The U.S. Fish and Wildlife Service is a government agency that works for the conservation, protection and enhancement of fish, wildlife and plants. The agency is responsible for the management of natural resources for the general public. It is also engaged in implementing and enforcing several environmental laws, such as the Endangered Species Act, Migratory Bird Treaty Act, and Marine Mammal Protection. The U.S. Fish and Wildlife Service manages more than 65 fish hatcheries and over 75 ecological services field stations, as well as the National Wildlife Refuge System. The agency also operates the Bureau of Sport Fisheries and Wildlife. It supports the federal aid program and works in partnership with nonprofit organizations and the state and federal agencies. In addition, the agency employs a staff of nearly 8,700 people and operates approximately 700 field offices. The U.S. Fish and Wildlife Service is a part of the Department of the Interior.