Starfish and brittle stars have been feasting on plastic since the 1970s, a new study revealing the scale of plastic pollution has found.

The Scottish Association for Marine Science (SAMS) in Oban, Western Scotland, delved into archived samples of sea creatures that lived four decades ago and found they had plastics in their stomachs.

The sea creatures lived in the Rockall Trough, an area of deep sea off of the west coast of Scotland, and fed from the sea bed 2,000 metres below the ocean surface.

The scientists found traces of eight different plastics, including polyester and nylon, in specimens alive between 1976 and 2015, with the levels of ingestion found to be similar throughout that period.

Winnie Courtene-Jones, a University of the Highlands and Islands PhD student at SAMS, said: “Mass production of plastics only began in the 1940s and 1950s, so it would be reasonable to expect less plastic in our earlier samples, with a subsequent upward trend to the present day levels, but we haven’t seen that. In fact, the level of microplastic ingestion is remarkably similar throughout the time series.

“This data shows, for the first time, the long-term prevalence of microplastic pollution in the deep sea and indicated that microplastics may have been present on the sea floor of the Rockall Trough prior to 1976.”

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SAMS deep-sea ecologist Dr Bhavani Narayanaswamy, Winnie’s lead supervisor and a co-author on the report, added: “To find such high levels of microplastic ingestion among deep sea creatures sampled more than 40 years ago shows that plastic pollution in our oceans is not a new problem.

“Previous studies have highlighted the current levels of plastic pollution, or given us a snapshot in time, but we need more long-term data like this if we are to find out the true extent of the problem.”