SA Navy responsible for beached Cape Town whales?

The South African Navy has rejected claims that its activities caused the beaching of 55 false Killer Whales at the weekend.

Commander Prince Tshabalala, spokesman at Navy Headquarters, said of the claims:
To be honest, we don’t even use sonars in our ships. There was a gunnery exercise, but the last exercise (was) three weeks ago, so any link would be highly unlikely.

The carcasses of false killer whales, shot after a pod of 55 beached at Kommetjie, to be taken to Vissershok dump site where researchers will dissect them.

The probability that we would be responsible is negligible. No study has been done to show that gunnery exercises affected the whales. Until such a study is done, until a scientist comes to us … (if a study proved it) then we would take responsibility, but until then we cannot take responsibility.

Reports in South African media claimed the Navy’s live-fire exercise in Simon’s Town, which is on the far side of the Cape Peninsula, caused the whales to beach. Still others claimed it was naval sonar that confused the animals. Commander Tshabalala added:

Actually, this was not an exercise (with ships). It was three days of practice shooting at the Lower North Gun Battery where we train our students in Simon’s Town.

Tshabalala pointed out that most of the firing would not even have been in the direction of the sea.

They normally shot in the direction of the air, for two hours at a time. The impact of that is minimal.

Media here reported the whales beached themselves on Saturday morning, with local volunteers trying to move them.

The Times reported a spokesman for the National Sea Rescue Institute (NSRI), Craig Lambinon, saying: “ More than five animals died naturally on the beach and others had to be shot.”

The whales repeatedly beached themselves after they had been refloated. The Star newspaper quoted an unnamed volunteer:

We took one out five times, but it made a U-turn and went back to shore.

The decision to shoot the beached whales was taken jointly by Marine and Coastal Management, the Mammal Research Institute, Table Mountain National Park and the Society for the Prevention of Cruelty to Animals (SPCA), the newspaper said. Post mortems were being done on the dead whales today, seeking a reason why an entire pod, or group, of whales would beach itself.

Deadly Impacts of Sonar

Studies have shown that human-produced ocean noise emanating from such sources as naval sonar equipment, ship traffic, and underwater drilling, among others, causes hemorrhage or other trauma to the marine mammals' auditory system, sometimes leading to permanent hearing loss, and, indirectly, death.

Mid-frequency sonar can emit continuous sound well above 235 decibels, an intensity roughly comparable to a Saturn V rocket at blastoff. Marine mammals have extraordinarily sensitive hearing, and there is no scientific dispute that intense sonar blasts can disturb, injure, and even kill them.

Whales exposed to high-intensity mid-frequency sonar have suffered physical trauma, including bleeding around the inner ears, brains, lungs and from the eyes, with severe lesions in their organ tissue.

At lower intensities, naval sonar has been shown to cause displacement from their natural habitat, and to interfere with the ability of marine mammals to navigate, avoid predators, find food, care for their young, and, ultimately, to survive.

In the past two decades, hundreds of stranded sea animals have been discovered on beaches worldwide. All of these instances have been correlated with sonar machinery.