1) and the international management aspects relevant to RFMOs (part of MSC Principle 3) and are based on publicly available fishery and RFMO data. Each of these Principles is evaluated in relationship to Performance Indicators (PIs) within each Principle.

The Evaluation report also includes detailed remarks on each stock, evaluations of the four RFMOs, and comprehensive reference citations.

Additional Report Findings
The report scores the main commercial tuna stocks (bigeye, yellowfin, albacore, and skipjack — but not bluefin) and each tuna RFMO (ICCAT, IATTC, WCPFC, and IOTC). An 80 is a passing score, below 60 is a failing score, and 60–79 would indicate a conditional pass, with the requirement that any deficiency is addressed within five years if a fishery were to become MSC-certified.

Other findings for each principle are as follows:

MSC Principle 1
The MSC’s Principle 1 states: “A fishery must be conducted in a manner that does not lead to overfishing or depletion of the exploited populations and, for those populations that are depleted, the fishery must be conducted in a manner that demonstrably leads to their recovery.”

Regarding stocks receiving passing scores:

  • Among seven tuna stocks in the Atlantic Ocean, two received an overall principle-level passing score: Yellowfin and Northern Albacore, which “has recovered from biomass reductions several decades ago”
  • Western Pacific Skipjack, Eastern Pacific Yellowfin, Eastern Pacific Bigeye, and Indian Ocean Skipjack all received principle-level passing scores.

In contrast, regarding stocks receiving failing scores:

  • In the Pacific, four stocks received overall principle-level failing scores: Western Yellowfin; North Albacore, South Albacore, and Western Bigeye, which has been undergoing a steady decline since the 1970s.
  • Likewise, in the Indian Ocean, Yellowfin, Bigeye, and Albacore all received overall principle-level failing
  • Yellowfin stocks in the Atlantic and Indian Oceans require rebuilding, as does Atlantic Bigeye.
  • Mediterranean Albacore and Indian Ocean Yellowfin had the most failing scores on individual performance indicators — including on stock rebuilding, harvest strategies and harvest control rules and tools.

MSC Principle 3
The MSC’s Principle 3 states: “The fishery is subject to an effective management system that respects local, national and international laws and standards and incorporates institutional and operational frameworks that require use of the resource to be responsible and sustainable.”

  • Two RFMOs — WCPFC and IATTC — received passing scores for all seven performance indicators under Principle 3.
  • The other two RFMOs — ICCAT and IOTC — received conditional passing scores on two performance indicators: “consultation, roles and responsibilities” and “compliance and enforcement.” ICCAT was given a conditional pass score for “legal and customary framework.” Other performance indicators include “long term objectives”; “fishery specific objectives”; “decision-making processes”; and “management performance evaluation.”
  • All four RFMOs received overall principle-level passing scores from the authors.

While the report focuses on tuna stock status and sustainability as well as on RFMO policies, it does not address national or bilateral fishing jurisdictions, gear- or fleet-specific ecosystem impacts, or specific fisheries’ ecosystems — all of which are also considered within the MSC assessment methodology.

Since 2011, ISSF has been an active stakeholder in MSC tuna fishery assessments and certifications. ISSF’s strategic objective is to develop and implement verifiable, science-based practices, commitments and international management measures to help all tuna fisheries become capable of meeting the MSC certification standard without conditions.

 

Dr. Gala Moreno: “Reel Insights”

Written by svanouse on . Posted in News, Videos.

We sat down with Dr. Gala Moreno to learn about her approach to marine-science and sustainable-fisheries research, which involves close collaboration with tuna fishers. This video is in Spanish with English subtitles.

Update to ISSF Participating Tuna Company Compliance Report Shows 100 Percent Conformance

Written by svanouse on . Posted in News, Press Releases.

The International Seafood Sustainability Foundation (ISSF) has released its Update to ISSF Conservation Measures & Commitments Compliance Report, which shows a first-ever conformance rate of 100 percent by 28 ISSF participating companies with all 21 ISSF conservation measures in effect as of December 31, 2016. ISSF Participating Companies account for about approximately 75% of the global canned tuna market.

As part of its commitment to transparency and accountability, ISSF engages third-party auditor MRAG Americas to assess ISSF Participating Companies’ compliance with ISSF’s conservation measures according to a rigorous audit protocol.

The November 2017 Update is based on audits conducted from May–November 2017 on measures where some companies had “minor” or “major” nonconformance. Improvements noted since the May 2017 ISSF Conservation Measures & Commitment Compliance Report include:

ISSF participating companies -- 75% of the canned tuna market -- have reached a #conservation milestone. Share on X
  • MRAG’s new audit showed 28 companies have corrected all non-conformances to become fully compliant with all 21 measures audited, compared to 22 fully-compliant companies in the May 2017 report.
  • None of the companies had minor non-conformances, as compared with five that did in May 2017. MRAG’s May report also showed that six companies had at least one major non-conformance, with a total of 12 major non-conformances found. As of the November 2017 update, all major non-conformances had been remediated.
  • Participating companies were able to close their compliance gap in 2016, moving from 97.5 percent (May 2017 report) to 100 percent full conformance.
  • The rate of full conformance has increased steadily each reporting period:
    • June 2015: 79.8 percent
    • June 2016: 87.2 percent
    • October 2016: 95.6 percent
    • May 2017: 97.5 percent
    • November 2017: 100 percent

The ISSF Conservation Measures & Commitments Compliance Report is published annually to track ISSF participating companies’ progress in conforming with ISSF conservation measures like these:

ISSF adopts new conservation measures regularly; four new measures were adopted in 2017, for example.

In addition to the summary compliance reports, third-party independent auditor MRAG Americas issues individual ISSF participating company reports that document in detail their compliance with conservation measures. Last year marked the first time that ISSF started publishing the individual company compliance reports on its website.

“Transparency and independence in the auditing process create the foundation for accountability that make our conservation measures effective, and each company’s actions influence and raise the bar for the other industry players,” said ISSF President Susan Jackson. “These companies have come a long way in making sustainability a part of their business strategy. They’re helping to make sure that they’re not only following the conservation measures on a path of continuous improvement individually, but that the companies as a group are also setting the tone for the entire tuna industry.”

More Information about ISSF Conservation Measures & Compliance
For long-term tuna sustainability, a growing number of tuna companies worldwide are choosing to participate with ISSF, follow responsible fishing practices, and implement science-based conservation measures. From bycatch mitigation to product traceability, ISSF participating companies have committed to conforming to a set of conservation measures and other commitments designed to drive positive change—and to do so transparently through third-party audits.

View ISSF Conservation Measures

View ISSA Compliance Policy

ISSF Report Analyzes Purse Seine Tuna Fishing Impacts on Sharks, Rays, and Other Species

Written by svanouse on . Posted in News, Press Releases.

Using data from Regional Fisheries Management Organizations (RFMOs), scientific observer programs, and its own at-sea research and skippers workshops, the International Seafood Sustainability Foundation (ISSF) has published an updated report that documents purse-seine tuna fishing’s impact on “non-target” species. The bycatch species covered in the report are sharks, whale sharks, rays, finfish, sea turtles, and billfish. While they are not bycatch species, the report also touches upon catches of undesirably small bigeye and yellowfin tunas.

Organized by species and including graphics and a full bibliography, “ISSF 2017-06: A Summary of Bycatch Issues and ISSF Mitigation Activities to Date in Purse Seine Fisheries, with Emphasis on FADs”:

  • Identifies issues of concern for each species
  • Summarizes the effectiveness of different bycatch-mitigation practices — at different stages of fishing operations — for either avoiding non-target species or reducing their mortality when caught
  • Describes ongoing ISSF bycatch research activities
  • Lists existing RFMO measures for minimizing bycatch
Not all non-target species are equally vulnerable to becoming bycatch in purse-seine fisheries. Share on X

“A Summary of Bycatch Issues” is intended to be a useful reference for fishers and tuna companies, scientists, regional fisheries management organizations (RFMOs), government agencies, nongovernment organizations (NGOs) including conservation groups, and others interested in helping fisheries to be more sustainable.

Report Data and Insights Can Guide Conservation Efforts

The November 2017 report, authored by ISSF staff and collaborating scientists Victor Restrepo, Laurent Dagorn, David Itano, Ana Justel-Rubio, Fabien Forget, and Gala Moreno, is an update of a 2014 publication.

Not all non-target species are equally vulnerable to becoming bycatch in purse-seine fisheries, and bycatch rates for a single species can vary across oceans. For some species, other fishing methods have higher bycatch than purse-seine fishing. Here are some key findings in the report:

  • SHARKS: 90% of sharks that become entangled in FAD nets in purse-seine fisheries are silky sharks (Carcharhinus falciformis); the oceanic whitetip shark ( longimanus) is another bycatch species. By avoiding setting on small schools of tuna (e.g. < 10 tons) around FADs, fishers could significantly reduce their catches of silky sharks by 20% to 40%, depending on the ocean. 
  • WHALE SHARKS: Whale shark (Rhyncodon typus) interaction rates with purse seiners are very low: The Western and Central Pacific Fisheries Commission (WCPFC), for example, recorded a set encounter rate of 0.94%. But any whale shark fishing mortality is a concern due to their life history and ecological significance. Time/area fishing closures do not appear effective for avoiding catching whale sharks, but best practice guidelines for their release exist. 
  • RAYS: Rays are not common bycatch in purse seine fisheries, at less than 0.1% by weight, and are mostly caught in free-school sets. Release from the deck is a viable alternative to release from the net. Fishers should avoid using hooks, wires or tightening slings and lifting or dragging by the gill slits or cephalic lobes.
  • SEA TURTLES: Sea turtles are caught in very small numbers by purse seiners, with most (greater than 90%) released alive relatively easily. Using non-entangling FADs can prevent turtle entanglement.
  • UNDESIRABLY SMALL BIGEYE AND YELLOWFIN TUNAS: Bigeye and yellowfin are not considered non-target species. Nonetheless, FAD fishing for skipjack stocks can result in higher catches of small bigeye and yellowfin, which can contribute to their overfishing. The species’ slower growth rates, higher longevity and higher age at maturity increase vulnerability to fishing. Mitigation efforts being evaluated include: adjusting the relative prices of small bigeye and skipjack tuna; setting species-specific quota; temporarily closing to fishing some areas of high concentrations; or managing the number of fishing sets on floating objects.

ISSF on Bycatch Mitigation

Since its inception in 2009, ISSF has dedicated resources and efforts to understanding bycatch issues in tuna fisheries (see “Related ISSF Activities” sections in the report). In addition to publishing scientific reports, ISSF hosts bycatch-mitigation workshops and publishes guidebooks and videos for skippers and other stakeholders. The Foundation also advocates science-based, mitigation measures to RFMOs through meetings and side events, position statements, and joint letters.

Commercial vessels catch about 4.7 million tons of tuna annually. Purse-seine vessels dominate large-scale tuna fishing, harvesting about 64% of the tropical tuna catch (skipjack, yellowfin, and bigeye tuna). Many purse seiners use Fish Aggregating Devices (FADs) or other floating objects to attract tuna to their nets, although they also may pursue sets on free-swimming tuna schools. More than half of the total tropical tuna landings globally are made by sets on FADs or other floating objects.

Bycatch occurs across most major tuna fishing methods — including longline, gillnet, and troll — and all fishing methods can affect the marine environment in multiple ways beyond bycatch.

“ISSF 2017-06: A Summary of Bycatch Issues and ISSF Mitigation Activities to Date in Purse Seine Fisheries, with Emphasis on FADs” can be downloaded from the ISSF site.

For more information on tuna stock health, see ISSF’s Status of the Stocks. For more information on FAD fishing and bycatch, see ISSF’s Questions and Answers about FADs and Bycatch.