W&L’s Robert Humston Receives Grant to Study the Trout Population in the Jackson River

By Brian Laubscher
October 29, 2024

Robert Humston, John Kyle Spencer Director for Environmental Studies and professor of biology at Washington and Lee University, has received a grant from the Virginia Department of Wildlife Resources (DWR) and Virginia Department of Environmental Quality (DEQ) to study recent declines in the trout population in the tailwaters of Virginia's Jackson River.

Humston requested and was approved for roughly $29,000 to analyze data supporting angler's claims that trout populations are declining in the Jackson River, which is considered one of Virginia's flagship wild trout fisheries. He and a team of student researchers are working in close collaboration with biologists from the DWR to assess the river's trout population across all stages of their life cycle.

"The Jackson River tailwater was regarded by many as one of the best trout fisheries in the Eastern U.S.," said Humston. "In recent years, there's been a persistent and unexplained decline in the number of trout in the river, which has negatively impacted the fishing experience. If we can determine what contributed to these population declines, we can hopefully rebuild and restore this unique and important resource."

Humston and a team of four student researchers began the study in May and will use a two-phased approach in producing their conclusions. They will use preexisting monitoring data to study and characterize the nature of the population decline and other biotic changes to the system, alongside changes in the physical conditions of the river such as temperature and streamflow. In addition, they are collecting new data to identify factors that could potentially regulate abundance in the system. With this combined approach, they hope to identify opportunities for improving conditions and restoring trout populations to previous levels.

Humston's team spent the summer conducting field studies to assess the trout spawning and juvenile habitat in the river, the impact on habitats from flood/pulse releases from the Gathright Dam upstream as well as the potential effects of environmental conditions such as flow, temperature and nutrient availability on trout abundance. At the same time, DWR biologists were combing the river for young-of-year trout and determining where they are most abundant. This fall, Humston is working with DWR biologists to monitor and map trout spawning activity over the 18-mile reach between the dam and the city of Covington, Virginia. They have also recruited assistance from local fishing guides.

"We are taking a comprehensive approach to assessing this problem, starting with the most important driver of population abundance: spawning and juvenile survival," Humston said. "There are so many factors that could be at play here, and more than one is likely contributing to these population declines. That's why we have employed this systematic and collaborative approach to this study."

Humston has been a member of the W&L faculty since 2008, conducting numerous research projects involving Virginia watersheds. He holds bachelor's degrees in biology and English from Bowdoin College and a doctorate in marine biology and fisheries from the University of Miami's Rosenstiel School of Marine, Atmospheric and Earth Science.

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