Discovery of a rare 'whale fall' allows scientists to explore a mystery

Researchers on the Exploration Vessel Nautilus found a natural whale fall off the coast of Southern California last Wednesday during a live broadcast.

Nick Ut/AP
A whale breaches close to the Harbor Breeze Cruises La Espada whale watching boat off the coast of the San Pedro section of Los Angeles on Aug. 1.

What happens when a mass of meat and bone weighing several tons falls to the ocean floor? A new civilization rises – crabs, sharks, worms, and all. After dying, a whale can support a community of organisms for 50 to 75 years.

That is one reason why finding a dead-whale community, or a “whale fall,” on the ocean floor is such a big deal for marine researchers. Another is that finding a natural whale fall is rare. Despite the odds, the Exploration Vessel Nautilus team stumbled upon a whale carcass last Wednesday on its tour of the Southern California Margin.

Coming across a natural whale fall is pretty uncommon,” one Nautilus researcher says in a live recording. “Most of the whale falls that have been studied have been sunk intentionally at a certain spot.”

One researcher can be heard saying that, based on the jaw, it was a species of baleen whale, probably a juvenile or a smaller species. 

The sighting is so unusual because “at the moment, the only way to find a whale fall is to navigate right over one with an underwater vehicle," Jon Copley, of the University of Southampton in England, said in a statement about a 2013 study of the first whale fall found off the coast of Antarctica.

It was in Dr. Copley’s study that researchers discovered a new species of zombie worm, one organism identified on the California whale’s bones. According to one Nautilus researcher, zombie worms burrow into the bones and digest the whale’s proteins and lipids.

Although they have been found on a few whale falls, much is still unknown about zombie worms, such as “how these tiny invertebrates can spread between the isolated habitats these whale carcasses provide on the seafloor," Adrian Glover, a researcher at the Natural History Museum in London, said in the statement.

The sustained mystery surrounding these communities prompts researchers to jump on the opportunity to watch a whale's decomposition in action when they know a whale has died. The Nautilus expedition has looked at one such whale that was “sunk on purpose, as an ecology study,” a researcher says in the video.

During this process researchers moved the whale to sea, attached it to seven tons of chain and steel scrap, and sunk it to the La Jolla Canyon’s bottom. By 2015, they had returned to the carcass twice to collect data.

The E/V Nautilus was founded in 2008 by Robert Ballard, professor of oceanography at the University of Rhode Island and discoverer of the Titanic, to “engage in pure ocean exploration.”

The ship’s current expedition is on the southern California margin where only 50 percent of the area has been mapped by high-resolution multibeam bathymetric coverage. Part of the expedition is shown live online, which is how one viewer could get his or her question answered in real time. 

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