Studying the behaviour of fishes in the sea at Loch Torridon, Scotland

Abstract

Abstract In the early 1960s, the Marine Laboratory Aberdeen began to examine the behaviour of fish in relation to mobile fishing gears. We were asked to investigate the role of sound in fish behaviour. We decided that our experimental work had to be done in the sea, as under “free-field” conditions the acoustic stimuli could be accurately presented and monitored. We located a suitable site at Loch Torridon and set up a field station there. We carried out unique experiments on the hearing of fishes, their behavioural responses to different sound stimuli, and the sounds made by the fishes themselves. Work was also carried out on the reflection of sounds by fishes, the noise made by fishing vessels and other sources, and the movements and foraging activity rhythms of Atlantic cod. The cod generally showed limited movements within defined home ranges. A large number of scientific papers were written, many of them in collaboration with scientists from other institutes, and other countries. This paper considers the lessons learned from our work, and especially the advantages of observing fish behaviour and carrying out experiments on fishes in the sea. We learned that the sound in the sea was very important to fishes, both the natural sounds, some of which they produce themselves, and sounds made by humans, which could have adverse effects upon them. We hope that this review will encourage a new generation of scientists to carry out field work, similar to ours, in other areas. Since our work, there has been a large increase in anthropogenic noise, particularly from offshore energy sources, but very little work has been done to help regulate and mitigate their effects upon fishes.