£1.85m study to investigate microbes “hitch-hiking” on marine plastics

Experts at the University of Stirling will lead a new £1.85 million project investigating how marine plastics transport bacteria and viruses – and the impact that may have on human health.

Scientists from the Faculty of Natural Sciences – working with the Universities of Bangor and Warwick – are aiming to understand how plastics act as vehicles, with the potential to spread pathogens within coastal zones, or even from country to country, and how that affects health.

Environmental biologist Dr Richard Quilliam is principal investigator on the new study, funded by the Natural Environment Research Council (NERC).

“While the impacts of marine plastics on wildlife are already well known, little research has been carried out to understand potential human health hazards posed by pathogens bound to their surface,” explained Dr Quilliam. “Our study will consider how pathogens bind to plastics in the ocean and how this process helps bacteria and viruses ‘hitch a ride’ to spread across the world – to places that they would never have ended up if they had just been floating freely.

“Potential impacts to humans could be caused through the food chain – for example, ocean zooplankton eat plastics, which are then eaten by fish and, ultimately, humans – or by people ingesting water, swimming in the sea or lying in the sand near marine plastics.”

The team will characterise the colonisation dynamics of pathogenic viruses, bacteria and toxic algae that bind to plastics and consider whether that process boosts their survivability, by offering protection from harmful ultraviolet light and predation.

“We will also seek to investigate whether toxic algae survives longer when it has something to bind on and a habitat to live in. We believe marine plastics may improve the survival and persistence of pathogens in the environment,” Dr Richard Quilliam added.

Dr Richard Quilliam, of the University of Stirling, will lead the new study.

The study will also analyse the behaviour of microplastics – small, barely visible pieces of plastic that enter and pollute the environment through waste water treatment works – that have become colonised by microbes, through rivers and estuaries and out into the ocean. In addition, the project will consider the role of microbes in the biodegradation of plastics.

Dr Quilliam said: “This is a novel research area and our work is likely to result in new environmental guidelines, strategies and management plans designed to reduce the likelihood of marine plastics being bound by pathogens.”

Professor Peter Golyshin, of Bangor University, said: “We will be estimating the amount and composition of microplastics entering UK rivers and coastal systems.

“We will then be modelling how long they take to reach coastal zones with high biodiversity and shellfisheries, depending on different weather scenarios. We will also estimate the potential of naturally-occurring microorganisms to colonise and degrade microplastic particles.”

The study – entitled Microbial hitch-hikers of marine plastics: the survival, persistence and ecology of microbial communities in the ‘Plastisphere’ – is funded under the fourth round of NERC highlight topics, which splits £24 million between 14 research projects.

NERC Associate Director of Research, Ned Garnett, said: “The highlight topics programme allows us to receive ideas from both the research community and users of environmental science to ensure that we are providing funding where it is most needed. The provision of top quality environmental research has never been more essential as we continue to tackle some of the greatest environmental challenges of our time.”