Underwater robot reveals ocean carbon storage in real time

The ocean is Earth's largest carbon sink, playing a critical role in regulating the global climate. With the effects of climate change posing increasingly larger threats to , understanding the ocean's capacity to store carbon has become especially urgent. To better observe the biological processes controlling carbon transport to the deep sea, MBARI scientists and engineers worked together to develop SINKER, a device that can measure what, when, and how much carbon is sinking into the deep sea.

SINKER—the SINKing Ecology Robot—features advanced cameras and microscopes to collect frequent real-time data about sinking to the seafloor in Monterey Bay. Marine snow is made mostly of biological material and brings large quantities of carbon to the deep sea.

"Right now, a huge limitation of carbon and is how we account for the biology that controls sinking carbon particles," explained Scientist Colleen Durkin, who leads MBARI's Carbon Flux Ecology Team. "Who makes these particles? How fast do they sink? How big are they? These details matter, and they change over both short and long time periods."

SINKER is equipped with five cameras to photograph particles of marine snow as they sink through a tube and onto a collection plate. This instrument provides real-time quantitative data about the transport of carbon to the deep sea. Credit: Julia Devine 2025 MBARI

Organic matter from the surface eventually sinks to the deep sea. Bits of dead plankton, poop, mucus, and other material called marine snow play an important, but poorly understood, role in the ocean carbon cycle. Credit: MBARI

MBARI’s cabled ocean observatory provides SINKER with continuous power so researchers can collect data for extended periods of time, transforming efforts to monitor carbon transport from the surface to the deep sea. Credit: MBARI

MBARI's new SINKER imaging system provides real-time observations of the tiny particles of marine snow that drive carbon storage in the deep sea, helping fill critical gaps in our understanding of Earth's carbon cycle. Image: Lila Luthy. Credit: 2025 MBARI