Microplastics pose a growing threat to estuarine health, especially in urban catchments. The purpose of the assessment was to identify the coastal waterways most contaminated by microplastics and provide a clear picture of the scale and type of microplastics in New South Wales (NSW) waterways. The study – the first large-scale study of its kind in Australia – provides the first baseline for NSW coastal waterways, enabling targeted management and policy action, as well as raising awareness within the community of the scale and spread of microplastic contamination. 

The report provides recommendations for future monitoring and intervention.

Key findings

• Microplastics were detected in all 120 waterways, with concentrations ranging from 0.02 to 34.80 particles per cubic metre.
• Highest contamination was found in urban waterways in the Hawkesbury–Sydney region, including Cooks River, Dee Why Lagoon, and Upper Parramatta River.
• Lowest contamination was found in minimally disturbed catchments on the state’s north and south coast – Myall Lake, Nadgee Lake, Middle Lagoon, Myall Broadwater and Wallaga Lake.
• Smaller particles (<1 mm) dominate, and items like packaging foam and pellets point to traceable sources and therefore are considered priority items.

The report is provided with an interactive dashboard.