In rivers, mussels are often found in aggregates known as mussel beds. Mussel beds are commonly composed of multiple species and multiple generations, are able to persist at the same location in a river for decades or more, and are patchily distributed throughout a river network. The mechanisms driving this persistence across patchy distributions remain unknown, but the stability of the sediment within mussel beds is thought to be critical to their survival. However, rivers frequently experience high-discharge events that move large amounts of riverbed sediment.  The need to understand exactly what riverbed instability means to mussel species is essential to reconciling these apparently contradictory views of mussel habitat.

 We employ a multidisciplinary approach to characterize and quantify mussel bed stability and physical habitat conditions. Site bathymetry is mapped using RTK-GPS, a single-beam sonar, lidar, and sidescan sonar, and river hydraulics are characterized with an acoustic doppler current profiler. The movement of rocks and mussels in and around mussel beds is monitored using radio frequency identification (RFID) and accelerometer technology to track live mussels, sediment, and surrogate mussels. This information is used to develop high-resolution habitat maps and hydraulic models, which provide quantitative information on what constitutes suitable mussel habitat.

As benthic organisms, mussels live fully or partially buried in river sediments and are often exposed to complex, near-bed hydraulic flows. These complex flows are ecologically important and influence key ecologically relevant transport processes. However, little is known about the interaction of mussels and this near-bed flow. 

Our lab investigates how partially exposed mussels interact with, and influence near-bed hydrodynamics. We conduct field studies and laboratory experiments to quantify how mussels increase the bed roughness, modify near-bed flows, and influence transport processes. 

Freshwater mussels are in sharp decline worldwide, which has led to loss of species and diversity, as well as loss of the important ecosystem services mussels provide. Re-establishing native mussel assemblages is critical to restoring ecosystems and the communities they inhabit whole. 

We are partnering with the US Geological Survey, US Fish and Wildlife Service, Michigan State University, and several state and county agencies to develop a toolbox to guide mussel restoration efforts. The toolbox features a holistic approach to identify suitable habitat for mussel restoration, enhance propagation efforts to support reintroduction, assess restoration success, and quantify the ecosystem response provided by mussel restoration. 

Pallid sturgeon (Scaphirhynchus albus) is an endangered fish that is endemic to the Mississippi River basin. Historically, pallid sturgeon would migrate hundreds of kilometers upstream the Missouri River and its tributaries to spawn. Subsequently, newly hatched free embryos would drift and disperse over hundreds of kilometers downstream, settling into shallow water, foraging habitats. However, a combination of overharvest, pollution, and severe habitat loss and alteration has fragmented pallid sturgeon populations, drastically reduced population sizes, and substantially decreased the length of available river required for the migration and drift phase of their life cycle.

Our lab is studying the drift and dispersal dynamics of pallid sturgeon early life-stages. We conduct flume experiments to improve understanding of how habitat features, such as bedforms or aquatic vegetation, influence the downstream drift and development through the first year of life. We also conduct complimentary field studies to better understand the transport phenomena associated with areas of both high and low catch-rates.

Environmental DNA analysis is a novel tool for detecting species and is now being implemented in species monitoring and bio-surveillance alongside traditional survey methods in aquatic systems. Knowing where and when to sample for eDNA is critical for a robust sampling design. In lotic environments, eDNA is likely to be sampled and collected some distance downstream from the DNA source. Understanding the spatial and temporal distribution resulting from eDNA transport, along with relevant biological properties such as decay and sorption, is necessary to provide the most accurate information about the source of DNA. However, eDNA transport is complicated by numerous environmental factors, and many uncertainties exist associated with the downstream transport of eDNA in lotic environments.

Our lab studies the transport mechanisms of eDNA in order to better understand how DNA persists in both space and time within river environments. We primarily work with eDNA from freshwater mussels, as mussels provide an ideal and relatively non-mobile source of DNA. This research combines field experiments and computational fluid dynamic modeling to predict the fate and transport of eDNA.