Artificial Light at Night May be Contributing to “Ecological Armageddon”

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Artificial Light at Night May be Contributing to “Ecological Armageddon”

– (International Dark Sky Association  – 17 July)

In 2017, drastic declines of insects were reported by a team of scientists in Germany. The research indicated that the biomass of flying insects decreased more than 75% over the 27-year study period.1

In a new study published in the Annals of Applied Biology, scientists from the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) investigate the relationship between insect declines and artificial light at night (ALAN), suggesting “that artificial lighting could be an overlooked driver of insect declines.” 2

According to an article published in ScienceDaily, the study found that traditional factors known to affect insect populations (climate change, pesticide use, and land changes) cannot fully explain the massive reduction in flying insect populations in the study area. For this reason, “the scientists analysed all recent studies on the effects of artificial light at night on insects, and found that there is strong evidence to suggest a credible link between light pollution and declines in insect populations.” 3

Maja Grubisic told Science Daily, “Half of all insect species are nocturnal. As such, they depend on darkness and natural light from the moon and stars for orientation and movement or to escape from predators, and to go about their nightly tasks of seeking food and reproducing. An artificially lit night disturbs this natural behaviour – and has a negative impact on their chances of survival.”

ALAN has strong potential to negatively impact rates of insect survival by interfering with reproduction, communication, and fragmenting insect populations. As the article notes, “…flying insects are attracted by artificial lights – and, at the same time, are removed from other ecosystems – and die from exhaustion or as easy prey. Additionally, rows of light prevent flying insects from spreading; causing a lack of genetic exchange within fragmented insect populations that could reduce their resistance to other negative environmental influences, which are especially pronounced in agrarian areas.”

The sharp decline in insect populations, referred to by many as “Ecological Armageddon,” has the potential for significant adverse impacts in natural and agricultural ecosystems. Insects play important roles in pollination, pest control, and nutrient cycling. Reduced insect populations could negatively affect biodiversity and crop production. With agricultural areas covering 11% of Earth’s land surface, the authors of this study stress, “a better understanding of the effects of ALAN in agroecosystems is urgently needed.”

  1. Hallmann, Caspar A., et al. “More than 75 percent decline over 27 years in total flying insect biomass in protected areas.” PloS one 12.10, 2017: e0185809.
  2. M. Grubisic, R.H.A. van Grunsven, C.C.M. Kyba, A. Manfrin, F. Hölker. Insect declines and agroecosystems: does light pollution matter? Annals of Applied Biology, 2018; DOI: 10.1111/aab.12440
  3. Forschungsverbund Berlin. (2018, June 19). Light pollution a reason for insect decline: Artificial lighting at night could be a reason for declining insect populations. ScienceDaily. Retrieved June 25, 2018 from www.sciencedaily.com/releases/2018/06/180619122456.htm