| The U.S. Navy conducts sound tests, called the Navy Surveillance Towed Array Sensor System Low Frequency Active sonar (SURTASS LFA), in the ocean to detect enemy submarines. They have been conducting two types of sonar testing - passive and active. Passive sonar listens for noises in the water. Active sonar sends out a loud, low-frequency signal and waits for responding signals that bounce off distant objects such as submarines. These sounds can spread across hundreds of thousands of square miles of ocean. Since these tests have been conducted the grey whale population has fallen from 17,000 to 9,000. Several species of beaked whales have been killed by exposure to the high intensity underwater sound. In early 2000, 16 beaked whales were beached in the Bahamas, they were hemorrhaging around the eyes and ears, indicating severe acoustic trauma. Not only have whales been killed but also dolphins, seals and sea turtles. Marine mammals depend on their sensitive hearing for essential activities like finding food and mates and avoiding predators. Since this sonar testing has been going on marine mammals are now endangered species. The Navy states that these tests need to be done because an undetected enemy submarine is an underwater terrorist. The Navy seeks to deploy these sonar tests in 80% of the world's oceans. |
