Plastic pollution along Australia’s metropolitan coastlines has dropped by more than a third over the last decade, according to new research by the country’s national science agency.
Coastal plastic waste in major cities has fallen by 39 per cent since 2013, the study, published in Marine Pollution Bulletin, found.
There was also a 16 per cent increase in surveyed sites where no debris was found.
The results were based on 1,907 surveys conducted across the six metropolitan regions of Hobart, Newcastle, Perth, Port Augusta, the Sunshine Coast, and Alice Springs.
Debris was recorded in inland, riverine and coastal areas within a 100km radius of each location.
“Three-quarters of the rubbish we find on our beaches is plastic, and flexible plastics, such as food packaging, are the most harmful to wildlife,” Dr Denise Hardesty, senior research scientist at the science agency, CSIRO, and co-author of the study, said.
The most commonly found items were polystyrene fragments, making up 24 per cent of debris, and cigarette butts, which accounted for 20 per cent. Other frequently recorded waste items included food wrappers, bottle lids and caps, and hard plastic fragments.
While Newcastle, Perth and the Sunshine Coast saw improvements, cities like Hobart and Port Augusta recorded a rise in coastal debris.
Port Augusta recorded the most food wrappers, while the Sunshine Coast had high counts of cigarette litter. Alice Springs, which has no coastal sites, reported the highest prevalence of beverage cans.
“Although there are still areas for concern, it's exciting to see a significant decrease in plastic pollution as people around the country are becoming more aware of the harmful effects of plastic waste on people, communities and wildlife,” Dr Hardesty said.
The research also highlighted socio-economic and land use patterns as key predictors of waste accumulation. Regions with intensive land use and greater disadvantage showed higher debris levels.
Australia has implemented a series of measures in recent years, including container deposit schemes and bans on single-use plastics, to tackle plastic pollution. The study suggests that such policies, combined with local clean-up campaigns and public education, are helping reduce the volume of plastic entering the environment.
“Understanding the types and amount of plastic pollution in our environment provides critical data to develop strategies to stop it ending up there in the first place,” Dr Steph Brodie, CSIRO research scientist and study co-author, said.
The new study builds on previous CSIRO research showing a 29 per cent reduction in plastic waste across Australia between 2013 and 2020.
Australia has pledged to phase out problematic and unnecessary plastics by 2025 and recycle or reuse all of its plastic waste by 2040 as part of its National Waste Policy.
Globally, plastic production has come to exceed 430 million tonnes annually, with only 9 per cent of waste being recycled, according to a 2022 OECD report.
The amount of plastic waste entering aquatic ecosystems could almost triple from 9-14 million tonnes a year in 2016 to a projected 23-37 million tonnes by 2040, according to the UN.
In December 2024, nations of the world assembled to negotiate a legally binding global plastics treaty. However, the talks fell off and will resume again in June.
