Plastic Pollution On Australian Coastline Drops 39% Over Last Decade

Plastic pollution on Australian coastlines has dropped by 39 per cent over the last decade, according to new CSIRO research. 

CSIRO researchers surveyed inland, riverine, and coastal habitats across six metropolitan regions across Australia, including Hobart, Newcastle, Perth, Port Augusta, Sunshine Coast and Alice Springs. 

A total of 8383 debris items were recorded across 1907 surveys within a 100-kilometre radius of each city.

The report, Drivers of environmental debris in metropolitan areas: A continental scale assessment presented the findings of a 2023 stratified survey of mismanaged waste of the six Australian metropolitan regions to establish a national baseline of environmental debris. 

Researchers compared their results to previous surveys carried out a decade ago, finding less coastal pollution overall, resetting a new baseline for further research. 

39% decrease in plastic pollution

The study revealed a significant 39% decrease in the national mean coastal debris density and a 16% increase in transects where no debris was detected. The findings provide evidence that historical policies, practices, outreach campaigns, clean-up efforts, and local custodianship have played a role in reducing debris in metropolitan coastal habitats. 

Dr Denise Hardesty, Senior Research Scientist from CSIRO and co-author, said with up to 53 million metric tonnes of plastic waste estimated to enter aquatic ecosystems by 2030, it was encouraging to see a significant decrease in plastic pollution on Australian beaches and coasts. 

“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 Hardesty said in a statement. 

“Along with a 39 per cent reduction in plastic waste in coastal areas, we also saw a 16 per cent increase in areas we surveyed with no plastic debris at all. Decreases of plastic pollution in the coastal environment were observed in Newcastle, Perth, and the Sunshine Coast, with increases in Hobart and Port Augusta,” Dr Hardesty said. 

Dr Hardesty expressed that there were still areas for concern, however she was excited 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.”

Types of debris found in plastic pollution

The report highlighted that the most commonly occurring debris items were plastic, but these were largely unable to be identifies to their use. Exceptions to  this included food wrapper/labels, cigarette butts, hard plastic bottle cap/lids, and polystyrene, which all commonly occurred in the survey.

Across Australia, hard plastic bottle cap/lids were the fifth most commonly occurring whole item (i.e. commonly present in a transect) and fifth most abundant whole item found (i.e. total number found across all transects), and ultimately were more common than beverage containers.

Cigarette butts were the most found whole debris item across inland, riverine and coastal surveys. 

The most prevalent items in each region were: 

• Alice Springs: beverage cans 
• Hobart: beverage bottles 
• Newcastle: cigarette butts 
• Perth: cigarette butts 
• Port Augusta: food wrappers/labels 
• Sunshine Coast: cigarette butts

Cigarette butts prevalent in plastic pollution

According to the continental scale assessment, the ubiquity of finding cigarette butts “across all surveyed environments” indicated that this item is “problematic for metropolitan regions of Australia.”

More than 16% of all debris found in Clean Up Australia surveys are cigarette butts, and a 2021 report from the World Wildlife Fund estimates that 8.9 billion cigarette butts are littered every year.

Dr Steph Brodie, CSIRO Research Scientist and co-author, said the surveys help to identify debris hotspots, understand how land use influences debris in the environment, and how waste ends up on our coastlines.  

“We found that areas with intensive land use and socio-economically disadvantaged areas tended to have higher levels of debris,” Dr Brodie said in a statement. 

“These results will help to inform waste management and can be used to evaluate and measure the effectiveness of plastic waste policies, practices and education campaigns to reduce debris in metropolitan regions,” Dr Brodie added. 

CSIRO’s research aims to end plastic waste, with a goal of an 80 per cent reduction in plastic waste entering the Australian environment by 2030.