Anthropogenic noise is an established global pollutant, with mounting evidence that noise from human activities (e.g., transportation, construction, and resource extraction) can impact behaviour, physiology, and fitness in a broad range of taxa. Establishing noise as a stressor and pollutant has been an evolving process where research methods, techniques, and investigative scope continue to change and develop. However, there still exists many unanswered questions, such as impacts on local community structures and populations. Therefore, evolution within the field of anthropogenic noise research (e.g., new study systems and technology) can be used to help researchers explore logistically challenging questions. This thesis presents an integrated body of research on the impacts of noise to aquatic life at varying levels of biological organisation: starting with impacts on individuals, moving to effects on interspecific interactions and local communities, and ending with population-level assessment. Importantly, I have strived to incorporate aspects of noise mitigation in each section. In Chapter One, I introduce anthropogenic noise, the importance of underwater sound to taxa, and outline the evolution of noise-related research. Then, I present data showing that real motorboat noise negatively affects egg-tending and nest defence in male damselfish on the Great Barrier Reef, but also provide evidence for the potential benefits of simple, yet effective, noise-mitigation strategy (Chapter Two). Following this, I provide evidence that playback of SCUBA noise hinders interspecific behaviour and alters community structure near ecologically important cleaning stations on the Mesoamerican Barrier Reef (Chapter Three). Moreover, by establishing acoustic disturbance as a mechanism for the negative impacts of diver presence, I am also identifying a potential avenue for mitigation. In Chapter Four, I develop and present an energetic and spatially explicit individual-based model that uses realistic projections of noise-pollution levels in the Northeast Atlantic to explore the impacts of noise to an important fish stock. Furthermore, I use the model to further unpick the population-level impacts of noise to the fish stock and use findings to develop and test a targeted noise-mitigation strategy to improve population-level outputs (Chapter Five). Finally, I discuss the implications of these findings, present important areas for further research, and critically discuss the management of noise in our oceans (Chapter Six).