Citizen science supports national reporting of a Sustainable Development Goal indicator: A case study of plastic debris density on beaches

Global momentum to address plastic pollution has led to the development of national processes to monitor plastics into and within the environment. The Sustainable Development Goals (SDGs) provide guidance for reporting on plastic pollution, although compiling national estimates remains a challenge. Data availability remains a key barrier, which could be addressed through engagement with the citizen science community, which collects and maintains data at a resolution suitable for SDG reporting. Here, we demonstrate a process that uses citizen science monitoring of plastic debris on beaches to report on SDGs at the national scale. The study uses the Australian Marine Debris Initiative (AMDI) Database, which is composed of data submissions from over 1400 organisations across Australia. The AMDI was used to provide initial estimates of plastic debris density both nationally and across Natural Resource Management areas (NRMs). Before analysis, the database was filtered for data quality and alignment with guidance for SDG reporting (i.e., SDG Indicator 14.1.1b), resulting in the analysis of 3144 events across 538 sites between 2014 and 2019 (inclusive). The average density of plastic debris on beaches across Australia was between 0.155 and 0.279 counts m⁻², with management relevant trends identified across NRMs. This study demonstrates the potential for the citizen science community to support SDG reporting and management processes, which could inform and enable actions to address plastic pollution.