Underwater Sound Levels Associated with Marine Pile Driving – Assessment of Impacts and Evaluation of Control Measures

摘要

The effects on fish and marine mammals of underwater sound pressure levels generated by piledriving in or near bodies of water has recently become an issue of major importance for thoseconstructing projects in the marine environment that involve impact pile driving. Mortalities and injuries tofish have occurred in association with pile driving for bridge projects in San Francisco Bay[JR1]. With thisrecent discovery, several bridge projects have been delayed in order to re-consult with resource agenciesand develop minimization measures to avoid or reduce adverse effects to listed species protected by theEndangered Species Act (ESA). On the Pacific Coast, there is frequently no available time window inwhich pile driving can be performed without adversely affecting ESA-listed species and Magnuson-Stevens Act (MSA) managed species. Additional information and clear acoustical thresholds for piledriving in aquatic environments are needed to protect these species and aid in the proper design ofimpact minimization methods. These acoustical thresholds are needed to facilitate project consultationwith both State and federal resource agencies. The use of these clearly defined thresholds andcompliance protocols would facilitate the timely and cost effective completion of pile-driving operations inaquatic environments.