Abstract
The potential for offshore wind energy as part of the energy transition is growing rapidly. The construction phases of offshore wind farms generate harmful underwater noise, but its effects on the marine environment have not been fully understood.
The aim of this thesis was to gather current knowledge through a literature review on the noise levels during the construction phases of offshore wind parks and the effects of underwater noise on the marine environment. Based on the literature review, an assessment was conducted on the construction phase impacts on the marine environment of the Eolus Offshore Finland Oy’s Navakka Offshore AB wind park project.
Underwater noise can affect marine animals by masking important environmental sounds and communication and by causing hearing damage and behavioral changes, as well as physical injuries. The nature and levels of underwater noise vary depending on the construction phase. Pile driving and explosions generate impulsive noise, while increased vessel traffic raises continuous low-frequency noise throughout the construction process. At its most severe, underwater noise can lead to direct or indirect mortality of marine animals. However, mitigation measures can reduce construction phase noise levels and minimize its impact on the marine environment.