Monitoring, Control and Surveillance, or MCS, underlies effective fisheries management. The often-quoted paper Recommended Best Practices for RFMOs makes it plain: Compliance with, and effective enforcement of, agreed conservation and management measures, supported by adequate MCS, are crucial to implementation [of management measures]. MCS provides the critical tools and systems to enable cross-referencing and verification of a vessel’s and the flag State’s implementation of and compliance with the agreed-upon management measures. In the Indian Ocean Tuna Commission (IOTC), the progressive transition to the implementation of harvest strategies (referred to as Management Procedures by the IOTC) is commendable. Unfortunately, the same impetus to strengthen MCS measures is lacking, despite recommendations from two Performance Review panels that clearly counseled the implementation of an integrated MCS program to address non-compliance by vessels and flag State members. The Commission needs MCS measures to implement the harvest strategies, because a strong and integrated regional MCS approach enables all IOTC parties to monitor the fulfillment of the obligations by their peers. An integrated regional MCS approach can also provide greater transparency increasingly expected by the market. Let’s consider the IOTC resolution that aims at rebuilding the yellowfin stock. The IOTC Science Committee advised a 20% reduction in catch from the 2014 catch levels in order to achieve a 50% chance of rebuilding yellowfin to a spawning biomass required to maintain the stock at maximum sustainable yield. This advice assumes that all IOTC parties will give effect to the measure and fulfill their obligations as agreed. But before we can even consider whether IOTC parties are compliant with the measure, we must recall that vessel logbook data for most fleets is incomplete and not submitted in a timely manner. There is poor implementation of port state measures across the region, and there is no centralised vessel monitoring system (VMS) an important MCS component to cross-reference a vessel’s position and likely activities at-sea. Moreover, there is very low observer coverage for all fleets in Indian Ocean tuna fisheries; for example, the IOTC requires only 5% observer coverage for the purse seine fleet (other ocean regions require 100% observer coverage). Fortunately, there are steps that IOTC can take to rectify this situation and the IOTC must make progress on them this year. Strengthening or adjusting IOTC’s existing MCS measures will ensure that such tools support IOTC parties and that IOTC conservation measures to protect and restore tuna stocks are effectively implemented. Steps toward an integrated regional approach to IOTC MCS include: * Strengthening the collection and reporting of accurate and timely catch and effort records. * Strengthening vessel monitoring systems consistent with best practices. The current IOTC VMS requires that vessels report only directly to their flag State, and these data are not analysed through the IOTC Compliance Committee. Without simultaneous reporting to both the flag State and Secretariat, there is no way to independently detect possible infractions and/or non-compliance. * Addressing weaknesses in the IOTC observer program, including through implementing electronic monitoring and reporting systems. Observer reports and data can be used for compliance monitoring and enforcement and provide independent verification of vessel catch and effort records, in addition to data on bycatch. Observer coverage is very low, and their reports are not used for compliance purposes in the IOTC. The IOTC must reform its observer program to increase coverage levels and ensure these data can be used for both scientific and compliance purposes. Electronic reporting and monitoring systems are important tools to achieving these goals. * Strengthening measures that regulate and monitor transhipment. The IOTC transhipment measure contains loopholes that can provide opportunities for IUU activities. For example, there is no definition of what constitutes a large-scale tuna longline vessel, there is no oversight over the issuance of exemptions to tranship at-sea, and VMS is not required on carrier vessels transhipping in-port. MCS systems are the other side of the harvest strategy coin. Only when harvest strategies and MCS tools are working in concert can the long-term sustainability of IOTC’s tuna resources be realised. The Commission should implement the recommendations from the performance review panels and work to strategically strengthen its suite of MCS tools while it continues the development and adoption of harvest strategies.