Auditory evoked potential in stranded melon-headed whales (Peponocephala electra): With severe hearing loss and possibly caused by anthropogenic noise pollution

• Published in: Ecotoxicology and Environmental Safety
• Main Authors: Zhi-Tao Wang, Alexander Ya Supin, Tomonari Akamatsu, Peng-Xiang Duan, Yi-Ning Yang, Ke-Xiong Wang, Ding Wang
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2021
• Subjects: Auditory evoked-potential; Audiogram; Melon headed whale; Hearing loss; Stranding; Environmental pollution; TD172-193.5; Environmental sciences; GE1-350; Killer Whale; Killer whale
• Online Access: https://doi.org/10.1016/j.ecoenv.2021.113047; https://doaj.org/article/b53e6785ac8144cc97eba42f9f146c75

Highly concentrated live mass stranding events of dolphins and whales happened in the eastern coast of China between June and October 2021. The current study adopted the non-invasive auditory evoked-potential technique to investigate the hearing threshold of a stranded melon headed whale (Peponocephala electra) at a frequency range of between 9.5 and 181 kHz. It was found that, at the frequency range of from 10 to 100 kHz, hearing thresholds for the animal were between 20 and 65 dB higher than those of its phylogenetically closest species (Pygmy killer whale). The severe hearing loss in the melon headed whale was probably caused by transient intense anthropogenic sonar or chronic shipping noise exposures. The hearing loss could have been the cause for the observed temporal and spatial clustered stranding events. Therefore, there is need for noise mitigation strategies to reduce noise exposure levels for marine mammals in the coastal areas of China.