In 1981, while living in Baltimore, I was thrilled to have the National Aquarium open. However, dolphins kept dying left and right. It was finally discovered that the filtration system was making a lot of noise and dolphins were dying from the stress it caused. Some were committing suicide.
If a filtration system can cause this type of tragedy, just think what 18 airguns firing sound waves at the ocean floor for miles will do to the marine mammals.
I truly question the value of seismic testing proposed by PG&E, which hopes to better predict earthquakes.