30 Aug 2017 Story Ecosystems and Biodiversity

Study suggests light pollution hurts pollinators, crop yields

Lightbulb inventions in the 19th century, the rapid proliferation of lighting systems in the 20th century, and today’s energy-efficient LED bulbs have brought immeasurable benefits for people and economies.

But, according to a new study published in Nature, artificial light also has a downside: It can distract nighttime pollinators, reducing their visits to flowers and ultimately causing a decline in fruit production.

“Pollinators are undergoing significant decline worldwide and this recently discovered additional threat to pollination is deeply concerning,” says UN Environment ecosystems expert Marieta Sakalian.

The researchers in Switzerland found that artificial light at night disrupted pollination networks, reducing visits of nocturnal pollinators to flowers by 62 per cent. This disruption caused a 13 per cent drop in fruit production, even though the plants also received numerous visits by daytime pollinators.

“During night it is often the scent that attracts the nocturnal pollinators but also other cues can be important, such as visual cues as the nocturnal pollinators have often very sensitive eyes,” lead author Dr Eva Knop told the BBC.

Plant pollination is essential to both natural ecosystems and crop production. It underpins the global food supply.

© Pixabay


Pollinator numbers are declining worldwide due to habitat loss, intensive agriculture, invasive species, pests, pathogens and climate change. And the problem could get worse, as artificial light at night is spreading at an estimated rate of 6 per cent per year, according to the study.

The UN Environment Assembly, the world's highest-level decision-making body on the environment, will consider pollution in all its forms when it meets in Nairobi, Kenya, from 4-6 December 2017. Learn more about the Assembly here, then join us in committing to #beatpollution for good.  

See our 2016 story on pollinators.

For more information: Marieta.Sakalian[at]unep.org