Author: Lynne Mandel

The Vessels Behind Global Tuna Catch | New research and transparency insights

Written by Lynne Mandel on September 24, 2026. Posted in eNewsletters, News.

A Global View of Tuna Fishing Fleets

Recent ISSF research provides new insights into the vessels behind three-quarters of the world’s tuna catch.

ISSF’s first global analysis of tuna longline fleets identified 7,288 unique vessels registered across five tuna RFMOs. The updated purse-seine fleet snapshot estimates 693 large-scale purse-seine vessels target tropical tuna worldwide, with a combined fish hold volume (FHV) of approximately 895,000 m³.Together, the analyses offer insights into fleet composition, distribution, and fishing capacity — highlighting the importance of complete, consistent, and transparent vessel data.

Review ISSF’s Latest Vessel Research

Vessel Transparency in Practice

Among large-scale purse-seine vessels targeting tropical tuna, 73% — representing 83% of FHV — are listed on the ProActive Vessel Register (PVR), while 58% — representing 69% of FHV — are listed on Vessels in Other Sustainability Initiatives (VOSI).

The PVR provides independently audited information on compliance with applicable ISSF conservation measures; VOSI shows vessel participation in other tuna sustainability initiatives.

Learn About ISSF Vessel Transparency Tools

DID YOU KNOW?

ISSF Participating Companies must ensure that 100% of the large-scale purse-seine vessels they purchase tropical tuna from are listed on the ProActive Vessel Register (PVR).

Learn more

ISSF IN THE NEWS

Science-based solutions and strong partnerships take centre stage at COFI37
Food & Agriculture Organization of the United Nations

IFBMM Opens Registration for Marine Megafauna Bycatch Forum
The Fishing Daily

IATTC adopts interim management procedure for Pacific bluefin, but again defers for tropical tunas
Seafood Source

New Purse-Seine Fleet Data + Insights from TUNA 2026 | ISSF’s latest fleet snapshot tracks capacity and transparency, while Susan Jackson reflects on progress and priorities for tuna fisheries

Written by Lynne Mandel on September 17, 2026. Posted in eNewsletters, News.

New Snapshot Tracks Global Purse-Seine Fleet Capacity

ISSF’s latest annual snapshot estimates 693 large-scale purse-seine vessels are fishing for tropical tuna, with a combined fish hold volume (FHV) of approximately 895,000 m³. Both vessel numbers and FHV increased about 3% over the past year.

The report also expands its analysis of vessel participation in ISSF transparency tools: 73% of vessels, representing 83% of FHV, are listed on the ProActive Vessel Register (PVR), while 58% of vessels, representing 69% of FHV, are listed on Vessels in Other Sustainability Initiatives (VOSI).

Explore the 2026 Purse-Seine Fleet Snapshot

Susan Jackson: Facing Tuna’s Challenges with Confidence

In a guest editorial for TUNA 2026, ISSF President and conference chair Susan Jackson reflects on progress in tuna fisheries — and opportunities to continue advancing science-based management, monitoring, and transparency.

Read the INFOFISH Editorial

DID YOU KNOW?

IMO number adoption among large-scale purse-seine vessels targeting tropical tunas has increased from 12% in 2011 to 99% today. Expanding IMO number use across more vessel types and sizes can further strengthen vessel identification and transparency.

Learn More

ISSF IN THE NEWS

IATTC Progress — and Priorities for 2027

Fish Focus reports on ISSF’s assessment of the 2026 IATTC annual meeting, including progress on Pacific bluefin tuna, South Pacific albacore, electronic monitoring, and ecosystem management — and key decisions deferred to 2027.

Read the Coverage

IATTC 2026 Outcomes + Advancing Ecosystem-Based Tuna Management | Plus: Inside tuna policy, governance, & transparency

Written by Lynne Mandel on September 10, 2026. Posted in eNewsletters, News.

IATTC Makes Progress, But Key Tuna Decisions Move to 2027

The IATTC made progress on Pacific bluefin tuna, South Pacific albacore, electronic monitoring, and ecosystem management at its annual meeting. But several major ISSF priorities, including a management procedure for tropical tunas and stronger shark conservation measures, were deferred. Read the new ISSF meeting recap for the outcomes and priorities heading into 2027.

Read the IATTC Meeting Review

Assessing the Environmental Impacts of Tuna Fisheries

An updated ISSF analysis examines the impacts of major tuna fishing methods on non-tuna species, habitats, and the broader marine environment. The report also reviews measures adopted by tuna RFMOs and ISSF to mitigate those impacts.

Explore the Environmental Impacts Report

Did You Know?

All four tuna RFMOs are already working with ecosystem indicators — but most are not yet routinely used to inform management decisions. A new ISSF technical report examines how ecosystem indicators can better inform fisheries management decisions.

Read the Technical Report

ISSF in the News

Inside Tuna Policy, Governance, and Transparency
How to Protect the Ocean

How do international fisheries policy and governance translate into progress for tuna fisheries? On the How to Protect the Ocean podcast, ISSF Vice President of Policy and Outreach Holly Koehler discusses RFMO decision-making, the evolution of tuna management, and how ISSF works across the tuna supply chain to advance conservation, transparency, and accountability.

Listen to the Conversation

New Insights on Global Tuna Fleets | Plus: Reducing ecosystem impacts and looking ahead to TUNA 2026

Written by Lynne Mandel on September 3, 2026. Posted in eNewsletters, News.

A Clearer Picture of the Global Tuna Longline Fleet

ISSF’s first global analysis of tuna longline fleets brings together vessel registry data from all five tuna RFMOs, providing a clearer picture of fleet composition, characteristics, and fishing capacity. The analysis of 7,288 unique longline vessels also identifies opportunities to improve the completeness, consistency, traceability, and transparency of vessel information that supports fisheries science and management.

View the Global Longline Fleet Analysis

Did You Know?

All tropical tuna RFMOs now prohibit netting material in drifting FADs. ISSF’s latest environmental impacts report reviews RFMO measures and other mitigation efforts addressing the impacts of tuna fisheries on non-tuna species and marine ecosystems.

Explore Environmental Impacts

ISSF President to Chair TUNA 2026

ISSF President Susan Jackson will serve as Chairperson of the 19th INFOFISH World Tuna Trade Conference & Exhibition, taking place September 14–16 in Bangkok. The global gathering will bring together tuna industry leaders, policymakers, RFMOs, researchers, and other stakeholders to discuss sustainability, trade, technology, traceability, and other issues shaping the future of the tuna industry.

Learn More About TUNA 2026

Q&A: Verifying Sustainability Commitments | Putting Transparency Into Practice

Written by Lynne Mandel on August 27, 2026. Posted in eNewsletters, News.

Q&A: Verifying Sustainability Commitments in the Global Seafood Supply Chain

What makes a sustainability commitment credible — and how can stakeholders know whether companies are following through?

ISSF President Susan Jackson and MRAG Americas Vice President Dr. Graeme Parkes discuss more than a decade of independent auditing of ISSF participating companies, including how audits work, why transparency matters, and what the results show about progress over time.

Explore the Q&A

Tracking Progress Through Independent Audits

ISSF’s latest compliance report provides independently audited results for 24 participating companies. For the 2025 audit period, companies achieved 98.8% conformance across 32 ISSF Conservation Measures.

See the Latest Results

Did you know?

ISSF uses independent audits, public reporting, and other transparency tools to verify participating company and vessel commitments.

Explore How Verification Works

ISSF In the News

Businesses, NGOs Push IATTC to Adopt Management Procedures for Tropical Tuna
SeafoodSource

New Q&A: Advancing Harvest Strategies | Plus: Tracking progress across 23 tuna stocks

Written by Lynne Mandel on August 20, 2026. Posted in eNewsletters, News.

Featured News

Q&A: Moving Harvest Strategies from Concept to Implementation

Harvest strategies are changing how tuna fisheries are managed — replacing year-to-year negotiations with pre-agreed rules that help managers respond more predictably as stock status changes.

In a new joint Q&A, ISSF President Susan Jackson and WCPFC Executive Director Rhea Moss-Christian discuss the progress tuna RFMOs have made in putting harvest strategies into practice, including WCPFC’s work on skipjack and North and South Pacific albacore. They also explore what this experience can teach the broader ocean governance community and how greater knowledge-sharing among RFMOs can accelerate progress globally.

Read the Q&A

Featured Content

Updated Evaluation Tracks Progress Against MSC Stock Requirements

How do the world’s major commercial tuna stocks measure up against Marine Stewardship Council Principle 1 requirements?

ISSF’s latest evaluation applies the MSC Fisheries Standard criteria for sustainable fish stocks to 23 major commercial tuna stocks. The analysis highlights continued improvements in stock status while also identifying where stronger harvest strategies and management procedures are still needed.

Explore the results, including a summary of key findings and the full technical report.

See the Latest Evaluation

Did You Know?

ISSF helps move fisheries science into practice. Our scientists work directly with tuna RFMOs and their scientific bodies, contributing research, technical expertise, and practical tools that support stronger fisheries management — from harvest strategies and bycatch mitigation to FAD management and electronic monitoring.

That sustained scientific engagement helps ensure that solutions are not only grounded in research but designed for real-world implementation.

Learn More About ISSF’s Science & Research

ISSF Shares 2026 Priorities for the IATTC Ahead of Annual Meeting
Fish Focus

Susan Jackson of the International Seafood Sustainability Foundation
Sea Change Radio Podcast

New: ISSF’s IATTC Meeting Preview | Top priorities for IATTC | Plus MSC updates

Written by Lynne Mandel on August 6, 2026. Posted in eNewsletters, News.

Featured News

Accelerating Progress Toward Stronger Fisheries Management for Eastern Pacific Ocean Tuna Fisheries

When the Inter-American Tropical Tuna Commission (IATTC) meets in late August, delegates will have an opportunity to turn recent advances in fisheries science and management into stronger conservation and management measures for Eastern Pacific tuna fisheries.

Over the past several years, IATTC has advanced management strategy evaluation (MSE) work for tropical tunas, adopted interim electronic monitoring (EM) standards, begun transitioning to fully biodegradable fish aggregating devices (FADs), and strengthened its compliance assessment process. The Commission’s latest scientific advice also indicates that bigeye, yellowfin, and skipjack tuna stocks in the eastern Pacific Ocean remain in healthy condition.

These advances provide a strong foundation, but additional action is needed to effectively manage tuna fisheries and their ecosystem. ISSF’s 2026 position statement highlights three priorities that can help IATTC continue making progress.

Read Our IATTC Preview

ICYMI

Updated ISSF Assessment Shows Continued Progress in Global Tuna Stock Management

ISSF has published the 2026 edition of An Evaluation of the Sustainability of Global Tuna Stocks Relative to Marine Stewardship Council (MSC) Criteria, an annual assessment that uses the MSC Fisheries Standard as a consistent benchmark to evaluate the world’s major tuna stocks. The latest report finds that 16 of 23 assessed tuna stocks now achieve a passing score for MSC Principle 1 (Sustainable Fish Stocks), up from 12 in the previous edition, reflecting improvements in stock status and fisheries management.

The report also shows continued progress in the adoption and implementation of harvest control rules, with nine of the 23 assessed stocks now managed under fully implemented, well-defined harvest control rules, compared with seven in the previous edition. While additional management improvements remain necessary for some stocks, the assessment provides a consistent framework for tracking progress over time and identifying priorities for continued improvement.

Read the Full Report

Did You Know?

ISSF participating companies demonstrate their commitment through independent audits and public reporting against ISSF conservation measures. Buyer and retailer sustainability policies increasingly reference ISSF participation and ISSF’s ProActive Vessel Register (PVR) and Vessels in Other Sustainability Initiatives (VOSI), helping companies transparently demonstrate progress toward procurement criteria and customer expectations.

Learn More About ISSF Participation

More Tuna Stocks Meet MSC Sustainability Criteria in 2026 Assessment | ISSF’s latest evaluation shows continued progress in stock status and fisheries management

Written by Lynne Mandel on July 30, 2026. Posted in eNewsletters, News.

Featured News

Updated ISSF Assessment Shows Continued Progress in Global Tuna Stock Management

Read the Full Report

ICYMI

Priorities for Eastern Pacific Ocean Tuna Fisheries

ISSF has published its position statement ahead of the 104^th meeting of the Inter-American Tropical Tuna Commission (IATTC), which will take place August 31-September 4, 2026, in Lisbon, Portugal.

The statement outlines ISSF’s priorities for strengthening tuna fisheries management, including science-based conservation measures, harvest strategies, electronic monitoring and reporting, observer coverage, FAD management, bycatch mitigation, shark protections, transshipment regulation, labor and social issues, compliance, and fishing capacity.

Read the IATTC Position Statement

Did You Know?

A new ISSF report identifies 7,288 unique tuna longline vessels registered across the world’s five tuna RFMOs — the first time these registries have been harmonized into a single global analysis.

Explore the Global Longline Fleet Report

New Global Longline Fleet Analysis | Plus ISSF’s IATTC Priorities and the Latest Status of the Stocks

Written by Lynne Mandel on July 23, 2026. Posted in eNewsletters, News.

Featured News

ISSF Publishes First Global Analysis of Tuna Longline Fleets Across All Five Tuna RFMOs

New technical report provides the first harmonized global analysis of longline fleet composition, vessel characteristics, and fishing capacity

ISSF has published Characteristics of Longline Fleets Registered in Tuna Regional Fisheries Management Organizations as of June 2026, a new technical report by Dr. Josu Santiago. Drawing on vessel registry information from all five tuna RFMOs, the report provides the first harmonized global analysis of the authorized tuna longline fleet, including vessel characteristics, fishing capacity, flag State distribution, and vessels operating across multiple RFMO convention areas.

For more than a decade, ISSF has published annual snapshot reports tracking the global large-scale tropical tuna purse seine fleet. This new report extends that work to tuna longline fleets for the first time, providing complementary analyses of the composition and fishing capacity of the world’s principal tuna fishing fleets.

Read the Longline Fleet Report

Featured Position Statement

Priorities for Eastern Pacific Ocean Tuna Fisheries

ISSF has published its position statement ahead of the 104^th meeting of the Inter-American Tropical Tuna Commission (IATTC), which will take place August 31-September 4, 2026, in Lisbon, Portugal.

Read the IATTC Position Statement

Did You Know?

97% of the global commercial tuna catch comes from stocks at healthy abundance levels, and nearly 100% comes from stocks not experiencing overfishing.

See the Status of the Stocks

Shark Awareness Day | Advancing Shark Conservation in Tuna Fisheries

Written by Lynne Mandel on July 16, 2026. Posted in eNewsletters, News.

July 14 marked Shark Awareness Day, an opportunity to recognize the important role sharks play in healthy ocean ecosystems and the collaborative efforts underway to reduce shark interactions in global tuna fisheries.

ISSF advances shark conservation through research, practical solutions to reduce shark bycatch and entanglement, guidance for fishers, and advocacy for stronger science-based fisheries management. This work helps address ecosystem impacts that are increasingly important to fisheries, seafood companies and broader sustainability initiatives while supporting continuous improvement across global tuna fisheries.

Featured Content

Q&A with Sonja Fordham

To mark Shark Awareness Day, ISSF spoke with Sonja Fordham, founder of Shark Advocates International and a member of ISSF’s Environmental Stakeholder Committee, about her perspective on the state of shark conservation.

In the Q&A, Sonja discusses why sharks are important to healthy ocean ecosystems, threats facing shark populations, encouraging advances in international fisheries management, promising innovations to reduce shark and ray bycatch, and the additional actions she believes tuna Regional Fisheries Management Organizations (RFMOs) should take to strengthen shark conservation.

Read the Q&A

Featured Resource

Explore ISSF’s Shark Conservation Resources

ISSF’s shark conservation work spans research, practical tools, policy engagement and industry collaboration to help reduce shark bycatch, improve shark survival and advance science-based fisheries management.

Explore our shark conservation resources, including:

Shark bycatch mitigation research
Guidance for fishers on safe handling and release
Information on non-entangling fish aggregating devices (FADs)
Longline and purse seine skippers’ guidebooks
Shark conservation recommendations for tuna RFMOs

Whether you’re looking for the latest science, practical guidance or policy resources, ISSF’s shark resource hub brings together the tools and information that support continued progress in shark conservation across global tuna fisheries.

Explore Shark Conservation Resources