The vast ocean dwarfs our efforts to understand it. Sensor-laden buoys, high-flying satellites and sophisticated computer models can only do so much to plumb the depths of the waters covering more than two-thirds of the planet.

But a creature with intimate knowledge of the ocean might help humans get a more accurate picture of what lies beneath. Sharks could serve as mobile, wide-ranging sensor systems, collecting data that improves our understanding of ocean conditions in ways that might inform fisheries management and other critical activities, according to new research in the journal npj Climate and Atmospheric Science.

“Sharks are already moving through parts of the ocean that are challenging for us to observe,” said Laura McDonnell, the lead author and a postdoctoral scientist at the Woods Hole Oceanographic Institution (WHOI) in Massachusetts. “This research shows that data they collect can help fill important gaps.”

Scientists have attached sensors to sharks for years, but usually with the intent of understanding what’s going on with the animals. In 2022 I spent five days on the Atlantic Ocean near Africa with a team of scientists catching sharks and drilling holes in dorsal fins to attach light-bulb-sized sensors. They wanted to know how the sharks’ behavior changed as they swam through patches of low-oxygen water.

Neil Hammerschlag, a co-author of the new paper, was using sensors in much the same way as a marine ecologist at the University of Miami (UM) when, in 2018, he spoke with UM atmospheric scientist Ben Kirtman about the possibility of using data from the sensors to study the ocean, rather than the fish.

“Marine predators like sharks naturally seek out dynamic ocean features such as fronts and eddies,” explained Kirtman. “These are areas where models often lack sufficient observations.”

As a Ph.D. student at UM, McDonnell took on the question of whether this might work.  In waters off the Northeast U.S. coast, McDonnell and colleagues attached sensors to the dorsal fins of 18 blue sharks and one shortfin mako shark in October 2021. Then they set them loose, like so many fast-moving drones.

In the following months, the equipment decorating the sharks’ fins collected moment-by-moment measurements of temperature and depth, two pieces of data critical to understanding the state of the ocean in a particular place. When the animals surfaced, the tags transmitted the information to satellite and on to the scientists. All told, they collected more than 8,200 snapshots of ocean conditions from the sharks. While the data was concentrated off the coast of the eastern U.S. north of Virginia, the sharks roamed as far south as Florida and out into the middle of the Atlantic. They also gave scientists glimpses of conditions at depths of almost 2,000 meters as they dove.

The researchers took this trove of information and used it to fine tune a computer program commonly used to model current ocean conditions based on data from ocean-going buoys and other sources. In certain parts of the ocean, the shark-enhanced approach was significantly closer to reality than the standard model, when scientists tested to see how well the models simulated ocean conditions during the time when the sharks were collecting the data. (The ability for computer models to accurately reconstruct past conditions is a standard test for ocean and atmospheric models.)

The improved performance was particularly notable along the shallow continental shelf, where it reduced the model’s error by 43% for November and 33% in December. That added up to the model being around 1.5°C closer to the mark when it came to sea surface temperatures, a significant improvement in an environment where subtle temperature shifts can drive major ecological changes.

 “For fisheries and coastal communities, small improvements in ocean forecasts can make a big difference,” said Camrin Braun, an oceanographer at WHOI who worked on the study. “Reducing uncertainty helps people plan, whether that’s where to fish, how to manage resources, or how to respond to changing conditions.”

That doesn’t mean sharks will be replacing other data-gathering, cautioned McDonnell. This was only a short-term experiment, and there is no mention of a more comprehensive effort to enlist sharks to the front lines of ocean forecasting. But it does show that tags formerly used to just understand the sharks could do double duty by shining more light onto broader mysteries of how the ocean is changing.

McDonnell, et. al. “Improved seasonal climate forecasting using shark-borne sensor data in a dynamic ocean.” npj Climate and Atmospheric Science. April 28, 2026.