Video: New concern over plastic pollution in Scottish coastal waters after Greenpeace research

Greenpeace said the problem is not as bad as some other regions of the world but criticised a lack of planning to address the issue.

Scientists collected samples in Scottish coastal waters last year, with a focus on the Hebrides in areas known to be important feeding grounds for basking sharks and seabirds such as gannets, puffins, razorbills and shearwaters.

Plastic waste and gannets at Bass Rock in Scotland.  Source (all pictures ): Greenpeace

A total of 49 samples were taken from waters around islands including Rum, Mull and Tiree as well as Loch Alsh, Loch Linnie, Loch Ness and the Firth of Forth.

They were then analysed at Greenpeace's laboratory in the University of Exeter, where it was found 31 samples contained microplastics.

Read More: Video - Health concern over plastic pollution on Scottish beaches

Greenpeace said the Beluga ship expedition gathered more data on plastic pollution in Scottish waters than any previously published survey.

Microplastics can carry a range of chemical additives and contaminants because of their synthetic nature and ability to absorb chemicals from sea water on to their surfaces.

Chemicals found in the samples include those used as additives in plastics like phthalate esters, heavy metals and flame retardants – some of which have been classified as "toxic to reproduction" or are suspected to have hormone disrupting properties.

The charity's oceans campaigner Tisha Brown said: "Although microplastics were found in two out of three samples, this isn't all bad news.

"The concentrations are lower than in many other regions of the world's oceans and hopefully Scottish marine life is at a proportionately lower risk than marine life in those areas.

"However, the results varied significantly in unpredictable ways and so we would need longer-term testing to be confident of average concentrations.

READ MORE: Video - Scotland becomes a pollution hotspot for 'killer' cotton buds

"The key finding here is that microplastics are present in some of Scotland's most remote and unspoilt waters.

"Threatened seabirds and other wildlife are already exposed to them, along with the fish stocks we eat, and there is currently no coherent process or even plan to stop this problem from getting worse.

“The root problem here is using an almost indestructible material to produce trillions of disposable products, and the solution is the three ‘R’s - reduce, reuse and recycle.

"First, we need to cut down on unnecessary plastic, then we need to switch single-use, disposable items for reusable alternatives, and then, finally, we need to make sure that whatever plastic waste we have left is recycled. But it must be done in that order – trying to recycle all the plastic waste we’re producing now is just not realistic.”

In January, the Scottish Government announced the sale and manufacture of plastic-stemmed cotton buds is to be banned, following concerns about the number being washed up on beaches after being flushed down toilets.

But Greenpeace UK says the move "is a step forward but quite a small one" as only around one per cent of what was found in the seas was cotton buds.

Microplastics are small pieces of plastic less than 5mm in size. Some are manufactured, such as the microbeads added to health and beauty products, while others are the result of larger plastics gradually breaking down.

These plastics are pervasive in marine environments, and they are known to harbour toxic substances such as heavy metals and phthalates.

READ MORE: Cotton buds to be banned across Scotland to cut marine pollution

Since many animals are known to eat microplastics, scientists are concerned about the toxic substances contained within them, as well as their capacity to accumulate within the animals and stop them from absorbing nutrients correctly.

Researchers from the University of Ghent in Belgium found in January, last year that seafood eaters are absorbing the plastic into their bloodstream with unknown effects on human health.

Scientists say that 99 per cent of the microplastics pass through the human body - but the rest are taken up by body tissues.

It is believed Europeans currently consume up to 11,000 pieces of plastic in their food each year. According to unpublished studies, fewer than 60 of these are likely to be absorbed - but they will accumulate in the body over time.

But there have been warnings that the amount of plastic absorbed from our food will increase as plastic pollution in the ocean gets worse.

Scientists on-board Greenpeace ship MV Beluga II collected samples with a focus on areas around the Hebrides known to be important feeding grounds for basking sharks and seabirds.

Sea water samples were collected in key foraging areas and around internationally significant seabird colonies including Bass Rock and the Shiant Isles, which are the home to over 20 seabird species including gannets, puffins, razorbills and shearwaters.

A total of 49 individual samples were then analysed by Greenpeace’s laboratory at the University of Exeter to determine the types of microplastics found, and any chemicals or contaminants carried on individual microplastic pieces.

Last year it emerged that 88 shoreline searches across Scotland found that over two out of three were littered with the lentil-sized plastic pellets known as 'nurdles'.

The Firth of Forth saw the highest concentration of the lentil-sized fragments, which measure less than a millimetre across, and are used as a raw material in the manufacturing industry to make new plastic products.

Beach cleans by the Marine Conservation Society have found that the average number of plastic cotton buds found per 100 metres in Scotland has soared from around nine in 2011 and 2012 events to 31 in the 2016 and 2017 campaigns.

The typical number found in the last two years was more than double that found in the previous two years of beach cleans and was higher than the UK average.

Environment Secretary Roseanna Cunningham said: “The Greenpeace research provides yet another powerful reminder of the need to tackle plastic pollution. We’re working hard to do exactly that – Scotland’s seas deserve the highest environmental protection.

“Through our litter and marine litter strategies, we are minimising the amount of plastic which gets thrown away. We aim to reduce waste by 15% and recycle 70% of all waste by 2025.

“We back the EU’s vision to phase out single-use plastics by 2030 - we are committed to introducing a deposit return scheme for drinks containers and have proposed a ban on plastic cotton buds, both of which pollute our natural environment.”