The scope of this study is pollution from marine plastic in Southeast Asia and East Asia, with a focus on the 13 member states of ASEAN+3: Brunei Darussalam, Cambodia, Indonesia, Lao PDR, Malaysia, Myanmar, The Philippines, Singapore, Thailand and Viet Nam (Vietnam), plus The People's Republic of China (China), Japan and The Republic of Korea (RO Korea) The objective is to provide a comprehensive review of the current knowledge and scientific research on pollution from marine plastics in ASEAN+3, as well as the approaches and work streams on this topic by international and regional intergovernmental bodies and initiatives that have a relevant mandate or scope in this sphere. The study is divided into two main parts. Part 1 focuses first on reviewing the status of scientific research on pollution from marine plastics in ASEAN+3. It includes an overall regional summary of this status and an analysis of the findings. Second, it reviews and discusses the mandates, approaches and status of work by international and regional intergovernmental bodies, as well as relevant regional public-private and fully-private initiatives that seek to combat pollution from marine plastics. Part 2 is a gap analysis between the scientific research and the information needs for policy-making purposes, with a focus on the Regional Action Plan on Marine Litter (RAP MALI) of the Coordinating Body on the Seas of East Asia (COBSEA) and the ASEAN Framework of Action on Marine Debris (FAMAD). The work of other regional bodies is also considered. This part also discusses regulatory approaches and obstacles to combat pollution from marine plastics based on four previous reviews. -Recommendations on research needed and ways to improve the science-policy-law interface are provided at the end.