Australia’s trash tide: what researchers found as they studied 20m pieces of beach rubbish
Plastic makes up 84% of the rubbish found on Australian beaches, according to analysis of a decade of clean-up efforts by more than 150,000 citizen scientists.
Since 2004, the Australian Marine Debris Initiative – launched by the nonprofit Tangaroa Blue Foundation – has documented more than 20m items of rubbish collected from beach clean-ups around the country.
New analysis of the database by University of New South Wales researchers has mapped national trends in marine debris over 10 years, finding 48% of the refuse originated from onshore sources such as litter.
The study, published in the journal Science of the Total Environment, found that 7% of the garbage originated from dumping at sea, while the source of 42% could not be definitively identified, due to the debris breaking down into smaller fragments. Most debris was found on the east coast of Australia.
The study’s lead author Jordan Gacutan, a PhD student at UNSW, said the analysis found stark differences in pollution across different regions. “Within sites near coastal capital cities, we’re finding … cigarette butts or things you’d expect from littering,” he said.
“But then when we get to remote areas like Cape York in far north Queensland, we’re seeing items like floats and plastic bottles that aren’t locally sourced – they’re coming from overseas or dumping at sea.”
Gacutan said the database provided an accountability measure to monitor the effectiveness of waste reduction initiatives. “What we’d like to see is this data being used to inform management plans locally,” he said.
The federal government’s National Plastic Plan – launched in March with a promise to make all packaging in Australia reusable, recyclable or compostable by 2025 – includes a component targeting marine plastic pollution. “To get to a stage where they know that their plans are effective or not, they really need data,” Gacutan said. “How you’d find if your actions were effective is through the consistent clean-up [and monitoring] of these areas.”
The Australian Marine Debris Initiative was made possible by the combined efforts of tens of thousands of volunteers at 2000 organisations, who not only cleared rubbish from Australian beaches but also sorted the items they found into categories such as plastic, glass, and metal.
“You’ve got organisations like Take 3 For The Sea, Seaside Scavenge and a few other pretty big clean-up organisations all contributing to this database, but also local ones such as local rotary clubs and local coast care groups,” Gacutan said.
The unified approach was an advantage, he added. “One of the problems we’re seeing in other countries is that different groups are calling the items they find different things, so when it comes to getting a national or state picture, it’s really difficult.”