Nightlights for stream dwellers? No, thanks

Date:  December 19, 2018

Source:  Ohio State University

Artificial light at night isn't just a health problem for those of us sitting in bed scrolling through Instagram instead of hitting the sack -- it hurts entire outdoor ecosystems.

When the critters that live in and around streams and wetlands are settling into their nighttime routines, streetlights and other sources of illumination filter down through the trees and into their habitat, monkeying with the normal state of affairs, according to new research from The Ohio State University.

"This is among the first studies to show that light at night has detrimental effects not just on individual organisms in the environment, but also on communities and ecosystems," said Mažeika Sullivan, lead author of the study, which appears today (Dec. 19, 2018) in the journal Ecological Applications.

"Nighttime light is having profound impacts that extend to the entire ecosystem," said Sullivan, director of Ohio State's Schiermeier Olentangy River Wetland Research Park and associate professor of environment and natural resources.

Though many people might not consider it, artificial light is a pollutant, changing the natural course of life for people, animals and plants, he said, adding that urbanization is rapidly increasing both in the United States and around the globe.

"We are experiencing this pollution that we don't think about, but it's all around us and it's chronic and it's happening everywhere -- from newly lit villages in rural Africa to streams alongside the highway in Columbus, Ohio," he said. "It's also unprecedented in Earth's history."

The new study explored the role of light on streams and wetlands in and around Columbus. Moonlight under a clear sky can give an illuminance of 0.1 to 0.3 lux, Sullivan said. The streams in the study were headwater streams draining into the Scioto and Olentangy rivers, with light ranging from 0.01 to 4.0 lux. Wetlands of the Olentangy River Wetland Research Park had lighting from 0 to 20 lux.

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