Blue Matter Science, led by CEO Dr. Tom Carruthers, is a leading organization dedicated to advancing marine science and sustainable fisheries management. With a background in marine biology, experimental ecology, and a PhD in applied mathematics from Imperial College, Tom is also an Adjunct Professor of Fisheries Science at the University of British Columbia. His passion for problem-solving in marine science drives his current focus on developing tools that support robust fisheries management.
In this two-part blog series, we delve into the nuanced landscape of MSE with Tom, unpacking the fundamental components that render MSE indispensable in our collective pursuit of ecologically responsible and economically viable fisheries management.
HS.org: In 50 words or less, can you explain what Management Strategy Evaluation (MSE) is and why it is an important tool in international fisheries management?
Tom: International fishery managers are tasked with implementing a harvest strategy that meets the objectives of diverse stakeholders, often in the face of large scientific uncertainties. MSE is a computer simulation approach that tests candidate harvest strategies across various scenarios for the fishery to identify those that can robustly achieve management objectives.
A common analogy for MSE is the testing of pilots using a flight simulator. In the MSE context, harvest strategies are the pilots being tested. Instead of flying conditions, MSE simulates a plausible range of biological, ecological, and exploitation scenarios for the fishery. Like a flight simulator, MSE can provide us with confidence that a harvest strategy (the pilot) will perform well over a wide range of conditions.
HS.org: What are the key components of an effective MSE process, and how do they interact to ensure the long-term sustainability of fisheries?
Tom: MSEs are pursued for various reasons, so ‘effective’ is somewhat case-specific. In the case of Atlantic bluefin tuna, there were difficulties in establishing a scientifically defensible assessment of the resource for use in decision-making. Essentially, there were many hypotheses for biology, ecology, and behavior that were similar to the data. For Bluefin, MSE was all about establishing a simple harvest strategy that was demonstrated to work robustly across all those hypotheses. The challenge in the South African sardine and anchovy fishery was establishing a harvest strategy that could allow for fishing without serious overexploitation of either species. In the case of the Bay of Fundy herring, MSE was used as a sort of ‘due diligence’ for a harvest strategy that had already been adopted and was in use. This might sound like a rather pedantic start of an answer to your question, but it goes to a point: arguably, the most important part of an MSE process is identifying a clear problem statement. Why MSE in this context?
There are three main parts to an MSE that interact in the adoption of a sustainable, robust harvest strategy:
Performance indicators are the basis for the scoring and comparison of harvest strategies. They are the lens through which all participants will view results. The performance aims of managers will be revealed when a harvest strategy is adopted. An effective MSE is one built around participation and communication. It should include a comprehensive consultation process with a range of stakeholders to ensure that their perspectives and values are communicated in results. Any legal requirements for fishery managers should also be expressed as performance indicators. Once established, the set of performance indicators provides a transparent account of harvest strategy strengths and weaknesses. It allows managers to explicitly consider trade-offs between, for example, extraction and conservation objectives. If the performance indicators part is done right, when a harvest strategy is adopted, it is clear why it was selected.
An effective MSE is one where managers have confidence in the adopted harvest strategy. That confidence arises from testing candidate harvest strategies against a wide range of plausible uncertainties (hypotheses) in current and future fishery conditions. Although science is usually the primary basis for developing these hypotheses, an effective MSE process includes stakeholder knowledge and experience, allowing a range of perspectives on the fishery to inform the selection of an appropriate harvest strategy.
Now that we have established how to score them and the conditions by which they will be tested, it is vital to focus on the harvest strategies – the pilots in the flight simulator analogy. An effective MSE is an open process that allows for testing a diverse range of harvest strategies developed by multiple development teams. These teams engage in a collaborative competition where harvest strategies are compared and refined. This diversity, friendly competition, and ingenuity process extracts every possible ounce of performance from a harvest strategy. Within the constraints specified by managers, anything goes. For me, it’s the most fun part of MSE!
If I’ve answered this correctly, it should be clear why MSE is such a powerful tool in establishing a long-term sustainable harvest strategy for a fishery. MSE is 1) inclusive, open, and transparent. 2) accounts for economic and biological definitions of sustainability in performance indicators, and 3) selects a harvest strategy that has been shown to provide sustainability across a range of hypotheses for the system.
HS.Org: Despite the proven benefits of harvest strategies and MSE, widespread adoption has been slow in some areas. What are the primary barriers to the broader adoption of these management approaches, and how can they be addressed?
Tom: Technical overhead. Previously, a serious impediment to MSE adoption was developing all the code to do the simulation work. Today, MSE packages like FLR and OpenMSE take much of this burden away from the process, allowing it to refocus on performance indicators, uncertainties, and harvest strategy design – the things that matter. However, the false perception of MSE as an expensive, burdensome, complicated techno-rats-nest persists. A big part of our collaboration with www.harveststrategies.org and The Ocean Foundation has been about showing people that this is no longer the case. We have been to management settings with OpenMSE, where managers and stakeholders were very organized, and harvest strategies were adopted in less than six months. A lot of managers and scientists don’t realize what is now possible.
Getting stuck in ‘Assessment mode’. The conventional approach to fisheries management is to develop a ‘best’ model of the fishery that is empirically validated by fitting to data and then used in management decision-making. Yes, you can look at alternative models and assumptions via so-called sensitivity analyses, but fundamentally the focus of stock assessment modelling is scientific veracity. That is not the focus of MSE, which is all about harvest strategy robustness. ‘Assessment mode’ is a condition that is a serious threat to the health of any MSE process. Scientists can get bogged down in the details of the models and data, which may affect perceptions of the stock but are often inconsequential to harvest strategy performance. Managers want to see stock assessments in their harvest strategies instead of simpler approaches that perform similarly. MSE projections are viewed as forecasts, not scenarios, for testing harvest strategies and so on. As is the case for many MSE problems, the solution is to do a thorough introduction to MSE and then get a demo MSE framework up and running as soon as possible so that all participants can see it in action and hopefully interact with it.
Indecision. MSE necessarily requires many decisions to be made, including who to include, when to hold meetings, when to draw a line on developing hypotheses, what performance indicators, what diagnostics, and what types of harvest strategies.
The list is enormous. This can drag out an MSE into an arduous process where momentum is lost to a point where new data and hypotheses emerge, and the process is stalled in a constant update loop. The best way to solve this is to employ an experienced chair of the process who can develop an MSE roadmap and maintain discipline on timelines.
HS.Org: How do you balance short-term economic interests with long-term fishery goals in MSE?
Tom: For most MSEs, the principal performance trade-off among harvest strategies is between what you take and what is left over in the water. Managers must navigate this trade-off between catches in the short term and biomass/catch outcomes over the longer term based on their established objectives and legal requirements. As a mere analyst, this is above my pay grade! Things are not as clear-cut as you might expect, however. I’m currently working on a harvest strategy for an invasive species.
Stay tuned for Part 2: Advanced Perspectives and Future Directions in Management Strategy Evaluation (MSE), where we dive deeper into the challenges, technological advances, and future directions of Management Strategy Evaluation in international fisheries management. Don’t miss the opportunity to learn more about how these modern approaches are shaping the sustainable future of our global ocean.
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Pacific saury, a small fish with a big role in the ecosystem, is also an important food source in several nations. However, the stock is both overfished and experiencing overfishing. To rebuild Pacific saury and sustain a productive and predictable fishery, the North Pacific Fisheries Commission (NPFC) is developing a management procedure (MP).
NPFC will convene its second Small Working Group on Management Strategy Evaluation for Pacific Saury (SWG MSE PS) on Sept. 12-13. This meeting follows the success of the first meeting in February. NPFC established this science-management dialogue group (SMD) in 2021, a forum for scientists, managers and stakeholders to work together as they strive to develop a MP and set a transparent and collective vision for the Pacific saury fishery.
NPFC aims to develop both an interim harvest control rule (HCR) by 2023 and a full MP, to be tested via management strategy evaluation (MSE), in three to five years. To kickstart this process, participants received comprehensive presentations at the first meeting that detailed best practices for MSE development and initial possibilities for a Pacific saury MSE. The group made progress towards the development of the interim HCR and corresponding short-term management objectives.
While a short-term HCR will improve the management of Pacific saury, only a full MSE-tested MP can provide precautionary and predictable management in the long term. An MSE identifies the best performing MP among competing objectives whilst balancing tradeoffs and accounting for uncertainties in the population, fishery and environment. As such, development of an MSE should take place at the same time as the short-term HCR.
At the upcoming meeting, participants will be asked to discuss management objectives and technical matters on operating models and performance measures, among other items related to the development of a MP.
A growing list of MSEs have been explored globally for shorter-lived species, including South Pacific jack mackerel and Northeast Atlantic mackerel. Pacific saury has a lifespan of two years, and so, NPFC can look to these other management bodies’ successes in developing MSEs for shorter-lived species as the MP is developed.
Initiation of the MSE process must not wait until the short-term HCR is complete. Undertaking these two processes simultaneously would benefit the NPFC in several ways. First, it allows the MSE to be informed by the progress made and decisions needed to complete the short-term HCR. Second, it would provide for a smoother transition between the two management measures.
It’s clear that MPs can provide a necessary solution to rebuild the Pacific saury stock – and the valuable fisheries that target it. Now it’s time to dive into the work.
A historic opportunity to adopt the first ever harvest strategy by a regional fisheries management organization dedicated to tunas (tRFMO) in the Pacific Ocean went unfinished this week at the Inter-American Tropical Tuna Commission’s (IATTC) 100th meeting held in Phoenix, Arizona, USA. After seven years of development, including management strategy evaluation (MSE) testing and a series of stakeholder meetings, a fully specified harvest strategy was ready for adoption for north Pacific albacore. While member states succeeded in adopting a proposal co-sponsored by Canada, Japan, and the USA that contained management objectives, reference points, and a monitoring strategy, they did not cross the finish line. The omission of a harvest control rule (HCR), the operational component of the harvest strategy that sets fishing levels based on population size, means north Pacific albacore management stays essentially unchanged on the water. IATTC will need to return to this issue next year to add a mechanism and trigger for management that can achieve the measure’s vision for the future, a hallmark of the harvest strategies approach.
But, there is still hope that this harvest strategy can make its way across the finish line in the Pacific this year! North Pacific albacore is jointly managed by both the IATTC and the Western and Central Pacific Fisheries Commission (WCFPC). The baton is now in WCPFC’s hands to determine how the harvest control rule will operate in the context of the full harvest strategy. Managers will have their next shot to recommend a fully specified harvest strategy at WCPFC’s Northern Committee meeting in October, helping to tee up adoption at WCPFC’s December Commission meeting. IATTC can then follow suit next year, especially as the measure passed this week includes a directive for IATTC to adopt an HCR in 2023.
While the population of north Pacific albacore is healthy, neither overfished nor experiencing overfishing, a harvest strategy offers predictable and effective management that will ensure the fishery stays on track. If the stock takes an expected turn due to environmental or biological factors, the HCR will kick in, providing sustainability while still maximizing catch. The fishery needs action now – history has shown that waiting for population collapse to pass management is a recipe for disaster. WCPFC still can make this harvest strategy happen in 2022, starting with the Northern Committee in October.
In a landmark decision by the Indian Ocean Tuna Commission (IOTC), managers have adopted a management procedure (MP) for bigeye tuna. Sponsored by Australia, the Maldives, Pakistan, Tanzania, South Africa, and the European Union, the proposal received broad support from member governments before adoption was finalized at the close of the IOTC Commission meeting today. The adoption of this MP sets two remarkable precedents for regional fisheries management organizations dedicated to tunas (tRFMOs), as IOTC has adopted the first full MP for any tropical tuna species and becomes the first to rely on harvest control rules (HCR) to manage more than one species, namely bigeye and skipjack tuna.
The final MP will set a catch limit for bigeye starting in 2024, the first ever cap on fishing mortality for the population, which is currently undergoing overfishing. The MP includes a directive to avoid overfishing and an overfished state with a 60% probability while the selected harvest control rule takes a “hockey stick” approach, whereby catch rates increase as the population increases, up to a defined target level. Through extensive management strategy evaluation (MSE) testing, the MP is designed to achieve the Commission’s goals, regardless of the inherent uncertainty about the species, fisheries, and future environmental conditions.
Eight years in the making, IOTC has undertaken a rigorous scientific modelling process, coupled with an inclusive dialogue among scientists, managers and other stakeholders, to convert that science into a tangible management procedure for bigeye tuna. After attending this week’s meeting, Shana Miller, Project Director of The Ocean Foundation’s International Fisheries Conservation Project and www.harveststrategies.org partner, said, “Congratulations to IOTC, led by Australia and its co-sponsors, for taking this critical step to solidify a sustainable future for bigeye tuna in the Indian Ocean, the highest priced of all tropical tunas. In so doing, IOTC solidified itself as a leader of the harvest strategies approach among tRFMOs.”
Today’s MP adoption is but one of many more to come at the tRFMOs. The future is bright: IOTC alone expects to finalize MPs for swordfish, albacore, and yellowfin tuna by 2024, which will benefit fish, fishermen, seafood markets, and consumers for years to come.
May is gearing up to be a big month for the Indian Ocean Tuna Commission (IOTC), as members plan to hold four policy and science meetings over the next two weeks. Two of those meetings – the Technical Committee on Management Procedures (TCMP) on May 13-14 and IOTC’s annual Commission meeting on May 16-20, will be crucial to the development and adoption of the RFMO’s harvest strategy portfolio. While a variety of harvest strategies, also known as management procedures (MPs), will be discussed at the TCMP, including those for albacore, skipjack, yellowfin, and swordfish, the big-ticket item will be the bigeye tuna MP. In development since 2014, a draft proposal of a comprehensive bigeye tuna management procedure, submitted by Australia, will be reviewed by the TCMP. Next week’s Commission meeting will then have the tremendous opportunity to adopt the measure, marking IOTC’s first-ever full MP, joining the skipjack tuna harvest control rule as the Commission’s only two pre-agreed frameworks for calculating and recommending catch quotas.
The Commission now has two main decisions to make regarding management objectives and candidate MPs. The management objective for the bigeye tuna fishery includes a mandate to avoid both overfishing and an overfished state, often referred to as being in the “green zone” of the Kobe plot. Objectives should be specific and measurable in the context of management procedures, but the probability by which the final MP must achieve this objective has yet to be decided. As part of the adoption process, the Commission still has to select between a 60% and 70% probability of being in the Kobe green zone in the specified years 2034-2038, with the latter providing a stronger assurance that the MP will be successful and maintain a sustainable stock.
The Commission must also decide between the two final candidate management procedures that the Scientific Committee recommended in 2021 after rigorous management strategy evaluation (MSE) testing. The two candidates are not too different, with both operating under a 3-year management cycle and limiting the fluctuation in catch limits between management periods to 15%. One of the candidate MPs takes a “hockey stick” approach, with catch rates increasing as the population increases, up to a certain population size where the target catch rate levels out resembling a hockey stick when plotting both catch and biomass on an X/Y graph. The other candidate MP relies more on the specified management objective, using internal projections to prescribe a catch limit that can best hone in on and achieve the objective.
Both candidate MPs were able to achieve the prescribed management objective with both a 60% and 70% probability. Performance between the two differs only slightly. The hockey stick MP shows slightly higher average catches while the other has more stable catches, including potentially a higher initial catch. Regardless of which management procedure the Commission selects, they will be choosing one that performs in a robust manner and is likely to succeed.
Although bigeye is not currently overfished, overfishing is occurring, and the MP can help to ensure that fishing levels are again sustainable. This will avoid depleting the stock to a dangerously low level that would likely then require tough management decisions to recover the stock, as IOTC is currently facing for yellowfin tuna.
While a few tuna-RFMOs have a management procedure or harvest control rules in place, no tuna-RFMO has adopted a second MP for another species under its jurisdiction, let alone a full MP for any of the tropical tunas. IOTC will have that chance when Australia champions the bigeye tuna MP at the meeting later this week, and if adopted, the RFMO would position itself as a global leader of management procedures. Hopefully, the dominant bigeye fishing members will join Australia in this effort.
It’s been over a decade since ICCAT began implementing science-based quotas to help recover Atlantic bluefin, the largest of the tuna species. It now appears that the species is on the verge of locking in those gains using one of the most effective forms of management – a harvest strategy. Next week’s Panel 2 meeting, to be held on 9-10 May 2022, offers a tremendous opportunity to make progress. Finalization of the management strategy evaluation (MSE), the simulation-based modelling tool that informs harvest strategy selection, is on track for completion by the 2022 Commission meeting. While the scientific work is largely complete after eight years in development, critical management decisions remain. The scientists will rely on these decision points as they continue their work, making it imperative that this upcoming dialogue proves fruitful and yields concrete outcomes that can be immediately fed into the MSE.
Most importantly, managers will be asked to operationalize management objectives by agreeing on the risk tolerances and associated timeframes that a harvest strategy must meet. First adopted in 2018, the initial conceptual management objectives include clauses that range from concurrently avoiding overfishing and the state of being overfished to limiting the percent change in catch quotas between management periods. Now it’s time to fill in the blanks of Resolution 18-03. To ensure an abundant future for both the species and fisheries, precautionary objectives would include a high probability (e.g., ≥70%) of achieving a healthy stock and a low probability (e.g., ≤10%) of reaching a dangerously small stock size (known as Blim).
In addition to objectives, managers must approve a path forward for narrowing down the current list of candidate harvest strategies, including so-called “tuning.” Tuning levels the playing field and allows an MSE to compare apples to apples. It requires all candidate harvest strategies to achieve a common performance level for one management objective, and then relative performance against other objectives can be compared. For example, in the case of the Atlantic bluefin MSE, all candidates must achieve a certain population size in 30 years relative to the population size that can produce maximum sustainable yield. Once they are “tuned” to achieve that level, one can compare relative catches and stability in catches of the harvest strategy options. For a common population status, ICCAT might opt to cull a candidate harvest strategy that has the lowest catch, for example.
While the main decision points for next week include endorsing tuning processes and operationalizing management objectives, the meeting will also touch on other necessary discussions surrounding the harvest strategy framework and path forward.
It’s a tall order for a two-day meeting, but the scientists have done an extraordinary job updating the MSE and preparing comprehensive results for review by managers. Now, it’s up to the managers to make the necessary decisions that will allow the development process to progress, ensuring that this precedent-setting harvest strategy will be adopted for Eastern and Western Atlantic bluefin tuna at ICCAT in 2022. At a recent webinar on harvest strategies at ICCAT, 100% of participants agreed that ICCAT should prioritize the implementation of the bluefin tuna harvest strategy at its upcoming Commission meeting. ICCAT and Panel 2 must heed this call, echoed from many others, managers, scientists, and stakeholders alike, and continue development without delay.
2021 marked a significant year for the proliferation of harvest strategies across tuna regional fishery management organizations (tRFMOs). First introduced to tRFMOs with the adoption of a harvest strategy for southern bluefin tuna a decade ago, this approach is now under development or in place at every single tRFMO, including in the Atlantic, Pacific, and Indian Oceans. Harvest strategies are now being called upon across the globe to transition to science-based, precautionary frameworks to manage a breadth of species. The result is greater transparency, inclusivity, stability, and sustainability in management of these ecologically important and commercially valuable fisheries.
In a momentous step, the International Commission for the Conservation of Atlantic Tunas (ICCAT) adopted its first comprehensive harvest strategy (also known as a management procedure) for north Atlantic albacore tuna last month, which will help lock in sustainable management and predictable market supply of this stock moving forward. While ICCAT had already adopted a harvest control rule (HCR) in 2017, additional specifications were needed to convert the albacore HCR into a full harvest strategy including details on the data collection and analysis methods used to trigger the HCR, and an exceptional circumstances protocol. In November, ICCAT also set the stage for adoption of a harvest strategy for Atlantic bluefin tuna next year. The new western Atlantic bluefin measure established management for 2022 only, leaving 2023 management to be set through a harvest strategy. And, three dialogue meetings among scientists, managers, and other stakeholders are also slotted for next year, giving ICCAT members ample opportunity to provide input into bluefin harvest strategies and better understand the options before selecting a final harvest strategy at next November’s meeting.
The Western and Central Pacific Fisheries Commission (WCPFC), too, has further cemented its dedication to the development of harvest strategies for its highly valuable fishery for skipjack, bigeye, yellowfin and South Pacific albacore tunas, through the scheduling of their first scientist-manager dialogue group meeting, which was first recommended by the Scientific Committee in 2017. Slotted for August 2022, this group will provide a forum for iterative exchange between managers and scientists to develop a transparent, collective vision for the stocks and fisheries. While WCPFC failed to adopt target reference points for bigeye and yellowfin tunas, there has never been a louder call from industry to advance harvest strategies in the region, bolstered by the Marine Stewardship Council’s (MSC) June 2023 deadline to adopt harvest strategies or risk losing their ecolabel certification. Also at its annual meeting this month, WCPFC restated its commitment to adopt harvest strategies for skipjack and south Pacific albacore in 2022, which would allow MSC fisheries to retain their certifications for those stocks. While the science will likely be ready, WCPFC’s managers have a great deal of work to carry out next year to enable adoption. The long overdue dialogue meeting will be critical to that effort.
Just east of the WCPFC, the Inter-American Tropical Tuna Commission (IATTC) adopted a new tropical tuna conservation and management measure at its October meeting, which now includes a directive to establish harvest strategies, starting with bigeye tuna. IATTC is using management strategy evaluation (MSE), a computer simulation tool that projects a fishery years into the future under a range of scenarios, to develop a harvest strategy for the stock by 2024, as is noted in the newly adopted conservation measure.
In the Indian Ocean, the development of harvest strategies is far along for bigeye and yellowfin. The Indian Ocean Tuna Commission (IOTC) should be heralded for the smooth and efficient development of the scientific elements needed to develop a harvest strategy, with bigeye tuna likely ready for adoption next year following substantial progress building the bigeye MSE framework in 2021. MSE processes are also underway for albacore and swordfish. Lessons from skipjack, however, where the catch limit has been exceeded in every year since HCR adoption in 2016, underscore the importance of agreeing to a quota allocation scheme to ensure science based TACs set through harvest strategies are not exceeded.
A mere decade since the adoption of the first tRFMO harvest strategy at the Commission for the Conservation of Southern Bluefin Tuna (CCSBT), this approach has become the gold standard for management, as it ensures the future sustainability and stability of tuna fisheries, benefiting fish, fishermen, and consumers for years to come. As of 2021, all tRFMOs have concrete commitments to develop and adopt harvest strategies within a specified timeframe. Within the next few years, the tRFMOs are poised to expand from just two full harvest strategies in place to twenty adopted, and www.harveststrategies.org will be here to report on progress and provide educational resources along the way.