Encouraging Progress at IOTC: New Measures for Key Stocks and Renewed Commitments to MSEs

April 23, 2025

AuthorRebecca Scott
Program Officer, The Ocean Foundation

The 29th annual meeting of the Indian Ocean Tuna Commission came to a close last week, following the 9th session of its Technical Committee on Management Procedures, IOTC’s science-management dialogue group on management procedures (MPs). There were encouraging steps forward on MPs for several fish stocks: allocated catch limits were set for bigeye and skipjack tuna, and funding was secured to restart the yellowfin MSE and kick off work on a management strategy evaluation (MSE) for blue sharks later this year.

Dividing the Pie: Swordfish and Skipjack

Last year’s Commission meeting saw terrific progress with the adoption of management procedures (MPs), also called harvest strategies, for both skipjack and swordfish that would set Total Allowable Catch (TAC) limits for the stocks. Remarkably, this marked the first-ever swordfish MP adopted by a tuna Regional Fisheries Management Organization (RFMO) and set the first TAC for swordfish in the Indian Ocean. Once an MP has been adopted for a stock, a critical next step is agreeing on an allocation scheme to implement the MP-based TAC. While the MP defines the overall ‘size of the pie’ (e.g., TAC), it’s the allocation scheme that determines how that pie is divided among member governments. Without it, the MP lacks both accountability and structure to ensure effective management. Unfortunately, the IOTC did not discuss a swordfish allocation scheme at this year’s meeting, putting the MP on hold until one can be agreed.

A 2016 harvest control rule (HCR) has set skipjack tuna catch limits through 2026; in the absence of a fully specified MP and allocation scheme, skipjack catches have exceeded the HCR-based TAC by as much as 30% each year since adoption. The MP adopted in 2024 will be used to set the TAC for the 2027-2029 period, and not a moment too soon – at a recent meeting, the IOTC Scientific Committee highlighted that environmental conditions (e.g., sea surface productivity) in the Indian Ocean are forecasted to enter a less favorable period for skipjack tuna recruitment, making it all the more critical to ensure that catches remain within agreed limits. At this year’s meeting, the Commission adopted a measure introducing an interim allocation plan to constrain catches from 2026, as well as a guide for how the future MP-based TAC will be allocated. After a decade of catch overages, this is a momentous step forward. The temporary approach is intended to bridge the gap until the Technical Committee on Allocation Criteria (TCAC) finalizes the proposed allocation scheme for the 2027-2029 TAC. The 15^th Meeting of the TCAC will take place in July 2025.

Bigeye tuna MP in action

Bigeye tuna is managed under an MP adopted by the IOTC in 2022. Operating on a 3-year management cycle, the catch limits previously set by the MP expire this year. At this year’s annual meeting, the Commission agreed to set a new bigeye TAC of 92,670 tons for 2026–2028, representing a 15% increase from the previous catch limit. This adjustment is in line with specifications of the adopted MP, which allows for a maximum 15% increase (or decrease) in TAC from the previous limit. The successful and timely adoption of this updated catch limit highlights the advantage of managing stocks via pre-agreed MPs that streamline decision-making and reduce the need for prolonged negotiations.

Importantly, the new measure includes country-specific catch limits for the 8 major harvesters. Unfortunately, this leaves many smaller harvesters allowed to maintain their catch and effort at recent levels. This combination of hard limits for the large harvesters and soft limits for the small harvesters raises concerns about over-shooting the agreed-upon TAC – a troubling possibility given the latest stock assessment, which concluded that bigeye tuna is overfished and likely undergoing overfishing.

Progress for shark management

At its 28^th annual meeting in 2024, the IOTC Commission requested that the Scientific Committee (SC) initiate an MSE process towards the development of an MP for blue sharks. With this year’s meeting wrapped, funding is officially on the table to move the work forward in the coming year. This is the most progress to-date by an RFMO towards management of a shark species via a MP – a huge step in the right direction for shark sustainability! A blue shark stock assessment is scheduled for completion later this year, which is well-timed for informing the development of Operating Models (OMs) for a blue shark MSE and ensuring that the MSE is grounded in the best available science.

No movement on yellowfin tuna

Two proposals – submitted by the European Union and Pakistan with South Africa – were brought to the Commission this year, each proposing interim catch limits for yellowfin tuna in 2026 and urging continued progress toward adopting an MP for the stock. However, both proposals were withdrawn until next year, after uncertainties in the catch-per-unit-effort (CPUE) data – a commonly used index of relative abundance in fisheries management – have been reviewed. The TAC for yellowfin will therefore remain at its current level.

Development of an MP for yellowfin tuna began in 2013, including the definition of limit and target reference points, with the first phase of MSE work kicking off in 2016. However, progress was put on hold due to issues with the OMs, which were based on a failed stock assessment model. With many of those issues now resolved in the latest assessment, the MP process should be restarted, and funding to support this work was secured at this year’s meeting.

A yellowfin MP will enable the IOTC to manage the fishery in a way that supports long-term sustainability, economic viability, and stability; continuing progress towards managing yellowfin in the Indian Ocean via a robust MP is the most efficient path to long-term sustainability. While the Commission has not set a target adoption date for a yellowfin tuna MP, some initial progress towards this work has begun and reference OMs will be presented by the 16^th meeting of the Working Party on Methods (WPM) in October 2025.

What’s Next:

Other meeting outcomes included general Commission support for incorporating climate change considerations in management frameworks to ensure a proactive approach to managing fisheries under climate-related risks. MSEs are an effective approach to advance these and other ecosystem-based fisheries management (EBFM) objectives, facilitating the development of MPs that are robust to and can explicitly account for the effects of climate change on target stocks.

Finally, adoption of an MP for albacore tuna was originally slated 2025. Although progress is behind schedule, the TCMP agreed last week that albacore is the next target IOTC stock for MP adoption. Operating models for an albacore MSE were agreed upon at the 9^th Working Party on Temperate Tuna (WPTmT) Data preparatory meeting in February 2025, and candidate MPs were to the TCMP meeting. Continued work on candidate MPs and the conditioning of operating models will be presented at the upcoming WPTmT Assessment Meeting in July, with an aim to present final results to the TCMP and Commission for MP adoption in 2026. At that point, IOTC will have MPs in place for 4 of its 5 major target stocks, leading RFMOs in application of the MP approach.