Publication Date:
2022-05-25
Description:
Author Posting. © The Company of Biologists, 2018. This article is posted here by permission of The Company of Biologists for personal use, not for redistribution. The definitive version was published in Journal of Experimental Biology 221 (2018): jeb171959, doi:10.1242/jeb.171959.
Description:
Documenting hearing abilities is vital to understanding a species’ acoustic ecology and for predicting the impacts of increasing anthropogenic noise. Cetaceans use sound for essential biological functions such as foraging, navigation and communication; hearing is considered to be their primary sensory modality. Yet, we know little regarding the hearing of most, if not all, cetacean populations, which limits our understanding of their sensory ecology, population level variability and the potential impacts of increasing anthropogenic noise. We obtained audiograms (5.6–150 kHz) of 26 wild beluga whales to measure hearing thresholds during capture–release events in Bristol Bay, AK, USA, using auditory evoked potential methods. The goal was to establish the baseline population audiogram, incidences of hearing loss and general variability in wild beluga whales. In general, belugas showed sensitive hearing with low thresholds (〈80 dB) from 16 to 100 kHz, and most individuals (76%) responded to at least 120 kHz. Despite belugas often showing sensitive hearing, thresholds were usually above or approached the low ambient noise levels measured in the area, suggesting that a quiet environment may be associated with hearing sensitivity and that hearing thresholds in the most sensitive animals may have been masked. Although this is just one wild population, the success of the method suggests that it should be applied to other populations and species to better assess potential differences. Bristol Bay beluga audiograms showed substantial (30–70 dB) variation among individuals; this variation increased at higher frequencies. Differences among individual belugas reflect that testing multiple individuals of a population is necessary to best describe maximum sensitivity and population variance. The results of this study quadruple the number of individual beluga whales for which audiograms have been conducted and provide the first auditory data for a population of healthy wild odontocetes.
Description:
Project funding and field support were provided by multiple institutions, including Georgia Aquarium, the Marine Mammal Laboratory of the Alaska Fisheries Science Center (MML/AFSC), and the Woods Hole Oceanographic Institution (Arctic Research Initiative, Ocean Life Institute and Marine Mammal Center). Field work was also supported by National Marine Fisheries Service Alaska Regional Office (NMFS AKR), U.S. Fish and Wildlife Service, Bristol Bay Native Association and Bristol Bay Marine Mammal Council, Alaska SeaLife Center, Shedd Aquarium and Mystic Aquarium. Audiogram analyses were initially funded by the Office of Naval Research award number N000141210203.
Description:
2019-05-08
Keywords:
Noise
;
Marine mammal
;
Cetacean
;
Odontocete
;
Arctic
Repository Name:
Woods Hole Open Access Server
Type:
Article
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