Light pollution itself is a broad topic. There are many leading effects of light pollution, however, I am focused on how light pollution affects wildlife. A main example of this would be that light pollution radically alters an animal's environment. Which is a large issue for species that rely on darkness and/or light.
Starting off, light pollution interferes with nocturnal animals by making their night seem like day. Some night creatures rely on darkness for communication. For example, fireflies use a complex system to communicate messages. The bioluminescent lights they emit from their bodies range from adult mating signals to young larvae warning off predators. Stray light can easily interfere with these messages.
Another example would be the interference of coyote communication . Coyotes howl more during the time of a new moon, when the sky is darkest. They most likely do this to reduce trespassing from other packs or to assist with hunting larger prey during dark conditions. Light pollution produces a brighter sky and most likely reduces the amount in which they howl. This could lead to the disruption of territorial making and group hunting coordination.
That being said, light pollution also affects many predator-prey relationships that are dependant on light. A recent study showed that, “more harbor seals congregated under artificial lights to eat juvenile salmon migrating downstream. When the lights were turned off, the seals ate less salmon.” Light pollution disrupts a natural balance resulting in the benefit of one species while putting the other at risk.
In addition, insects such as moths are attracted to the light. Meaning millions are killed annually due to hot components. This is an example of how light pollution can affect a food chain because when moths die, bats and birds lose a food chain. Basically, light pollution can harm many, if not all, the species that rely on insects as a food source.
Overall, there really is no win-win situation. Too much light is a disruption to the environment and the systems that come with it. Nature comes with a balance and when that balance is interfered with, wildlife and ecosystems are left with a negative impact.