Microplastic ingestion by two mullet species in the Breede Estuary, South Africa

Microplastic (MP) ingestion by two mullet species (the South African mullet Chelon richardsonii and grooved mullet C. dumerili) in a warm-temperate estuarine system on the south coast of South Africa was investigated in relation to fish size, the MP concentrations in sediment and the estuary reach. Small fish (<200 mm TL, all juveniles) ingested MP concentrations one order of magnitude greater than large fish (≥200 mm TL) in all estuary reaches, possibly reflecting the transition from planktivorous feeders to benthic detritivores. The concentration of MPs ingested differed significantly (p < 0.01) between the two mullet species, which could be ascribed to different feeding ecologies during their juvenile phases.