Predicting risks from acoustic deterrents

Increasingly, the use of man-made sound (‘acoustic deterrents’) is sought to lessen humanwildlife<br/>conflicts by discouraging predation, displacing species away from harmful stimuli,<br/>or reducing damage to property and resources. In the marine environment, Acoustic Deterrent<br/>Devices (ADDs) are used by the aquaculture industry globally. ADDs produce loud, mid- to<br/>high-frequency noise to deter pinnipeds from predating on caged finfish. However, the<br/>widespread and long-term use of these devices in coastal environments could pose<br/>considerable risks for target (pinnipeds) and non-target (e.g., cetaceans) species which also<br/>inhabit areas adjacent to aquaculture. This thesis contributes new knowledge towards our<br/>understanding of the risks posed to marine mammals from exposure to ADD noise. An<br/>energy-flux acoustic propagation model was used to demonstrate that ADD noise is a<br/>significant contributor to coastal soundscapes on the west coast of Scotland, able to propagate<br/>far beyond the source and aquaculture cages. Modelling showed that both harbour porpoises<br/>and harbour seals would be repeatedly exposed to ADD noise, with predicted noise levels in<br/>some instances exceeding thresholds which could result in either a temporary or permanent<br/>hearing impairment. A habitat modelling approach indicated that ADD noise was also a<br/>significant driver of harbour porpoise distributions on this coastline. Highlighting that<br/>animals could be displaced from, seek out or remain within disturbed habitats. These results<br/>show that ADD noise can become a considerable source of underwater noise pollution within<br/>coastal environments, and poses significant risks (e.g., auditory impairment and<br/>displacement) for marine mammals at both individual and population-level scales.

Name dc:type.qualificationname

Doctor of Philosophy (awarded by UHI)

Level dc:type.qualificationlevel

Doctoral Thesis

Grantor dc:publisher.institution

University of the Highlands and Islands

Year dc:date.issued

2022

Author dc:creator

• Findlay, Charlotte

Advisors dc:contributor.advisor

• Wilson, Ben
• Risch, Denise

Language dc:language

eng

Identifier

oai:pure.atira.dk:studenttheses/567ed873-1f10-470e-a393-364b4d4d05e8

OAI identifier oai:identifier

oai:pure.atira.dk:studenttheses/567ed873-1f10-470e-a393-364b4d4d05e8