Tolerance and Growth of Adult Schizothorax prenanti Exposed and Re-Exposed to Supersaturated Gas Downstream of a Dam

Total dissolved gas (TDG) is suggested to be one possible explanation for the extensive mortality of endemic fish suffered from bubble disease (GBD). We investigated effects water depth on adult Schitzothorax prenanti susceptibility GBD in TDG supersaturated 11.5 km downstream Dagangshan dam a two-year (2016–2017) live cage study. The probability survival significantly increased at greater depth. 1–2 m was reduced 50% that 0–1 and rate 2–3 25% m. Fish survived in-situ exposure 2016 were relocated equilibrated observed 274 d investigate sublethal GBD. surviving showed substantial reduction growth compared control group. During flood discharge period 2017, re-exposed after recovery (274 d) water. decreased 35% newly introduced fish. Our results contribute protection aquatic organisms improvement eco-friendly hydroelectric operations Yangtze River.