Plastic in the Thames: a river runs through it

Paul Clark (Natural History Museum)

Dave Morritt (Royal Holloway University of London)

River Thames ca. 2006River Thames ca. 2006

2012 fyke net survey

Summary

• 8,490 items collected in a three month period

• Predominantly plastics

• Over 20% of items were sanitary products

• Evidence for sub-surface transport of rubbish in the River Thames

• See Morritt et al. (2014) Mar. Poll. Bull.78: 196 - 200

Mitten crab gut contents

• UG students at RHUL– Knots of plastic fibres

found in Chinese mitten crabs from Chelsea

– Plastic fibres in flatfish from the inner Thames Estuary and Isle of Sheppey

Photos: Emma Powell

Provisional study at two sites in the Thames estuary

Samples collected at Erith (fixed nets) and Isle of Sheppey (trawls)

Thames fish

• 76 fish examined (Erith and Isle of Sheppey)

• Up to 75% of flounder had plastic fibres in their guts

• 20% of smelt had plastic fibres in their guts

Flounder, Platichthys flesus Smelt, Osmerus eperlanus

Examples of the type of plastic fragments and fibres found in the guts of Thames fish

The total percentage of fish with plastic fibres in the gut (green) and the percentage of these fish with fibres of different colours (red, black, blue and clear)

Identification of plastic polymers

• Fourier Transform Infrared Spectroscopy (FT-IR) was used to characterise collections of similar fibres.

• Spectra were compared to spectra in the available database to obtain the best match.

• Fibres included black and red polyamides, acrylic and polythene.

Example of spectrum for red fibres matched to Poly(ethylene tetraphthalate)

Example of a spectrum for red fibres matched to low density polyethylene

Conclusions

• We have evidence for substantial sub-surface movement of plastic litter in the Thames as well as floating litter and litter cleared from the banks.

• Preliminary work demonstrates that at least three species in the Thames ingest plastics.

• We continue to study sub-surface plastic litter in the Thames .

Cleaner Thames campaign

• Launched 30th September

• Website: www.pla.co.uk/Cleaner-Thames

• Film: https://youtu.be/9bsLmgzpHQE

• Twitter: @LondonPortAuth #cleanerthames

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