The five-year ReefClean Australian Microplastic Assessment Project (AUSMAP)(2019-2023) has collected 126 samples from 44 sites, providing valuable insights into microplastic pollution in the Great Barrier Reef (GBR). The recently added March 2023 samples mark the conclusion of this study, highlighting both the seasonal and varying nature of microplastic loads and the low overall levels of microplastics compared to densely populated areas. However, the project underscores the need for continued monitoring to analyse the effects of climatic variances and address the sources of microplastics.
This study identified hotspots and regions more at risk from microplastic pollution within the GBR. Dominant microplastic types remain hard plastic fragments which are categorised as secondary microplastics resulting from the breakage of larger plastic items. This trend has been consistent since sampling began in 2019, indicating ongoing inputs of hard fragments into GBR catchments.
The dataset gathered from the ReefClean project now serves as the baseline for future surveys, enabling comparisons at each site and across Natural Resource Management (NRM) regions. However, the outcome of the study is the necessity for ongoing monitoring to understand the effects of larger climatic variations, such as the El Niño Southern Oscillation (ENSO), on microplastic loads in the GBR. Biannual monitoring is recommended to facilitate timely intervention according to AUSMAP’s hotspot scale, allowing relevant stakeholders, including councils, communities, and government agencies, to collaboratively address the sources of microplastic pollution and safeguard the health of the Great Barrier Reef.