The behavioural effects of anthropogenic noise on Rainbow Trout in a holding facility

Abstract

There is a growing concern within the scientific community about the effects of anthropogenic noise on fish. Pile driving creates large amounts of noise, and especially in the creation of bridges it has the ability to affect fish. Additionally, fish are now being used in research studies within laboratories and can be exposed to a wide variety of noises. Chronic exposure to extreme noises can lead to an increase in stress, reduced growth, and ultimately mortality. The purpose of this thesis is to explore what behavioural effects sounds from pile driving and closing doors have on the behaviour of Rainbow Trout (Oncorhychus mykiss). To determine their effects, parameters measured were the amount of time spent hiding, in groups and in the upper portion of the tank, on a reference day, while the trout were exposed to recorded sounds, and during breaks with sounds that simulated pile driving and closing doors. The effects to the test sounds were limited to the amount of time spent in groups, which was higher during the reference day when no noise was playing, suggesting fish were dispersing as a result of the sounds. No differences in the amount of time spent hiding or in the upper portion of the tank were found as they were approximately the same during the reference and test days. Although effects were limited to group behaviours, the effects of our tests sounds may have had an impact cortisol levels, which was not tested.