Abundance and characteristics of microplastics in retail mussels from Cape Town, South Africa

With the increased occurrence of plastics in the marine environment, ingestion of microplastics (MPs) by marine invertebrates such as mussels is increasing globally. This study investigated the occurrence of microplastics in mussels sold at supermarkets and wholesalers in Cape Town, South Africa. Soft tissue was extracted from mussels, digested and identified by microscopy and FTIR-ATR. MP filaments (70%) and fragments (30%) were the only types of MPs identified and an average of 0.04 MPs/g soft tissue and 3.8 MPs/mussel recorded. Blue/green (44%) and black/grey (40%), smaller than 2000 μm were the most prominent MPs recorded and the main polymer type was filamentous polyethylene terephthalate (PET). Our results suggest that retail mussels in Cape Town do not contain as high concentrations of MPs when compared to other investigations and routine monitoring of seafood in the country is suggested.