A systematic review on the behavioural responses of wild marine mammals to noise: the disparity between science and policy

TitleA systematic review on the behavioural responses of wild marine mammals to noise: the disparity between science and policy
Publication TypeJournal Article
Year of Publication2016
AuthorsGomez, Catalina, Lawson Jack, Wright Andrew J., Buren Alejandro, Tollit Dominic, and Lesage Veronique
JournalCanadian Journal of Zoology
Volume94
Pagination801-819
ISBN Number0008-4301
EndNote Rec Number11316
Abstract

Noise can cause marine mammals to interrupt their feeding, alter their vocalizations, or leave important habitat, among other behavioural responses. The current North American paradigm for regulating activities that may result in behavioural responses identifies received sound levels (RL), at which individuals are predicted to display significant behavioural responses (often termed harassment). The recurrent conclusion about the need for considering context of exposure, in addition to RL, when assessing probability and severity of behavioural responses led us to conduct a systematic literature review (370 papers) and analysis (79 studies, 195 data cases). The review summarized the critical and complex role of context of exposure. The analysis emphasized that behavioural responses in cetaceans (measured via a linear severity scale) were best explained by the interaction between sound source (continuous, sonar or seismic/explosion) and functional hearing group (a proxy for hearing capabilities). Importantly, more severe behavioural responses were not consistently associated with higher RL, and vice versa. This indicates that monitoring and regulation of acoustic effects from activities on cetacean behaviour should not exclusively rely upon generic multi-species RL thresholds. We recommend replacing the behavioural response severity score with a response/no response dichotomous approach that can represent a measure of impact in terms of habitat loss and degradation.