Vulnerability of larval and juvenile white sturgeon to barotrauma: can they handle the pressure?

• Published in: Conservation Physiology Vol. 1; no. 1; p. cot019
• Main Authors: Brown, Richard S., Cook, Katrina V., Pflugrath, Brett D., Rozeboom, Latricia L., Johnson, Rachelle C., McLellan, Jason G., Linley, Timothy J., Gao, Yong, Baumgartner, Lee J., Dowell, Frederick E., Miller, Erin A., White, Timothy A.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 11.07.2013
• Subjects: Barotrauma; Physiological aspects; White sturgeon; hydroturbine; white sturgeon; larvae; swim bladder; hydropower; Barotrauma
• ISSN: 2051-1434; 2051-1434
• DOI: 10.1093/conphys/cot019

Techniques were developed to determine when fish are vulnerable to barotrauma when rapidly decompressed during hydroturbine passage. Sturgeons were decompressed in early life-stages and X-ray radiographs were taken to determine when gas was present in the swim bladder. Barotrauma was observed on day 9 and greater than 75 days after hatching. Techniques were developed to determine which life stages of fish are vulnerable to barotrauma from expansion of internal gases during decompression. Eggs, larvae, and juvenile hatchery-reared white sturgeon (Acipenser transmontanus; up to 91 days post hatch; d.p.h.) were decompressed to assess vulnerability to barotrauma and identify initial swim bladder inflation. Barotrauma-related injury and mortality were first observed 9 d.p.h., on the same day as initial exogenous feeding. However, barotrauma-related injury did not occur again until swim bladder inflation 75 d.p.h. (visible at necropsy and on radiographs). Swim bladder inflation was not consistent among individuals, with only 44% being inflated 91 d.p.h. Additionally, swim bladder inflation did not appear to be size dependent among fish ranging in total length from 61 to 153 mm at 91 d.p.h. The use of a combination of decompression tests and radiography was validated as a method to determine initial swim bladder inflation and vulnerability to barotrauma. Extending these techniques to other species and life-history stages would help to determine the susceptibility of fish to hydro turbine passage and aid in fish conservation.