Scientists reveal plastics problem
Marine creatures living in the deepest parts of the ocean have been feeding on microplastic particles for at least four decades, a study has revealed.
Researchers at the Scottish Association for Marine Science (SAMS) at Dunstaffnage delved into the institute’s archived samples from the Rockall Trough, an area of deep sea off the west coast, to assess the extent of microplastic ingestion in bottom-dwelling starfish and brittle stars.
Traces of eight different plastics, including polyester and nylon, were found in specimens that lived more than 2,000 metres below the ocean surface between 1976 and 2015 – and the levels of ingestion were similar throughout that period.
Across the time series, scientists found nearly half of the starfish and brittle stars sampled had ingested microplastics, defined as small pieces of plastic less than five millimetres in size. When ingested by sea creatures, microplastics may be retained in their bodies and passed up the food chain.
The study, published in Environmental Pollution, follows on from SAMS research in 2017, which was the first to quantify the levels of microplastic ingestion in marine creatures living at depths of
2,200 metres.
Author Winnie CourteneJones, a UHI 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.
‘We were only able to gather this evidence by using archival specimen collections and I would encourage those with access to such repositories to consider using these in order to broaden our knowledge of historical plastic pollution, which will help us tackle our modern-day problem.’
Researchers at the Dunbegbased SAMS had access to historical records collected from the annual Ellett Line scientific cruise, which began in 1975 and takes samples and observations at monitoring stations between Scotland and Iceland.