More than half of the species whose feces were analyzed had evidence of plastic in them, according to researchers looking into how much plastic tiny mammals in England and Wales were exposed to.
Researchers from the University of Sussex, the Mammal Society, and the University of Exeter claim in a paper that was published in Science of the Total Environment that the densities of plastic excreted were equal to those found in human investigations.
Fiona Mathews, Professor of Environmental Biology at the University of Sussex, says:
“Much is known about the impact of plastic on aquatic ecosystems, but very little is known about the same with terrestrial systems. By analysing the droppings of some of our most widespread small mammals, we’ve been able to provide a glimpse of the potential impact plastic is having on our wildlife and the most commonly found plastics leaking into our environment.”
Graduate Emily Thrift, Prof. Fiona Mathews, Dr. Frazer Coomber, and the Mammal Society, along with Dr. Adam Porter and Prof. Tamara Galloway of the University of Exeter, are the authors of the research. It identifies plastic polymers in four of the seven species for which they obtained fecal samples. The brown rat, field vole, wood mouse, and European hedgehog were all discovered to be plastic positive.
Researchers discovered that plastic ingestion was occurring across locations as well as across different dietary habits of herbivores, insectivores, and omnivores, contrary to their expectations that samples from urban areas would contain higher plastic concentrations and samples from herbivorous species would contain less plastic.
Emily Thrift, MSci graduate from the University of Sussex, says:
“It’s very worrying that the traces of plastic were so widely distributed across locations and species of different dietary habits. This suggests that plastics could be seeping into all areas of our environment in different ways. We’re also concerned that the European hedgehog, and field vole are both species suffering declines in numbers in the UK.”
The team examined 261 faecal samples using equipment at the Greenpeace laboratory at the University of Exeter, and found that 16.5 percent of them included plastic. The most prevalent types found were polynorbornene, polyester, and polyethylene (which is frequently used in single-use packaging) (used mainly in the rubber industry).
This study brings the focus home, into our lands and in some of our much beloved mammal species. Further it demonstrates that the amount of plastic waste we produce is having an impact. We must change our relationship with plastic all together; moving away from disposable items and moving towards replacing plastic for better alternatives and establishing truly circular economies.
Dr. Adam Porter
All the plastic-positive species, with the exception of the wood mouse, included polyester, which made up 27% of the fragments that were detected. The report notes that microfibres, which are widely used in the textile and fashion industries, might enter the waste water system through household washing and then end up on the soil through the use of sewage sludge as fertilizer.
In the study, more than a quarter of the plastics were also “biodegradable” or “bioplastics.” The scientists caution that even while these plastics may break down more quickly than polymers, they can still be consumed by small mammals, and more studies are required to determine their true biological effects.
The study’s findings of microplastics, according to the scientists, are most likely to have been ingested directly or through the consumption of contaminated prey by various species. Researchers suggest that animals may eat plastics as food or chew on macroplastics used as nesting material or as a means of disentanglement.
Another issue that the authors are concerned about and call for more research into is the possible influence of plastics on the food chain.
Prof. Fiona Mathews adds:
“We really need to get a deeper understanding of the implications of plastic ingestion on land mammals and the potential impacts this has on their conservation status. In our study, droppings from European hedgehogs carried the highest quantity of plastic polymers. As a species, they are already in decline in the UK for reasons that are largely unknown, and they are classified as Vulnerable to Extinction on the IUCN-compliant regional Red List.”
“European hedgehogs consume earthworms and previous studies have found these to contain microplastics. So we really need further research to establish the scale and route of exposure more precisely, and to assess prevalence in predatory species that consume small mammals, so that we can take adequate steps to try to protect our declining wildlife from plastics.”
Andy Bool, CEO of the Mammal Society says:
“The Mammal Society is proud to have helped and part-funded this research as it represents an important step into the study of the impact of plastics on terrestrial mammals. With a number of small mammal species experiencing worrying declines in numbers it highlights one of the challenges they face. We can all make a difference to help protect them from this threat by reducing the amount of single use plastic we use and reusing and recycling what we do use properly.”
Dr. Adam Porter, NERC Post-Doctoral Research Fellow at the University of Exeter says:
“In the UK, plastic pollution can often seem like a problem somewhere else when most images are of polluted shorelines of tropical landscapes, or charismatic organisms like turtles or sea lions.”
“This study brings the focus home, into our lands and in some of our much beloved mammal species. Further it demonstrates that the amount of plastic waste we produce is having an impact. We must change our relationship with plastic all together; moving away from disposable items and moving towards replacing plastic for better alternatives and establishing truly circular economies.”
