With reflections rippling on the waves, coastlines all around the world are exposed to our night lights. Young turtles are an iconic example of how our light pollution can have an impact on wildlife – in some areas, juveniles are fooled into heading away from the sea and into urban areas by the dazzle. In the UK, too, marine species can be affected by the unnatural light.
The dog whelk Nucella lapillus is a nocturnal predator, a slow-moving mollusc that preys upon the barnacles and limpets of the rocky shore. It is, however, also vulnerable to other, larger coastal predators.
When exposed to a simulation of light pollution, whelks have been found to adjust their behaviour in comparison to those experiencing more natural darkness. Under light pollution, they forage more – perhaps making the most of the extra lighting – but seek shelter less, even in the presence of cues that their own predators were nearby.
The findings show how light pollution in coastal areas can influence the behaviour of a species, as well as lead to a potentially risky strategy that could have knock-on effects throughout the intertidal ecosystem.
Originally published in News in Brief – Biosphere Magazine Issue 25
Underwood, C. N., Davies, T. W. and Queirós, A. M. (2017), Artificial light at night alters trophic interactions of intertidal invertebrates. Journal of Animal Ecology, doi:10.1111/1365-2656.12670