Following the news that the UK government is to ban plastic microbeads by the end of 2017, a team of scientists led by the University of Oxford has discovered the first evidence of microplastics being ingested by deep-sea animals.
Researchers working on the Royal Research Ship (RRS) James Cook at two sites in the mid-Atlantic and south-west Indian Ocean found plastic microfibres inside creatures including hermit crabs, squat lobsters and sea cucumbers at depths of between 300m and 1800m.
This is the first time microplastics – which can enter the sea via the washing of clothes made from synthetic fabrics – have been shown to be ingested by animals at such depth.
The results are published in the journal Scientific Reports.
Dr Michelle Taylor of Oxford University’s Department of Zoology, and Stipendiary Lecturer in Biology at St Anne's, lead author of the study, said: ‘An important aim of this research expedition was to collect microplastics from sediments in the deep ocean – and we found lots of them. Given that animals interact with this sediment, such as living on it or eating it, we decided to look inside them to see if there was any evidence of ingestion.
‘We found plastic microfibres inside a wide range of animals, including corals, squat lobsters and sea cucumbers. It’s the first evidence that deep-sea animals are ingesting these microfibres.
‘What’s particularly alarming is that these microplastics were found in the deep ocean, thousands of miles away from land-based sources of pollution.’
Microplastics are generally defined as particles under 5mm in length and include the microfibres analysed in this study and the microbeads used in cosmetics that will be the subject of a government ban. Among the plastics found inside deep-sea animals in this research were polyester, nylon and acrylic. Microplastics are roughly the same size as ‘marine snow’ – the shower of organic material that falls from upper waters to the deep ocean and which many deep-sea creatures feed on.
The animals were collected using a remotely operated underwater vehicle. The study, funded by the European Research Council (ERC) and the Natural Environment Research Council (NERC), was a collaboration between Oxford, the University of Bristol, the Natural History Museum in London, and Staffordshire University’s Department of Forensic and Crime Science, which made sure the results were robust and the study was free from potential contamination.
Dr Claire Gwinnett, Associate Professor in Forensic and Crime Science at Staffordshire University, said: ‘Existing forensic approaches for the examination of fibres are tried and tested for their robustness and must stand up to the scrutiny of the courts of law. These techniques were employed in this research in order to effectively reduce and monitor contamination and therefore provide confidence in the fact that the microplastics found were ingested, and not from the laboratory or other external contaminant.
‘Using forensic laboratory techniques, we have identified that microplastics are present in ingested material from deep sea creatures. Forensic science is still a fairly new science, but we are delighted that our work and techniques are starting to inform other sciences and important environmental research such as this.’
Dr Taylor added: ‘While we can’t say for sure what the source of these microplastics is, it’s possible they could have entered the ocean from synthetic clothing, carpet cleaning or fishing nets – there are so many of these plastics out there.
‘There has been no research into the potential effects on deep-sea creatures of ingesting plastics. But, given the impact on other animals, it’s likely to be bad for their health and survival.’