USGS scientists collecting a water-quality sample from Loma Verde Wash in Saguaro National Park, Arizona, as part of the USGS's Amphibian Research and Monitoring Initiative. Hydrologists and herpetologists are collaborating to understand the causes of amphibian declines and malformations. Hydrologists are providing expertise on the hydrology and water quality of study areas, and information on hydrologic and water-quality factors that may be impacting amphibian populations -- from the Amphibian Research and Monitoring Initiative (AMRI) Photo Gallery