Polarized light pollution: a new kind of ecological photopollution

Abstract

The alteration of natural cycles of light and dark by artificial light sources has deleterious impacts on animals and ecosystems. Many animals can also exploit a unique characteristic of light – its direction of polarization –as a source of information. We introduce the term “polarized light pollution” (PLP) to focus attention on the ecological consequences of light that has been polarized through interaction with human‐made objects. Unnatural polarized light sources can trigger maladaptive behaviors in polarization‐sensitive taxa and alter ecological interactions. PLP is an increasingly common byproduct of human technology, and mitigating its effects through selective use of building materials is a realistic solution. Our understanding of how most species use polarization vision is limited, but the capacity of PLP to drastically increase mortality and reproductive failure in animal populations suggests that PLP should become a focus for conservation biologists and resource managers alike.

Phototaxis and polarotaxis hand in hand: night dispersal flight of aquatic insects distracted synergistically by light intensity and reflection polarization

“…Unfortunately, this phenomenon is not as rare in nature as we think at first. Lamplit car parks, solar panels near indicator lighting and illuminated glass buildings, for example, have the potential to significantly disrupt the ecosystem by simultaneous photopollution and polarized light pollution (Bernáth et al 2001;Longcore and Rich 2004;Rich and Longcore 2006;Horváth et al 2009Horváth et al , 2010a. The follow-up investigation of the generality of this phenomenon could be an interesting and important task of future research.…”

“…asphalt roads, oil lakes, black plastic sheets used in agriculture, shiny dark-coloured cars, solar panels and collectors) -mimicking the reflection-polarization characteristics of water surfaces -may confuse flying, water-seeking polarotactic water insects. These man-made polarizing reflecting surfaces cause daylong polarized light pollution, that has disastrous consequences for polarotactic insects (Horváth and Zeil 1996;Kriska et al 2006;Bernáth et al 2001;Horváth et al 2009Horváth et al , 2010a.…”

Polarized light pollution of matte solar panels: anti-reflective photovoltaics reduce polarized light pollution but benefit only some aquatic insects

“…Photovoltaic solar panels are strong sources of a form of photopollution known as polarized 73 light pollution (PLP, Horváth et al 2009Horváth et al , 2010a 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 Observers counted reaction groups (how many times a horsefly individual reacted to a given 177 test surface with aerial looping, touch-down, or landing, excluding repetitions by the same individual 178 before flying away) and reaction items (how many times a given reaction element -looping, touching, 179 landing -was performed by a given horsefly, including repetitions by the same individual before flying 180 away). For example, if 4 horseflies reacted with aerial looping and each horsefly performed 3 loops 181 above a test surface, then reaction groups = 4, and reaction items = 4 × 3 = 12.…”

Insights from chironomid oviposition is useful to visual pest control

“…Since misidentification of appropriate oviposition sites is common (e.g. Horváth & Zeil, 1996;Kriska et al 2006;Horváth et al, 2009), polarized reflecting egg-traps should be highly effective in controlling species with a similar life-style to that of C. transvaalensis.…”

“…Natural surfaces do not reflect more than 0.7 partial polarization (e.g. Horváth et al 2002) while higher polarization reflections are created by man-made substances such as oil, car paint or window glasses Malik et al 2008;Horváth et al, 2009). These surfaces can reflect up to 1.0 partial polarization (especially when viewing from Brewster angle or in case they are made of fully polarizing sheets) hence can be more appealing to the insects.…”