Using non-lethal shocking techniques, biologists from the N.C. Wildlife Resources Commission and Progress Energy in late-April and early-May collected four females and four males in a 6-mile stretch of river immediately downstream of Blewett Falls in Anson and Richmond counties.
Of the eight captured, two were recaptures from previous years. Biologists fitted five fish with radio transmitters and began tracking the radio-tagged fish to monitor the fishes' movements and to help them understand more about these elusive fish and their preferred habitats.
"The most important thing that the radio-tagged fish can do is lead us to other robust redhorse, especially in the spring during the spawning season, said Ryan Heise, aquatic nongame coordinator for the Wildlife Commission.
"We hope to get a better idea of how many robust redhorse are in the Pee Dee River. The radio-tagged fish can also help us learn what areas of the Pee Dee River are important for these fish throughout the year."
Biologists will continue to monitor tagged robust redhorse every month through 2006.
To maximize their chances for success during this year's sampling, biologists concentrated their efforts in the Blewett Falls area and broadened the sampling window to ensure they were working under optimal water temperatures and conditions for robust redhorse spawning.
"Robust redhorse seek shallow gravel bars and shoals in the spring and the rest of the year we believe they spend their time in deep, snag-filled pools - habitats that are difficult to access," Heise said. "Despite our earlier poor success rates, we were optimistic this time around and brought five radio tags, hoping we would use at least a few. We never imagined we would use all five!"
Early monitoring shows that robust redhorse are capable of moving great distances. One fish had moved 12 miles downstream while two others swam 33 miles downstream into South Carolina.
"We initially caught the fish on what we think were spawning areas and these three headed downstream probably to where they reside most of the year," Heise said.
"Two fish haven't moved much, however it is so early in this research that it is tough to know what the fish are up to. We will learn more as we capture, tag and track more fish."
While biologists are learning much about the robust redhorse, they still have many questions about its habitat, life history and survival for the future.
A large, long-lived member of the redhorse sucker group, the robust redhorse can reach up to 30 inches in length and weigh up to 17 pounds.
Its thick, robust body with rose-colored fins and a fleshy lower lip give the fish its descriptive name.
Biologists believe the robust redhorse, first discovered in the Yadkin River in 1870, was once common in the river and may have been present as far upstream as Winston-Salem.
However, the species remained a mystery, unknown to biologists until two individuals were captured nearly 100 years later.
In 1980, one robust redhorse was captured in the Savannah River in Georgia. In 1985, another robust redhorse was captured in the Pee Dee River in North Carolina.
The identification of these redhorses was not clear until more specimens were collected in 1991 in Georgia.
These sightings, while sporadic, delighted biologists because they indicated that wild populations still existed in several rivers in Georgia and North Carolina.
However, the continued existence of these remnant populations is tenuous, for the usual suspects for their decline still exist: river impoundments, predation by introduced nonnative species, and significant deterioration of habitat due to sedimentation and water pollution.
It's not all doom and gloom for the rosy fish, however. Efforts are under way to help direct the recovery of the robust redhorse to - well - robust populations.
Leading this effort is the Robust Redhorse Conservation Committee (RRCC), which comprises 13 state and federal natural resource agencies, private and public industries including hydropower interests and conservation groups.
The RRCC, established in 1995, is responsible for developing and managing a recovery plan for the imperiled robust redhorse.
"Robust redhorse studies on the Pee Dee River have been a collaborative effort among many interested parties, including the Wildlife Commission, Progress Energy, U.S. Fish and Wildlife Service, the N.C. Museum of Natural Sciences, the S.C. Department of Natural Resources, South Carolina Aquarium and Duke Energy," Heise said.
"They have all contributed to the field work and are key to helping this species recover."
Research and management for the robust redhorse in North Carolina are part of the N.C. Wildlife Action Plan, which benefits the health of fish, wildlife and people by conserving wildlife and natural places.
This project was funded through the Nongame and Endangered Wildlife Fund, which is the primary source of state funds for the Commission's Faunal Diversity and Aquatic Nongame programs.
The Commission uses this fund, which supports non-game species research and management, to generate matching money for federal grants.
Learn more about the Nongame and Endangered Wildlife Fund or the N.C. Wildlife Action Plan.