The EU, Norway and UK face a pivotal moment for the management of a key Northeast Atlantic forage fish
North Sea herring, a small pelagic forage fish, has long been a cornerstone of European fisheries and is vital to both the marine ecosystem and the coastal economies that depend on it. But, like other internationally-shared fisheries in the Northeast Atlantic such as those for mackerel, blue whiting and Atlanto-Scandian herring, the North Sea herring fishery also has had challenging periods in its management, including historic periods of overfishing. However, an upcoming negotiation could mark a monumental shift in how North Sea herring and other key fisheries are managed, both in terms of sustainability and with regard to their important role in the marine ecosystem.
Fisheries managers can adopt a new long-term management strategy (LTMS) for North Sea herring in two planned rounds of trilateral meetings among the European Union, Norway and the United Kingdom, scheduled in the weeks of 27 October and 17 November. This LTMS – the regional term used in the Northeast Atlantic for harvest strategy or management procedure – would include a harvest control rule (HCR) to set annual catch limits. If followed, these limits could lead to sustainable management for many years to come. The strategy would set clear benchmarks and rules for future changes in allowable catch while recognizing herring’s crucial role in the marine ecosystem. This plan would ensure that the fishery not only meets long-term human demand but also accommodates the needs of key predators such as seabirds.
State-of-the-art science backs the North Sea herring management proposal
Nearly two years of collaborative scientific work by the International Council for the Exploration of the Sea (ICES) underpins the development of a North Sea herring harvest strategy, work that has been scientifically tested using a process called management strategy evaluation (MSE). This tool tests a variety of HCRs using computer simulations to find out which ones can best achieve the desired long-term sustainability and precautionary objectives for the fishery while providing predictable and high annual catches for the fishing sector, markets and consumers.
At the request of the three negotiating Parties, an ICES Workshop on Management Strategy Evaluation for North Sea Herring convened in early 2024 to conduct an MSE to test the ability of several harvest strategies in achieving various management objectives. The MSE process covered a range of ecological scenarios and reflected key scientific and management uncertainties to help determine the best possible management approach.
The MSE tested HCRs under a plausible range of natural conditions. These incorporated biological parameters for the species based on an ecosystem model that included a spectrum of predator-prey dynamics and examined scenarios that reflect natural variability and potential environmental influences on the productivity of herring. By integrating these ecological considerations, ICES scientists provided informed evaluation and advice to the Parties on a management framework that acknowledges herring as part of a dynamic ecosystem.
A balanced harvest strategy could help secure North Sea herring’s sustainability
With several science-based options now on the table, managers need to adopt their preferred harvest strategy and use it to set a total allowable catch (TAC) limit for 2026. One of the options, known as Management Strategy 3 (MS3), has gained traction among the parties. And while it isn’t the most precautionary option available, it does offer a good balance of stock health, total allowable catch and acceptable levels of stability and risk. If implemented successfully, it would help to ensure future sustainability.
Over the summer, the Parties jointly asked ICES to reissue their annual catch advice for herring based on the particular management parameters of MS3. But the coming weeks are pivotal. By adopting this harvest strategy, including it in their publicly available Agreed Record of negotiations and using it to set their future catch limits, managers can lock in a transparent, scientific and rule-based framework that provides predictability and stability for operators in the region and takes ecological considerations into account.
But adopting the harvest strategy isn’t enough. To really succeed, the Parties should also develop what is known as an Exceptional Circumstances Protocol. This would set clear parameters for whether and when the LTMS should be re-evaluated while allowing adaptability in cases of changes on the water.
The North Sea herring MSE process shows what’s possible when scientists, managers and stakeholders work together. Now, with a clear evidence base and consensus within reach, managers have a rare opportunity to set a new management precedent and secure the future of the iconic North Sea herring fishery. They can then chart a path forward for other important Northeast Atlantic fisheries such as mackerel and Atlanto-Scandian herring.
Ashley Wilson works on The Pew Charitable Trusts’ international fisheries project.
The www.HarvestStrategies.org team is thrilled to announce the launch of a new course series: “Management Procedures for Sustainable Tuna Fisheries,” developed in partnership with the FAO eLearning Academy. There are five educational modules that cover topics related to management procedures (MPs), from setting the vision for the future of the fishery with management objectives, to testing candidate MPs using management strategy evaluation (MSE), to implementation using the MP feedback loop.
The five courses include:
Together, the courses amount to approximately 6.5 hours of learning. Once completed, users can take a final test to earn an FAO eLearning Academy digital certification badge, which can lead to expanded employment opportunities, among other benefits.
The course is designed for a wide range of learners, including fishery managers, fishery scientists, industry professionals, environmental stakeholders, and others. It’s relevant to both tuna and general RFMOs, as well as domestic fisheries. The open-source, free-to-use content can also be used by colleges and universities for academic training. All that is needed is an FAO eLearning Academy log-in (Click here to register for free!).
While the series is currently available only in English, Spanish and French versions will be launching within the next few months. For learners eager to apply their new knowledge to an MP development process close to home, we are pleased to offer a limited number of follow-up, customized, live sessions, tailored to the audience’s interests, either online or in-person. Please email info@harveststrategies.org to learn more!
This course has been many years in the making, and we would like to give a tremendous thank you to our project sponsors and partners, most notably the Common Oceans Tuna Fisheries Project, which is funded by GEF and implemented by FAO. The Pew Charitable Trusts and International Seafood Sustainability Foundation (ISSF) also helped with content development and review. We are also indebted to our Project Advisory Committee and a focus group of esteemed fisheries managers, scientists, and industry representatives whose review and input greatly improved the materials.
Please visit the FAO eLearning Academy to take one – or ideally, all! – of the courses to deepen your understanding of management procedures and strengthen your ability to engage meaningfully in the development and adoption process. It will help to ensure your priorities are reflected in the process, and you might even have a little fun along the way!
Stay tuned for an announcement about our next quarterly webinar, which FAO will host as the official launch of the course!
The Inter-American Tropical Tuna Commission (IATTC) convened for its annual meeting in Panama City last week. At the start of the year, the plan was to adopt harvest strategies for both bigeye and Pacific bluefin tuna at the Commission meeting, which would have revolutionized tuna management in the eastern Pacific. Unfortunately, the bigeye tuna management strategy evaluation (MSE) work wasn’t complete, and the Pacific-wide bluefin regulatory body was unable to reach consensus on selection of a harvest strategy when it met in July, precluding IATTC from adoption for both stocks in Panama. However, important groundwork was laid at the meeting to advance harvest strategies for several of its valuable stocks in the coming year.
A new measure was adopted for tropical tunas, which commits to finalizing the bigeye MSE in 2026 to enable harvest strategy adoption next year. To facilitate the process, the new Working Group on MSE will meet three to four times between now and then to discuss management objectives and provide feedback and direction on the preliminary performance results of the candidate harvest strategies being considered.
The MSE for Pacific bluefin is complete, and governments are selecting among a handful of candidate harvest strategies projected to meet objectives. To advance the discussions toward consensus, IATTC members agreed to hold an intersessional meeting of the joint working group with the Western and Central Pacific Fisheries Commission (WCPFC) in early 2026, which is a very important step toward adoption.
South Pacific albacore is currently unmanaged in the eastern Pacific, but that could soon change as terms of reference were agreed upon for a new joint working group with WCPFC on management of the stock. WCPFC is slated to adopt a harvest strategy for South Pacific albacore later this year, and this new working group strives to develop complementary management for the eastern part of its range.
IATTC members also agreed to establish a working group on dorado, also known as mahi-mahi. This commercially and recreationally targeted species is highly valued, yet to date lacks international management in the Pacific and beyond. IATTC scientists completed an MSE for the stock in 2019, but it was never used for management. This new working group will facilitate new assessment efforts and reopen the door for future development of a harvest strategy for the stock.
HarvestStrategies.org also participated in a side event hosted by the FAO Common Oceans Program, where we highlighted the educational materials we’ve developed on harvest strategies and MSE, including exciting news about our soon-to-be-released eLearning course. It’s our hope that these communication tools will provide valuable support as IATTC works to bring multiple harvest strategies across the finish line next year.
IATTC is currently the only tuna management body without a harvest strategy in place. While IATTC adopted a harvest strategy for North Pacific albacore in 2023, the output of the rule is “fishing intensity,” which cannot be implemented until converted into total allowable catch and/or effort. While that conversion was slated for agreement last year, talks have continuously stalled, and members have agreed to finish the job in 2026.
With harvest strategy adoption slated for both bigeye and Pacific bluefin, as well as agreement on how to implement the North Pacific albacore harvest strategy, 2026 is shaping up to be a milestone year for harvest strategies at IATTC!
The North Pacific Fisheries Commission (NPFC) is one of the youngest Regional Fisheries Management Organizations (RFMOs), established in 2015. Its objective is to ensure the long-term conservation and sustainable use of fishery resources in the Convention Area while protecting the marine ecosystems of the North Pacific Ocean where these resources are found.
Since 2018, I have participated in NPFC Scientific Committee (SC) meetings and its subsidiary group meetings, witnessing how the NPFC has progressed toward a science-based management framework through collaborative scientific efforts among its members. This progress is particularly evident in the stock assessment and management of two NPFC priority species—Pacific saury (Cololabis saira) and Chub mackerel (Scomber japonicus).
The NPFC SC has been enhancing its understanding and capacity to develop management strategy evaluation (MSE) for its priority species since 2019. Each year, the NPFC SC nominates and provides financial support for SC representatives to attend relevant scientific training sessions and meetings, fostering their expertise in this field. In February 2025, I was nominated and selected as an SC representative to participate in a one-week capacity building activity organized in collaboration with Blue Matter Science in Vancouver, Canada. This capacity building activity aimed to develop a stock assessment model and MSE framework for another NPFC priority species—Neon flying squid (Ommastrephes bartramii). The Small Scientific Committee on Neon Flying Squid (SSC NFS), established in 2024, is still in its early stages but is committed to developing a science-based approach to management of the species. To date, only two SSC NFS meetings have been held to assess the fishery status and evaluate data availability among NPFC members.
Before traveling to Vancouver, I reviewed the available data and confirmed that annual catch and catch per unit effort (CPUE) data were available and sufficient to support the development of a type of assessment model called a surplus production model under data-moderate conditions. This was significant since people often think of squid fisheries, like other short-live species, as data-poor. I attempted to fit surplus production models (i.e., SPiCT) to both the winter-spring and autumn cohorts of Neon flying squid, but only the model for the autumn cohort successfully met the diagnostic criteria for acceptable model performance.
During my visit to Vancouver, I received technical guidance from Blue Matter Science scientists—Drs. Tom Carruthers, Adrian Hordyk, and Quang Huynh—to develop an MSE framework for Neon flying squid using their OpenMSE package. We constructed and conditioned an age-structured operating model (OM) in OpenMSE to align with the SPiCT-derived biomass and harvest rate estimates for the autumn cohort. Additionally, we designed catch- and effort-based harvest control rules (HCRs) to evaluate the performance of output versus input controls.
To approximate the 12-month lifespan of this species in the OpenMSE age-structured OM, we specified high mortality rates to effectively remove each cohort from the population after age-1.
Through closed-loop simulations using the OpenMSE package, we evaluated the management trade-offs between constant catch/effort HCRs and index-based empirical HCRs for the NFS autumn cohort. Our results demonstrate that effort control exhibits greater resilience than catch control, with maintaining current effort levels showing a 62.55% probability of sustaining stock biomass above current levels after 20 years while simultaneously maintaining a 62.65% probability of catches exceeding current levels.
The findings of this study are preliminary because certain input data and parameters remain to be finalized. We recommend that the SSC NFS collect and share finer catch and effort data to develop a monthly time-step OM for Neon flying squid, enabling more precise evaluation of seasonal biological and fishing dynamics. Such finer data would significantly improve in-season management assessments by allowing simulation of fisheries dynamics at finer temporal scales and better evaluation of management approaches using previous year’s data – though we note these have limited value for short-lived species since last year’s data contain no information about subsequent cohort abundance, so in-season management would be worth testing. Additionally, OpenMSE’s multi-stock modeling capability could facilitate development of a joint model integrating both autumn and winter-spring stocks to evaluate comprehensive management procedures for NFS fisheries.
Given the limited capacity within the NPFC SC, I hope established modeling packages like OpenMSE can be applied to more NPFC priority species – particularly Pacific saury and Chub mackerel – to help transition the NPFC toward modern, MSE-based management systems.
Climate change has substantial implications for global fisheries. In fact, scientists project that related losses in fish biomass production in the coming decades will occur in many regions, including countries such as the Federated States of Micronesia and Portugal, that rely substantially on aquatic foods for their domestic protein supply. Further, climate change is already causing changes to geographic species distributions and species life histories, including aspects such as growth and reproduction, for stocks around the world.
In the face of these and other severe impacts, fisheries managers can develop and implement climate adaptive fisheries management measures including harvest strategies (HS), which are also known as management procedures. These strategies shift management of a fish stock from short-term and reactive decision-making to longer-term objectives, such as growing a fish population’s size, to support sustainable and profitable fisheries. HS are underpinned by a scientific assessment process known as management strategy evaluation (MSE), which ensures that management objectives can be met under a variety of environmental conditions. HS are also designed to help fisheries adapt to changing conditions.
To learn more about the intersection of HS and climate change, we performed a rapid review of recent peer-reviewed literature and found that:
To date, the results of this review have been shared with several RFMOs, including the North Pacific Fisheries Commission, the South Pacific Regional Fisheries Management Organisation, and the International Commission for the Conservation of Atlantic Tunas, and we hope that more fisheries managers will consider the results of the science in thinking through the role that harvest strategies can play in navigating the impacts of climate change to fisheries.
Dr. Emily Klein and Dr. Ellen Ward are officers working on The Pew Charitable Trusts’ conservation support and conservation science teams.
Ellen Ward, Ph.D., works with Pew’s conservation support team, where she focuses on furthering climate adaptation and resilience solutions in the U.S. and internationally.
Prior to joining Pew, Ward worked for the National Oceanic and Atmospheric Administration (NOAA) as an international affairs specialist focused on climate change, water resources, and deep seabed mining, including representing the agency at negotiations of the International Seabed Authority in Jamaica. She previously worked on habitat conservation issues for NOAA Fisheries in Alaska and on water resources management for the Government of Yukon, Canada.
Ward holds a bachelor’s degree in physics from Columbia University and a master’s and Ph.D. in earth system science from Stanford University.
Emily Klein, Ph.D., leads Pew’s work to design research projects that use innovative analytical and modeling tools to improve what we know about marine and freshwater systems, and the human connections to them. She also works to advance inclusion, diversity, and equity within Pew, across our grantees, and in the natural sciences.
Before joining Pew, Klein studied the complex connections between people and nature to support future sustainability with Boston University’s Frederick S. Pardee Center for the Study of the Longer-Range Future. While there, she managed a project in collaboration with the Bureau of Ocean Energy Management to apply ecosystem models to inform decisions about sand mining for beach renourishment in offshore waters of the New England and the mid-Atlantic regions. Prior to this work, Klein employed models and other tools to support marine management and decision-making, including for marine protected areas under climate change in the Antarctic, and to investigate interactions between management and fishing communities.
Klein holds a bachelor’s degree in ecology, behavior, and evolution from the University of California at San Diego, a master’s in environmental conservation and doctorate in natural resources and earth systems science from the University of New Hampshire.
Pacific bluefin tuna make headlines in the world’s most prominent media outlets. “Overfishing causes Pacific bluefin tuna numbers to drop 96%.” “Massive tuna nets $3.1 million at Japan auction.” “Quota for big Pacific bluefin tuna to rise 50% amid stock recovery.” Next month, there is an opportunity for Pacific bluefin to earn their best headline yet: “Agreement on management procedure locks in long-term sustainability.” And that’s exactly what we hope we’ll be posting on this blog in mid-July.
In response to the decimation of the species to just 2% of its unfished level, Pacific bluefin managers called for the development of a management procedure (MP) to be tested using management strategy evaluation (MSE). The first dialogue meeting of scientists, managers, and stakeholders took place in 2018 to provide input on management objectives and other MP elements. Fast forward 7 years, and we have a final MSE, with 16 candidate MPs in the running for selection by the IATTC-WCPFC Northern Committee Joint Working Group on Pacific Bluefin Tuna (JWG) when it meets in Toyama, Japan, July 9-12. To prepare for that meeting, the JWG will host a webinar next week to review the final results and offer a Q&A session.
The key remaining decisions include:
For the TRP, we support neither the most aggressive nor the most conservative fishing rate, instead preferring a middle option to balance long-term catch and conservation.
For the ThRP, we support a level that is an adequate distance from the LRP to ensure that it is not breached.
For the LRP, we again support one of the central options that balances the tradeoffs between fishing and stock status objectives. We oppose the candidate MPs that do not include an LRP because LRPs are an essential element of all MPs, ensuring that the stock does not drop to a dangerously low level.
We do not have a position on the West:East split, but note that because the two options did not show much difference in terms of their conservation performance, a compromise between the values tested could also be considered as a viable alternative. Most importantly, the split should not prevent agreement on an MP next month.
The completed MSE represents the best available science for Pacific bluefin and provides performance results for stock status, catch, and fishery stability across a range of uncertainties related to stock productivity, fishery efficiency, and catch underreporting. By agreeing to an MP, the JWG will put the valuable stock on a path toward long-term fishery sustainability and profitability, with catches projected to increase over time for almost all candidate MPs as the stock is allowed to fully recover.
This is great news for the fishing industry and the seafood supply chain, all the way to the consumer of this coveted sushi selection. Adopting an MSE-tested MP could also open the door to for industry to secure sustainable seafood certifications, such as through the Marine Stewardship Council (MSC), increasing the bottom line for industry. Fishers will benefit from the predictability and transparency of a pre-agreed approach for setting annual catch limits, a stark contrast to the current ad hoc approach of political negotiations for 50 tonnes of quota here or 500 tonnes of quota there.
The deliberations of the following month have been in the making for almost a decade. Check back here in mid-July for the outcomes of the JWG meeting, which will hopefully pave the way for formal MP adoption in the western Pacific (at WCPFC) and eastern Pacific (at IATTC) later this year.