Coastal Animals Lose Advantage To Camouflage Due To Artificial Light at Night, Study Claims

Coastal species and other animals that rely on darkness are slowly losing the advantage of camouflage because of the advancements in lighting cities and coastlines. According to Science Daily, the new study shows that the increasing energy efficient broad-spectrum lighting potentially disrupts the visually guided ecological processes.

The team demonstrated in the study that these novel lighting technologies improve the ability of predators to identify their prey against a natural background. Since the effect varies depending on the color of each organism, certain color variations may be at higher risk.

(Photo : Pixabay/dimitrisvetsikas1969)
Animals Lose Advantage of Camouflage As Lighting in Cities, Coasts Improve

Artificial Light Affects Camouflage Mechanisms of Coastal Species

The study, titled "Broad Spectrum Artificial Light at Night Increases the Conspicuousness of Camouflaged Prey," published in the Journal of Applied Ecology, led by researchers from the University of Plymouth and Plymouth Marine Laboratory (PML) is the first to examine the potential for artificial light at night (ALAN) to affect camouflage of coastal species.

The team used a well-established model to compare how Littorinid snail that is found along coastlines would be affected under different forms of lighting, Phys.org reported. This spectrum included the natural light from the Sun and Moon, the 20th-century narrow-spectrum Low-Pressure Sodium (LPS), and the three types of modern broad-spectrum lighting, such as High-Pressure Sodium (HPS), Light Emitting Diodes (LEDs), and Metal Halide (MH).

They found that all snails under the LPS lighting effectively camouflage, but it loses this advantage when illuminated under LEDs, MH, and even the natural lighting from the Sun and Moon. Most of the time, the yellow snails appear to be more visible than the brown and olive.

Study senior author Dr. Thomas Davies said that about a quarter of the planet is now being affected by the night-time light pollution in which 85% is caused by LED bulbs, highlighting the findings of the study that advances in lighting in cities have repercussions for humans and animals.

Dr. Tim Smyth, a co-author of the study, added that the ability to light the environment 24/7 transformed the urban areas in the past 100 years and ushered the world into Urbanocene, the era of shifting from the orange glow to the more energy-efficient broad spectrum of LEDs that lets humans perceive color at night more accurately.

But study lead author Oak McMahon said that the findings clearly show that the new lighting technologies will reduce the camouflage mechanisms of animals and affect both humans and animals.

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Ways to Reduce ALAN in Coastlines

According to the news release from the University of Plymouth, an estimated 23% of the world's surface is affected by ALAN, with an increase of 2.2% between 2012 and 2016. These numbers are pretty alarming and should be addressed to reduce the adverse effects of light pollution.

Researchers have highlighted in the study a variety of mitigation methods for the perusal of city planners and environmental managers, especially when considering the ecological impacts of the advances in lighting in cities.

The mitigations mentioned in the study include reducing the amount of light being used, shielding lights to reduce their effects on the environment, manipulating the spectra of lighting to reduce its ecological impacts, and using part-night lighting in times of peak demand.

Although the study may highlight the advantages of using narrow-spectrum lighting to avoid these environmental impacts, researchers said that light pollution's effects are more than affecting the camouflage of species. The effects of ALAN extend beyond what is seen on camouflage and would likely impact all of the ecologies.