Deadly Sonar

This short article I found at ocean.com titled Deadly Sonar The Brain Crushing Sound was about the use of sonar affecting and even killing marine mammals. High power military sonars send off acoustic signals which can cause biological damage to the mammals such as brain injuries, behavioral changes and sometimes death.

"On March 15, 2000 the Navy conducted an intense active sonar exercise in the Bahamas, emitting high-energy, mid frequency sonar at between 215 and 235dB, creating powerful sound and pressure waves through the water. Sound at 235dB produces a pressure wave 300,000 times more intense than an 180dB sound, and 100 billion times more intense than a 120dB sound, which is like a loud motorboat engine."
In this case, on March 15th 2000, 14 animals ( whales and dolphins) were stranded on the shores of the Northeast and Northwest Providence Channel, and 7 of them had died, they believe the sonar used that day was the cause.

( www.ocean.com )