Indian Ocean Fishery Managers Must Strengthen Oversight
Sustainability of stocks worth billions of dollars hinges on modernizing and enforcing rules

The Indian Ocean Tuna Commission (IOTC), which is responsible for the conservation and sustainable use of tuna fisheries valued at more than $8 billion, should reaffirm its commitments to precautionary, science-based management—and compliance with its own rules—when it meets in La Réunion 13-17 April. Although IOTC has made progress in recent years to end overfishing, primarily through the adoption of management procedures and electronic monitoring standards, stronger implementation of these rules and programs is needed to ensure their success.
Implementation of management procedures is critical to ensuring sustainability
By adopting management procedures (MPs) for skipjack and bigeye tunas and swordfish, IOTC made significant progress towards modernizing how it does business. MPs, also known as harvest strategies, focus on long-term objectives such as species health and sustained fishery profitability. Historically, fisheries management focused on near-term catch limits, which had to be constantly renegotiated.
Under an MP, Commission members agree in advance (pre-agree) on benchmarks to determine future changes in allowable catch. For example, if a fish population is healthy—as Indian Ocean swordfish is—catch levels can stay the same or even increase over time. And if the population declines, limits will go down. By pre-agreeing to these rules, regional fisheries management organization (RFMO) members reduce the guesswork and politically driven negotiations in fishery management decisions.
However, without clear implementation guidelines, an RFMO cannot ensure the efficacy of an MP. At the La Réunion meeting, IOTC members must take clear steps to outline how the recently adopted swordfish and tuna MPs will work. This would make these measures far more effective and allow the Commission to start work on more MPs without delay.
This is particularly significant for Indian Ocean yellowfin tuna, which does not have an MP in place and has historically been subject to some of IOTC’s heaviest fishing pressure and most contentious debates on catch limits. Commission members had started work on an MP for the stock but halted it for technical reasons. Now, however, they have a timely reason to restart it: a recent promising stock assessment that shows an improved outlook for yellowfin. Completing that MP soon would go a long way towards avoiding future overfishing.
Further, the improved outlook for Indian Ocean yellowfin illustrates the value of MPs: If one had been in place for the stock, it’s possible that IOTC could have already allocated more catch to fishers based on the new science.
Increased oversight of fisheries needed to enforce the rules
Even as MP development moves forward, IOTC should redouble efforts to enforce existing rules.
In 2023, IOTC became the first RFMO to adopt electronic monitoring (EM) standards for its fisheries. EM helps to increase independent observation of fishing activity cost-effectively using technology, including onboard gear sensors and video cameras. Now, IOTC should raise requirements for observer coverage—including EM—and put these technologies that meet the minimum standards into wider use across its vast network of vessels.
There are other tools IOTC should use to track vessels, as well as to ensure that fish that reach the marketplace are legally caught. These include a satellite-based vessel monitoring system that automatically shares vessel location information with all IOTC members and a catch documentation system that electronically tracks catch from the boat through the supply chain. IOTC should take steps this year to advance both of these efforts, alongside an expanded EM program.
While IOTC has made progress to adopt sustainable management measures over recent years, it hasn’t done enough to implement them. This year, Commission members should take concrete steps to enforce existing MPs, continue developing more MPs for other species and ensure that all rules are effectively followed. Only then can IOTC accurately claim it is doing all it can to help its fisheries and members thrive.
Glen Holmes works on The Pew Charitable Trusts’ international fisheries project.