Of Whales and War
Last week, U.S. District Judge Florence-Marie Cooper rejected President Bush's attempt to exempt the U.S. Navy from laws protecting endangered whales. The judge noted that President Bush's order was constitutionally suspect, leaving her injunction against sonic blasts in place. Such underwater bursts put whales and other marine mammals at risk. They are also part of a long relationship between whales and human warfare.
For much of the 20th century, the typical lab of a whale biologist was about 20 feet above the open sea. On the flensing deck of factory whaling ships, cetologists examined blubber thickness, stomach contents, gonads and earwax layers. They learned a lot about dead whales: What they had eaten and when they had become sexually mature. The layers of wax provided an indication of age.
World War II interrupted these studies and the business of whaling. German whale chasers were employed instead to hunt Allied submarines, and Japanese whaling ships transported miniature submarines across the Pacific to attack Pearl Harbor. The suspension of the hunt likely saved many whales in the Southern Hemisphere, at least for a while. Yet the extensive use of depth charges and bombs in the north probably killed thousands of cetaceans.
It wasn't until after the war that biologists probed the ocean and began to listen to the whales themselves. The acoustician William Schevill made the first recordings of cetaceans in the wild in the 1950s, going on to describe the calls of more than 30 marine mammal species, including sperm whales, blue whales, dolphins and seals. Schevill's knowledge of these underwater sounds was so extensive that he helped defuse a tense moment between the United States and the Soviet Union during the Cold War. Low-frequency blips had been detected in the oceans, and the American military suspected that the Soviets were using these sounds to locate U.S. submarines. Schevill and colleagues found the source: fin whales produce trains of blips for about 15 minutes, followed by a two- or three-minute pause when they surface to breathe.
As it turned out, these sounds were being used for detection, but fin whales weren't considered a national threat. (This didn't stop the military from using whales as target practice at the time.) Often feeding where the light of the sun is reduced to that of starlight, whales use sound to locate prey. Whales also rumble, grunt, gurgle and sing - using their voices to attract mates, stay in touch with their offspring, and navigate the shelves, seamounts and islands in the ocean.
This dependency on sound makes whales vulnerable to the rising level of noise in the ocean. The number of cargo ships has tripled in the past 75 years, with bigger ships plying the seas each year. Bio-acoustician Chris Clark describes these chronic sounds as a "smog of human-generated acoustic noise." The constant buzz, which can impact whales' ability to hunt and reproduce, is punctuated by intense pulses from seismic air guns, used to map petroleum deposits on the shelf. These pulses, some of the loudest sounds produced by humans, reach across oceans and may be responsible for the stranding of whales in Mexico. The United States is right to protest commercial whale hunts that violate the suspension of whaling, but we should also protect the soundscape where the world's largest mammals reside.
Naval exercises using midfrequency sonar for antisubmarine training harm whales. There is evidence that gas-bubble disease in whales - the bends - is associated with sonic exposure. Mass strandings of beaked whales have occurred around the world after military tests. In 2000, 14 beaked whales and two minkes stranded in the Bahamas after the U.S. Navy deployed midfrequency sonar. In the lab, cetaceans avoid noise and increase breathing rates, a sign of stress. In the modern ocean, there may be nowhere for dolphins and whales to go.
Biologists are now calling on governments to reduce ocean noise and limit damage from military maneuvers. Judge Cooper's injunction came after the Navy rejected regulations proposed by the California Coastal Commission. The Navy now shuts down sonar exercises if marine mammals or sea turtles are seen in the immediate area, but it continues to reject other commonsense measures. State regulators had approved naval exercises if the military avoided important cetacean habitats, worked in daylight when whales could be spotted, and expanded the safety zone between sonar and whales. Until such steps are taken, naval tests put ocean life at risk.
Joe Roman is a visiting fellow at the University of Vermont and author of "Whale" (Reaktion, 2006).
© 2008 San Francisco Chronicle