Field Electronarcotization, Anesthesia and Sonic Transmitter Implantation of Free-Ranging Robust Redhorse (Moxostoma robustum) in the Broad River System of Georgia
Johanna Mejia-Fava1, DVM; Stephen J. Divers1, BVetMed, DZooMed, DACZM, DECZM (Herpetology), FRCVS; Byron J. Freeman2,3, PhD; Carrie A. Straight3, MS; Jörg Mayer1, Dr. med.vet, MSc, DABVP (ECM), DECZM (Small Mammal)
1Department of Small Animal Medicine and Surgery (Zoological Medicine), College of Veterinary Medicine, The University of Georgia, Athens, GA, USA; 2Georgia Museum of Natural History, The University of Georgia, Athens, GA, USA; 3Odum School of Ecology, The University of Georgia, Athens, GA, USA
The robust redhorse (Moxostoma robustum) is an imperiled catostomid species which was rediscovered in 1980 and is only found in three Atlantic slope drainages in Georgia, South Carolina, and North Carolina. Many studies have shown that these fish migrate upstream to spawn and river dams can block migratory routes and alter water flow leading to loss of spawning habitats.1 Between 1995 and 1998, 39,000 robust redhorse juveniles were reintroduced into the Broad River system, Georgia, which is currently a population above the fall line, the remaining wild population occurs downsteam.2 The purpose of this study was to assess the movement and survival of free ranging fish following electronarcosis, chemical anesthesia and surgical transmitter implantation of sonic transmitters and microchips. Twenty robust redhorse (15 males and 5 females) were anesthetized using buffered MS-222 at 150 ppm and surgically implanted with transmitters over a 1-yr period. Each transmitter was 3.5 cm long and weighed 11 g. Pre-operative medications included meloxicam (0.2 mg/kg IM) and ceftazidime (22 mg/kg IM). The fish ranged from 439–555 mm standard length and from 1,890–3,434 grams. The first 6 fish were tagged 25 mo ago and the second group (14 fish) were implanted 13 mo ago. Underwater receivers have recorded 90,000+ sonic detects within the reservoir and river. One signal has been stationary since 2 weeks post surgery and one transmitter was not detected again after 2 mo post surgery. This field anesthesia and surgical implantation procedure appears safe and of value in tracking the movements of fish for needed data on population status, distribution, spawning, and habitat use.
1. Bigford, T. 2004. American Fisheries Society draft study report and policy statement on dam removal. Fisheries. 29:34–35.
2. Freeman, B.J., C.A. Straight, J.R. Knight, and C.M. Storey. 2002. Evaluation of robust redhorse (Moxostoma robustum) introduction into the Broad River, GA spanning years 1995–2001. Section VI report submitted to GDNR, 68.