Grabowski, T. B., and C. A. Jennings. 2009. Post-release movements and habitat use of stocked robust redhorse in the Ocmulgee River, Georgia. Aquatic Conservation: Marine and Freshwater Ecosystems 19:170-177.
Abstract
Robust redhorse Moxostoma robustum is an imperiled, potadromous fish in the southeastern United States. Initial recovery efforts have focused on supplementing existing populations and establishing refugial populations through extensive stocking programs. However, assessment of the success of these programs has not yet been conducted, and there are few reports evaluating the effectiveness of such programs with other potadromous species.
2. Radio telemetry was employed to assess the effectiveness of a stocking program aimed at addressing whether stocked individuals would remain in an area free of introduced predators and ascertaining the ability of stocked fish to integrate into a resident population.
3. Hatchery-reared robust redhorse were captured from refugial populations established in other river systems and were transferred to the Ocmulgee River, Georgia where a population hatchery-reared individuals and an unknown number of wild fish resides.
4. These transferred robust redhorse exhibited an exploratory phase for the first three months before adopting behavior patterns, including spawning migrations that were consistent with those reported for wild fish in other systems. However, some individuals seemed unable to locate suitable spawning habitat.
5. Approximately half of the radio-tagged fish remained within the area free of introduced predators.
6. At least some radio-tagged robust redhorse fully integrated into the resident population as evidenced by their presence in spawning aggregations with resident individuals.
7. The effectiveness of a stocking program is dependent upon the ability of stocked individuals to integrate into an existing population /or replicate the behavior and functionality of a resident population. Evaluations of stocking programs should incorporate assessments of behavior in addition to surveys to estimate abundance and survivorship and genetic assessments of augmentation of effective population sizes.