Are microplastics a big problem?

What are microplastics?

Microplastics are very small particles of plastic debris with a diameter of less than five millimetres.

In 2004, Richard Thompson OBE FRS, Professor of Marine Biology and Director of the University’s Marine Institute, was the first to describe their long term accumulation and coin the term 'microplastics' in his landmark paper, 'Lost at Sea: Where Is All the Plastic?'.

Ever since, Richard, who founded and heads our International Marine Litter Research Unit, has been working to establish where those microplastics are accumulating, what the potential consequences are for wildlife and to identify solutions to help stem the flow of plastics to the ocean.


Where do microplastics come from?

  • Particles arising from the breakdown of larger items of plastic litter in the environment, such as plastic packaging and water bottles.
  • Microfibres shed from textiles during use.
  • Particles resulting from tyre abrasion.
  • Tiny particles that have been manufactured for use in products such as cosmetics (sometimes called microbeads).
  • Spillage of tiny particles of plastic that are the feedstock for the production of other plastic items.

While news articles often describe heavily contaminated locations. It’s now clear that plastic and microplastics contaminate shorelines worldwide.

Our work has so clearly shown, that microplastics are present in every sample of beach sand, whether it’s in Australia, Asia, Europe, North or South America. We’ve looked in the deep sea, in Arctic ice, in the gut of hundreds of fish from the English Channel, and we’ve found microplastic contamination everywhere.

Professor Richard Thompson, OBE FRS

<p>Close-up of a study of microplastics.</p>
<p>Fibres floating in water</p>

Scale of the problem

It is estimated that there are now trillions of microplastic particles in the marine environment.

For example, some of our own research has shown that up to 94,500 microbeads could be released from an exfoliant in a single use; and that a single 6kg load of washing could release over 700,000 fibres to waste water. Some of these are likely to pass through waste water treatment and into the environment.

It is estimated that plastics (including microplastics) could take hundreds or even thousands of years to break down and therefore plastics debris is accumulating in our oceans year on year. Microplastics can be mistaken for food by birds and marine life and there is evidence that this can cause harm.

Microplastics have been documented in all five of the ocean’s subtropical gyres and some of the greatest accumulations of microplastic are found thousands of miles from land.

Gyres are circular ocean currents formed by the Earth's wind patterns and the forces created by the rotation of the planet.

Microplastics have even been found in the snow at Mount Everest.


Watch a video about scientists identifying microplastics close to the summit of Mount Everest.

Are microplastics harmful?

Microplastics are of concern because of their widespread presence in the oceans and the potential physical and toxicological risks they pose to organisms.

Microplastics can be ingested by a wide range of animals and have been found in organisms ranging in size from small invertebrates to large mammals. 

Laboratory studies have shown there is potential for this to lead to harmful effects and it is estimated that unless we change our ways there, within this century, will be wide scale and potentially irreversible effects in the natural environment

While there are still many unanswered questions about the amounts of microplastic debris that might be accumulating and the types of harm they could present, there is a growing consensus we should urgently take action to reduce the flow of plastic into the environment.

How is the University pioneering research and leading change?

Influencing international policy

Nearly two decades of world-leading research into the effects of marine plastics on our environment by Plymouth researchers, led by Professor Thompson, has resulted in repeated scientific breakthroughs which has influenced national and international legislation.

Our work on this topic has helped inform governments around the world. Former US President, Barack Obama, signed a bill outlawing the sale and distribution of toothpaste and exfoliating or cleansing products containing microbeads, which are a type of microplastic. The UK, Canada and New Zealand followed with legislation on microbeads

Our ground-breaking research and subsequent policy impact on microplastics pollution in the oceans has repeatedly been recognised including the highest honour that can be bestowed upon a higher education institution – a Queen’s Anniversary Prize for Higher and Further Education.

Find out more about the impact of our International Marine Litter Research Unit

Meet our experts

Professor Richard Thompson OBE FRS


A decade-and-a-half on from his seminal microplastics paper, Professor Thompson has mapped out much of the territory upon which our understanding of both the impacts of plastics and the potential solutions are based.  

I became interested in plastics when I found litter arriving on the shorelines where I was studying marine biology. I helped with beach cleans, and this is where I made a key observation. That the most abundant pieces of plastic litter, the small ones, were not being counted or removed. This prompted me to ask the question what are the smallest items of plastic in the marine environment – that question led to the first paper on microplastics.”

Under his leadership, Plymouth has produced more scientific publications on the subject of marine plastic than any other university worldwide.

“My mission is to further our understanding of the impacts of litter on the environment and society, and even more importantly to identify the solutions and steps necessary to achieve them.”

Find out more about Richard's research

Dr Imogen Napper

Dr Imogen Napper, has an undergraduate degree in biomedical science, a masters degree in biotechnology, and working within the International Marine Litter Research Unit has recently completed her PhD looking at the sources of microplastic contamination.

Find out more about Imogen's research

Dr Winnie Courtene-Jones

Dr Winnie Courtene-Jones is a marine biologist who focuses on understanding the long-term fate, prevalence and impacts of plastics and microplastics on aquatic ecosystems. She has given talks at national and international conferences and spoken at UK and EU Parliament as a microplastics expert.

Find out more about Winnie's research

Scientific discoveries

  • H 2004 – First scientific paper describing microplastics
  • H 2007 – First paper on chemical transport to organisms by microplastic
  • H 2008 – First paper showing ingestion and retention of microplastics by organisms
  • H 2011 – First paper showing global distribution of microplastics
  • H 2013 – First paper showing microplastic ingested by natural populations of commercially important fish
  • H 2014 – First papers showing substantial accumulation of microplastics in Arctic and deep sea
  • H 2015 – First paper quantifying microbeads from cosmetic products
  • H 2017 – First paper quantifying release of microfibres from textiles
  • H 2018 – First paper showing distribution of nanoplastic throughout the body of a marine invertebrate
  • b Read our research publications

Marine degree courses, research and education – in Britain's Ocean City

Students consistently choose Marine at Plymouth over other locations for courses related to the sea. Plymouth boasts one of the most prestigious clusters of marine teaching, research and educational organisations in Europe. 

Top 10 University for Geology, Environmental, Earth and Marine Sciences in the UK
– Times Higher Young University rankings 2019

Find out about studying marine at Plymouth