The sound of whining drills fills the air around Tyler Wirth’s workbench. Five foot tall robots line the table behind him. It may look like a typical day at Scripps Institution of Oceanography's Instrument Development Group lab. But there’s a somber undertone.
Wirth is repairing what could be some of the last robots of this kind.
“It’s sad,” said Wirth, who is an engineer and scientist at Scripps Institution of Oceanography. “I spent a career, my Ph.D., working on this project.”
He works on autonomous robots called Biogeochemical-ARGO floats. They take measurements of the world’s oceans and transmit that information to Scripps researchers using satellites. For more than a decade, the devices have been a part of a global effort to monitor the ocean’s health. They collect data more than a mile below the ocean surface that helps scientists better understand problems such as ocean acidification, extreme weather events and ecosystem decline.
“It has the biology, the geology, chemistry kind of wrapped up into one thing. And that's what these floats are, kind of aim to do,” Wirth said. “A one-stop shop of measuring everything that we can possibly measure in the ocean.”
The federal funding for the program expires in October. The National Oceanic and Atmospheric Administration informally agreed to offer financial support to continue the project, Scripps said. But the Trump administration's 2025 budget cuts to NOAA gutted the organization’s ability to cover the costs.
NOAA declined an interview. But a NOAA spokesperson confirmed it is unable to support the continuation of the biogeochemical program. Without outside funding, the Biogeochemical-ARGO program will end.
A revolutionary robot
BGC-ARGO is one branch of a larger global ocean observing system. It’s a relatively new addition to the overall ARGO mission, which includes three other specialized float fleets. The most well known array of robots, CORE ARGO, has been measuring the ocean’s temperature and salinity for decades. But that only gave Scripps researchers a glimpse into the full picture. Researchers likened it to watching TV in black and white.
In 2010, when BGC-ARGO began, more sensors were added to the floats to measure oxygen, chlorophyll and acidity, a switch flipped to reveal a color picture of the ocean’s health.
Susan Wijffels, a senior scientist at Woods Hole Oceanographic Institution, has been a part of the ARGO program since the beginning. She witnessed how the expansion unlocked insights about the ocean previously unknown to scientists.
“It's revolutionary that we can sit in our office and get an oxygen profile or get a nitrate profile from the middle of the southern ocean in winter,” Wijffels said.
The detailed snapshots of gases in the ocean showed researchers like Wijffels how the environment might change living conditions for marine life. For example, more nitrate in the water could lead to harmful algae blooms.
In the past, ocean observations were made with satellites, ships, or devices anchored to the bottom of the ocean. Satellites and ships can only capture information from the ocean’s surface. And anchored devices are limited to the location they are moored to. ARGO’s ability to autonomously roam the ocean grants access to below the surface and to remote swatches of the sea.
Big breakthroughs
About 500 of the BGC floats are checking up on the world’s oceans right now. They’re deployed off ships in hard-to-reach places from the middle of the Atlantic to the Arctic. Then, they do their own thing.
“They’re just buoyancy driven. So, it just has an external balloon that inflates and deflates and allows it to go up and down,” said Sarah Purkey, who is an oceanographer at Scripps. “It has a little bit of electronics, and then it has a bunch of D-cell batteries.”
A float can live up to five years in the ocean. With its sensors, it can observe 2,000 meters below the surface. Every 10 days, it comes back up and uses its antenna to transmit data via satellites.
The data it collects are especially important for discerning how the ocean interacts with greenhouse gases in the atmosphere, Purkey said.
“One of the things we're trying to understand is how the ocean takes up carbon and how that might change in the future. And that's going to help us understand how much residual carbon is left in the atmosphere,” she said. “And we need to know that number in order to understand and predict how the Earth will continue to warm up.”
The U.S. Navy, forecasters and major research centers around the world use this data. Jennifer McWhorter, a scientist at the University of Miami, harnessed the information to identify the impacts of extreme weather in the ocean.
In a study published earlier this year, she showed how hurricanes bring deep-ocean nutrients to the surface. It was the first time a BGC float collected data under a hurricane as it was happening, she said. The insight revealed that hurricanes can increase the amount of plankton in the food web far below the surface.
“We’re at a really exciting place where we’re just starting to understand all of these processes a little bit better,” she said. “And, we really need to keep those floats out there so we can study these important changes for ecosystems.”
Funds in troubled waters
For five years, a $53 million grant from the National Science Foundation funded the project. But when the Trump administration cut hundreds of millions of dollars from NOAA’s budget in 2025, Scripps oceanographer Lynne Talley saw the writing on the wall.
“There was no hope that NOAA at that point could be coming up with any more money for anything because they fired 10,000 people, including the people that we work with the most closely,” she said.
By Scripps calculations, the program costs taxpayers around 10 cents a year each. It's relatively inexpensive compared to ships and satellites. But costs of losing the program will be greater, according to Purkey.
The lack of replenishing federal funds comes at a critical time. This year, there is a potential for a super El Niño. Such an event could lead to severe property damages, flooding and ecosystem disruption. If the program halts, scientists will lose one way to measure how these types of extreme events are changing marine ecosystems.
“If we take away that network. If we don't maintain it, you don't only lose the science, but you lose your ability to see what's coming,” she said
Eighteen countries contribute to the floats’ global network. But the United States deploys about half of them. The hundreds of domestic floats will stop collecting data as their batteries die. While American scientists may not be able to continue leading this part of the effort, Talley is hopeful their international partners will continue the work.
“Our stopgap is that other countries expand,” she said. “The U.S. will clearly lose its position. But I don’t care at this point. I want this observing system to survive.”
Soon, the last floats from the project will leave Scripps’ lab in San Diego. As they begin to roam the world’s oceans Scripps researchers plan to embark on their own journey: to search for funding in every way possible.
Their next step is to look to Congress and philanthropic organizations to continue the program.
