The section augments the detailed analysis of noise effects in the Draft EIR with a discussion of the behavioral responses of different marine species to underwater sound from Project construction (pile driving) and operation. First, the hearing bandwidth and auditory thresholds of different marine species are presented. Next, a calculation of species-specific hearing threshold (dBht) sound levels for construction and operation sound is presented. Finally, the zone of behavioral response is provided for each species, and conclusions are drawn regarding the Project’s effect on marine mammals, sea turtles, and fish. Underwater construction sound from the Project is in the low frequency bands. Vessel underwater sound has its energy peak well below 1,000 Hz1, and pile driving sound for the Project is concentrated in the very low frequencies below 250 Hz.
The existing data on these two items are presented below for the following families of marine animals:
• Toothed Whales
• Baleen Whales
• Hair Seals
• Sea Turtles