CANBERRA (Reuters) - Military exercises planned by Australia and the United States next month off the Australian coast could result in large-scale whale deaths or injuries, the International Whaling Commission said.

A humpback whale "breaches" the surface by propelling most of its body from the sea in Hervey Bay off the east coast of Australia August 7, 2006. Military exercises planned by Australia and the United States next month off the Australian coast could result in large-scale whale deaths or injuries, the International Whaling Commission said. REUTERS/Russell Boyce

Powerful warship sonars could also cause widespread whale beachings, the commission’s Scientific Committee said in a report released at this week’s IWC meeting in Alaska.

The report, released as Japan leads a push to overturn a global moratorium on whaling, urged both Australian and U.S. military chiefs to take action to prevent the exercises causing “injurious or lethal effects” among whales.

More than 120 military aircraft, tanks and 30 warships, including nuclear-powered aircraft carriers and submarines will take part in the Talisman Sabre exercise.

Held every two years, the exercise will involve about 7,500 Australian soldiers and 20,000 U.S. marines and sailors in Queensland state.

Both countries should have a “response team” readied in case of mass whale beachings during the amphibious exercise, the committee report said.

Past studies have shown high intensity sonar can severely injure whales, causing internal bleeding and tissue damage.

When exposed to powerful sound pulses, some whales appear to swim to the nearest beach and become stranded, eventually dying unless saved through human intervention.

An Australian military spokesman said marine mammals, currently migrating north from the Antarctic to warmer Australian waters to breed, would need to be clear of the exercise area before ships would be allowed to operate sonar.

“Marine mammal management procedures require ships to check for marine mammals in their vicinity, with safe-to-operate zones set dependent upon the type of equipment being used or activity being undertaken,” he said.

“Lookouts and warfare officers are trained to detect and report marine mammals at long visual ranges.”

But environmental activists say the powerful undersea sonar pulses can travel many kilometers in the right conditions.

Defense officials earlier this month confirmed that submarines would enter the Great Barrier Reef Marine Park during the exercise, but promised the environment was in no danger.

“It gives us an opportunity for both the Australian and U.S. military forces to practice what our profession is,” Australian Defence Force Warfare Centre commander Brigadier David McKaskill told local newspapers.

Environmental and peace activists are planning demonstrations during the June 18-24 exercises with a “Peace Convergence” on the training area.