Dr. Steven Bartell is Senior Principal at CARDNO, USA. He has extensive experience and technical skills in quantitative ecosystem analysis, ecological modeling, and ecological risk assessment. He has contributed extensively to the development of the USEPA Framework and Guidelines for Ecological Risk Assessment. Bartell has applied his modeling skills in assessing ecological risks posed by eutrophication, ionizing radiation, chemical contaminants, invasive species, habitat degradation, and altered hydrology. He has also developed complex aquatic ecosystem models in support of ecosystem management and restoration. Dr. Bartell has designed and implemented adaptive management programs for large river systems for the U.S. Army Corps of Engineers. Dr. Bartell was contracted by the National Park Service to develop and implement a risk-based decision model to assist managers in the Everglades National Park in determining the impacts of hydrological alterations in South Florida on endangered resources within the Everglades. Dr. Bartell has contributed extensively to the peer-reviewed technical literature with books and articles.