Every species, like every person, is unique, with its own history and destiny and when species are lost, ecosystems start to lose functionality and become more prone to collapse.
Humans have unintentionally affected the lives of Polar Bears through pollution and global warming as well and as a result of this their natural habitat continues to be destroyed. For example if the icy water of the Arctic region continue to melt, the water is full of toxins and chemicals that can destroy the seals they depend on for food. Polar bears are known as an umbrella species hence many animals are connected to polar bears via a food web like the arctic fox that depends on the polar bear for food as they eat the left over seal remains after the polar bear is done. In 2008, the polar bear became the first animal to be added to the Endangered Species Act list of threatened species because of global warming. According to research polar bears have one of the slowest reproductive rates. In the course of their lifespan females produce an average of only five litters