Microplastics in decapod crustaceans sourced from Australian seafood markets

Microplastic abundance and characteristics were assessed in five decapod crustaceans purchased from seafood markets and collected in coastal waters around Australia (South Australia, New South Wales, Queensland, Northern Territory, and Western Australia). Three species of prawns (king, banana and tiger prawns) and two species of crabs (blue-swimmer and mud crabs) were analysed. Muscle tissues and gastro-intestinal tracts in prawns, and gastro-intestinal tracts in crabs, were chemically digested, with microplastic identification verified using Fourier Transform Infrared spectroscopy. Forty-eight percent of crustaceans contained microplastics. Prawns and crabs had 0.8 ± 0.1 and 1.6 ± 0.1 pieces per individual, respectively, with spatial patterns evident. Microplastics were predominantly fibres (98%) of blue (58%) and black (24%) colours with polyolefin including polyester the most prevalent polymers. Overall, compared to a systematic review we performed of microplastics in decapod crustaceans worldwide, microplastic loads in crustaceans from Australia were in the lower range of plastic contamination.