Miniscule plastic particles with the potential to cause havoc in our waterways and oceans have been found in the stomachs of over a quarter of fish sampled in Sydney Harbour.

Named microplastics, the tiny plastic fragments, beads and fibres are sometimes made directly as beads, and sometimes created by the break-down of plastics used in clothing, packaging, fishing gear, nappies and wipes.

“Often too small to be removed by wastewater filtering, microplastics eventually find their way from our drains to our waterways and oceans,” says Professor Emma Johnston, who helped launch the World Harbour Project in the Sydney Harbour Research Program.

“Once ingested by marine life, they can block the passage of food in the gut and potentially transfer directly into the bloodstream to cause disease. Toxins and chemicals bound to the tiny plastics also affect fish health.”

Emma investigates human impacts on marine ecosystems at the University of New South Wales (UNSW) and advises the New South Wales Government on the environment. Informed by the results of the Sydney Harbour Research Program, governments are now beginning to act to counter the spread of microplastics.

Counter methods include the reduction in use of non-essential tiny plastic microbeads in pharmaceutical products, and filter designs that could slow the flood of microplastics into the oceans through wastewater.

Inaugural Director of the Sydney Harbour Research Program at the Sydney Institute of Marine Science and a Professor of Marine Ecology and Ecotoxicology at UNSW, Emma is now the University’s Pro-Vice-Chancellor of Research.

In 2015 she won the Department of Industry and Science Eureka Prize for Promoting Understanding of Australian Science Research.