Biologists conduct surveys, studies, and assessments of various natural habitats and water resources. They ensure programs and environmental activities are in compliance with laws and regulatory programs, such as the Clean Water Act, the Rivers and Harbors Act, Marine Protection, Research and Sanctuaries Act, etc. USACE Biologists throughout the United States conduct activities to preserve wildlife and aquatic habitats, monitor nuisance vegetation and invasive species, and act as environmental consultants.