Plastic litter is everywhere and now decomposed microplastics have been found in varying concentrations in blue mussels and water in the intertidal zone on some of South Australia’s most popular and remote beaches.

Flinders University researchers warn that this means microplastics are now ending up in human food, including wild and sea-farmed fish and seafood from the Southern Ocean and Gulf waters. formerly pristine South Australia.

“Our findings shed light on the urgent need to prevent microplastic pollution by working with communities, industries and government to protect these fragile marine systems,” says Professor Karen Burke da Silva, lead author of a new paper coming soon. to be published in Total Environmental Science.

The Flinders University research team sampled varying levels of microplastics at 10 popular beaches across South Australia, from Coffin Bay and Port Lincoln on the west coast to Point Lowly and Whyalla on Spencer Gulf, to beaches popular Adelaide metropolitan areas as well as Victor Harbor, Robe and Kangaroo Island.

“Low to medium levels of microplastics (less than 5 mm) measured in the common blue mussel (Mytilus spp.), a filter feeder affected by ecosystem conditions, were measured to analyze the main types of pollution affecting the environment, and using plastic was the main culprit,” says Professor Burke da Silva.

Microplastics are ubiquitous in our marine environment and tend to be more abundant in mussel samples near major cities, with levels four times higher at Semaphore Beach compared to more distant Ceduna on the Eyre Peninsula.

“By investigating the microplastic load in the mussel, we draw attention to the implications of microplastic pollution on South Australia’s unique marine ecosystems and the local human food chain,” says Janet Klein, the first author of the item.

Microplastic contamination at Semaphore Beach and then Hallett Cove up to four times higher than testing at Ceduna, and twice as high as Coffin Bay on the Eyre Peninsula.

Trillions of microplastic particles exist in the world’s oceans, with the highest concentrations recently found in shallow seafloor sediments off Naifaru in the Maldives (at 278 kg particles^-1) and lowest reported in Antarctic Southern Ocean surface waters (3.1 x 10^-2 particles per m³).

For the first time, the new study from Flinders University has measured the presence of microplastics on the South Australian coastline, in areas important for both shipping, fishing and tourism, as well as other industries and local communities.

The concentration of microplastics in SA intertidal water was found to be low to moderate (mean = 8.21 particles l⁻¹ ±4.91) compared to global levels and abundance of microplastics in mussels (average = 3.58 ± 8.18 individual particles⁻¹), within the range also reported globally.

Plastic types include polyamide (PA), polyethylene (PE), polypropylene (PP), acrylic resin, polyethylene terephthalate (PET), and cellulose, suggesting synthetic and semi-synthetic particles from products single-use, short-lived fabrics, ropes and ropes from the fishing industry.

“The areas examined include some globally significant biodiversity hotspots, including the breeding ground of the large cuttlefish in the northern Spencer Gulf and more diverse marine ecosystems than the Great Barrier Reef (such as Coffin Bay), so the cleaning and prevention measures are long overdue,” says Professor Burke da Silva.

“Besides harvesting blue mussels, we also need to consider the impact of microplastic particles entering other parts of the human food chain with microplastic pollution expected to increase in the future.”

The article, “Microplastics in intertidal water of South Australia and the mussel Mytilus spp.; the contrasting effect of population on concentration,” was published in Total Environmental Science.