Acoustic deterrent devices (ADDs) are used in attempts to mitigate pinniped depredation on aquaculture sitesthrough the emission of loud and pervasive noise. This study quantified spatio-temporal changes in underwaterADD noise detections along western Scotland over 11 years. Acoustic point data (‘listening events’) collectedduring cetacean line-transect surveys were used to map ADD presence between 2006 and 2016. A total of 19,601listening events occurred along the Scottish west coast, and ADD presence was recorded during 1371 listeningevents. Results indicated a steady increase in ADD detections from 2006 (0.05%) to 2016 (6.8%), with thehighest number of detections in 2013 (12.6%), as well as substantial geographic expansion. This study de-monstrates that ADDs are a significant and chronic source of underwater noise on the Scottish west coast withpotential adverse impacts on target (pinniped) and non-target (e.g. cetaceans) species, which requires furtherstudy and improved monitoring and regulatory strategies.