For billions of years, nights—especially moonless nights—were dark. However in the last 150 years human urbanisation has transformed our nocturnal landscape, so that now more than one third of the human population is no longer able to see the Milky Way. Light pollution is expanding every year by around 6%, affecting more organisms, including plants, fungi, bacteria and animals. Artificial light can interrupt vegetative growth of plants, disturb communication between fireflies, misdirect movement of turtles or result in birds’ choir starting earlier.
Some seabirds are also affected by light pollution. These birds land on the ground in lit-up areas. Due to their anatomy, specially adapted for life at sea, they are generally unable to take off again. On the ground, they can be hit by a car or be depredated by cats or dogs. Luckily hundred of volunteers and communities world-wide organise rescue campaigns, searching for grounded birds in order to release them back to sea. Many seabirds are saved this way, but for some help comes too late, or they are never found. 
There are ways to improve our outdoor lights, so that they work optimally for humans, and ensure minimal disturbance, not only to seabirds, but also other animals.