The US Navy is testing a low frequency active sonar system that has already been shown to have harmed whales. Tests in Hawai'i directed specifically at humpback whales resulted in the animals leaving the test area, while a swimmer in the water during a broadcast emerged with symptoms a doctor described as similar to a trauma patient. Furthermore, another sonar test operated by the US Navy this year off Abaco Island, Bahamas is implicated in the mass stranding of five species of whales and dolphins the same day. At least seventeen animals were stranded, and nine died. Normally, one or two strandings at most are recorded throughout the Bahamas per year.
