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.