Human survival depends on access to clean water but agriculture and urbanization dump hundreds of millions of tons of fertilizers and other pollutants into freshwater ecosystems every year. This causes eutrophication, toxic cyanobacteria blooms, and expansive hypoxic dead zones that damage ecosystems and undermine human food and water security. Anthropogenic pressures on aquatic ecosystems are expected to intensify due to population growth and increasing meat consumption through the middle of the century. To address this crisis, we are developing new ecohydrological tools to assess the capacity of catchments to retain and eliminate pollutants. Using data from agricultural and urban landscapes in western France and the Intermountain West, we are testing biogeochemical proxies of where water goes, how long it stays there, and what happens along the way. We are developing new approaches to managing human activity with a large group of ecohydrologists from the U.S., Europe, Central America, China, and Africa.
1. What determines a catchment’s resilience to human disturbance?
2. Why do some catchments retain or remove nutrients and contaminants, while other readily export inputs to rivers, lakes, and estuaries?
3. How long will it take ecosystems to recover after we reduce pollutant loads?