This video is called Navy Sonar & Whales.
April 8, 2009
Military sonar blamed for mass dolphin strandings
Tests on a captive dolphin have demonstrated that hearing can be lost for up to 40 minutes on exposure to sonar. Hearing is the most important sense for dolphins and other cetaeceans, and losing it is likely to cause them to become disorientated and alarmed.
The finding by the Hawaii Institute of Marine Biology may explain several strandings of dolphins and whales in the past decade. Most strandings are still thought to be natural events, but the tests strengthen fears that exercises by naval vessels equipped with sonar are responsible for at least some of them. …
Dr Mooney said that this could explain three of the best-known strandings that have been linked to military sonar – in the Bahamas, the Canaries and Hawaii – because all three regions had a mountainous underwater topography.
In the Bahamas in March 2000, 16 Cuvier’s beaked whales and Blainville’s beaked whales and a spotted dolphin beached during a US navy exercise in which sonar was used intensively for 16 hours. …
Observations by researchers while carrying out the tests, which are reported in the journal Biology Letters, showed that even though the dolphin involved was well accustomed to man-made noises and disturbances, it suffered subtle behavioural changes, which could cause further confusion.
See also here.
The whale, a male specimen of the Blainville’s Beaked Whale (Mesoplodon densirostris), was seen circling the area for two days, then ended up dead at the seashore on Wednesday morning, witnesses said: here.