Study confirms: microplastics have entered our food chain

New research from Flinders University has found further evidence of microplastics in our food chain. In southern Australia’s most popular and remote beaches, microplastics were found in blue mussels and the surrounding water.

The research team considers this a warning that our food chains are now polluted with plastic waste. From wild-caught fish and ocean-farmed seafood, microplastics are polluting the Southern Ocean and gulf waters of South Australia.

The world’s oceans are littered with plastic waste that breaks down into smaller fragments, known as microplastics. The highest concentration of microplastics have been reported in the shallow sea floor in the Maldives and lowest reported in the surface waters of the Antarctic Southern Ocean.

To measure concentrations of microplastics, the researchers analyzed samples from 10 beaches in South Australia’s coastline. These areas are important for shipping, fishing and tourism, along with other industries and local communities.

The results showed that microplastic concentrations in the intertidal water are low to moderate compared to global levels. Microplastic concentrations in mussels are also within the range reported globally. 

Blue mussels were studied because they are directly affected by ecosystem conditions. This allowed the research team to investigate the types of pollution that are affecting the local environment, “and single use plastics was the main offender” said study senior author Professor Burke da Silva.

Microplastics are usually abundant in mussel samples near large towns and cities. The experts found that concentration levels were four times higher at Semaphore Beach compared to the more remote beaches.

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

The types of plastics found in these beaches were synthetic, suggesting they came from single-use, short-life cycle products, fabrics, ropes and cordage from the fishing industry. 

“The areas examined include some biodiversity hotspots of global significance – including the breeding ground of the Great Cuttlefish in the Northern Spencer Gulf and marine ecosystems more diverse than the Great Barrier Reef (such as Coffin Bay), so cleanup and prevention measures are long overdue,” said Professor da Silva.  

“Apart from the harvesting of 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 findings demonstrate the urgent need to prevent plastic pollution. The research team concludes that this can only be done by working with the industries that produce these products, local communities, and government to best protect our ocean ecosystems.

The study is published in the journal Science of The Total Environment.

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By Katherine Bucko, Earth.com Staff Writer