Arctic Light Pollution and its Effect on Marine Life

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According to National Geographic, research by biologist Geir Johnsen indicates that Arctic light pollution is one of the leading causes of endangered marine species.

What is Polar Night?

During the midwinter, the Arctic Circle sky is a dark path blind to human eyes. As the Earth tilts, the sun seems to never rise beyond the horizon, creating this dark, Polar Night. During these Arctic Polar Nights, organisms whose species depend on natural light for orientation or navigation take their cues from the moon, stars, and aurora borealis. These natural lights guide ecosystems, direct marine life, and tell land animals when migration season begins, as well as where to hunt for food and when to search for a mate.

What is light pollution?

Light pollution is artificial light that falls on a habitat and/or ecosystem. In the Arctic, climate change has thinned the ice enough to allow artificial light from vessels to penetrate the dark ocean. As a result, organisms that normally depend on the dark become disturbed by the unexpected and unusual brightness.

How does light pollution affect marine life?

Zooplankton, as small as they may be, provide nourishment for marine animals like fish, seabirds, seals, whales, and polar bears. Microscopic algae in the world’s oceans produce an astounding 50% of the Earth’s oxygen. According to Nature Communications Biology, artificial light during Arctic Polar Night alters predatory behavior, interaction among marine life, and the migration patterns of some species. Light pollution penetrating 656 feet deep confuses zooplankton that usually go without light for days, altering their lives drastically. Additionally, research has shown that light pollution diverts marine organisms closer to the equator, also affecting migration.

Sea turtles, specifically, are the most threatened species from light pollution. Adult female sea turtles give birth to their offspring at night in sandy beaches. Light pollution makes it difficult for mother turtles to procure a dark, safe spot to lay their eggs. Newborn sea turtles are born with an innate sense of survival. They are born to locate the ocean’s bright horizon line and to walk away from landward silhouettes. Today, however, when these hatchlings are born, city lights confuse them and they end up traversing across illuminated roads, into civilization, and amidst danger instead of their beloved ocean. Sadly, as a result of light pollution, millions of newborn sea turtles are killed each year.

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