Sea Creature’s Snot Palace Sequester’s Carbon

June 17, 2020

Close-up view of a giant larvacean, a small, nearly transparent sea animal

Perhaps we should learn more about the creatures we share the planet with before we kill them.

LA Times:

It was decades ago when Bruce Robison first looked through the plexiglass sphere of a submersible and spotted a most curious critter in the waters off Central California.

Nearly transparent and no larger than a fist, the squishy tadpole-like animal was surrounded by an enormous balloon of mucus about 3 feet wide. Robison could discern chambers intricately inflated within this sticky structure, speckled with particles of food and plant debris. 

Robison spent years in the open ocean studying these gelatinous animals, which are too large and too fragile to bring back into a lab. Known as giant larvaceans, they inhabit seas across the world. Tens of thousands of them live just outside Robison’s office in Monterey Bay. 

He and fellow researchers eventually learned that these creatures and their snot palaces play an outsize role in helping the ocean remove planet-warming carbon dioxide from the atmosphere — one more part of a vast and underappreciated system that makes the ocean an unsung hero of climate change.

Covering more than 70% of Earth’s surface, the ocean has absorbed more than a quarter of the carbon dioxide released by humans since the Industrial Revolution, and about 90% of the resulting heat. 

“We’re just on the edge of this tremendous change in how we perceive and understand how the ocean works,” said Robison, a senior scientist at the Monterey Bay Aquarium Research Institute. “If an alien civilization from some other solar system were to send an expedition to Earth to look at the dominant life forms on this planet, they wouldn’t be up here walking around with us. They’d be exploring the deep ocean.”

With giant larvaceans, or Bathochordaeus, scientists and engineers at the Monterey Bay institute finally figured out a way to study their inner workings. In a new studypublished recently in the journal Nature, the team described how they were able to scan the animals with lasers mounted onto a 12,000-pound robot, and then reconstruct the mucus structure into a 3-D model.

Like radiologists with a CT scan, the scientists were able to piece together the intricate architecture within the mucus apparatus, called the “house,” and study how water moves through these delicate structures. Suddenly they could see chambers and passageways they never knew existed.

The larvacean essentially lives inside two mesh-like filters: A smaller inner house, containing inlet filters and fluted chambers, is surrounded by a coarser outer house that can blow up to be 1 meter across. This outer filter traps plant debris and food particles too big for the animal to eat, while the inner filter guides smaller pieces into its mouth.

Giant larvaceans, or Bathochordaeus.

Larvaceans use their tails to constantly pump water through both filters — as much as 21 gallons an hour. All told, scientists calculated that the giants in Monterey Bay could filter all the water between 100 and 300 meters deep in as little as 13 days — equivalent to about 500 Olympic-sized swimming pools per hour.

Once the mucus gets clogged, usually every 24 hours or so, the larvacean abandons the filter and moves on to make a new one. This netting of mucus, packed with carbon-rich particles, then collapses like a punctured balloon — sinking a significant load of carbon to the deep sea floor and locking it away from reentering the atmosphere.

Ordinarily, massive quantities of carbon drift through the ocean as “marine snow,” tiny particles of plants, fecal matter and other debris that shower down the water column.

These tiny particles sink very slowly, however, and often get eaten by other organisms on the way down — which brings the carbon back up the food chain. So scientists were amazed by the mucus houses, which clump together so many particles (not to mention microplastics) that everything sinks much faster to the bottom. Here, the carbon in effect becomes sequestered and unable to reenter the upper systems.

giant larvacean

Kakani Katija, who engineered the laser system and heads the Monterey Bay institute’s Bioinspiration Lab, said these animals can also teach us new ways to design filters or expandable structures — perhaps to use underwater or even in outer space.

“Here’s an animal that creates a structure that’s a few millimeters in size, but somehow blows it up to a meter in size,” said Katija, lead author of the Nature study. “There is still so much we don’t know, and every time we develop a new tool or new technique, that just opens up the world to us in a very different way.”

2 Responses to “Sea Creature’s Snot Palace Sequester’s Carbon”

  1. dumboldguy Says:

    Let’s hear it for the giant larvaceans! OOH-Rah! I only learned about them myself a few days ago on another site, and the contribution they make to a better planet is unbelievable and enormous—-all while simply feeding and hoping to meet other GL’s so they can make little ones.

    We know next to nothing about the oceans and the critters that live there, many of which we will likely drive to extinction before we know how important they are to the biosphere. Have no fear, though. We will go back to the moon and on to Mars instead of studying the Earth, so we WILL have lots of nice rocks to look at while the planet dies.

  2. Roger Walker Says:

    ‘Useless’ pure science comes up with yet another winner.

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