Hyunjeong works on the plastic pollution and marine litter efforts of the Coordinating Body on the Seas of East Asia Secretariat, administered by the United Nations Environment Programme. She has worked with local and national governments, businesses, and coastal communities on solutions to prevent plastic pollution and protect marine and coastal ecosystems in the East Asian Seas region. Her areas of expertise include ocean governance, marine litter knowledge management, and fostering regional and global cooperation to address marine plastic pollution.