International Marine Litter Research Unit

A worldwide problem

Marine litter is a global environmental problem with items of debris now contaminating habitats from the poles to the equator, from the sea surface to the deep sea.

This litter has negative consequences for wildlife, for economies and on human health. Over 700 species, including commercially important fish and shellfish, are known to encounter marine litter in the environment. The vast majority of the litter found on shorelines, at the sea surface and that affecting marine life is plastic, and it has been estimated that up to 12 million tons of plastic litter could be entering the ocean every year. There are solutions, and some of these are out lined in our recent co-authored publication in Science and associated report, but it is clear there is an urgent need for action on a global scale. That is why as well as working on marine and freshwater projects in the UK and Europe our team are working internationally with recent projects in India (Ganges Nat Geo) and on a global scale via our science leadership role with eXXpedition.

Our mission

The International Marine Litter Research Unit has a mission – to further our understanding of the impacts of litter on the environment and society, and to identify the solutions and the pathways necessary to achieve them.

At the forefront of marine research

The International Marine Litter Research Unit is proud to stand at the forefront of research in this area. In 2004 our team was the first to reveal the widespread occurrence of microscopic particles of plastic debris at the sea surface and on shorelines – pieces which we described as microplastics. We have published numerous scientific papers and reports on this topic, have advised governments and international organisations worldwide and we continue to research not only the extent of the problem, but also the solutions.

Our research publications


Our findings are underpinned by research conducted by the team at the University of Plymouth and in collaboration with other leading scientists worldwide. This expertise has guided industry, informed educational and artistic initiatives that raise awareness, and has provided evidence for government agencies and international organisations such as the United Nations.

Discovering microplastics

In 2004, Professor Richard Thompson OBE and his team showed that microplastic particles have accumulated in oceans since the 1960s and are now present worldwide. The International Marine Litter Research Unit described the accumulation of fragments of plastic debris in the oceans and much of its focus is on these microplastics.

Our work has shown that microplastic debris now contaminates shorelines worldwide; that they are present in substantial quantities in remote locations such as the deep and the Arctic. A range of marine organisms including commercially important species can ingest these pieces and laboratory studies have shown there is potential for this to lead to harmful effects.

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.

Our impact

Marine litter: how can we save the environment from the plastic in our seas?

"On the one hand, plastics bring immense benefits to society, and on the other hand, the accumulation of end-of-life plastics is creating a global environmental challenge."

Join Professor Richard Thompson OBE FRS, Director of the Marine Institute, to learn about impact of marine litter and how we might solve this growing environmental problem.

This lecture was prepared for secondary schools as part of FUTURES2020, a festival of discovery exploring the past, creating the present and imagining the future.

Informing policy

From the first publication on microplastics in 2004, we have dedicated much of the last two decades to understanding the environmental impacts of plastics in the ocean. Our work has influenced policy worldwide, and we are now working to provide the evidence that will underpin the most appropriate solutions.

Giving evidence to Parliament:

  • Evidence on microplastics for the plastic bag tax (evidence 2014, tax introduced 2015).
  • Evidence on microbeads (evidence 2015, ban 2018).
  • Evidence on fibres from textiles (evidence 2018, final report 2019).

A timeline of key dates and achievements

Plastic pollution and the planet

In the UK, scientists have for years been saying that more needs to be done to combat the problems posed by marine litter and microplastics. But it is only by creating a sea change in public ways of thinking that we can bring about a positive change.

Read Professor Thompson's opinion piece

Animating the issues