Project Seeks to Map and Reduce Ocean Noise Pollution Dave McNew/Getty Images A rare and endangered blue whale offshore near Long Beach, Calif. When a hurricane forced the Nautilus to dive in Jules Verne's "Twenty Thousand Leagues Under the Sea," Captain Nemo took the submarine down to a depth of 25 fathoms, or 150 feet. There, to the amazement of the novel's protagonist, Prof. Pierre Aronnax, no whisper of the howling turmoil could be heard. "What quiet, what silence, what peace!" he exclaimed. That was 1870. Today - to the dismay of whale lovers and friends of marine mammals, if not divers and submarine captains - the ocean depths have become a noisy place. The causes are human: the sonar blasts of military exercises, the booms from air guns used in oil and gas exploration, and the whine from fleets of commercial ships that relentlessly crisscross the global seas. Nature has its own undersea noises. But the new ones are loud and ubiquitous. Marine experts say the rising clamor is particularly dangerous to whales, which depend on their acute hearing to locate food and one another. To fight the din, the federal government is completing the first phase of what could become one of the world's largest efforts to curb the noise pollution and return the sprawling ecosystem to a quieter state. It is no small ambition: the sea covers more than 70 percent of the planet's surface. But scores of the ocean visualizations have now been made public. The federal effort seeks to document human-made noises in the ocean and transform the results into the world's first large sound maps. The ocean visualizations use bright colors to symbolize the sounds radiating out through the oceanic depths, frequently over distances of hundreds of miles. Several of the larger maps present the sound data in annual averages - demonstrating how ages in which humans made virtually no contribution to ocean noise are giving way to civilization's roar. The overall purpose is to better understand the cacophony's nature and its impact on sea mammals as a way to build the case for reductions. "It's a first step," Leila T. Hatch, a marine biologist and one of the project's two directors, said of the sound maps. No one's ever done it on this scale. The National Oceanic and Atmospheric Administration began the effort in 2010 at the behest of Jane Lubchenco, a prominent marine biologist who is the first woman to head the agency. Dr. Hatch and her colleagues assembled a team of sound experts, including HLS Research, a consulting firm in La Jolla, Calif. This summer, they unveiled their results on the Web, as did a separate team of specialists that sought to map the whereabouts of populations of whales, dolphins and porpoises. Michael Jasny, a senior policy analyst with the Natural Resources Defense Council, a private group in New York that has sued the Navy to reduce sounds that can harm marine mammals, praised the maps as "magnificent" and their depictions of sound pollution as "incredibly disturbing." "We've been blind to it," Mr. Jasny said in an interview. The maps are enabling scientists, regulators and the public to visualize the problem. Once you see the pictures, the serious risk that ocean noise poses to the very fabric of marine life becomes impossible to ignore. Legal experts say the new findings are likely to accelerate efforts both domestically and internationally to deal with the complicated problem through laws, regulations, treaties and voluntary noise reductions. The government already has some authority to regulate oceanic sound in United States waters through the Endangered Species Act and the Marine Mammal Protection Act, though exemptions to these laws exist for the military. The International Maritime Organization, a United Nations body responsible for improving marine safety and reducing ship pollution, also has the authority to set acoustic standards. In the past few years, encouraged by the United States, it began discussing how to achieve voluntary noise reductions. Since many commercial vessels are registered abroad, and most shipping noises arise in international waters, the organization's backing is seen as crucial for reductions to be substantial enough to have global repercussions. "Right now we're talking about nonbinding guidelines," said Michael Bahtiarian, an adviser to the United States delegation to the maritime organization and a senior official at Noise Control Engineering, a company outside Boston that specializes in reducing ship noise and vibrations. At a minimum, the goal is to stop the increases.