A passive acoustic approach to impact assessment of large underwater explosions on marine fauna — planning, analyses, and lessons learned

In the summer of 2021, the US Navy conducted Full Ship Shock Trials (FSSTs) involving three large underwater explosions off the coast of Florida, USA. We were involved in collecting underwater acoustic recordings for the Naval Undersea Warfare center to validate their underwater acoustic propagations models with. Opportunistically, we also collected additional underwater acoustic recordings to facilitate assessing potential acoustic responses of marine fauna to the explosions. Our analyses yielded findings that were mostly inconclusive, except for one case involving absence of acoustic behavior response from fishes on the continental shelf. Here, we outline the planning and data collection process, describe our analyses and findings, and highlight limitations that led to the inconclusive outcomes. Finally, we offer suggestions for improving the success of behavior response studies during future FSSTs or during other large underwater explosions.