Plastic degradation at sea: the role of microbial diversity in marine sediments
A new study shows that losing microbial diversity can halve the ability of marine sediments to break down biodegradable plastics
The study ‘Microbial diversity loss constrains plastic degradation in marine sediments’, authored by researchers from the University of Alicante together with IEO-CSIC, Western Sydney University and IRNAS-CSIC, was published in Environmental Pollution. It looks at how the loss of microbial diversity, one of the effects of global change, affects the breakdown of biodegradable plastics in marine sediments.
In a six-month laboratory experiment, the researchers progressively reduced the diversity of microbial communities in marine sediments. They then tested five plastics with different levels of biodegradability, under both nutrient-poor and nutrient-rich conditions.
The results show that reducing microbial richness can cut the capacity of marine sediments to degrade plastics by up to half in nutrient-poor conditions. The effect was strongest for the most biodegradable materials, and degradation slowed gradually as diversity declined. Nutrient enrichment partly made up for these losses when diversity was low.
Overall, the research shows that preserving microbial diversity is essential both for healthy marine ecosystems and for biodegradable plastics to deliver on their promise in the long term.