Artificial night lighting should be limited where possible due to its impact on the environment, scientists said. A team of experts led by the University of Exeter collected data from over 100 studies and found out exactly how light pollution affects animals and plants. The results are published in the journal Nature Ecology and Evolution.
Research shows that levels of melatonin (a hormone that regulates sleep cycles) decreased under artificial lighting at night in all species studied. They showed changes in body and behavior, especially during wakefulness and sleep.
“Many studies have examined the effects of artificial night lighting on certain species or communities,” explains Professor Kevin Gaston of the Environmental Institute at the University of Exeter. “However, we pooled the results and found that light pollution has the greatest effect on hormone levels, the daily activity of animals, and the offspring of living species in general.”
People may think that it is all about powerful light, but problems arise even at rather low levels of artificial light, scientists emphasize. For example, in rodents, which are mostly nocturnal, the duration of activity is usually shortened by night lighting. And in daytime birds, artificial lighting has led to an increase in the duration of activity – their singing and foraging begins earlier.
Previous research has also shown that nighttime lighting has a wide range of effects, from reducing insect pollination to earlier budding in spring. Like climate change, night lighting seems to benefit certain species in some regions. Yet Professor Gaston stresses that the point of the study was to address the issue of light pollution and thus reduce lighting where possible.
Night lighting is a human initiative and is extremely damaging to the natural world. Historically, we haven’t really worried about the impact of night lighting. Only now are we seeing its consequences. In fact, we need to treat light like any other pollutant. Obviously, we cannot turn off the lights all over the world, but we can reduce the use of light unnecessarily and unnecessarily.
Professor Kevin Gaston