A RIVER IN THE LAB

Ok, not a real river. It’s a flume, a high-tech water channel that simulates river conditions in a controlled lab environment. The flume allows researchers to test river conditions like flow velocity and sediment types, which are difficult and sometimes dangerous to study in the wild.

“Out in the real world, we don’t have control over what the river’s going to do,” said Micah Wyssmann, Ph.D., assistant professor in the Division of Natural and Built Environment. “But in the lab, we can use the flume to isolate and test different variables in a way that’s just not possible at a real river.”

By manipulating these variables, Wyssmann and his team hope to understand how freshwater mussels from the Black River, a 300-mile-long tributary of the White River in southeastern Missouri and northeastern Arkansas, respond to different conditions and use that knowledge to guide smarter river management across Missouri and beyond.

Tracking Mussel Behavior

Freshwater mussels from the Black River take center stage in the flume, where sensors quietly track and monitor two key behaviors: burrowing and filter feeding.

“We’re using several quantitative methods to track their behavior,” Wyssmann said. “Burrowing, which is when they bury themselves partially or fully in river sediments to protect themselves, tells us how they interact with the sediment conditions they are in. Filter feeding, which is when they remove food particles like algae and bacteria from water through siphoning, gives us insight into their overall activity levels.”

The mussels move through the flume like tiny engineers, shifting sediment and filtering water with each siphon. Within hours, water green with algae can turn clear, showing how mussels naturally filter and clean rivers.

By manipulating flow velocity and sediment type in the flume, Wyssmann can see how the mussels respond to these variables.

“For sediment types, some mussels prefer gravel while others prefer sand,” Wyssmann said. “But beyond simply observing what type of sediment they prefer in rivers, it’s difficult to determine what specific conditions are best for each species.”

By analyzing their behavioral responses under these varying conditions, Wyssmann aims to identify preferred habitats and develop quantitative flow guidelines that outline ranges for river depth, velocity and duration that support mussel health.

“We’re trying to answer two big questions,” Wyssmann said. “What are the preferred habitat conditions for different mussel species? And how can we manage river flows to support those habitats?”

Engineering Meets Ecology

This research is the intersection of hydraulic engineering and ecosystem, also known as eco-hydraulics.

“Hydraulics is the term we use to describe water flow,” Wyssmann explained. “Eco-hydraulics explores how that flow interacts with ecosystems including fish, mussels and vegetation. It’s a field where many questions remain.”

The UMKC flume, naturally decked in blue and gold, comes equipped with high-powered lasers and high-resolution cameras that measure flow velocities down to the micron. For context, that’s smaller than a single strand of hair.

“This level of detail lets us document flow behavior and understand how hydraulic infrastructure affects river dynamics,” Wyssmann said.

Traditionally, engineering and ecology have been studied separately but Wyssmann sees great value in bringing them together.

“This intersection represents a research gap,” he said. “By combining technical engineering expertise with ecological questions, we can answer things that haven’t been possible before.”

The lab’s findings also help guide environmental flow strategies, or “e-flows,” which describe the quality, quantity and timing of water needed to keep rivers healthy. Observing mussels in the lab allows Wyssmann to figure out which flows keep them happy, which in turn keeps the whole river ecosystem healthy. These insights are often difficult to gather from field data alone.