Speakers
R. Eugene Turner
R. Eugene Turner is the 71st LSU Systems Boyd Professor and resides in the Department of Oceanography and Coastal Sciences. He has been active in the scientific aspects of coastal environmental management, including the low oxygen (hypoxic) zone off the Mississippi River and wetland conservation, restoration and management since he came to Louisiana in the Pleistocene. He worked on the BP oil spill and is currently in collaboration with three Sovereign Tribes in Louisiana. His most recent book project is Sustainability Science: The Emerging Paradigm and the Urban Environment.
Presentation Description
A century-long snapshot of water quality at the end of the Mississippi RiverVarious air and water pollution issues in the US were confronted in the last 60 years using national policy legislation, notably the Clean Water Act (CWA) and the Clean Air Act (CAA). Focal points were the concentrations of bacteria, oxygen, lead, and sulphate which are discussed here for the terminus of the Mississippi River for before and after these pollution abatement efforts. Microbial concentrations increased or were stable from 1909 to 1980 but decreased about 3 orders of magnitude after the 1970s, while the average oxygen content increased. A large decline in lead concentration occurred after the 1960s, along with a less dramatic decline in sulphate concentrations. The pH of the river was a low of 5.8 in 1965 as sulfur dioxide emissions peaked and averaged 8.2 in 2019 after emissions declined. Decades of efforts at a national scale created water quality improvements and are an example for addressing new and existing water quality challenges. New agents of often unknown effects are added to waterways whose stocks and transformations need monitoring, minimization and prohibitive actions. The Midwest landscape has increased rainfall and agricultural drainage lead to changes in water quantity and quality including increased carbon loss, rising alkalinity and higher nitrate concentrations. There are links between nitrate in drinking water and birth defects, bladder cancer and thyroid cancer. Today’s agricultural and urban nutrient loadings are dominant controlling influences on the size and severity of coastal hypoxic zones. The strictly nutrient-related issues are co-developing with ocean acidification and climate change whose cumulative and synergistic interactions may be even more socially and ecologically significant. The promulgation and acceptance of the CWA and CAA demonstrate how public policy can change for the better for everyone who is demonstrably ‘downstream’ in a world of cycling pollutants.