Abstract
Underwater sound levels during offshore wind foundation installation may have significant behavioral and physiological impacts on marine mammals. The rapid growth of offshore wind development has led to the need for further acceleration of construction schedules by means of simultaneous installation of multiple foundations. While offshore wind development projects in the USA are proposing the concurrent pile-driving approach as part of the overall construction schedule, the resultant underwater acoustic impacts on marine mammals have not yet been thoroughly analyzed. In this chapter, the effects on the underwater sound field due to the concurrent installation of a monopile with a jacketed pin pile using an impact hammer at various separation distances are assessed. In addition, acoustic ranges to the relevant regulatory thresholds for auditory injury (AUD INJ) and behavioral disturbance of marine mammals are presented and compared to ranges from traditional single pile installation.