AbstractIn 1974 and 1975 a series of trials were made to investigate the effectiveness of sound as a deterrent to marauding seals at salmon netting stations. A feasibility trial was followed by experimental work on a captive juvenile Common seal. A wide variety of sounds including pure tones, Killer whale calls and recorded loud noises were transmitted and responses were recorded on videotape. While one sound appeared to elicit an alarm reaction, habituation was rapid. Field trials were carried out at netting stations at the mouth of the River Tweed which frequently suffer damage from Grey seals. Although the frequencies used spanned the entire hearing range of seals, no sound was consistently effective in scaring seals from the nets. It is concluded that the prospect of an acoustic deterrent is remote.