Microplastic is increasingly polluting our environment, coming into contact with bees and other insects. When bees ingest these plastic particles, they damage their organs and change their behaviour, which in turn affects systems such as pollination and pest control. These are the results of a new study published in the journal Nature Communications.
Particles between one micrometre and five millimetres in size are called microplastics; anything smaller are nanoplastics. Their harmful effects are well known in water and for some individual species, but there have been no systematic reviews on how the particles affect large-scale ecosystems. To fill this gap, a team from the University of Freiburg, Germany, reviewed and combined the results from several studies for the first time.
The authors were particularly interested in how pollinator insects come into contact with microplastics and the consequences of ingesting these particles, not just for the insects themselves but also for the ecosystems that are dependent on them and for agricultural production.
The researchers identified multiple sources of microplastics, including plastic films, fertilizers, polluted water, and atmospheric depositions. The plastic particles accumulate in the soil, and pollinators then use them as food or to build nests.
In addition, the team also showed that when bees ingest microplastics, it damages their digestive system, weakens their immune system, and leads to changes in their behaviour. As a result, bees become more susceptible to diseases and pollinate plants less effectively. A decline in pollination will inevitably affect crop yield. Overall, plastic pollution will further aggravate existing problems with regard to the global food supply.
“We find microplastic in the gut of bees and see how wild bees use plastic to build nests. We, therefore, urgently need to investigate what interaction this has with other stressors, such as climate change, for the bees and their pollination services,” said Prof. Alexandra-Maria Klein from the University of Freiburg.
Finally, plastic particles also exacerbate the threats of other environmental stressors, such as pesticides, chemical pollution, fungi, and pathogens. Some areas may become hotspots, where plastic particles interact with harmful viruses and trigger adverse effects on pollinators and the stability of the food system.
However, The authors warn that more research is needed to understand the growing problem of plastic pollution and find solutions to it. “It is already clear today, however, that there is a pressing need for political control of plastic pollution,” concluded Prof. Klein.
Sheng D, Jing S, He X, Klein A, Köhler H, Wanger T (2024). Plastic pollution in agricultural landscapes: an overlooked threat to pollination, biocontrol and food security. In: Nature Communications 15, 8413. DOI: 10.1038/s41467-024-52734-3