Artificial Light At Night Research Articles

Artificial light at night alters progression of cold neuropathy in a sex-dependent manner in a mouse model of type II diabetes mellitus

Artificial light at night (ALAN) is a pervasive circadian rhythm disruptor. Exposure to ALAN is associated with detrimental effects on physiology and behavior, including disrupted metabolism, immune function, endocrine function, and pain behavior. Given the detrimental effects of ALAN and other circadian rhythm disruptors on pain, we sought to understand how ALAN may alter the progression and severity of diabetic neuropathy. To do this, we used a previously reported high-fat diet and streptozotocin injection protocol to induce a type II diabetic phenotype in ∼8 week old female and male mice and then exposed the mice to either control or ALAN lighting conditions in 14:10 h light-dark cycles for 4 weeks. Male mice housed in control conditions exhibited reduced responsiveness to cold pain; in contrast, ALAN blunted this effect in male mice. ALAN exposure also elevated blood glucose and altered body mass loss in male mice. These effects were not present in female mice. The results of this study highlight the need to consider and study ALAN exposure and sex as a biological variable as risk factors in the treatment and mitigation of pain.

Endocrine disruption in teleosts and amphibians is mediated by anthropogenic and natural environmental factors: implications for risk assessment.

Environmental variation in the Anthropocene involves several factors that interfere with endocrine systems of wildlife and humans, presenting a planetary boundary of still unknown dimensions. Here, we focus on chemical compounds and other impacts of anthropogenic and natural originsthat are adversely affecting reproduction and development. The main sink of these endocrine disruptors (EDs) is surface waters, where they mostly endanger aquatic vertebrates, like teleost fish and amphibians. For regulatory purposes, EDs are categorized into EATS modalities (oestrogenic, androgenic, thyroidal, steroidogenesis), only addressing endocrine systems being assessable by validated tests. However, there is evidence that non-EATS modalities-and even natural sources, such as decomposition products of plants or parasitic infections-can affect vertebrate endocrine systems. Recently, the disturbance of natural circadian light rhythms by artificial light at night (ALAN) has been identified as another ED. Reviewing the knowledge about EDs affecting teleosts and amphibians leads to implications for risk assessment. The generally accepted WHO-definition for EDs, which focuses exclusively on 'exogenous substances' and neglects parasitic infections or ALAN, seems to require some adaptation. Natural EDs have been involved in coevolutionary processes for ages without resulting in a general loss of biodiversity. Therefore, to address the 'One Health'-principle, future research and regulatory efforts should focus on minimizing anthropogenic factors for endocrine disruption. This article is part of the theme issue 'Endocrine responses to environmental variation: conceptual approaches and recent developments'.

Outdoor artificial light at night and incident cardiovascular disease in adults: A national cohort study across China

Cardiovascular diseases (CVDs) become a major public health concern. Evidence concerning the effects of outdoor artificial light at night (ALAN) on CVD in adults is scarce. We aimed to investigate the extent to which outdoor ALAN could affect the risk of CVD over a exposure range. Data from the China Health and Retirement Longitudinal Study, a population-based longitudinal study, launched in 2011–2012 and follow up till 2018, covering 28 provinces, autonomous regions and municipalities across mainland China. This study included 14,097 adults aged ≥45 years. Outdoor ALAN exposure (in nanowatts per centimeters squared per steradian) within 500 m of each participant's baseline residence was obtained from satellite image data. CVD was defined from medical diagnosis. The population was divided into three groups based on outdoor ALAN exposure from low to high. Cox regression model was used to estimate the association between outdoor ALAN exposure and incident CVD with hazard ratios (HRs) and 95 % confidence intervals (CIs). The mean (SD) age of the cohort was 57.6 (9.1) years old and 49.3 % were males. Outdoor ALAN exposure of study participants ranged from 0.02 to 39.79 nW/cm2/sr. During 83,033 person-years of follow-up, 2190 (15.5 %) cases of CVD were identified. Both low (HR: 1.21; 95 % CI: 1.02—1.43) and high (HR: 1.23; 95 % CI: 1.04—1.46) levels of outdoor ALAN exposure group were associated with higher risk of CVD compared with intermediate levels of outdoor ALAN exposure group. Body mass index was a significant effect modifier in the association between outdoor ALAN and risk of CVD, with stronger effects among those who was overweight or obese. The findings of this study suggest that low and high outdoor ALAN exposure were associated with a higher risk for CVD. More attention should be given to the cardiovascular effects associated with outdoor ALAN exposure.

Species sensitivities to artificial light at night: A phylogenetically controlled multilevel meta-analysis on melatonin suppression.

The rapid urbanization of our world has led to a surge in artificial lighting at night (ALAN), with profound effects on wildlife. Previous research on wildlife's melatonin, a crucial mechanistic indicator and mediator, has yielded inconclusive evidence due to a lack of comparative analysis. We compiled and analysed an evidence base including 127 experiments with 437 observations across 31 wild vertebrates using phylogenetically controlled multilevel meta-analytic models. The evidence comes mainly from the effects of white light on melatonin suppression in birds and mammals. We show a 36% average decrease in melatonin secretion in response to ALAN across a diverse range of species. This effect was observed for central and peripheral melatonin, diurnal and nocturnal species, and captive and free-living populations. We also reveal intensity-, wavelength-, and timing-dependent patterns of ALAN effects. Exposure to ALAN led to a 23% rise in inter-individual variability in melatonin suppression, with important implications for natural selection in wild vertebrates, as some individuals may display higher tolerance to ALAN. The cross-species evidence has strong implications for conservation of wild populations that are subject to natural selection of ALAN. We recommend measures to mitigate harmful impacts of ALAN, such as using 'smart' lighting systems to tune the spectra to less harmful compositions.

Changing streetlighting schemes and the ecological availability of darkness.

Artificial light at night (ALAN), from streetlights and other sources, has a wide variety of impacts on the natural environment. A significant challenge remains, however, to predict at intermediate spatial extents (e.g. across a city) the ALAN that organisms experience under different lighting regimes. Here we use Monte Carlo radiative Transfer to model the three-dimensional lighting environment at, and just above, ground level, on the spatial scales at which animals and humans experience it. We show how this technique can be used to model a suite of both real and hypothetical lighting environments, mimicking the transition of public infrastructure between different lighting technologies. We then demonstrate how the behaviour of animals experiencing these simulated lighting environments can be emulated to probe the availability of darkness, and dark corridors, within them. Our simulations show that no single lighting technology provides an unmitigated alleviation of negative impacts within urban environments, and that holistic treatments of entire lighting environments should be employed when understanding how animals use and traverse them.

Light pollution disrupts circadian clock gene expression in two mosquito vectors during their overwintering dormancy

Artificial light at night (ALAN) is an increasingly important form of environmental disturbance as it alters Light:Dark cycles that regulate daily and seasonal changes in physiology and phenology. The Northern house mosquito (Culex pipiens) and the tiger mosquito (Aedes albopictus) enter an overwintering dormancy known as diapause that is cued by short days. These two species differ in diapause strategy: Cx. pipiens diapause as adult females while Ae. albopictus enter a maternally-programmed, egg diapause. Previous studies found that ALAN inhibits diapause in both species, but the mechanism is unknown. As the circadian clock is implicated in the regulation of diapause in many insects, we examined whether exposure to ALAN altered the daily expression of core circadian cloc genes (cycle, Clock, period, timeless, cryptochrome 1, cryptochrome 2, and Par domain protein 1) in these two species when reared under short-day, diapause-inducing conditions. We found that exposure to ALAN altered the abundance of several clock genes in adult females of both species, but that clock gene rhythmicity was maintained for most genes. ALAN also had little effect on clock gene abundance in mature oocytes that were dissected from female Ae. albopictus that were reared under short day conditions. Our findings indicate that ALAN may inhibit diapause initiation through the circadian clock in two medically-important mosquitoes.

Artificial light at night affects the timing of roosting by Chimney Swifts

Understanding the impact of anthropogenic threats, such as light pollution, on biodiversity is necessary to establish effective guidelines to protect diminishing wildlife. In this study, we examined the effect of artificial light at night (ALAN) on the roosting behaviour of Chimney Swifts Chaetura pelagica, a highly threatened migratory bird species that lives commensally with humans, where it often breeds and roosts in artificial structures such as chimneys. Although Chimney Swifts are known to use time of sunset in combination with temperature, wind and season to coordinate roost entry, we predicted that high ALAN exposure would override these natural cues and lead to a delayed entry compared with sites with less light pollution. To test this, we examined the effects of ALAN on the start and end times of entry to 21 roosting sites located along a light pollution gradient in New Jersey and the New York Metropolitan area. We found that ALAN was a significant predictor of roosting entry time, with birds entering later in sites with more light pollution. While Chimney Swifts initiated roosting earlier in the summer months compared with the autumn, this effect was absent in areas with high light pollution. These findings highlight the need to determine the causes and consequences of light pollution effects.

Association between exposure to outdoor artificial light at night during pregnancy and glucose homeostasis: A prospective cohort study

Background: Outdoor artificial light at night (ALAN) has been linked to an elevated risk of diabetes, but the available literature on the relationships between ALAN and glucose homeostasis in pregnancy is limited.Methods: A prospective cohort study of 6730 pregnant women was conducted in Hefei, China. Outdoor ALAN exposure was estimated using satellite data with individual addresses at a spatial resolution of approximately 1 km, and the average ALAN intensity was calculated. Gestational diabetes mellitus (GDM) was diagnosed based on a standard 75-g oral glucose tolerance test. Multivariable linear regression and logistic regression were used to estimate the relationships between ALAN and glucose homeostasis.Results: Outdoor ALAN was associated with elevated glucose homeostasis markers in the first trimester, but not GDM risk. An increase in the interquartile range of outdoor ALAN values was related to a 0.02 (95% confidence interval [CI]: 0.00, 0.03) mmol/L higher fasting plasma glucose, a 0.42 (95% CI: 0.30, 0.54) μU/mL increase in insulin and a 0.09 (95% CI: 0.07, 0.12) increase in homeostatic model assessment of insulin resistance (HOMA-IR) during the first trimester. Subgroup analyses showed that the associations between outdoor ALAN exposure and fasting plasma glucose, insulin, and HOMA-IR were more pronounced among pregnant women who conceived in summer and autumn.Conclusions: The results provided evidence that brighter outdoor ALAN in the first trimester was related to elevated glucose intolerance in pregnancy, especially in pregnant women conceived in summer and autumn, and effective strategies are needed to prevent and manage light pollution.

Artificial light at night suppresses the day-night cardiovascular variability: evidence from humans and rats.

Artificial light at night (ALAN) affects most of the population. Through the retinohypothalamic tract, ALAN modulates the activity of the central circadian oscillator and, consequently, various physiological systems, including the cardiovascular one. We summarised the current knowledge about the effects of ALAN on the cardiovascular system in diurnal and nocturnal animals. Based on published data, ALAN reduces the day-night variability of the blood pressure and heart rate in diurnal and nocturnal animals by increasing the nocturnal values of cardiovascular variables in diurnal animals and decreasing them in nocturnal animals. The effects of ALAN on the cardiovascular system are mainly transmitted through the autonomic nervous system. ALAN is also considered a stress-inducing factor, as glucocorticoid and glucose level changes indicate. Moreover, in nocturnal rats, ALAN increases the pressure response to load. In addition, ALAN induces molecular changes in the heart and blood vessels. Changes in the cardiovascular system significantly depend on the duration of ALAN exposure. To some extent, alterations in physical activity can explain the changes observed in the cardiovascular system after ALAN exposure. Although ALAN acts differently on nocturnal and diurnal animals, we can conclude that both exhibit a weakened circadian coordination among physiological systems, which increases the risk of future cardiovascular complications and reduces the ability to anticipate stress.

Alleviate light pollution by recognizing urban night-time light control area based on computer vision techniques and remote sensing imagery

Light pollution caused by unreasonable and excessive use of outdoor artificial light at night (ALAN) has become one of the fastest growing and most urgent global environmental problems. Therefore, the International Dark-Sky Association advocated the more controlled use of ALAN in urban area to protect night-time environment and enable sustainable development. However, relevant research and lighting planning are still in the enlightenment stage. This study focused on a typical city experiencing significant ALAN growth, combining night-time remote sensing imagery, urban big data and other muti-source heterogeneous data to systematically research urban night-time light status. We first analyzed the spatio-temporal evolution pattern of ALAN. Subsequently, advanced computer vision algorithms were proposed to recognize the night-time light control area (NLCA) based on the perspective of supply and demand balance. Results suggest both the ALAN intensity and area have grown rapidly over the past decade in the study area, with the intensity increasing by 82 % and the area expanding by 42 %. And a 108.5-square-kilometre area of the NLCA was intelligently delineated, for where the ALAN intensity was more than the demand of population, indicating that the management of the night-time light environment an urgent matter. Therefore, this study proposed practical management solutions according to the different functional zones in city within the NLCA, for further promoting the green transformation and smart upgrading of urban outdoor lighting. To sum up, our research offers a novel approach to resolving the issue of urban light pollution by recognizing the NLCA, as well as facilitating energy conservation and emission reduction.

Artificial light at night affects fish passage rates in two small‐sized Cypriniformes fish

AbstractAn increasing presence of instream structures such as weirs, dams, culverts and reservoirs degrades habitats, fragments rivers and blocks fish movements worldwide. Longitudinal river movements are fundamental for many fish species and the most widespread solution to restore longitudinal connectivity is the implementation of different fish passage solutions. Fishway functionality, however, is highly variable. To design a functional fishway, several aspects of the fish's interaction with its environment need to be taken into consideration. Artificial light at night (ALAN) can affect a range of different behaviours in fish, from activity and movement to feeding and predator–prey relationships. In a fish passage setting, fish are exposed to artificial light at night (ALAN) in the form of light pollution, but, sometimes, also as part of the fish passage solution. Although likely highly species specific, the effect of artificial light on fish passage behaviour has been little explored. Here we study the passage behaviour of two small‐sized fish species, European gudgeon (Gobio gobio) and Italian riffle dace (Telestes muticellus), over a scaled deep side notch weir in a hydraulic flume in three different light conditions: daylight, darkness and ALAN. Although both species passed the obstacle at high efficiencies under all light conditions, their passage behaviours were influenced by light, particularly at the higher levels. While ALAN reduced passage success and resulted in delayed passage for gudgeon, riffle dace passed at higher rates under the artificial light compared to night treatment. Both results indicate a risk of negative effects from ALAN on passage performance at real fishways—or movement rates in lit areas of natural streams—for both species. Independent of light conditions, individuals of both species also passed faster after repeated trials, demonstrating learning in a fish passage context.

The Effect of Naturally Occurring Dietary Chemicals and Food-Borne Mycotoxins on DNA Methylation and Cancer - A Review

Food-borne mycotoxins (FBM) can have severe effects, causing sickness or even death shortly after consuming contaminated food. Chronic exposure to mycotoxins is linked to cancer development and immune deficiencies. DNA methylation plays a role in diseases like cancer, influencing the expression of genes that regulate tumor growth. Mycotoxins can lead to crop loss, chemical production, and uncontrolled fungi growth. Aflatoxins, a type of mycotoxin, increase cancer risk and cause severe illnesses. Artificial Light At Night (ALAN) affects melatonin secretion, influencing global DNA methylation in cancer cells. FBM-ALAN shows promise against cancers by restoring normal expression of critical tumor suppressor genes and correcting abnormal DNA methylation. Abnormal DNA methylation can lead to diseases like cancer by silencing tumor suppressors and overexpressing oncogenes. Understanding DNA methylation is crucial for regulating gene expression and preventing illness in eukaryotic cells.

A sustainable world requires darkness at night

Multiple environmental challenges face today’s world. One of the most damaging but least widely recognized arises from artificial light at night (ALAN). Light pollution is now known to be harmful to human health, mainly through disruption of hormone production and of human circadian rhythm, which causes sleepless nights, depression, anxiety, hypertension, diabetes and contributes to some types of cancer. ALAN is also bad for the environment. Almost all species of animals and plants are adversely impacted by light pollution, and not just nocturnal animals. Light pollution also wastes large amounts of energy, and as much as 35% of exterior lighting energy costs could be saved by better lighting. Light pollution also prevents astronomers and astrotourists being able to see so many stars. Astrotourism is booming in several countries and is beneficial for the local economy, especially so in parts of New Zealand, but this niche form of tourism is endangered by ALAN.

Persistent exposure to artificial light at night (ALAN) accelerates metamorphosis and colonization in larvae of marine shellfish

The ongoing course of urbanization has led to excessive use of artificial light at night (ALAN), which has rapidly become an important source of pollution in many cities. The Pacific abalone (Haliotis discus hannai) Larvae were kept under a 12/12 h light/dark photoperiod (DD) in order to determine the effects of ALAN on embryonic development. To simulate the street lighting conditions at night, the artificial light was switched on from 18:00 until midnight (AD) or until 06:00 the next day (ND). Moreover, Groups AD and ND had a considerably greater hatching success rate and metamorphosis rate than Group DD (P < 0.05), whereas Group DD had a significantly longer hatching period and course to complete the metamorphosis of the larvae (P < 0.05). Transcriptomic analyses showed that members of Groups AD and DD had considerably higher expression levels of genes involved in ribosome biogenesis, spliceosome function, and the mRNA surveillance pathway. Prostaglandin B2, L-palmitoylcarnitine, stearic acid, palmitic acid, leukotriene C4, and arachidonic acid were screened by non-targeted metabolomics as differential metabolic markers that played a vital role in the response of larvae to different ALAN conditions. Multi-omics correlation analysis suggested that five pathways related to fatty acid synthesis, catabolism, and metabolism, such as biosynthesis of unsaturated fatty acids and arachidonic acid metabolism, were enriched in each comparison. Further quantitative analysis showed that compared to Group DD, 33 out of 50 fatty acids were upregulated in Group AD, and the levels of almost all fatty acids were increased in Group ND, which in turn suggested that fatty acids played a vital role in the physiological response of larvae to illumination changes. The findings of this work were significant for the unbiased and full-scale assessment of the ecological effects of ALAN, as well as the structural stability of the marine benthic community.

Identification of illumination source types using nighttime light images from SDGSAT-1

ABSTRACT The constant need for decarbonization has led to the replacement of artificial light at night (ALAN) with light-emitting diodes (LEDs), inducing blue light pollution and its consequent adverse effects. As a result, there is an urgent need for the development of a technique for the rapid, accurate, and large-scale discrimination of the various illumination sources. The newly launched Sustainable Development Science Satellite-1 (SDGSAT-1) can play this role by supplementing the existing nighttime light data with multispectral and high-resolution features. Along these lines, in this work, a novel approach to identify various types of illumination sources using machine learning in SDGSAT-1 images was proposed, taking Beijing as a worked example. The results indicate that: (1) The method can effectively distinguish the various types of light sources with an overall accuracy of 0.92 for ALAN and 0.95 for streetlights. (2) The illumination patterns can be clearly depicted, indicating distinct spatial heterogeneity in ALAN along Beijing’s 5th Ring Road. (3) Statistically significant disparities between road classes and streetlight types were detected, with a notable increase in LED streetlight usage as the road class diminishes. This work emphasizes the crucial role of SDGSAT-1 in analysing ALAN, providing valuable insights in urban lighting management.

Molecular mechanisms of artificial light at night affecting circadian rhythm disturbance.

Artificial light at night (ALAN) pollution has been regarded as a global environmental concern. More than 80% of the global population is exposed to light pollution. Exacerbating this issue, artificially lit outdoor areas are growing by 2.2% per year, while continuously lit areas have brightened by 2.2% each year due to rapid population growth and expanding urbanization. Furthermore, the increasing prevalence of night shift work and smart device usage contributes to the inescapable influence of ALAN. Studies have shown that ALAN can disrupt endogenous biological clocks, resulting in a disturbance of the circadian rhythm, which ultimately affects various physiological functions. Up until now, scholars have studied various disease mechanisms caused by ALAN that may be related to the response of the circadian system to light. This review outlines the molecular mechanisms by which ALAN causes circadian rhythm abnormalities in sleep disorders, endocrine diseases, cardiovascular disease, cancer, immune impairment, depression, anxiety and cognitive impairments.

Association between exposure to outdoor artificial light at night and the risk of preterm birth.

This study aimed to investigate the association between outdoor artificial light at night (ALAN) exposure during pregnancy and the risk of preterm birth (PTB). A retrospective case-control study was conducted, and data were collected from pregnant women residing in Beijing, China. The level of ALAN exposure during pregnancy was estimated using remote sensing satellite data. Propensity score matching was utilized to match the control group. Logistic and multivariate linear regression were used to analyze the association between ALAN and the risk of PTB. The odds ratio (OR) and partial regression coefficient (β) with 95% confidence interval (CI) were utilized to assess the association. A total of 2,850 pregnant women were enrolled in this study. ALAN (nW/cm2/sr) exposure was higher in the PTB group than in the control group during first trimester (mean ± standard deviation: 25.30 ± 17.91 vs. 17.56 ± 14.74, p < 0.001) and second trimester (27.07 ± 18.10 vs. 21.93 ± 16.08, p < 0.001). A negative association was found between ALAN exposure and gestation day in the first (β = -0.151, 95%CI: -0.217 to -0.085, p < 0.001) and second trimesters (β = -0.077, 95%CI: -0.139 to -0.015, p = 0.015). ALAN was identified as a risk factor for PTB during the first trimester (OR = 1.032, 95%CI: 1.025-1.040, p < 0.001) and the second trimester (OR = 1.018, 95%CI: 1.011-1.025, p < 0.001), while no significant association was observed in the third trimester. Our study suggesting that exposure to outdoor ALAN, especially during first and second trimester, was associated with the risk of PTB. These findings highlight the potential impact of ALAN on pregnancy health and offer new insights into the risk of PTB.

Artificial night‐time lighting and nutrient enrichment synergistically favour the growth of alien ornamental plant species over co‐occurring native plants

Abstract Insights into ecological drivers of alien plant invasions can be gained through comparative studies of growth and fecundity of invasive alien plants versus those of co‐occurring non‐invasive alien plants and native plants across environmental conditions in common garden settings. Habitats that harbour alien plant species in many ecosystems globally are presently experiencing light pollution resulting from artificial light at night (ALAN) and increased rates of nutrient enrichment of the soil. However, the potential interactive effects of ALAN and nutrient enrichment on invasiveness of alien plant species remain unknown. Here, we performed a common‐garden experiment to test the interactive effects of ALAN and soil nutrient enrichment on the growth of a random set of ten alien (five invasive and five non‐invasive naturalized) and seven co‐occurring native ornamental plant species that are commonly cultivated within urban and peri‐urban areas of Nairobi city in Kenya. We predicted that a simultaneous increase in photoperiod via ALAN and nutrient enrichment will favour growth of invasive alien plant species over that of non‐invasive alien and native plant species. We grew the 17 plant species under natural daylight (ALAN−) versus natural daylight followed by ALAN (ALAN+) and fully crossed with two levels of nutrient enrichment (low vs. high) and competition (competition vs. no‐competition against a native plant Ocimum gratissimum) treatments. Under simultaneous high‐nutrient and no‐competition treatments, ALAN enhanced mean total biomass of invasive and non‐invasive naturalized alien species by 61.1% and 131.4%, respectively but decreased that of native plant species by 34%. In contrast, under simultaneous high‐nutrient and competition treatments, ALAN enhanced mean total biomass of invasive alien plant species by 68.6% and that of non‐invasive naturalized alien species by 51.9% and native species by 35.4%. High‐nutrient treatment enhanced flower formation more strongly in invasive and non‐invasive naturalized alien plants than in native plants. The invasive and non‐invasive naturalized alien species grew taller than native species across the light, nutrient, and competition treatments. Synthesis: The present findings suggest that light pollution and nutrient enrichment may jointly confer growth advantage to invasive alien plant species over that of co‐occurring native plant species and enhance invasiveness of alien plant species.

Does a flashing artificial light have more or conversely less impacts on animals than a continuous one? A systematic review

Background: Light pollution has been increasingly recognised as a threat to biodiversity, especially with the current expansion of public lighting. Although the impacts of light intensity, spectral composition and temporality are more often studied, another component of light, its flicker frequency, has been largely overlooked. However, flashing light could also have impacts on biodiversity, and especially on animal behaviour and physiology. Objective: This systematic review aimed at identifying the reported physiological and behavioural impacts of flashing light on animals when compared to continuous light. Methods: We followed the standards recommended by the Collaboration for Environmental Evidence (CEE) in order to achieve a comprehensive, transparent and replicable systematic review. Citations were primarily extracted from three literature databases and were then screened for relevance successively on their titles, abstracts and full-texts. Retained studies were finally critically appraised to assess their validity and all relevant data were extracted. Only studies which compared a flashing light to a continuous one were included. Results: At first, we found 19,730 citations. Screening and critical appraisal resulted in 32 accepted articles corresponding to 54 accepted observations—one observation corresponding to one species and one outcome. We collated data on four main taxa: Aves (the most studied one), Actinopterygii, Insecta and Mammalia as well as on plankton. Conclusions: The impacts of flashing light are currently critically understudied and varied between species and many light specificities (e.g. frequency, wavelength, intensity). Therefore, no definitive conclusions could be drawn for now. Thus, research on flashing light should be pressingly carried out in order to better mitigate the impacts of Artificial Light at Night (ALAN) on wildlife. In the meantime, we would recommend precautionary principles to be applied: flashing lighting should be limited when not deemed essential and flicker frequencies managed to prevent animals from experiencing any potential harm from flashing light.

Artificial light at night impacts night-time activity but not day-time behaviour in a diurnal coral reef fish

An important, yet overlooked form of anthropogenic pollution is sensory pollution, and one of the most pervasive forms of sensory pollution is artificial light at night (ALAN). Despite the growing use of ALAN across the globe, limited research has examined the impacts of ALAN on coral reef fish. This study aims to further our understanding of the behavioural impacts of light pollution on fish by exposing the humbug damselfish (Dascyllus aruanus) to ALAN (∼15–25 lux, white LED light) over a period of 14 days, in situ. We assessed nocturnal activity, and diurnal shelter use and emergence time following a simulated threat in natural (control) and ALAN conditions. D. aruanus colonies exposed to ALAN were active at night and were lacking cryptic colouration observed in control fish, however this altered nocturnal activity did not appear to impact the diurnal behaviours we measured. Our findings provide critical insight into the impact of ALAN exposure to nocturnal behaviour of a diurnal fish and highlight the potential for increased risk of nocturnal predation under ALAN. Further studies with a longer ALAN exposure time will help illuminate the extent of behavioural changes and implications caused by ALAN in shallow coral reef systems.