Dr Nestler was awarded a BS in Biology from Valdosta State College (1972), MS in Zoology from the University of Georgia (1976), and PhD in Zoology from Clemson University (1980). He worked as an ecologist at the US Army Engineer Research and Development Center (formerly Waterways Experiment Station) from 1980 to his retirement in 2010. After retirement he worked for a variety of national and international clients. Prior to retirement he led a large, interdisciplinary team dedicated to understanding, simulating, and forecasting effects of Corps of Engineers water resources projects on inpool and downstream environmental quality. He is still active in issues involving coastal and river environmental sustainability, coastal and river large-scale ecosystem restoration, fish passage, fish movement analysis and forecasting, advanced habitat modeling methods, and Eulerian-Lagrangian-agent modeling methods. He also served as the Director, Environmental Modeling and System-wide Assessment Center at ERDC and was the Co-Director of the Tropical Environmental Research Center at the University of Puerto Rico at Mayagüez. His research focus is to couple tools used by engineers with tools used by ecologists into a single seamless system to facilitate comprehensive, multi-disciplinary investigations of aquatic systems.