The latest court ruling over the use of mid-frequency navy sonar off the coast of California points it out clearly: when it comes to national security, nothing is more important, not even the lives of the whales and dolphins. You might think things have finally come to an end in this matter, but they are just beginning, environmentalists warn.

Joel Reynolds of the Natural Resources Defense Council said Wednesday’s decision places marine mammals “at greater risk of serious and needless harm.” However, he added, the decision is a narrow ruling that leaves in place four of the injunction’s six safeguards. “it is significant that the court did not overturn the underlying determination that the Navy likely violated the law by failing to prepare an environmental impact statement.”

The dispute between environmentalists and the Navy has been a very controversial one. On the one hand, environmentalists pleading for the safety of marine mammals argued the use of sonar for training is of no immediate necessity. On the other hand, President Bush made several attempts to exempt the Navy from submitting to such regulations “in support of worldwide operational and combat activities,” saying the training was essential for national security.

But an early January decision limited the use of mid-frequency sonar within 12 miles off the coast of Southern California, in order to mitigate the negative impact on marine mammals. In January, a judge concluded that since under federal rules, humans are to wear ear protection when using the sonar, the animals have the right to be protected too.

Two months later, the Ninth Circuit Courts of Appeal upheld the January decision, forcing the navy to comply with a set of regulations which included not using the sonar within 12 miles of the coast of California, avoid the use of sonar in whale habitats, shut down the sonar when mammals are within 2,200 yards, and monitor the mammals.

But the decision made by the Supreme Court this week overturned all that. Chief Justice John Roberts wrote in the majority decision that the lower courts failed to properly assess the necessity of using the sonar in training. “Forcing the Navy to deploy an inadequately trained anti-submarine force jeopardizes the safety of the fleet,” Roberts wrote, adding that this would result in harm to national security interests, as opposed to harm to an unknown number of marine mammals that environmentalists study and observe.

But environmentalists will not give up, especially considering the large number of mammals at stake. The waters off the southern coast of California are extremely rich in marine habitat, NRDC noted, and includes 5 endangered species of whales.

The Navy even admitted that the damage from 14 sonar exercises would temporarily deafen at least 8,000 whales, and would cause permanent injuries to over 500 whales.

The sonar is known to be able to harm marine mammals by affecting their echolocation systems, causing them to become stranded and perhaps stop feeding and breeding. Eight years ago, scientists found evidence of the harmful effects of sonar on marine mammals after discovering whales from four different species stranded on beaches in the Bahamas following the use of mid-frequency sonar in a Navy training exercise.

That particular incident caused the area’s population of Cuvier’s beaked whales to nearly disappear, NRDC says. The same effects have also been observed in the Canary Islands, Greece, Madeira, the U.S. Virgin Islands, Hawaii and in other places on the globe.

The environmentalists explained that the sonar causes the whales to suffer physical trauma, including bleeding around the brain, ears and other tissues, but also show symptoms of severe cases of “the bends,” an illness that occurs when surfacing too quickly after diving in deep waters. “The clear implication is that debilitating and lethal injuries are occurring in whales exposed to sonar at sea, perhaps by altering their dive patterns,” NRDC wrote.