Short communicationPresence of microplastic in the digestive tracts of European flounder, Platichthys flesus, and European smelt, Osmerus eperlanus, from the River Thames

- Plastic fibres were found in Thames fish.
- Up to 75% of flounder ingested plastic fibres.
- Most fibres were black.
- Fibres were identified as acrylic, nylon, polyethelene, PET and polyamides.

Like many urban catchments, the River Thames in London is contaminated with plastics. This pollutant is recorded on the river banks, in the benthic environment and in the water column. The present study was conducted to assess the extent of microplastic ingestion in two River Thames fish species, the European flounder (Platichthys flesus) and European smelt (Osmerus eperlanus). Samples were collected from two sites in Kent, England; Erith and Isle of Grain/Sheppey, near Sheerness, with the latter being more estuarine. The results revealed that up to 75% of sampled European flounder had plastic fibres in the gut compared with only 20% of smelt. This difference may be related to their diverse feeding behaviours: European flounder are benthic feeders whilst European smelt are pelagic predators. The fibres were predominantly red or black polyamides and other fibres included acrylic, nylon, polyethylene and polyethylene terephthalate and there was no difference in occurrence between the sites sampled.

Percentage of fish - The first bar (green) represents the percentage of the sampled fish that had one or more plastic fibres in each sample. The subsequent bars (red, black, blue, clear) show the percentage of the sampled digestive tracts at each site which contained the different colour fibres. Some fish ingested several different coloured fibres and thus the sums of the bars does not equate to 100%. (b) Percentage of fibres - the percentage of fibres that were red, black, blue and clear in each sample. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)124