A new international study has found that the concentration of plastics and microplastics in some lakes is worse than in ‘garbage patches’ of oceans, and debris is reaching the most remote places of the world.
The research, published in the journal Nature, involved institutes from across the world including the UK Centre for Ecology & Hydrology (UKCEH).
Scientists collected water samples from 38 lakes and reservoirs in 23 countries across six continents, representing different environmental conditions. Samples were then sent to the University of Milan-Bicocca for analysis for the presence of plastic particles over 0.25mm in size.
The study involved 79 researchers belonging to the international Global Lake Ecological Observatory Network (GLEON). They say it is the first time that in some cases concentrations of plastic found in freshwater environments are higher than those found in plastic islands in the ocean, so-called ‘garbage patches’.
Lakes containing the highest contamination by plastic included some of the main sources of drinking water for communities and were also important to the local economy, such as Lough Neagh in Northern Ireland, Lake Maggiore in Italy, Lugano on the Switzerland/Italy border and Tahoe in USA. Samples collected at Windermere by UKCEH showed the lake had very low concentrations of plastic in surface water.
UKCEH freshwater ecologist Heidrun Feuchtmayr, one of the co-authors of the study, says: “This is the first standardised global survey of abundance and type of plastic pollution in lakes and reservoirs and our research demonstrates the scale of freshwater plastic pollution globally.”
Veronica Nava of the University of Milan-Bicocca, lead author of the study, adds: “Plastic that accumulates on the surface of aquatic systems can promote the release of methane and other greenhouse gases.”
There is widespread concern about the impact that plastic debris is having on aquatic species and ecosystem function, though more data is needed to determine the effects of these pollutants on organisms in the environment.
Scientists involved in the study hope their work will inform reviews of pollution reduction strategies and waste management processes.
Nava et al. 2023. Plastic debris in lakes and reservoirs. Nature. DOI: 10.1038/s41586-023-06168-4