Date of Award


Publication Type

Master Thesis

Degree Name



Biological Sciences


Anthropogenic noise, Behaviour, Freshwater fish, Morphology, Physiology


Higgs, Dennis




There is increasing concern about the effect of underwater noise on fish behavior due to the increasing elevations of anthropogenic noise levels — primarily caused by the expansion of urban developments, transportation networks and freshwater resource extraction methods. Despite this increasing study, there is conflicting evidence on the impact of underwater noise to fish behaviour, morphology and physiology and its possible role as an environmental stressor. I performed experiments on two local Great Lakes fish, the black bullhead (Ameiurus melas); a species with known hearing specializations, and the yellow perch (Perca flavescens); a species with basic sound detection. Choosing these species allowed us to test and compare the morphological, physiological and behavioural response of these fish to local noise sources. Even at relatively low sound levels we saw clear behavioural effects of enhanced noise levels despite no obvious morphological or physiological stress. At higher noise levels we observed apparent indications of both behavioural and morphological impacts of noise on bullhead. Here we also determined that after both acute and chronic exposure of noise, bullhead were less active and sheltered more, and also exhibited hair cell damage in the saccule region of the auditory organ. These results suggest that there are sublethal effects of anthropogenic noise on fish behaviour and physiology which may have direct implications on species fitness. Our current understanding of noise effects on freshwater fish is lacking and it is imperative to study a diversity of species to fully understand the impacts of noise on fish both for environmental and aquaculture concerns.