Vol. 57, 2018

(update: 2018.12.01; 12.17) 

The Effects of Continuous Acoustic Stress on ROS Levels and Antioxidant-related Gene Expression in the Black Porgy (Acanthopagrus schlegelii)

Hao-Yi Chang¹, Tzu-Hao Lin², Kazuhiko Anraku3, and Yi Ta Shao^1,4,*

¹Institute of Marine Biology, National Taiwan Ocean University, Keelung 202, Taiwan. E-mail: luck77995@gmail.com
²Department of Marine Biodiversity Research, Japan Agency for Marine-Earth Science and Technology, Kanagawa, 237-0061, Japan. E-mail: schonkopf@gmail.com
³Fisheries Department, Kagoshima University, Kaogoshima 890-0056, Japan. E-mail: anraku@fish.kagoshima-u.ac.jp
⁴Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 202, Taiwan

(Received 13 September 2018; Accepted 11 November 2018; Communicated by Pung-Pung Hwang)

Hao-Yi Chang, Tzu-Hao Lin, Kazuhiko Anraku, and Yi Ta Shao (2018) Short-term exposure to strong underwater noise is known to seriously impact fish. However, the chronic physiological effects of continuous exposure to weak noise, i.e. the operation noise from offshore wind farms (OWF), remain unclear. Since more and more OWF will be built in the near future, their operation noise is an emerging ecological issue. To investigate the long-term physiological effects of such underwater noise on fish, black porgies (Acanthopagrus schlegelii) were exposed to two types of simulated wind farm noise—quiet (QC: 109 dB re 1 μPa / 125.4 Hz; approx. 100 m away from the wind turbine) and noisy (NC: 138 dB re 1 μPa / 125.4 Hz; near the turbine)—for up to 2 weeks. Measurement of auditory-evoked potentials showed that black porgies can hear sound stimuli under both NC and QC scenarios. Although no significant difference was found in plasma cortisol levels, the fish under NC conditions exhibited higher plasma reactive oxygen species (ROS) levels than the control group at week 2. Moreover, alterations were found in mRNA levels of hepatic antioxidant-related genes (sod1, cat and gpx), with cat downregulated and gpx upregulated after one week of QC exposure. Our results suggest that the black porgy may adapt to QC levels of noise by modulating the antioxidant system to keep ROS levels low. However, such antioxidant response was not observed under NC conditions; instead, ROS accumulated to measurably higher levels. This study suggests that continuous OWF operation noise represents a potential stressor to fish. Furthermore, this is the first study to demonstrate that chronic exposure to noise could induce ROS accumulation in fish plasma.

Key words: Black porgy, Underwater noise, Reactive oxygen species, Antioxidant, Auditory evoked potential.

*Correspondence: Tel: +886-2-24622192 ext. 5327. Fax: +886-2-24629381. E-mail: itshao@mail.ntou.edu.tw

Supplementary Materials: Fig. S1 | Fig. S2 | Fig. S3