Project Description

Audiograph: Haro Straight, USS Shoup sonar test event

Audiograph: C-53 Sonar from Haro Straight

Mid-Frequency military sonar has proven one of the most troubling acoustical assaults on marine life, particularly associated with catastrophic strandings of marine mammals. The most common victims have been odontocetes – toothed whales and dolphins, but Minke whales have also washed up on the shore after the use of these sonars.

“Mid-Frequency” is considered between 1 kHz and 10 kHz – within the human auditory band. When noises have been correlated to events they have been ranging sonars – extremely loud chirps and tones used for navigation and surveillance. But increasingly more complicated signals are being deployed that may have varying impacts on various animals.