In March 2000, a total of 16 whales of three kinds beached themselves in the Bahamas due to interference from sonar equipment on U.S. naval vessels, and six of them died. This was not an isolated case. In September 2002, altogether 14 whales of several kinds got stuck on the beach four hours after a Spanish military exercise in the Canary Islands. In July 2004, during a Pacific Rim military exercise, 200 whales became stranded in shallow seawater off the Hawaiian coast soon after the U.S. Navy began a sonar test.

Before the USNS Impeccable was intercepted and driven away by Chinese fishermen and the Chinese fishery department, it had been using its sonar system. Not long after, an adult humpback whale measuring more than 10 meters became stranded on the beach in Hong Kong. It was the first time a beached whale had turned up in that area.

Facing mounting evidence, the U.S. Navy had to admit in an official report that its use of sonar "perhaps" led to several whale stranding cases. An environmental evaluation by the U.S. military found that 170,000 sea mammals had been disturbed or harmed during 14 military rehearsals along the California coast.

On August 6, 2007, a U.S. federal judge banned the use of high-intensity sonar in military exercises off the coast of California. The U.S. Navy has also decided to stop anti-submarine training in Hawaii to prevent lawsuits.

The South China Sea is China's only tropical sea, and it contains the most abundant and diverse marine life in China. The U.S. Navy has sailed thousands of kilometers on "measurement missions" in other countries' EEZs, using advanced sonar systems, and hasn't hesitated to carry out devastating experiments. It has potentially caused great damage to marine ecosystems.

The United Nations Convention on the Law of the Sea indeed stipulates that countries have navigation rights in other countries' EEZs. But the convention also states that a coastal country has sole ownership of the biological and non-biological resources inside its EEZs, as well as sovereign rights of exploitation, exploration, maintenance and management. A coastal country can also enact its own laws to prevent, control and reduce pollution.

These navigation rights refer to "innocent passage," on which point the U.S. Navy obviously cannot stand. Therefore, it is necessary and perfectly justifiable for China to dispel U.S. Navy surveillance ships from its EEZs to protect its marine environment and resources.

The author is with the Fishery Administrative Bureau of Nanhai District, Ministry of Agriculture