Slime Houses of Pinky-Size Plankton Cycle Carbon

Floating in this mucus balloon is a tiny critter with a big impact on ocean ecology. Giant larvaceans inflate a complex slime structure and pump organic particles through it to concentrate them and filter feed. When the house gets clogged, the larvacean wriggles free and makes a new one. The abandoned house sinks through the water.It becomes a nutrient source for other communities, and traps the carbon in the particles at the bottom of the ocean. But scientists didn’t know how much carbon these creatures were moving, or even their feeding rates. The houses are too fragile to study in the lab, so the scientists brought the lab to them—200-400 meters below the surface. They launched a remotely operated vehicle called DeepPIV. And cast a laser sheet through the slime cloud to track particle movement. The study revealed the larvaceans in Monterey Bay could graze their entire depth range in less than two weeks. One species even claimed filtration record for zooplankton—almost 80 liters per hour. The details of the gooey structure, and how larvaceans even construct it, is still a mystery.