A mysterious clicking sound detected thousands of feet below the surface of the Pacific Ocean has revealed fascinating information about California’s elusive population of sperm whales.
The endangered giant sperm whale, which is the loudest animal on the planet, is rarely seen in Monterey Bay in central California and is difficult to study due to its ability to dive long and deep.
But a hydrophone (underwater microphone) embedded in the seafloor and connected to the Monterey Bay Aquarium Research Institute in Moss Landing made an incredible discovery after recording audio from up to 100 miles away for seven years.
During this time they captured a series of strange choppy-like sounds that started slowly and then accelerated into a continuous crackling sound, similar to the hum of television static.
“It almost sounded like a human machine,” said Will Oestreich, a U.S. National Science Foundation postdoctoral fellow at MBARI. SF gate.
But after sifting through a mountain of data, Oestreich realized that these sounds were actually echolocation clicks from not one but several sperm whales hunting together in the area.
A mysterious clicking sound detected thousands of feet below the ocean surface off the coast of central California has revealed valuable information about the elusive population of sperm whales in Monterey Bay.
A hydrophone (pictured), or underwater microphone, embedded in the seafloor and connected to the Monterey Bay Aquarium Research Institute (MBARI) in Moss Landing, captured a series of clicks that piqued the curiosity of Will Oestreich, US National Science Foundation postdoctoral researcher MBARI fellow
Sperm whales are known to produce the loudest biological sound on Earth (reaching up to 200 decibels) and use these powerful clicks to hunt in the dark depths of the ocean.
‘Every click is a fraction of a second. “It’s really a needle in a haystack, even though it is the loudest biological sound known on Earth,” Oestreich said.
‘It’s a really interesting tool for us researchers, because they tell us things about their own lives. They are one of the main predators (deep sea tigers) and their behavior reflects a food web that is difficult for us to study.’
The groundbreaking study published in Movement Ecology documented how these whales frequent Monterey Bay much more regularly than previously thought, particularly in late fall and winter.
This timing contrasts with previous findings from Alaska, where summer vocalizations were more common, suggesting possible seasonal migrations that align with changing ocean conditions in the North Pacific Transition Zone, where prey is abundant.
Oestreich’s analysis went beyond simple presence detection.
Using advanced algorithms, he tracked individual whales by analyzing the time between clicks, which corresponds to body size, revealing the presence of adult males, females with calves and younger whales, all indicative of the importance of Monterey Bay to the population.
The researchers also detected codas, unique sound patterns that can act as “cultural identifiers” for different social groups.
Oestreich noted that these findings have implications for conservation.
Sperm whale populations are still recovering from commercial whaling, and understanding their presence in protected areas like the Monterey Bay National Marine Sanctuary could help inform protections against risks like noise pollution and ship strikes.
“These are the predators with the largest teeth on the planet,” Oestreich said. “They’ve been here all this time and we just didn’t realize.”
Sperm whales, known for producing the loudest biological sound on Earth, reaching up to 200 decibels, use these powerful clicks to hunt in the dark depths of the ocean.
On July 14, Monterey Bay Whale Watch documented its first sperm whale sighting in nearly eight years, with its distinctively small dorsal fin and enormous head just above the water’s surface.
‘We hit the whale watching jackpot!’ the organization told the Sacramento Beehighlighting how rare it was for the sperm whale to swim to the boat.
In a video posted by Monterey Bay Whale Watch, the gray predator could be seen gliding on the surface and exhaling through a hole located on the left side of its iconic curved head. Moments later, its enormous tail rose from the water before submerging once more.
Sperm whales, which grow up to 52 feet long and weigh 90,000 pounds, are the largest toothed predator on Earth. Known for their extraordinary deep diving abilities, sperm whales can hold their breath for more than an hour and dive between 2,000 and 10,000 feet in search of prey, feeding on fish, sharks, and squid.
For nearly 180 years, until 1980, these whales were a major target of commercial whalers, and this legacy has left the species in danger of extinction, according to NOAA.
Fascination with sperm whales increased earlier this year when their characteristic “clicking” sounds made headlines.
MIT scientists analyzed the clicks of more than 8,000 sperm whales, revealing an alphabet-like system, suggesting these animals can hold conversations.
“We often hear them clicking on the hydrophone in the @mbari_news soundscape listening room in the bay, but we never see them,” MBWW said.
