ABINGDON, Va. — Students at Virginia Highlands Community College are learning that fish bones can be good storytellers.
Nearly 40 students — not all of them biology majors — dissected fish recently in search of a special type of ear bone called an otolith, which can reveal the age of fish.
The purpose of the research project is to learn more about the population growth of the mountain redbelly dace, a fish that has been discovered in the streams at Hungry Mother State Park that is not native to the area. Its presence there has worried some conservationists, who hope to preserve native fish populations by keeping the mountain redbelly dace confined to its natural habitats.
The project is an ongoing collaboration with the Virginia Department of Game and Inland Fisheries, the Virginia Department of Conservation and Recreation and Virginia Highlands Community College.
According to Dr. Kevin Hamed, a biology instructor at the community college who is leading the study, efforts have been made in the past two years to collect and remove mountain redbelly dace from an unnamed tributary that feeds into Hungry Mother Reservoir. While mountain redbelly dace are abundant in other river systems in Virginia, North Carolina and West Virginia, they have occasionally made their way into other ecosystems, likely with the help of fishermen who use them as live bait.
Hamed explained that the mountain redbelly dace pose a problem to their sister species, the Tennessee dace, also located in a stream at Hungry Mother State Park. Tennessee dace are rare in Virginia and are listed as state-endangered, so preserving any natural occurrence of the Tennessee dace is important to Virginia conservationists.
“The Tennessee dace are … of a high conservation concern, so any possible threat has to be met with adaptive management plans,” said Hopkins. That means removing any mountain redbelly dace found in Hungry Mother and transporting them to Hamed’s students, who dissect them to learn how rapidly they may be reproducing.
There is concern that the mountain redbelly dace could out-compete the Tennessee dace — or hybridize with them — threatening the population. Hamed is also concerned that the invasion of the redbelly dace will prevent ideal conditions for the Tennessee dace to spawn and reproduce.
Rings in their ears
Nathan Ferguson, a freshman at the college, has helped Hamed with the research project throughout the year. He is using his work with the project to fulfill requirements for an honors component course, designed to sharpen skills and deepen knowledge in the biology field.
After earning his associate in science degree from Virginia Highlands Community College, Ferguson plans to transfer to Virginia Tech to receive a dual major in wildlife conservation and environmental studies.
During the project, Ferguson and the other students take the removed mountain redbelly dace and dissect them, recording each fish’s sex and the number and weight of any eggs. The last step is to remove the ear bone of the invasive dace to help learn about the aging process.
“The ear bones, or otoliths, act as tree rings do,” said Ferguson. “Throughout the spring and summer, the fish eat a fair amount but slow down throughout the fall and winter. This causes the fish to grow during the spring and summer. Once the spring and summer ends, then the otolith has a dark band entered in the bone, which looks like a ring. This continues throughout the life of a fish.
“Through this project, we are able to control the number of mountain redbelly dace within Hungry Mother, and one day we hope that we can erase them from that specific area,” said Ferguson.
Mountain redbelly dace are mostly found in the New River System but hardly anywhere in the Tennessee River System, where Tennessee dace thrive.
“The research will indicate if our efforts are having an impact with the population of the invasive dace. Maybe the population is becoming older, which may mean there is less reproduction going on,” said Hamed.
Conserve, connect, protect
Chanz Hopkins, a fisheries technician for the Virginia Department of Game and Inland Fisheries, said his role was to instruct the students on removing, prepping and aging the otoliths so they can collect the data.
“This is a similar exercise that is taught at Virginia Tech in the fisheries techniques and ichthyology classes,” he said.
“Tennessee dace have not yet been observed in the same tributary as the mountain redbelly dace, but they exist in Hungry Mother Creek just above the reservoir, so we want to keep the mountain redbelly dace from spreading in the system, where they could compete and possibly overtake the native Tennessee Dace,” said Hopkins.
“We work hard to conserve and manage all of the state’s wildlife resources, and a project like this one is also a great outreach opportunity to connect and help educate students who will have a future role in our field of study. This study correlates with our mission statement: Conserve, Connect and Protect,” he added.
Hamed said research projects like this one help to fuel students’ eagerness to learn.
“Many of the students who are helping with the project are considering careers in fisheries biology,” said the instructor. “This project will give them the tools to make them better prepared.
“The project is offered to all students across different majors who want to learn more about preserving our natural resources.”