The United States is about to lose its clearest view of a fast-changing ocean. Starting this month, the National Science Foundation (NSF) began pulling more than 900 deep-sea instruments out of the water, dismantling four of the five major arrays of the Ocean Observatories Initiative (OOI), a network of moorings and seafloor sensors that streams continuous, real-time data on the physical, chemical, and biological state of the Atlantic and Pacific. The network was built to run for 25 years. It will not make it to ten.
This is a national security story as much as a science story. Understanding the ocean is critical to food security, disaster preparedness, military readiness, and anticipatory risk management of potential climate tipping points. Shutting off ocean observation means the United States is creating a blind spot that puts it on the back foot, unable to prepare for a climate-changed future or more broadly assess undersea developments, at a time when its strongest competitor, China, is doubling down on ocean monitoring.
The Endurance Array off the Pacific Northwest comes out first, this month. The Station Papa Array in the Gulf of Alaska, the Irminger Sea Array, and the Pioneer Array on the East Coast are set to follow in the summer of 2027.
Three risks illustrate that this is a security problem in addition to a science loss.
First, the United States is about to stop watching the Atlantic’s circulation, just as it wobbles. The sensors that sit in the Irminger Sea between Greenland and Iceland are central to measuring the Atlantic Meridional Overturning Circulation (AMOC). This is the system of currents that carries warm water north and helps keep the climate across North America and Europe stable. The moorings in the Irminger capture the deep-water mixing that drives the whole conveyor. Models can estimate changes to the AMOC, but only sensors in the water can show what is actually changing.
The timing could hardly be worse. New studies published this April found the AMOC is weakening faster than the models expected, and that the chance of a collapse this century now looks higher than 50 percent. A shutdown would shift the tropical rain belts that feed millions of people, drive harsh winters and summer droughts across Europe, and increase sea level rise on the U.S. Atlantic coast. These impacts would lead to negative security outcomes such as food shocks, stress on U.S. allies, mass displacement, and damage to coastal bases and critical infrastructure. With the closure of the Irminger Array, the world has even less insight into an uncertain yet highly impactful climate tipping point.
The second risk is nearer-term and closer to home. The Endurance Array sits off the coast of Oregon and Washington, in waters that produce about a quarter of the world’s annual fish catch. Its sensors track the marine heatwaves, low-oxygen zones, and shifting chemistry that shape the region’s fisheries. Data streams about this region of the ocean are being turned off just as scientists warn of a likely extreme El Niño hitting later this year, a weather pattern which will amplify already strong climate-driven heat waves. Research published last month found that removing the U.S.-led system would increase errors in measuring ocean heating, degrading warning for storms, heatwaves, and El Niño.
The Endurance Array also sits in one of the most dangerous seismic zones in the country, the Cascadia margin, where a major earthquake and tsunami would threaten ports and the supply chains that depend on them, naval facilities, and millions of residents. Ships can run expeditions to gather some data that could help provide warning of such an event, but they are costly and can only stay out so long. Fixed sensors deliver a continuous feed that is hard to replace.
The third risk is strategic. As Washington pulls its civilian sensors out of the water, Beijing is racing to put more in. Under what China calls its “Transparent Ocean” strategy, the government is building a seabed-to-space sensing network, cabled seafloor observatories, moored arrays, and long-range gliders measuring similar temperature, salinity, and sound-speed data that the Ocean Observatories Initiative collected. This system is still mostly aspirational. As one expert told a congressional commission, China has “the ambition, though not yet the capacity.” But the direction of policy change is unmistakable. China is working to see more of the ocean, and the United States is choosing to see less.
While the U.S. military continues to operate its own ocean data collection, the loss of civilian capacity in the United States still creates a security challenge. A public record like the OOI helps to fill gaps and build a more complete picture of the ocean that can be leveraged across all government agencies. Further, the dismantling of the OOI is part of a larger pattern of cuts from this administration that add up to a blind spot greater than the sum of its parts. From attempting to shut down the National Center for Atmospheric Research (NCAR), a core climate and weather facility, to reducing resources for the National Weather Service, to cutting funding for NOAA’s cooperative research institutes, the administration is choosing both to ignore changes in the physical world it has to operate in, and curb its ability to respond to those changes.
Managing the risks outlined above, an Atlantic circulation that may be tipping, hazards along U.S. coasts, a forthcoming El Niño, and maintaining a strategic edge against U.S. competitors all require robust data to inform decision-making. The United States is choosing to navigate a more volatile ocean with diminishing visibility, as one oceanographer put it. That is a terrible choice for any country trying to navigate today’s complex, cascading risk environment.
The OOI removal, once complete, would be hard to reverse. Once ships haul moorings up from thousands of meters down, the data record stops and the gap cannot be backfilled. A resumption of the program could start a new record later, but could never recover the years not measured. Rebuilding the network from scratch would cost far more than keeping the current one running.
The window is still open for fixes to this problem. There may be room for legal action to challenge the removals. One avenue could be an Administrative Procedure Act challenge, brought by OOI’s manager or a similarly affected party, arguing that NSF’s decision was arbitrary and capricious — for instance, that the agency failed to adequately justify dismantling the arrays or to follow required process. A separate question is whether unwinding a program Congress chose to fund implicates legal constraints on impoundment.
Also, Congress could pass legislation to prevent the use of funding for further removals next year or require the administration to consider selling the arrays to a trusted partner, though fast action is needed because the equipment, once removed, is effectively lost. The European Union is a potential buyer; in response to U.S. cuts, it recently announced investment in a new program, “Ocean Eye,” that is designed to provide 35 percent of the global ocean observation system by 2035. The goal is simple. Maintain awareness and prevent surprise. The cost of watching is small next to the cost of being caught off guard to changes in the world’s oceans.
