Posted on July 13, 2022
Microplastics are tiny plastic litter measuring less than five millimetres. They either come from large pieces of plastic which have broken down over time, or from pellets used in industry and cosmetic products.
The highest concentration at the sites tested in the last two years was found off the north west coast of Skye, where surface water was estimated to contain 28,566 microplastics per square kilometre.
The single biggest source of microplastic litter in 2021 and 2022 came from flakes of plastic-based paint.
Studies suggest microplastics are “highly detrimental” to the health of the wildlife that they come into contact with in the ocean. They can also transfer dangerous contamination up the food chain, with potentially serious consequences for human health.
Environmental campaigners described the quantities of microplastics in Scottish waters as “truly alarming” due to the “devastating” impact the litter has on “marine life, human health and climate change”.
The Scottish Government argued that “marine litter is a global challenge” and pointed out that it had taken actions to ban some single-use plastics. It added that it is supporting efforts to “improve scientists’ understanding of the microplastic pollution problem”.
The data was released to The Ferret under freedom of information law. It is an update on figures published by Marine Scotland last year which showed the results of microplastic sampling in Scottish surface waters between 2014 and 2020.
Of the 81 Scottish locations tested in 2021 and 2022, 64 contained microplastics. On average the areas which contained microplastics had an estimated 5,000 items in them per square kilometre.
The figures provide a breakdown of the types of microplastic litter which were found. These include polystyrene, fragments and fibres from larger waste which has degraded, nurdles — small pellets which are the building blocks of all plastic production — and the paint flakes.
Some marine regions which showed high concentrations of microplastics between 2014 and 2020, were not surveyed in 2021 or 2022. This includes the two areas where the highest concentrations of microplastics have been found so far, Clyde and the Solway Firth.
A site in the Solway Firth south of Kirkcudbright — where there were an estimated 91,128 items per square kilometre in 2016 — had the highest concentration of microplastics found in Scottish waters.
High levels of microplastics have also previously been found in areas of the Firth of Forth and at Loch Long, near Helensburgh.
Map of microplastic concentrations found in Scotland’s seas 2014-2022:
Each of Scotland’s 16 marine regions have now been tested since 2014, with microplastics found in areas of all of them.
Marine Scotland has attributed the high concentrations of microplastics in the Forth and Tay and Clyde regions to the fact that they are offshore of Scotland’s most densely populated and highly industrialised areas.
The Solway Firth is close to some major industry in England and this has been blamed for the high levels of microplastics off the south west coast.
While the Marine Scotland survey looked specifically at surface waters, there is also evidence that microplastics are present in large numbers throughout Scotland’s seas.
In March 2022, it was shown for the first time that microplastics from European rivers had made their way to the Arctic, with potentially damaging implications for the polar ecosystem.
The exact impacts of the widespread distribution of microplastic pollution is not currently known. But numerous studies have shown that microplastics have a significant impact on marine environments that they come into contact with.
When they are absorbed by animals through the food they eat, they can cause potentially fatal health problems. Other dangerous pollutants in water also gather on the surface of microplastics meaning that they can be passed up the food chain.
Some research has suggested that humans could be consuming more than 100,000 microplastic particles each year and there are concerns that some of the chemicals in the plastics could be harmful to our health.
Plankton and other microorganisms produce a huge amount of oxygen, and also absorb carbon dioxide, which stops it from entering the atmosphere and causing global warming.
High concentrations, even in the most remote areas, suggest that plastic pollution is ubiquitous in our environment. This has a devastating effect on marine life, human health and climate change
Kim Pratt, Friends of the Earth Scotland
Santillo said: “It’s difficult to find much good news here, but the higher concentrations of microplastics found near population centres implies that a significant amount of the plastic in Scottish waters may have a Scottish origin.
“That means that efforts made in Scotland to reduce plastic waste can make a significant impact on the levels of plastic around the Scottish coast and in Scottish marine life.”
Young said: “The research we do beneath the surface frequently finds even more on the seabed.
“In 2015, the Scottish Government set out in their National Marine Plan the requirement that ‘properties and quantities of marine litter do not cause harm to the coastal and marine environment’, these figures suggest that plan is largely being ignored.
“There has been robust science done to understand the sources of microplastics, the Scottish Government must redouble its efforts to reduce and eventually stamp these out, as well to ensure that any residual amounts do not enter our waters.”
Read more from The Ferret on Scotland’s waste here
“The level of micro plastics found in our oceans is truly alarming. High concentrations, even in the most remote areas, suggest that plastic pollution is ubiquitous in our environment. This has a devastating effect on marine life, human health and climate change,” Pratt said.
A Scottish Government spokesperson said: “Marine litter is a global challenge, affecting the world’s oceans, seas, coastlines and shores.
“Our refreshed Marine Litter Strategy, to be published later this year, has an action plan to reduce sources of large litter such as fishing gear, and micro such as plastic pellets.
“Scotland has banned microbeads in rinse-off personal care products and was the first in the UK to ban plastic-stemmed cotton buds. We have also implemented a ban on many single-use plastic products often found as beach litter and are introducing the UK’s first deposit return scheme next year.
“We will also continue to support developments in microplastic monitoring, improving scientists’ understanding of the microplastic pollution problem, and enabling more effective solutions that can be taken across the world to protect our environment.”
A spokesperson for INEOS’ Grangemouth plant pointed out that plastics had “positively” transformed the world and played an important role in lots of sectors.
They said: As a major manufacturer of essential chemicals as well as plastics we take our responsibilities to the environment very seriously.
“Today, we are manufacturing a range of plastics that are replacing and displacing fossil based raw materials, creating a circular economy where plastics can be used as a raw material for new plastics time and time again.”