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Scientists issue warning after discovering unexpected behavior shift in young coastline fish: 'It makes them all behave unnaturally'

This threat isn't just impacting the behavior of aquatic species.

This threat isn't just impacting the behavior of aquatic species.

Photo Credit: iStock

Scientists are warning that the allure of artificial light from coastlines is seemingly too powerful for young fish to ignore, altering their behavior and perhaps leading them into deadly traps. 

What's happening?

As detailed by The Guardian, a new study found that artificially lit corals were attracting "two to three times more fish compared to the naturally lit control site," according to lead author Jules Schligler, with the international coral ecosystem research centre in Mo'orea, French Polynesia.

Schligler speculated the light was creating a sort of "midnight fridge." It is unclear whether predators are simply following larval fish to the light or whether they are attracted to the light themselves, but it was apparent that the artificial illumination was altering behavioral patterns.

"The artificially lit coral could be like a midnight fridge full of tasty plankton that are drawn to the light too," Schligler told The Guardian. "The plankton attract the larvae, and then the larvae are followed by their predators. Or it might be both the light itself and the prospect of food that attract them. Either way it makes them all behave unnaturally."

The analysis examined only two species, the yellowtail dascyllus and the blue-green chromis, but Schligler believes the findings can be applied to other marine life. 

Oren Levy, the head of laboratory for molecular marine ecology at Bar-Ilan University in Israel, told The Guardian that Schliger's results were consistent with his own research. 

Why is this concerning?

Our biodiverse oceans provide a plethora of benefits, helping to regulate Earth's temperatures and providing food and livelihoods for billions of people globally. 

However, Schligler told The Guardian that his work reveals artificial light is a "threat to marine animal populations and coastal ecosystems," with the midnight fridge potentially disrupting the delicate natural balance that helps keep our waters healthy. 

Light pollution isn't just impacting the behavior of our aquatic friends; it's negatively affected the mating behaviors of fireflies and the spawning of coral (which protect against storms and are a source of compounds for cancer medicines) and led to mass-collision deaths of birds.

According to UCLA, it also impairs natural sleep processes, which can lead to groggy mornings and hinder our bodies' abilities to fight diseases. 

What is being done about problematic light pollution?

Schligler, whose findings were presented in Prague at the Society for Experimental Biology conference, told The Guardian that more research could provide valuable data to help protect our marine ecosystems. 

"And we can start to take light into account for things like marine protected areas," Schligler said. 

Both he and Levy also highlighted the simple, practical solutions already available to reduce disruptive light pollution, including timers and shades

Other actions people can take include installing energy-saving motion sensors (reducing electric bills to boot), shielding lights so they point only downward, and chatting with family and friends about how to help, according to the U.S. Fish and Wildlife Service's Dark Skies Initiative.

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