Science Center Objects

Our nation’s rivers have many uses. People have altered the flow of some rivers through diversions, dams, and water use.  Such changes can affect fish populations and our scientist work to understand these effects by answering such questions as “How is survival of young fish affected by streamflow patterns?” and “How do fish communities respond to changes in water management?”

Measuring water velocities during historic low-flows

Measuring water velocities during historic low-flows, Middle Oconee River near Athens, GA. (Public domain.)


Quantifying Effects of Flow Variability on Riverine Biota

Ecologists have shown that many ecological processes in rivers, including organism growth, reproduction, survival and dispersal, are attuned to natural patterns of streamflow variability.  However, to predict how riverine biota will respond to flow alteration caused by, for example, water diversions and dam operations, ecologists need to understand the mechanisms through which changes in streamflow affect plant and animal populations.  Therefore, we are conducting field studies and analyses to test hypothesized effects of streamflow variability on population (survival, reproduction, extirpation, colonization) and trophic (primary production and consumption) dynamics.




Scientist collecting stream data

(Public domain.)


WaterSMART: Apalachicola/Chattahoochee/ Flint River (ACF) Basin

The DOI WaterSMART (Sustain and Manage America’s Resources for Tomorrow) initiative is developing data and tools to help water managers identify current and future water shortages, for humans and for freshwater ecosystems. Fishes, for example, can decline in diversity and abundance when streamflow becomes too low, for too long.  However, ecologists find that effects of declining streamflow can vary depending on stream characteristics and on traits of local species, confounding predictions of ecological outcomes.  Scientists thus need data on ecological responses to low streamflow in differing physical and biological contexts to better inform water management decisions.