Ecological light pollution
The effect that artificial light has upon organisms is highly variable,[2] and ranges from beneficial (e.g. increased ability for predator species to observe prey) to immediately fatal (e.g. moths that are attracted to incandescent lanterns and are killed by the heat).
The most acute affects are directly next to streetlights and lit buildings, but the diffuse light of skyglow can extend out to hundreds of kilometers away from city centres.
The presence of light at night can result in "seasons out of time",[8] changing the behavior, thermoregulation, and hormonal functioning of affected organisms.
Near city centers the level of skyglow often exceeds that of the full moon,[12] so the presence of light at night can alter these behaviors, potentially reducing fitness.
Dragonflies searching for water either to drink or in which to lay eggs often land on roads or other dark flat reflective surfaces such as cars and remain there until they die of dehydration and hyperthermia.
Studies carried out by Nederlandse Aardolie Maatschappij b.v. (NAM) and Shell have led to development and trial of new lighting technologies in the North Sea.
[56] Juvenile seabirds may also be disoriented by lights as they leave their nests and fly out to sea causing events of high mortality.
[27] To minimise mortality rescue programs are conducted on many islands giving a second chance to thousands of seabird fledglings.
Save water from dehydration in hot day flying and part of the bird's navigation system works with stars in some way.
In the worst recorded ceilometer kill-off, on October 7–8, 1954, 50,000 birds from 53 different species were killed at Warner Robins Air Force Base.
Trees and herbaceous plants rely on the photoperiod, or the amount of time in a day where sunlight is available for photosynthesis, to help determine the changing seasons.
When the hours of sunlight decrease, plants can recognize that autumn is underway and begin to make preparations for winter dormancy.
Light pollution can also cause leaf stoma to remain open into the night, which leaves the tree vulnerable to infection and disease.
Artificial light causes plants to think that spring has arrived and it is time to begin producing leaves for photosynthesizing again.
Small herbaceous plants that are exposed to artificial lighting potentially face a greater risk, as more of their body is illuminated.
It is possible that artificial light draws them closer to the shoreline, where they face a greater risk of predation from birds and mammals.
[4][41] Because melatonin is a powerful anti-oxidant, it is hypothesized that this reduction can result in an increased risk of breast and prostate cancer.
[44][45][46][47] Likewise, animal models have been studied demonstrating unavoidable light to produce adverse effect on mood and anxiety.
[51] Exposure to blue light in humans, especially at night, has been associated with decreased melatonin, leading to sleep disorders and stress.
[56] Since polarized moonlight is believed to be used by many animals for navigation, this screening is another negative effect of light pollution on ecology.
