Sky News has learned that up to 190,000 tonnes of plastic microfibres from our clothes could be making their way into our oceans every year, prompting calls for manufacturers to take action.
In each washing load, clothes shed hundreds of thousands of fibres. From the dirty washing water, many escape sewage systems and make their way into our waterways and the food chain.
Professor Richard Thompson from Plymouth University told Sky News: "Substantial numbers of fish and shellfish are now contaminated with small pieces of plastic, including fibres.
"And actually because they don't degrade, unless we take action to reduce those plastics we are only going to see more and more of them in marine life in the future."
Unlike other plastics, microfibres are so small that it is almost impossible to see them with the naked eye.
Under a microscope, however, they've been found in the stomachs of both fish and seabirds.
Ingesting plastic often makes animals feel full, meaning many later die of starvation.
Research by consulting group Eunomia has found that 190,000 tonnes of plastic microfibres make their way into the ocean every year.
That is the weight of 1,357 blue whales, and significantly more than the well documented 35,000 tonnes that come from microbead cosmetics.
Sophie Mather, who's worked in the textiles industry for decades, has decided to take action. Along with researchers at Leeds University, she is crowdfunding to develop a new technology that would change how certain materials, like nylon and polyester, are actually made.
She said: "The fashion industry really needs to do a lot more about this. We are seeing fabrics like fleece that are bad fabrics. Those lose a lot of fibres when we are washing them and we need to know more about it."
But it seems that unlike the cosmetics industry, fashion retailers aren't tackling the issue.
Sky News contacted 10 of Britain's biggest clothing brands, including Arcadia Group, Marks & Spencer and New Look.
Only one store, H&M, said it was actively working to address the concerns over microfibres. Other companies said they welcomed more research, but as yet, hadn't made any changes.
Much like H&M, the small surfing brand Finisterre, based in Cornwall, is keen to use more eco-friendly materials.
As big advocates of wool, which naturally decomposes in the ocean, they're researching the extent of the problem.
Brand manager Debbie Luffman told Sky News: "First of all we want to get to the facts to understand the issue and which fibres are the main offenders and how they are affecting fish.
"Really, it's about building a tool box together. How can we make better fibres that have a lesser impact?"
Early research suggests that it is older clothes that shed the most when you wash them.
However, experts warn that without greater support and action from the fashion industry, the problem will get considerably worse over time.