Samples were collected from 2014 to 2020 from the sea surface around Scotland’s coast in a study funded by agencies Marine Scotland and the Scottish Environment Protection Agency (SEPA).
Three boats towed catamaran swimmers attached with sampling nets to “provide a preliminary assessment of the extent of floating microplastics in Scotland's seas and to identify any hotspots for more targeted future sampling”. Each sample tested for plastic in one square kilometre of water.
Published in Marine Pollution Bulletin, researchers found that the highest levels of microplastics were in the Solway and the Firths of Clyde and Forth.
The Firth of Clyde samples included microplastics found at Loch Long, which cuts through 20 miles of coast from the North Sea on the west of Scotland and is a tourist hotspot.
The lowest levels were found in the Outer Hebrides, Orkney Islands, Shetland Isles, North Coast, Moray Firth and the North East.
The research also found that fragmented plastics account for almost 70% of the microplastics found. “This may suggest that the microplastics in Scotland's seas are predominantly from the breakdown of larger items and the polymer composition of these fragments suggests that much of it may be due to the breakdown of consumer products such as bags, bottles and food containers,” according to the report.
Microplastics are small pieces of plastic that range from 1 um to 5 mm, and are dangerous to both the environment and aquatic life. Researchers reported in 2017 that more than 690 marine species including seabirds, turtles and fish have ingested microplastics.
The study also noted the huge impact that increased reliance on plastic has had on the globe. “Large scale production of plastics only began in the 1950s, with a total global production of 2 million metric tonnes in 1950.
“In 2019 the total global production of plastics had reached 368 million metric tonnes, with the total global production of plastics from 1950 to 2015 estimated at 8300 million metric tonnes. It has been estimated that as much as 8 million metric tonnes of plastic waste enters the oceans annually.”
Nik Turner, litter prevention manager at Loch Lomond & The Trossachs National Park, told the Daily Record: “The marine environment within the national park is extremely rich in biodiversity and we have been working for a number of years now to tackle the issues around marine litter and pollution that affect our coastal environment and communities.
“With an estimated 80% of marine litter starting on land, the work we do to manage litter everywhere in the national park reduces the amount that might wash or be blown into lochs and rivers, therefore preventing it from entering the marine environment in the first place.”
Microplastics in sea surface waters around Scotland is available here.