Total dissolved gases induced tolerance and avoidance behaviors in pelagic fish in the Yangtze River, China

Qianfeng Ji; Kefeng Li; Yuanming Wang; Ruifeng Liang; Jingjie Feng; Quan Yuan; Peng Zhang; David Z Zhu

doi:10.1016/j.ecoenv.2021.112218

Total dissolved gases induced tolerance and avoidance behaviors in pelagic fish in the Yangtze River, China

Ecotoxicol Environ Saf. 2021 Apr 9:216:112218. doi: 10.1016/j.ecoenv.2021.112218. Online ahead of print.

Authors

Qianfeng Ji¹, Kefeng Li¹, Yuanming Wang², Ruifeng Liang¹, Jingjie Feng¹, Quan Yuan¹, Peng Zhang¹, David Z Zhu³

Affiliations

¹ State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China.
² State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China. Electronic address: wangyuanming1991@126.com.
³ Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.

PMID: 33845365
DOI: 10.1016/j.ecoenv.2021.112218

Abstract

Total dissolved gas (TDG) supersaturation caused by dam operations can cause fish gas bubble disease (GBD) and even fish kill. Few studies have examined the effects on pelagic species. Here, we examined the tolerance and avoidance characteristics of silver carp (Hypophthalmichthys molitrix), a pelagic fish widely distributed in the Yangtze River basin in China, under stress caused by TDG supersaturation. Silver carp had an average mortality rate of 7.5% ± 1.8%, 92.5% ± 1.8%, and 97.5% ± 1.8% under 130%, 140% and 150% TDG supersaturation for 72 h of exposure, respectively. The average median lethal time (LT₅₀) of silver carp was 18.1 h and 8.0 h under 140% and 150% TDG supersaturation, respectively. Bubbles and congestion appeared in the fins, gills and skin of silver carp. Silver carp can detect and avoid high TDG supersaturation. Significant avoidance behaviors were displayed by silver carp and the final avoidance rate was over 80% under 130% or above TDG conditions. The results of this study indicate that 130% TDG supersaturation triggered silver carp avoidance behaviors, and can be considered as the tolerance threshold.

Keywords: Avoidance behaviors; Gas bubble disease; Pelagic fish; Tolerance; Total dissolved gas; Yangtze River.