“It’s almost like the plastic pollution is getting the bacteria’s appetite going,” said Dr Andrew Tanentzap of the University of Cambridge’s Department of Plant Sciences, senior author of the research.
“The bacteria use the plastic as food first, because it’s easy to break down, and then they’re more able to break down some of the more difficult food – the natural organic matter in the lake.
“This suggests that plastic pollution is stimulating the whole food web in lakes, because more bacteria means more food for the bigger organisms like ducks and fish.”
For the study, scientists cut up plastic bags from four major UK shopping chains and shook them in water until their carbon compounds were released.
They then mixed the water with water from lakes and measured bacterial activity after 72 hours.
Within just three days, around 50 per cent of the carbon leached from the bags had been taken up by the bacteria.
Scientists believe that the plastic pollution is “priming” the bacteria for rapid growth, which, in turn, makes them better at breaking down other natural carbon compounds in the lake.
The effect varied depending on which bacterial species were present, with some being better than others at dealing with the pollution.