TY - JOUR A1 - Vega, Catherine Perez A1 - Hölker, Franz A1 - Zielinska-Dabkowska, Karolina M A1 - Jechow, Andreas T1 - Polarised light pollution on river water surfaces caused by artificial light at night from illuminated bridges and surroundings T2 - Journal of Limnology N2 - Artificial light at night originating from bridge illumination can cause polarised light pollution when it is reflected at water body surfaces. This alters the optical conditions of a river at night and potentially interferes with natural polarisation signals from, for example, moonlight. Therefore, this type of light pollution could detrimentally change the behaviour of organisms sensitive to polarised light, a navigational cue and signal known to be used e.g. by flying water-seeking insects to detect suitable aquatic habitats to reproduce and lay eggs. So far, polarised light pollution from artificial light at night is understudied. Here, we quantify polarised light pollution at the water’s surface near seven illuminated bridges crossing the river Spree in Berlin. Our measurements show for the first time, that nocturnal bridge illumination induces polarised light pollution towards potential flying paths of polarotactic aquatic insects. On average, around 9% of the water surfaces at the investigated bridges were highly polluted by polarised light, with values ranging between 3 and 12 % for each bridge. Thus, polarised light pollution from artificial light at night is an emergent pollutant for aquatic systems. Future work on this topic should include more comprehensive measurements, further ecological studies on its impacts and the development of sustainable lighting solutions that can contribute to the protection of riverine nightscapes. Y1 - 2024 UR - https://opus4.kobv.de/opus4-fhbrb/frontdoor/index/index/docId/3176 VL - 83 SP - 1 EP - 13 PB - PAGEPress ER -