@article{VegaJechowJamesAetal.2023, author = {Vega, Catherine Perez and Jechow, Andreas and James A., Campbell and Zielinska-Dabkowska, Karolina M. and Hoelker, Franz}, title = {Light pollution from illuminated bridges as a potential barrier for migrating fish-Linking measurements with a proposal for a conceptual model}, series = {Basic and Applied Ecology}, volume = {74}, journal = {Basic and Applied Ecology}, publisher = {Elsevier}, issn = {1618-0089}, doi = {10.1016/j.baae.2023.11.001}, pages = {1 -- 12}, year = {2023}, abstract = {Illuminated bridges have become important assets to navigable aquatic systems. However, if artificial light at night (ALAN) from illuminated bridges reaches aquatic habitats, such as rivers, it can threaten the river's natural heterogeneity and alter the behavioural responses of migratory fish. Here, via a pilot study, we quantified levels of ALAN at illuminated bridges that cross a river and, propose a conceptual model to estimate its potential implications on two migrating fish species with contrasting life histories. Night-time light measurements on the river Spree in Berlin were performed continuously along a transect and in detail at seven illuminated bridges. Photometric data of the pilot study showed rapidly increased and decreased light levels at several illuminated bridges from which we derived several model illumination scenarios. These illumination scenarios and their potential effect on migrating Atlantic salmon smolts (Salmo salar) and European silver eel (Anguilla anguilla) are presented as a conceptual model, considering illuminated bridges as behavioural barriers to fish migration. ALAN's adverse effects on freshwater habitats must be better researched, understood, managed, and properly communicated to develop future sustainable lighting practices and policies that preserve riverscapes and their biodiversity.}, language = {en} } @article{VegaHoelkerZielinskaDabkowskaetal.2024, author = {Vega, Catherine Perez and H{\"o}lker, Franz and Zielinska-Dabkowska, Karolina M and Jechow, Andreas}, title = {Polarised light pollution on river water surfaces caused by artificial light at night from illuminated bridges and surroundings}, series = {Journal of Limnology}, volume = {83}, journal = {Journal of Limnology}, publisher = {PAGEPress}, doi = {10.4081/jlimnol.2024.2173}, pages = {1 -- 13}, year = {2024}, abstract = {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.}, language = {en} }