Filter-Feeding Plankton Clean Carbon Out Of The Oceans

Filter-Feeding Plankton Clean Carbon Out Of The Oceans
Giant larvaceans build filters to pluck food out of the ocean, and in the process, they store a bunch of carbon.

The ocean absorbs a lot of our industrial carbon dioxide, and plankton filters a lot of it once it's there. But new research shows one specific species of plankton filters carbon faster than the others — probably thanks to its house.

Giant larvaceans build delicate water filters out of mucus and pump water through them to keep them inflated. The wispy outer filter can get more than 3 feet wide to catch stuff that floats by. The curved inner filter guides particles toward the larvacean so it can eat.

Until now, we hadn't studied how giant larvaceans filter the water around them. They're so fragile they can't really be removed from the ocean. So researchers used a remote vehicle packed with lasers and cameras to study them where they live.

They calculated there were enough plankton to filter carbon and other nutrients out of all the water in their range in Monterey Bay in just a couple weeks. 

When a filter gets clogged with enough material, the larvacean drops it, and it drifts to the bottom of the ocean. All the carbon it cleaned out of the shallower water ends up on the seafloor — or as lunch for other creatures — and can stay out of the atmosphere for millions of years.