Nocturnal animals keep getting lost — and light pollution is to blame
Crustaceans in the spotlight
We tested this idea using the tiny sand hopper (Talitrus saltator), a coastal crustacean that is known to use the moon to guide its nightly foraging trips. Less than one inch long, sandhoppers are commonly found across Europe’s sandy beaches and named for their ability to jump several inches in the air.
They bury in the sand during the day and emerge to feed on rotting seaweed at night. They play an important role in their ecosystem by breaking down and recycling nutrients from stranded algae. If you turn over washed-up seaweed on an evening beach walk, you should have no trouble finding them.
In our study, we recreated the effects of artificial skyglow using a white LED light in a diffusing sphere that threw an even and dim layer of light over a beach across 19 nights between June and September 2019. During clear nights with a full moon, sand hoppers would naturally migrate towards the shore where they would encounter seaweed. Under our artificial skyglow, their movement was much more random.
They migrated less often, missing out on feeding opportunities which, due to their role as recyclers, could have wider effects on the ecosystem.
Artificial skyglow changes the way sandhoppers use the moon to navigate. But since using the moon and stars as a compass is a common trait among a diverse range of sea and land animals, including seals, birds, reptiles, amphibians, and insects, many more organisms are likely to be vulnerable to skyglow. And there’s evidence that the Earth at night is getting brighter. From 2012 to 2016, scientists found that Earth’s artificially lit outdoor areasincreased by 2.2% each year.
As researchers, we aim to unravel how light pollution is affecting coastal and marine ecosystems, by focusing on how it affects the development of different animals, interactions between species and even the effects at a molecular level. Only by understanding if, when, and how light pollution affects nocturnal life can we find ways to mitigate the impact.
This article is republished fromThe ConversationbySvenja Tidau, Postdoctoral Researcher in Marine Biology,Plymouth University;Daniela Torres Diaz, PhD Candidate in Biology,Aberystwyth University, andStuart Jenkins, Professor of Marine Ecology,Bangor Universityunder a Creative Commons license. Read theoriginal article.
Story byThe Conversation
An independent news and commentary website produced by academics and journalists.An independent news and commentary website produced by academics and journalists.
Get the TNW newsletter
Get the most important tech news in your inbox each week.
