Estimating reef fish discard mortality using surface and bottom tagging: Effects of hook injury and barotrauma. Rudershausen, P., J., Buckel, J., A., & Hightower, J., E. Canadian Journal of Fisheries and Aquatic Sciences, 71(4):514-520, 2014.
Estimating reef fish discard mortality using surface and bottom tagging: Effects of hook injury and barotrauma [pdf]Paper  abstract   bibtex   
We estimated survival rates of discarded black sea bass (Centropristis striata) in various release conditions usingtag.recapture data. Fish were captured with traps and hook and line from waters 29.34mdeep off coastal North Carolina, USA,marked with internal anchor tags, and observed for release condition. Fish tagged on the bottom using SCUBA served as a controlgroup. Relative return rates for trap-caught fish released at the surface versus bottom provided an estimated survival rate of 0.87(95% credible interval 0.67.1.18) for surface-released fish. Adjusted for results from the underwater tagging experiment, fish withevidence of external barotrauma had a median survival rate of 0.91 (0.69.1.26) compared with 0.36 (0.17.0.67) for fish with hooktrauma and 0.16 (0.08.0.30) for floating or presumably dead fish. Applying these condition-specific estimates of survival tonon-tagging fishery data, we estimated a discard survival rate of 0.81 (0.62.1.11) for 11 hook and line data sets from waters 20.35mdeep and 0.86 (0.67.1.17) for 10 trap data sets from waters 11.29 m deep. The tag-return approach using a control group withno fishery-associated trauma represents a method to accurately estimate absolute discard survival of physoclistous reef species.

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