scholarly journals How dark is a river? Artificial light at night in aquatic systems and the need for comprehensive night‐time light measurements

2019 ◽  
Vol 6 (6) ◽  
Author(s):  
Andreas Jechow ◽  
Franz Hölker
2018 ◽  
Author(s):  
Nikolas J Willmott ◽  
Jessica Henneken ◽  
Caitlin J Selleck ◽  
Therésa M Jones

The prevalence of artificial light at night (ALAN) is increasing rapidly around the world. The potential physiological costs of this night lighting are often evident in life history shifts. We investigated the effects of chronic night-time exposure to ecologically relevant levels of LED lighting on the life history traits of the nocturnal Australian garden orb-web spider (Eriophora biapicata). We reared spiders under a 12-hour day and either a 12-hour natural darkness (~0 lux) or a 12-hour dim light (~20 lux) night and assessed juvenile development, growth and mortality, and adult reproductive success and survival. We found that exposure to ALAN accelerated juvenile development, resulting in spiders progressing through fewer moults, and maturing earlier and at a smaller size. There was a significant increase in daily juvenile mortality for spiders reared under 20 lux, but the earlier maturation resulted in a comparable number of 0 lux and 20 lux spiders reaching maturity. Exposure to ALAN also considerably reduced the number of eggs produced by females, largely associated with ALAN-induced reductions in body size. Despite previous observations of increased fitness for some orb-weavers in urban areas and near night lighting, it appears that exposure to artificial night lighting may lead to considerable developmental costs. Future research will need to consider the detrimental effects of ALAN combined with foraging benefits when studying nocturnal insectivores that forage around artificial lights.


Author(s):  
Nikolas J Willmott ◽  
Jessica Henneken ◽  
Caitlin J Selleck ◽  
Therésa M Jones

The prevalence of artificial light at night (ALAN) is increasing rapidly around the world. The potential physiological costs of this night lighting are often evident in life history shifts. We investigated the effects of chronic night-time exposure to ecologically relevant levels of LED lighting on the life history traits of the nocturnal Australian garden orb-web spider (Eriophora biapicata). We reared spiders under a 12-hour day and either a 12-hour natural darkness (~0 lux) or a 12-hour dim light (~20 lux) night and assessed juvenile development, growth and mortality, and adult reproductive success and survival. We found that exposure to ALAN accelerated juvenile development, resulting in spiders progressing through fewer moults, and maturing earlier and at a smaller size. There was a significant increase in daily juvenile mortality for spiders reared under 20 lux, but the earlier maturation resulted in a comparable number of 0 lux and 20 lux spiders reaching maturity. Exposure to ALAN also considerably reduced the number of eggs produced by females, largely associated with ALAN-induced reductions in body size. Despite previous observations of increased fitness for some orb-weavers in urban areas and near night lighting, it appears that exposure to artificial night lighting may lead to considerable developmental costs. Future research will need to consider the detrimental effects of ALAN combined with foraging benefits when studying nocturnal insectivores that forage around artificial lights.


2021 ◽  
Vol 75 (11) ◽  
Author(s):  
Christina Elgert ◽  
Topi K. Lehtonen ◽  
Arja Kaitala ◽  
Ulrika Candolin

Abstract Artificial light at night is increasing globally, interfering with both sensory ecology and temporal rhythms of organisms, from zooplankton to mammals. This interference can change the behaviour of the affected organisms, and hence compromise the viability of their populations. Limiting the use of artificial light may mitigate these negative effects. Accordingly, we investigated whether the duration of artificial light affects sexual signalling in female glow-worms, Lampyris noctiluca, which are flightless and attract flying males to mate by emitting glow that is interfered by light pollution. The study included three treatments: no artificial light (control), 15 min of artificial light, and 45 min of artificial light. The results show that females were more likely to cease glowing when the exposure to light was longer. Furthermore, small females were more likely to cease their glow, and responded faster to the light, than larger females. These findings suggest that glow-worms can react rapidly to anthropogenic changes in nocturnal light levels, and that prolonged periods of artificial light trigger females to stop sexual signalling. Thus, limiting the duration of artificial light can mitigate the adverse effects of light pollution on sexual signalling, highlighting the importance of such mitigation measures. Significance statement Interest in the effects of artificial light at night on animal behaviour has increased in recent years. With evidence for its negative impact accumulating, potential remedies, such as limiting the duration of light exposure, have emerged. To date, however, knowledge on the effectiveness of these methods has remained very limited. We show that female European common glow-worms, which are wingless beetles that glow to attract flying males to mate, responded to prolonged artificial light exposure by discontinuing their glow. Such non-glowing females are not expected to find a mate, making it difficult for them to reproduce. Hence, our study indicates that the duration of artificial light should be limited to protect this night-active beetle and its opportunities for effective sexual signalling. Because many other nocturnal species also need darkness, this study provides valuable information for the development and use of less disruptive night-time lights.


2015 ◽  
Vol 282 (1816) ◽  
pp. 20151745 ◽  
Author(s):  
Kylie A. Robert ◽  
John A. Lesku ◽  
Jesko Partecke ◽  
Brian Chambers

Change in day length is an important cue for reproductive activation in seasonally breeding animals to ensure that the timing of greatest maternal investment (e.g. lactation in mammals) coincides with favourable environmental conditions (e.g. peak productivity). However, artificial light at night has the potential to interfere with the perception of such natural cues. Following a 5-year study on two populations of wild marsupial mammals exposed to different night-time levels of anthropogenic light, we show that light pollution in urban environments masks seasonal changes in ambient light cues, suppressing melatonin levels and delaying births in the tammar wallaby. These results highlight a previously unappreciated relationship linking artificial light at night with induced changes in mammalian reproductive physiology, and the potential for larger-scale impacts at the population level.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5599 ◽  
Author(s):  
Nikolas J. Willmott ◽  
Jessica Henneken ◽  
Caitlin J. Selleck ◽  
Therésa M. Jones

The prevalence of artificial light at night (ALAN) is increasing rapidly around the world. The potential physiological costs of this night lighting are often evident in life history shifts. We investigated the effects of chronic night-time exposure to ecologically relevant levels of LED lighting on the life history traits of the nocturnal Australian garden orb-web spider (Eriophora biapicata). We reared spiders under a 12-h day and either a 12-h natural darkness (∼0 lux) or a 12-h dim light (∼20 lux) night and assessed juvenile development, growth and mortality, and adult reproductive success and survival. We found that exposure to ALAN accelerated juvenile development, resulting in spiders progressing through fewer moults, and maturing earlier and at a smaller size. There was a significant increase in daily juvenile mortality for spiders reared under 20 lux, but the earlier maturation resulted in a comparable number of 0 lux and 20 lux spiders reaching maturity. Exposure to ALAN also considerably reduced the number of eggs produced by females, and this was largely associated with ALAN-induced reductions in body size. Despite previous observations of increased fitness for some orb-web spiders in urban areas and near night lighting, it appears that exposure to artificial night lighting may lead to considerable developmental costs. Future research will need to consider the detrimental effects of ALAN combined with foraging benefits when studying nocturnal insectivores that forage around artificial lights.


2021 ◽  
Vol 50 (Supplement_1) ◽  
Author(s):  
Jessica Stanhope ◽  
Craig Liddicoat ◽  
Philip Weinstein

Abstract Background There is a growing body of evidence that exposure to greenspace is good for our health: spending time in greenspace can improve depressive symptoms, obesity, and sleep problems, and reduce the risk of breast and prostate cancer. We also know that exposure to outdoor artificial light at night (O-ALAN) is associated with increased risk of breast and prostate cancer, and can worsen depression, obesity and sleep problems. As both greenspace exposure and O-ALAN have been implicated in the same health outcomes, we aimed to establish if O-ALAN was itself correlated with greenspace, potentially confounding spatial epidemiological studies of greenspace and health outcomes (and vice versa). Methods We investigated the correlation between greenspace diversity (Shannon diversity index of National Vegetation Information System’s vegetation classes within 3 km radius buffer zones), and night-time light data (NOAA/NCEI Nighttime Visible Infrared Imaging Radiometer Suite Day/Night Band 2015 Annual Composite product), in Australian major cities. Results We identified an inverse correlation between O-ALAN and greenspace diversity. Conclusions The finding makes intuitive sense because more developed areas are likely to have fewer trees and more artificial light, which is consistent with our hypothesis that that O-ALAN could be confounding studies of the relationship between greenspace and health. Without considering the potential confounding effects of O-ALAN, public health-driven initiatives such as greenspace conservation and restoration in urban environments may not be optimised for health benefits. Key messages Spatial epidemiological studies of greenspace exposure and health should include O-ALAN as a potential confounder (and vice versa).


2021 ◽  
Author(s):  
Rekha Sodani ◽  
Udit Nandan Mishra ◽  
Subhash Chand ◽  
Indu ◽  
Hirdayesh Anuragi ◽  
...  

Light is crucial environmental factor for primary resource and signalling in plants and provide optimum fitness under fluctuating environments from millions of year. However, due to urbanization, and human development activities lot of excess light generated in environment during night time and responsible for anthropogenic generated pollution (ALAN; artificial night light pollution). This pollution has cause for serious problem in plants as it affects their processes and functions which are under the control of light or diurnal cycle. Plant biorhythms mostly diurnal rhythms such as stomatal movements, photosynthetic activity, and many more metabolic processes are under the control of period of light and dark, which are crucially affected by artificial light at night. Similarly, the crucial plant processes such as pollination, flowering, and yield determining processes are controlled by the diurnal cycle and ALAN affects these processes and ultimately hampers the plant fitness and development. To keep in mind the effect of artificial light at night on plant biorhythm and eco-physiological processes, this chapter will focus on the status of global artificial night light pollution and the responsible factors. Further, we will explore the details mechanisms of plant biorhythm and eco-physiological processes under artificial light at night and how this mechanism can be a global threat. Then at the end we will focus on the ANLP reducing strategies such as new light policy, advanced lightening technology such as remote sensing and lightening utilisation optimisation.


2021 ◽  
Vol 8 (7) ◽  
pp. 210866
Author(s):  
Ayumu Mukai ◽  
Koki Yamaguchi ◽  
Shin G. Goto

Seasonal changes in temperature and day length are distinct between rural and urban areas due to urban warming and the presence of artificial light at night. Many studies have focused on the impacts of these ubiquitous signatures on daily biological events, but empirical studies on their impacts on insect seasonality are limited. In the present study, we used the flesh fly Sarcophaga similis as a model insect to determine the impacts of urbanization on the incidence and timing of diapause (dormancy), not only in the laboratory but also in rural and urban conditions. In the laboratory, diapause entry was affected by night-time light levels as low as 0.01 lux. We placed fly cages on outdoor shelves in urban and rural areas to determine the timing of diapause entry; it was retarded by approximately four weeks in urban areas relative to that in rural areas. Moreover, almost all flies in the site facing an urban residential area failed to enter diapause, even by late autumn. Although an autumnal low temperature in the urban area would mitigate the negative effect of artificial light at night, strong light pollution seriously disrupts the flesh fly seasonal adaptation.


Author(s):  
Philip James

Elements of the physical aspects of urban environments determine which micro-organisms, plants, and animals live in urban environments. In this chapter, climate, air, water, soil, noise, and light are discussed. Urban environments are affected by the climate of the region in which they are located, and in turn and create their own, distinctive urban climate. Air, water, and soil are all affected by urbanization. Pollution of these elements is common. High noise levels and artificial light at night (ALAN—a new phenomenon) are both strongly associated with urban environments. Details of both are discussed. The discussion in this chapter provides a foundation for further exploration of the diversity of life in urban environments and for later exploration of how organisms adapt to urban living, which will be discussed in Parts II and III.


2021 ◽  
Vol 197 ◽  
pp. 111012
Author(s):  
Jessica Stanhope ◽  
Craig Liddicoat ◽  
Philip Weinstein

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