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Perkin, E. K., Hölker, F., Tockner, K., & Richardson, J. S. (2014). Artificial light as a disturbance to light-naïve streams. Freshw Biol, 59(11), 2235–2244.
Abstract: Summary
Artificial light at night is prevalent in human-dominated landscapes, and streams in these landscapes can be expected to be affected by artificial lights. We hypothesised that artificial light at night would reduce the activity of aquatic insects, resulting in reduced drift rates, lower fish growth rates and lower leaf litter decomposition rates.
We tested these hypotheses by installing street lights to reaches in four forested, natural streams of coastal British Columbia each paired with a control reach. Cutthroat trout (Oncorhynchus clarkii) are the top predators in these streams and feed mostly on terrestrial and drifting aquatic invertebrates.
We found that the night-time drift of aquatic invertebrates in lit reaches was ˜50% of the drift in dark reaches. However, the density of emerging aquatic insects, the density of insects falling into reaches, leaf litter decomposition rate and the number and growth rate of trout caught were not significantly different between the dark and experimentally lit reaches.
We conclude that, while short-term exposure to artificial light during the summer changes invertebrate behaviour, it does not significantly alter other trophic levels in forested headwater streams. Our results suggest that low levels of artificial light do not strongly influence stream ecosystems, but future research should determine whether this is true for all seasons and longer-term exposure to light.
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Scheibler, E., Roschlau, C., & Brodbeck, D. (2014). Lunar and temperature effects on activity of free-living desert hamsters (Phodopus roborovskii, Satunin 1903). Int J Biometeorol, 58(8), 1769–1778.
Abstract: Time management of truly wild hamsters was investigated in their natural habitat in Alashan desert, Inner Mongolia, China during summer of 2009, 2010, and 2012. Duration of activity outside their burrows, duration of foraging walks, and nocturnal inside stays were analyzed with the aim to elucidate impact of moon, ambient, and soil temperature. Animal data were determined using radio frequency identification (RFID) technique; for that purpose, individuals were caught in the field and marked with passive transponders. Their burrows were equipped with integrated microchip readers and photosensors for the detection of movements into or out of the burrow. Lunar impact was analyzed based on moon phase (full, waning, new, and waxing moons) and moon disk size. A prolongation of aboveground activity was shown with increasing moon disk size (Spearman rho = 0.237; p = 0.025) which was caused by earlier onsets (rho =-0.161; p = 0.048); additionally, foraging walks took longer (Pearson r = 0.037; p = 0.037). Temperature of different periods of time was analyzed, i.e., mean of whole day, of the activity phase, minimum, and maximum. Moreover, this was done for the current day and the previous 3 days. Overall, increasing ambient and soil temperatures were associated with shortening of activity by earlier offsets of activity and shorter nocturnal stays inside their burrows. Most influential temperatures for activity duration were the maximum ambient temperature, 3 days before (stepwise regression analysis R = 0.499; R (2) = 0.249; F = 7.281; p = 0.013) and soil temperature during activity phase, 1 day before (R = 0.644; R (2) = 0.283; F = 7.458; p = 0.004).
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Olsen, R. N., Gallaway, T., & Mitchell, D. (2014). Modelling US light pollution. Journal of Environmental Planning and Management, 57(6), 883–903.
Abstract: This paper uses a unique US dataset to study the economic causes of light pollution at the local (county) level. Light pollution has been shown to have negative consequences for both wildlife and humans. Light pollution is a form of pollution commonly ignored by environmental professionals. Traditionally, light-pollution models focus on population-based explanations. This paper confirms the importance of population in understanding light pollution. However, the results highlight the importance of economic variables, especially local economic development, in explaining the existence and extent of light pollution. Estimated models show, for example, that local employment patterns, personal income, roads and energy use are all important explanatory variables. By highlighting the connections between light pollution and specific types of local economic activity, this paper provides policy makers with additional information that they can use to improve public policies intended to safeguard the environment and local wildlife.
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de Miguel, A. S., Castano, J. G., Zamorano, J., Pascual, S., Angeles, M., Cayuela, L., et al. (2014). Atlas of astronaut photos of Earth at night. Astronomy & Geophysics, 55(4), 4.36–4.36.
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Kamrowski, R. L., Sutton, S. G., Tobin, R. C., & Hamann, M. (2014). Potential applicability of persuasive communication to light-glow reduction efforts: a case study of marine turtle conservation. Environ Manage, 54(3), 583–595.
Abstract: Artificial lighting along coastlines poses a significant threat to marine turtles due to the importance of light for their natural orientation at the nesting beach. Effective lighting management requires widespread support and participation, yet engaging the public with light reduction initiatives is difficult because benefits associated with artificial lighting are deeply entrenched within modern society. We present a case study from Queensland, Australia, where an active light-glow reduction campaign has been in place since 2008 to protect nesting turtles. Semi-structured questionnaires explored community beliefs about reducing light and evaluated the potential for using persuasive communication techniques based on the theory of planned behavior (TPB) to increase engagement with light reduction. Respondents (n = 352) had moderate to strong intentions to reduce light. TPB variables explained a significant proportion of variance in intention (multiple regression: R (2) = 0.54-0.69, P < 0.001), but adding a personal norm variable improved the model (R (2) = 0.73-0.79, P < 0.001). Significant differences in belief strength between campaign compliers and non-compliers suggest that targeting the beliefs reducing light leads to “increased protection of local turtles” (P < 0.01) and/or “benefits to the local economy” (P < 0.05), in combination with an appeal to personal norms, would produce the strongest persuasion potential for future communications. Selective legislation and commitment strategies may be further useful strategies to increase community light reduction. As artificial light continues to gain attention as a pollutant, our methods and findings will be of interest to anyone needing to manage public artificial lighting.
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