Waterside lighting drastically disrupts wildlife in the surrounding ecosystemLeave a Comment
Ecological impacts of new lighting concepts on ecosystems should be considered by landscape — and urban planners, lighting engineers, ecologists
Posted: 20 Oct 2017 06:22 AM PDT
Streetlights near waterways attract flying insects from the water and change the predator community living in the grass beneath the lights, new research has found. The findings show that artificial night-time lighting could have implications for the surrounding ecosystem and biodiversity, which should be considered when designing new lighting concepts.
Artificial night-time lighting is increasing worldwide at a rate of approximately 3-6% a year. One drawback of street lighting is its effect on flying insects, many of which have an insatiable attraction to these lights.
“Artificial lighting at night-time is a major component of global environmental change and a threat to biodiversity….This is particularly true near rivers and lakes, where human populations are concentrated.”
Aquatic ecosystems such as rivers and lakes are heavily interconnected with the ecosystems of their banks and shores. Introducing artificial lighting along riverbanks or lakeshores could have disruptive effects on these fragile ecosystems…
…The researchers found that there were many more insects leaving the water from the illuminated ditch. The lights may have made it easier for larger fish to hunt and eat smaller fish that normally prey on insects, allowing more insects to survive and thrive.
As expected, the team also found far more flying insects near the illuminated lamps themselves, compared with the lamps that were never on. This seems to have had a knock-on effect on predators living in the grass below the lamps. “The abundance of several nocturnal spiders increased at the illuminated bank, and their activity was extended into the day, while the abundance of nocturnal ground beetles decreased,” says Manfrin.
The study shows just how disruptive artificial lighting can be for wildlife. “We showed that artificial light affects insect behaviour, and that this has the potential to change ecosystem dynamics…
Alessandro Manfrin, Gabriel Singer, Stefano Larsen, Nadine Weiß, Roy H. A. van Grunsven, Nina-Sophie Weiß, Stefanie Wohlfahrt, Michael T. Monaghan, Franz Hölker. Artificial Light at Night Affects Organism Flux across Ecosystem Boundaries and Drives Community Structure in the Recipient Ecosystem. Frontiers in Environmental Science, 2017; 5 DOI: 10.3389/fenvs.2017.00061