Public urged to track 'nurdles' on Scotland's beaches
The public are being urged to help track the spread of tiny plastic pellets known as "nurdles" on Scotland's beaches.
There are concerns about the impact the pellets have on seabirds and the marine environment.
The puffin is believed to be one of the species most at risk.
The coloured pellets are the building blocks of the plastics industry and are used to manufacture a wide range of everyday products.
The size of a lentil, they are easily spilled and washed away.
Environmental campaigners are calling on the industry to do more to prevent nurdles ending up in the sea.
Scottish companies say they are already responding to the challenge.
The Brand-Rex factory in Glenrothes, which manufactures data cables, uses billions of the pellets every week.
The factory's drains have filters installed and spillages are carefully swept up.
Operations manager Paul Richardson said: "I like to spend a lot of time outdoors, whether that be in the hills or at the beach, so for me it's a good cause to take on board.
"But as a business, it's also very important to us."
The pellets are transported around the country by the lorry load.
They may be manufactured in Scotland or shipped in from abroad.
Grangemouth is at the heart of Scotland's trade in plastic pellets.
Industrial giant INEOS says it is working to ensure "zero pellet loss" because it's good for the environment and its business.
Local haulier, Iain Mitchell, is also aware of the damage lost shipments of nurdles can cause.
He told BBC Scotland: "It makes me feel pretty sad as a Scotsman that some of these beautiful beaches that we have around our coastline are spoiled with the pellets.
"It's horrendous. It really is."
Analysis by BBC Scotland environment correspondent David Miller
Once you know what you're looking for, you may find yourself stumbling across nurdles when you least expect it.
I have spotted them on the beaches of the Clyde and the Forth, but reports regularly come in from more isolated stretches of coastline.
They may be tiny but they're contributing to a big problem.
The news that around 15% of puffins have plastics in their bodies will come as a surprise to many.
And there are other worries too.
The pellets attract and concentrate background pollutants and should be handled with care.
That is why gloves are recommended for anyone collecting nurdles from the beach.
Work to assess the impact of the pellets, and other plastics, on the human food chain is continuing.
We can't do much about the pellets which have already been lost, but simple changes could make a big difference.
That's why the plastic industry is promoting Operation Cleansweep.
A brush and a shovel may prove to be the most effective way of preventing spilled nurdles ending up in our seas and on our beaches.
Heightened awareness of the problem is leading to changes in working practices.
But the industry acknowledges there is a problem and is funding research into the impact of plastics on our marine environment.
Kim Christiansen of Plastics Europe said: "What exactly happens out in the environment is not fully known yet.
"This is why we work with scientists under the UN environment programme, financing their work to look into the fate and the sources of plastics in the oceans".
In the Firth of Forth, important seabird colonies on the Bass Rock and the Isle of May are close to shipping lanes and only a few miles from major industrial sites.
Mark Newell of the Centre for Ecology and Hydrology studies the impact of plastics on seabirds.
He said: "We've looked at the stomach content of puffins and found that maybe about 15% of puffins will have some plastic within them.
"Certainly, these very small plastic pellets are a bigger problem for something like a puffin than the larger plastic items that will affect some of the other species."
Reports from volunteers across Scotland, and beyond, are being used by the environmental charity, Fidra, to build up a detailed picture of the problem.
Dr Madeleine Berg, of Fidra, said: "It helps us build up an evidence base and collect data to really show industry that there is a problem on our beaches.
"So if you're on your beach, just keep telling us about any nurdles you find and we'll be really interested to hear and it'll help to contribute to solving the problem."