The research, published in Nature Communications, took place at Lizard Island and examined how the rumble of outboard motors affected young ambon damselfish, which are eaten by dusky dottybacks.
As well as doubling the number of damselfish devoured, the team discovered that motor boat noise increased stress levels in the fish by 33%. The scientists also found the noise made damselfish six times less likely to “startle” and dart away when a predator made its move. Even when they did startle, they were 22% slower. The study was the first to use real motor boats to provide the noise, rather than the recordings usually used in research.