Characterization of Underwater Sounds Produced by Bucket Dredging Operations

This technical note presents a characterization of underwater sounds produced by bucket dredging operations in Cook Inlet, Alaska. Both continuous sounds, such those produced by propellers, pumps, and generators, and repetitive sounds produced by particular dredging events (e.g., dredge bucket striking the channel bottom, jaws of bucket clamping shut) are potential sources of underwater noise. This note examines the intensity, periodicity, and attenuation of emitted sounds from bucket dredging operations and how they are influenced by factors including substrate type, hydrodynamic conditions, equipment maintenance, and skill of the dredge plant operator.