The research team
Bas Boots
Senior Lecturer
Dr Dannielle Green, Dr Bas Boots, Leon Stone
ARU research on the effects of plastic pollution in aquatic and terrestrial environments has helped safeguard the environment from single-use plastics and will help prevent the substitution of conventional plastics with biodegradable alternatives before ecotoxicological effects are known.
It has been used as evidence to shape national and international policy, and reduce the single-use plastic footprint of key businesses. It has also raised awareness of plastic pollution, encouraging governments, businesses, and individuals to take action against it.
Senior Lecturer
Single-use plastics account for 40% of global plastic production annually, and 50-70% of the plastic litter in marine, freshwater and terrestrial environments. Microplastics (pieces of plastic smaller than 5mm) are the most abundant solid waste on Earth.
While we have a reasonable understanding of the threat that (micro)plastic litter can pose to individual organisms, we know less about the harm it causes to biodiversity and ecosystem functioning.
We also need to increase our understanding of the effects of bio-based, biodegradable plastics, which have been increasingly adopted as an alternative to conventional, single-use plastics.
This research on microplastics was the first to evaluate how plastic pollution can affect entire communities of organisms and ecosystem functioning, rather than individual species in isolation.
Dr Green and Dr Boots conducted their research in a mesocosm (an outdoor experimental system that examines the natural environment under controlled conditions) featuring natural, flowing seawater with intact sediment cores.
They found that adding microplastics altered nutrient cycling by decreasing the flux of inorganic nutrients (including ammonium and silicate) from the sediment. They also discovered a reduction in the biomass of microphytobenthos (microscopic, primary producers in sediment).
In muddy sediment, dominated by Ostrea edulis (European flat oysters), adding microplastics caused species known to be indicators of pollution (e.g. oligochaetes) to become dominant.
The researchers also investigated the effects of smoked cigarette butts – another type of single-use plastic litter. They found that that smoked cigarette butts reduced the germination success and shoot length of Trifolium repens (white clover) by 27% and 28% respectively, and that of Lolium perenne (perennial ryegrass) by 10% and 13%.
They also found that butts reduced the root biomass of clover by 60%, and the plastic filter on its own negatively affected germination success, shoot length and root biomass.
Dr Green and Dr Boots discovered that microplastics made from polymers that are marketed as biodegradable or compostable, such as polyactic acid (PLA) can have similar effects on marine and terrestrial ecosystems to commonly-used non-biodegradable polymers, such as high-density polyethylene (HDPE) and polyvinyl chloride (PVC).
These types of microplastics disrupted the immune systems of blue mussels, filtration rates of Mytilus edulis (blue mussels) and Crassostrea gigas (Pacific oysters), and biomass of Apporrectodae rosa, an endogenic earthworm.
They also altered the biodiversity and abundance of marine organisms, decreased the biomass of algae and plants in marine and terrestrial ecosystems, and altered marine sediment nutrient cycling.
Dr Green and Dr Boots also assessed the impacts of glitter as little on freshwater ecosystems for the first time, finding that biodegradable, cellulose-based, traditional (PET) polymers, and mineral (mica) glitters all had similar effects on plants and algae. For example, cellulose-based glitter led to an increase of non-native snails.
We have mapped our REF 2021 impact case studies against the United Nations' Sustainable Development Goals (SDGs).
The 17 SDGs, adopted by all UN Member States in 2015, are an urgent call for action. They recognise that ending poverty and other deprivations must go hand-in-hand with strategies that improve health and education, reduce inequality, and spur economic growth – all while tackling climate change and working to preserve our oceans and forests.
This case study is mapped to SDG 12: Ensure sustainable consumption and production patterns, target 12.4.
Contact us if you would like to learn more about our REF results, collaborate with us on research or access our expertise to support your business.