Light pollution causes more harm than simply ruining the view during a starry night. A new study has found that clownfish can’t raise any young when exposed to artificial light. 

The study observed 10 pairs of clownfish, with each pair in their own tank. Half of the clownfish couples experienced light as they would in a natural coral reef, with 12 hours of light and 12 hours of darkness. 

The other half of the clownfish were exposed to a low level of artificial light at night to mimic the light pollution from an average coastal town. 

Twice a year more than 5 million birds from at least 250 different species fly through the city of Chicago alone as they head toward Canada in the spring and return south toward Central and South America in the fall. Though beautiful, the Windy City’s skyline can prove fatal to a number of birds who collide with glass-covered or illuminated buildings. 

Studies have estimated at least 100 million bird deaths related to light pollution in cities throughout the United States per year, and some estimates put that number closer to one billion deaths per year.