Our Changing Ohio River: Climate, Water Quality, and Harmful Algal Blooms


Speaker: Emily Elliott, University of Pittsburgh.

The Ohio River basin is not only vast, but its waterways are a vital economic, ecological, and recreational resource for the 15 states within basin boundaries. Yet, a half-century after the Clean Water Act, major challenges remain to make the Ohio River fishable, swimmable, and drinkable. For example, in 2015 and 2019 unprecedented blooms of the toxin-producing harmful algal bloom, Microcystis aeruginosa, extended along 600 and 300 miles of the mainstem Ohio River, respectively. Given the unusual nature of these extensive blooms and the potential impacts to human and ecological health, it is imperative to understand factors contributing to bloom formation. I will highlight ecological, hydrological, and climatic changes in the Ohio River over the past 40 years and explore how these factors may be interacting to fundamentally change the ecology and biogeochemistry of the Ohio River. Long-term trends in flow and two key nutrients that contribute to algal bloom proliferation (nitrogen, phosphorous) are evaluated using a U.S. Geological Survey model called Weighted Regressions on Time, Discharge, and Season (WRTDS). Our model results are placed in the context of current river management strategies, efforts to curb nutrient pollution, and a basin-wide push for federal designation as a restoration target.
This event will take place Monday, September 25,2023 at Noon in person at Earth Theater.