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Author: Mary Sestric

IATTC Meeting Outcomes

Featured Blog

Eastern Pacific Ocean Tuna Fisheries

Wins for Transshipment, Harvest Strategies and Compliance Reforms, but Misses on Measures for Stronger FAD Management, Increased Observer Coverage, and Protections for Sharks

At the conclusion of the annual meeting of Inter-American Tropical Tuna Commission (IATTC), the International Seafood Sustainability Foundation (ISSF) is reflecting on the outcomes for Eastern Pacific Ocean (EPO) tuna fisheries. While we are disappointed that the Commission did not address our top ask on improved fish aggregating device (FAD) designs, we are pleased that managers made headway on important topics like at-sea transshipment measures, harvest strategies, and compliance reforms.

Here is a review of the results of the IATTC meeting against our organization’s priorities as outlined in our 2022 position statement.

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Featured Report 

Slight Decrease in Purse Seine Vessels Overall, and Fewer Large Scale Purse Seine Vessels Fishing for Tropical Tuna Species Globally 

ISSF has updated its Large-Scale Tuna Purse Seine Fishing Fleets report for July 2022. The total number of purse seine vessels, calculated based on data from the five tuna Regional Fisheries Management Organizations (RFMOs), has decreased slightly from 1,855 in 2021’s report to 1,808 today. 

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Featured Infographic

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ISSF Statement in Response to IATTC Special Meeting

The action by IATTC at its emergency Commission meeting held on December 22 — a meeting and decision that ISSF and its stakeholders called for earlier this month — keeps crucial “status quo” fishing effort and catch limit provisions and active FAD limits in place for 2021. This decision ensures that the valuable tuna resources and the marine ecosystems of the Eastern Pacific Ocean (EPO) will not be unmanaged for 2021. And it gives the Commission an opportune period to develop and adopt new comprehensive tuna management measures for 2022, including science-based limits on FADs and floating objects (e.g., active numbers, sets, deployments, etc.), that fully implement scientific advice. 

ISSF calls on IATTC parties to work collaboratively throughout next year to hold detailed, inclusive discussions that will lead to decisive and science-based action for the protection of EPO tuna stocks and their marine ecosystems. Regardless of meeting format in 2021, ISSF will pursue all opportunities to help guide IATTC and all tuna RFMOs, member governments, industry, vessels, FIPs and NGOs on the complex issues they must navigate for sustainable global tuna stocks and their ecosystems.

ISSF to IOTC: Listen to Your Scientists, Take Immediate Steps to Protect Yellowfin

The International Seafood Sustainability Foundation (ISSF) published its position statement in advance of the 23rd Session of the Indian Ocean Tuna Commission (IOTC) in Hyderabad, India, June 17-21.  

ISSF’s highest priority item for IOTC is the adoption of an effective rebuilding plan for yellowfin tuna, one that gives full effect to the recommendations from IOTC’s Scientific Committee. In 2018, the Scientific Committee reported that catches of yellowfin tuna exceeded by 3% the management measures previously agreed by the Commission that called for reductions in catches; reductions that did not even meet the scientific advice.

“Fisheries managers must act to protect Indian Ocean yellowfin,” said ISSF President Susan Jackson. “The scientific evidence regarding the status of Indian Ocean yellowfin is well-documented and concerning, and the IOTC has the power to adopt management measures that will rebuild this stock. The IOTC must heed the advice of its Scientific Committee and adopt effective management measures to reverse the decline of this critical resource.”

For yellowfin tuna, a species that is subject to overfishing, an over-catch of 3% places further stress on this resource. According to ISSF, IOTC should adopt an effective rebuilding plan for yellowfin tuna that: gives full effect to the advice of the IOTC Scientific Committee and achieves a healthy spawning biomass for the species by 2024 with at least 50% probability.

ISSF also advocates that IOTC:  

  1. Adopt species-specific harvest strategies as soon as possible, particularly for yellowfin tuna, and conduct a review of the limit reference points (LRPs) in Resolution 15/10 to allow for the adoption of harvest control rules by 2020.
  2. Urgently address data gaps in artisanal fisheries, especially for gillnets.
  3. Strengthen monitoring, control and surveillance (MCS) measures, such as vessel monitoring systems (VMS) and the regional observer scheme (ROS), to support data collection, monitoring and the implementation of harvest strategies.
  4. Strengthen fish aggregating device (FAD) management, including of supply and tender vessels; ensure full implementation of non-entangling FADs; and support testing of biodegradable FADs.
  5. Amend Res. 11/04 to require 100% observer coverage on large-scale purse seine vessels; adopt the ROS Standards for national programs; and develop electronic monitoring/electronic reporting (EM/ER) standards so that EM can be used to ultimately achieve 100% observer coverage in purse seine and longline fisheries.
  6. Continue to strengthen the IOTC compliance assessment process.

Read the full IOTC Position Statement, available in English or French, on the ISSF website.

ISSF Global Priorities for Tuna RFMOs

ISSF is committed to advocating for science-based approaches, policies and conservation measures to advance tuna fisheries sustainability. The following are ISSF’s Global Priorities for Tuna RFMOs, specifically, the Indian Ocean Tuna Commission (IOTC), the Inter-American Tropical Tuna Commission (IATTC), the International Commission for the Conservation of Atlantic Tunas (ICCAT) and the Western and Central Pacific Fisheries Commission (WCPFC):

  • Implementation of rigorous harvest strategies, including harvest control rules and reference points;
  • Effective management of fleet capacity, including developing mechanisms that support developing coastal state engagement in the fishery;
  • Science-based FAD management & non-entangling FAD designs;
  • Increased member compliance with all adopted measures adopted, and greater transparency of processes reviewing member compliance with measures;
  • Strengthened MCS measures and increased observer coverage, including through modern technologies such as electronic monitoring and e-reporting; and;
  • Adoption of best-practice bycatch mitigation and shark conservation and management measures.


What’s Fair Game on the High Seas?

Sustainability-driven new research could one day help tuna fisheries cast their nets more selectively, mitigating unintentional “bycatch” of undersized fish and off-limits species.

The key development is an innovative application of electronic fish-finders like those commonly used by commercial tuna fleets. A multinational research team conducted the investigation under the sponsorship of the International Seafood Sustainability Foundation (ISSF).

In a research article titled Acoustic Discrimination of Tropical Tuna, published today in PLOS ONE, the peer-reviewed open-access journal of the Public Library of Science, the ISSF team’s findings address a chronic challenge for commercial fishing fleets: How is it possible to identify and harvest mature, sustainable tuna without disturbing young fish or other species in the same vicinity?

As corresponding author Gala Moreno, Ph. D., explains, “If you’re working with land animals, you can walk right up to the herd and count them by size and species. But, typically, fish are out of your reach, hard to see, and constantly moving in three dimensions.”

Tuna support some of the world’s largest and most valued fisheries. The prevailing technique in many tuna fisheries worldwide employs large “purse seine” nets to collect everything that swims inside a circle of up to 500 meters (about a third of a mile) across and as much as 180 meters deep. Typically, purse-seine fishing is conducted near fish-aggregating devices (FADs), passive structures built to exploit marine life’s tendency to gather beneath floating objects.

In an ideal scenario, a purse-seine vessel would head for a given FAD where shipboard or FAD-based electronics have detected a promising mass of fish. Then (again, ideally) the crew would set its net and haul in a uniform catch of mature skipjack tuna, a favored species that’s considered plentiful enough to be caught sustainably.

In practice, however, FADs attract mixed populations that include unacceptably small skipjack, as well as yellowfin and bigeye tuna of all sizes, which can be proscribed in certain waters. But sorting them out before the net closes in is practically impossible. A technology capable of analyzing the proportions of various tuna species swimming together, at a distance, would:

  • Help fishing-vessel skippers selectively target sustainable species
  • Save fuel and reduce marine-engine emissions by guiding vessels more directly to the right fishing grounds
  • Reduce wasteful bycatch and the mortality of vulnerable species

Current acoustic technology can detect schools of tuna around FADs remotely, but so far no conventional onboard or FAD-mounted device can distinguish fine detail such as fish sizes or species. Based on innovative field work, performed at sea on commercial fishing vessels, the new paper explores a technique for repurposing standard echolocation devices to predict not only the quantities but also the mix of sizes and species in an aggregation of fish.

A key factor is the gas-filled swim bladder that regulates buoyancy in most bony fishes. The interface between the trapped gas and the bladder envelope is an effective sound reflector. Marine echolocation devices work primarily by emitting powerful sonic pulses, then reading the sound that bounces back from that interface or other tissue. Each species reflects certain frequencies more strongly than others, so each presents a distinctive acoustic signature.

Bigeye and yellowfin are equipped with similar swim bladders, but skipjack make do with no swim bladders at all. The resulting difference in acoustic signatures could eventually help skippers distinguish skipjack from bigeye and yellowfin remotely.

Although acoustic properties have long been used to assess the abundance and species of fish other than tuna, the ISSF team’s work has produced the first sonic-discrimination data that could lead to practical, selective tuna fishing techniques around FADs in the tropics.

Instruments on board the team’s host vessel supplied an unprecedented level of calibrated acoustic data describing the frequency responses of tropical tuna. Measurements stemming from the vessel’s capture of entire tuna aggregations were vastly more reliable than comparable data gathered in earlier surveys involving smaller-scale fishing operations.

According to Dr. Moreno, “Our research opens the door to several positive developments: faster growth of knowledge about the acoustic properties of tropical tunas; the advantages of close collaboration with commercial operations in support of science; definition of the conditions necessary for applying this technology for selective fishing; and projections of other uses of direct acoustic observations, as direct indices of tropical tuna abundance, to support tuna conservation.”



Financial Disclosure
The research reported in the present document was funded by the International Seafood Sustainability Foundation and the Common Oceans ABNJ Tuna Project. The research was conducted independently by the authors. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.