New MBARI technology reveals ocean carbon storage in real time

SINKER is an innovative new instrument equipped with advanced microscopes and cameras to collect detailed data about carbon sinking in marine snow.

Why It Matters

The ocean and its inhabitants remove carbon from the atmosphere, playing a key role in regulating Earth’s climate. New imaging systems will help researchers better understand which ecological and biological processes help carbon sink to the deep sea.

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 marine ecosystems, 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 marine snow 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 climate models 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 allows researchers to observe the biology of marine snow by logging thousands of snapshots of tiny organic particles sinking to the deep seafloor over the course of months, and eventually years. MBARI researchers hope that this instrument will improve our understanding of carbon storage in the deep sea and how this process might be changing.

The ocean-climate connection

Microscopic phytoplankton draw carbon dioxide from surface waters as they grow, enabling the ocean to absorb vast amounts of this greenhouse gas. As larger plankton consume phytoplankton, poop, and die, sinking organic material takes carbon away from the atmosphere and sends it to the ocean’s depths. Known as the biological pump, this process locks carbon away in the deep sea for decades or even centuries.

Tiny particles of yellowish-brown organic material collect on the lens of a camera system moored to the deep seafloor. The background is solid black. — 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. Image: © MBARI

Despite being an essential part of the carbon cycle, scientists still have many unanswered questions about sinking particles in the deep ocean. Chemistry, physics, and biology all control the transport of carbon to the ocean’s depths, but the biological processes are the most challenging to observe and realistically model. The harsh conditions and remoteness of the deep sea make it difficult to observe marine snow. We cannot predict the biological source of sinking particles, which has limited our ability to model how much carbon is exported. We do not know how fast particles sink, which controls how deep a particle is transported and, in turn, how long it is stored away from the atmosphere. The relevant time scales over which these processes vary are also largely unknown.

MBARI’s Carbon Flux Ecology Team studies the ocean’s role in cycling carbon. Durkin and her team are working to understand how ocean biology controls the amount of carbon that makes its way to the deep sea.

Collaboration inspires innovation

An MBARI mechanical technician welds the metal frame of a scientific instrument. The technician is wearing a black welding helmet, gray sweatshirt, and black pants. In the background is a machine shop workbench. — The SINKER imaging system builds upon more than two decades of MBARI engineering innovation and was constructed in-house by our team. Image: Calista Kerba © 2025 MBARI

Researchers have historically relied on extrapolating short-term datasets to predict long-term patterns, but have missed the episodic and unpredictable events that occur between field expeditions. Durkin and her team had a bold goal: to link Earth’s complex carbon calculus to the living ocean—anything that produces or consumes marine snow—to help scientists better model our changing climate.

Answering such difficult questions about marine snow and ocean carbon transport involved an interdisciplinary team of MBARI scientists and engineers.

“Collaborating across disciplines forces everyone on the team to think outside their comfort zone and, in many ways, think much bigger,” said Durkin. “These initial conversations turned into an ambitious goal to observe sinking particles with an innovative new instrument.”

The team determined they wanted an instrument that could photograph sinking particles anywhere from tens of micrometers to a few centimeters in size, collect data as frequently as every single second, and operate in the deep sea for more than a year. MBARI engineers got to work developing the SINKER imaging system. They identified the best cameras to use, then designed a frame, circuit boards, and underwater housings. Most of SINKER’s components were then built from scratch in-house by fabricators and technicians in MBARI’s machine shop.

A leap forward

An illustration shows the design of a scientific instrument. At the center is a black plastic cylinder with several brown organic particles sinking through and landing on a round plate. At the bottom is the silver metal camera housing. On either side are two black cylinders intersecting the cylinder at the center. The background is blue-green water. — 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. Illustration: Julia Devine © 2025 MBARI

SINKER combines multiple imaging systems to provide a detailed look into the biological and physical processes that influence sinking carbon.

As particles sink through a central collection tube, three cameras take photos to measure the particles’ sinking speed. After the particles land on a collection plate, two upward-facing cameras take photos so researchers can measure the size, shape, and composition of each individual particle. Every two hours, a brush wipes off the imaging plate to keep it from being completely clogged with too many particles.

“SINKER leverages tools and technologies that have been developed at MBARI over the past decade,” said Senior Electrical Engineer Paul Roberts. “This solution represents a significant technological advancement in measuring a wide range of variables related to sinking carbon particles.”

“Measuring multiple variables at once allows us to gather detailed quantitative biological observations of carbon export,” said Senior Research Specialist Crissy Huffard. “SINKER’s five cameras give us many different views of sinking particles, which we hope will help us answer fundamental questions about ocean carbon sequestration.”

What’s next

MBARI researchers first deployed SINKER in July during a cruise aboard our research vessel Rachel Carson. Moored on the seafloor and powered by MBARI’s cabled ocean observatory, SINKER continuously collects data from a research site just outside Monterey Bay at a depth of 900 meters (approximately 3,000 feet) and then transmits those findings to shore, giving researchers a window to the deep ocean.

A scientific instrument sits on the deep seafloor. The instrument has a silver metal frame with a green plastic grate at the bottom and several bricks of orange foam at the top. In the center is a silver housing for a camera and several brightly colored cables. The background is dark brown seafloor and black water. — 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. Image: © 2025 MBARI

The team plans to retrieve the system in December, analyze the data, and make adjustments to the instrument design where needed. When that process is complete, they intend to deploy SINKER again for at least a year, if not longer.

“The long-term goal is to have SINKER plugged in for many years so we can understand how carbon flux changes over time, both from day to day and across seasons,” said Durkin. “At some point, we hope we can bring this technology to other cabled observatories so we can begin to understand carbon export in a variety of different ocean environments.”

Learning more about sinking carbon will help researchers better understand how the ocean regulates Earth’s climate and predict how changing ocean conditions will affect marine life and ecosystems. The data from SINKER will be able to provide invaluable information that policymakers need to inform decision-making about the ocean.

This work was funded as part of the David and Lucile Packard Foundation’s longtime support of MBARI’s work to advance marine science and technology to understand a changing ocean. Operations for MBARI’s cabled ocean observatory, the Monterey Accelerated Research System (MARS), are made possible with support from the US National Science Foundation.

Story by Science Communication Associate Lila Luthy

For additional information or images relating to this article, please email pressroom@mbari.org.

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