As researchers continue to gain insight into plastic pollution around the planet, much of the focus is on marine organisms and, of course, humans themselves.
UK scientists have set their sights on small land mammals and have found traces of plastic in more than half of the species analysed, with an apparently equal distribution across locations and even dietary habits.
Much is known about the impact of plastic on aquatic ecosystems, but very little is known about the same with terrestrial systems. By analyzing the droppings of some of our most widespread small mammals, we have been able to offer insight into the potential impact plastic is having on our wildlife, and the most commonly found plastics seeping into our environment.
Fiona Mathews, Professor of Environmental Biology at the University of Sussex.
Scientists explored the question of whether small mammals in the UK are ingesting microplastics by collecting 261 faecal samples from seven different species, and examining them with a form of infrared microscopy. This revealed the presence of plastic polymers in 16.5% of the samples and in four of the seven species: the European hedgehog, the field mouse, the country vole and the brown rat were all ‘positive for plastic’.
The scientists expected to see higher concentrations of plastics in samples collected in urban locations and lower concentrations among herbivores. To their surprise, they found that ingestion occurred indiscriminately in all locations and in animals with different feeding habits, including herbivores, insectivores, and omnivores.
It is very worrying that the traces of plastic were so widely distributed between places and species of different feeding habits. This suggests that plastics could be seeping into all areas of our environment in different ways. We are also concerned that the European hedgehog and the country vole are two species that are experiencing a decline in numbers in the UK.
Emily Thrift, author of the study from the University of Sussex.
Interestingly, the scientists also found that more than a quarter of the plastics were bioplastics, which are designed to degrade more easily than traditional forms. The team believes that the plastics reached the animals through direct ingestion, where they are mistaken for food or nesting materials, or inadvertently, through consumption of contaminated prey.
In the UK, plastic pollution can often seem like a problem elsewhere, when most images are of polluted coastlines in tropical landscapes, or of charismatic organisms like turtles or sea lions.
This study brings the spotlight home, to our lands and to some of our much-loved mammalian species. Furthermore, it shows that the amount of plastic waste we produce is having an impact. We must change our relationship with plastic in its entirety; moving away from disposable items and moving towards replacing plastic with better alternatives and establishing truly circular economies.
Adam Porter, study author.