20 March 2018

Professor Peter Lay

Prof Peter Lay

Dr Liz Carter

Dr Liz Carter

by Dr Anna Renfrew

Researchers at the School of Chemistry in collaboration with UNSW are using new analysis methods to learn more about plastic contamination in Australia’s fish.

Plastic waste is one of the most prevalent forms of pollution in the marine environment, a result of increasing plastic consumption and poor waste management. One of the most dangerous forms of this pollution are microplastics, particles that are less than 5 mm in diameter, and small enough to be ingested by fish. As well as the risks that these particles pose to marine life, they are a pathway for toxic chemicals to enter the food chain and pass into human diets. As such, there is a pressing need for more research to understand the environmental significance of this link.

Most studies in this area use visual inspections to identify microplastics in fish, but this does not give any information on the type of plastic and where it might have come from. Now Professor Peter Lay and Dr Elizabeth Carter from the Vibrational Spectroscopy Core Facility have used a new approach to solve this problem, by applying a combination of ATR-FTIR (Attenuated Total Resonance-Fourier Transform Infrared) and Raman spectroscopy to analyse the gut content of commonly eaten fish.

Working with Professor Emma Johnston from UNSW, the team looked at samples of three species, yellow-fin bream, sea mullet and silverbiddy, all taken from Sydney Harbour. By applying a statistical technique called principal component analysis, they were able to identify 80% of the ingested material in the fishes’ gut. The analysis revealed the most common microplastics to be polyester, acrylic-polyester blend, and rayon fibres, which are all commonly used in clothing.

Now with an ARC linkage grant of $786,000, the team will work with Parley for the Environment and the state water corporations of Victoria and South Australia to apply their analytical techniques to a wider sample area. By using vibrational spectroscopy to reliably determine the plastic contaminants in fish, the project will identify the main contributors to marine plastic pollution, helping to guide policies to reduce fibre emissions and develop eco-friendly alternatives.

Further reading: DOI: 10.1016/j.envpol.2017.11.085