What characteristic of double-stranded DNA determines the ability of one strand to make an exact copy of the other strand?

An area affected by an oil spill can become unhabitable for the sea birds' source of food because of toxic poisons and in turn, make it uninhabitable to the sea birds. The animals that depend on the birds for food will have fewer available options for prey and their population may lower. If the area affected by the oil spill has low biodiversity it will have a great effect on the food web.