Effective monitoring, control and surveillance (MCS) is critical for the success of marine conservation and management. As States begin to negotiate a new international agreement concerning areas beyond national jurisdiction (ABNJ), there is growing interest in how MCS tools and policies can be applied to this vast global commons. Co-organised by IDDRI and the High Seas Alliance, this side event will provide an opportunity to hear about existing technological tools for MCS in ABNJ and possible future technological developments, as well as discuss how a new international agreement could contribute to the implementation of technological tools and development of an effective global MCS framework for ABNJ. Glen Wright will present the main conclusions of a recent workshop organised by IDDRI in the framework of the STRONG High Seas project.