A recent comprehensive review has highlighted the detrimental impacts of nano- and microplastics on bees and other helpful insects, emphasizing that these tiny plastic particles hinder their ability to pollinate. This represents a significant threat to global food security.
Nano- and microplastic particles (NMP) are becoming increasingly prevalent in both urban and rural environments, where they come into contact with bees and other valuable insects. When these insects consume plastic debris from their food or the atmosphere, it can harm their organs and alter their behavior, inhibiting their capability to perform essential ecosystem functions such as pollination and pest management. Consequently, plastic pollution poses serious threats to biodiversity, agricultural productivity, and food security on a worldwide scale. These are the key insights from a new review published in the journal Nature Communications, which involved a collaborative effort from an international team, including researchers from the University of Freiburg.
Sources of Plastic on Agricultural Land
Microplastics range in size from one micrometer to five millimeters, while smaller particles are classified as nanoplastics. Although the harmful effects of NMP in aquatic environments and on specific species have been documented, there has been a lack of systematic reviews focusing on their impact on agricultural ecosystems. To address this issue, the authors of this review analyzed 21 previously published studies for the first time. They aimed to understand how pollinator and beneficial insect exposure to NMP occurs and what consequences result from their ingestion, particularly for the ecosystems reliant on them and for agricultural productivity.
The researchers successfully identified various sources that contribute to the presence of NMP on farmland, including plastic films, fertilizers, contaminated water, and airborne particles. These plastic particles accumulate in the soil, with pollinators and beneficial insects, crucial for pest management, consuming them from both food and air or utilizing them in nest construction.
Potential Impact of Plastic on Bees and Agriculture
The study findings indicate that when bees consume NMP, it can result in damage to their digestive systems, compromised immune responses, and altered behaviors. This makes bees more vulnerable to diseases and could reduce their effectiveness in pollinating plants. ‘We discover microplastics in the guts of bees and observe wild bees using plastic as nesting material. Therefore, we urgently need to explore how this interacts with other stressors, like climate change, impacting bees and their pollination abilities,’ says Prof. Dr. Alexandra-Maria Klein, co-author of the study and an expert in nature conservation and landscape ecology at the University of Freiburg. A decline in pollination services negatively impacts crop yields, suggesting that plastic pollution could worsen existing vulnerabilities in the global food supply, according to the researchers.
Compounding Effects of Environmental Stressors
Additionally, NMP compounds the dangers posed by other environmental stressors, such as pesticides, chemical pollutants, fungi, and pathogens. Certain areas may become ‘hotspots’ where plastic particles interact with harmful viruses. These interactions can severely affect pollinators and subsequently jeopardize the entire food system’s stability.
Nevertheless, the researchers acknowledge the limitations in their review. Notably, there is limited data on critical pollinators and advantageous insects like bumblebees and ladybugs. Moreover, the current information does not allow for a nuanced analysis of the effects of varying sizes and concentrations of NMP. The urgency for further research is clear to gain a deeper understanding of the growing issue of plastic pollution and to seek effective solutions. ‘It is evident that immediate political action is needed to regulate plastic pollution,’ remarks Klein.
The study included contributions from researchers at Westlake University (Hangzhou, China), Zhejiang University (Hangzhou, China), Fudan University (Shanghai, China), and the Universities of Freiburg and Tübingen.
