Scientists at the University of Delaware are testing whether sharks can serve as mobile ocean-observing platforms, collecting measurements that could help researchers better understand and forecast hurricane intensity along the U.S. East Coast.
The project involves attaching conductivity, temperature and depth (CTD) tags to sharks. As the animals swim and dive, the instruments collect measurements through the water column. When the sharks surface, the tags can transmit data via satellite.
The University of Delaware described the research in a July 28, 2025 article. Reuters reported on the project on August 8, 2026, as researchers continued developing the technology.
A persistent challenge in hurricane forecasting
Scientists have become increasingly effective at predicting the paths of hurricanes, but forecasting how strong a storm will become remains more difficult.
Ocean conditions are an important factor. Warm water provides energy to tropical cyclones, while colder water beneath the surface can affect the amount of heat available to a storm as it approaches the coast.
The Delaware researchers are particularly interested in the heat content of the ocean’s upper layer, known as the mixed layer.
“We are really most interested in the heat content of the top layer of the ocean, which is known as the mixed layer,” Aaron Carlisle, a University of Delaware professor and principal investigator, told Reuters.
“This is the part of the water column that really drives hurricane intensity – warmer mixed layer equals stronger hurricane – as it holds the heat that feeds hurricanes,” Carlisle said, according to news report.
The objective is to determine whether measurements collected by sharks can give researchers additional information about these conditions across the Mid-Atlantic.
Sharks as mobile research platforms
Scientists have previously used marine animals such as seals to collect oceanographic data. CTD instruments attached to diving animals can record conditions at different depths while the animals move through the ocean.
The Delaware team is adapting that concept to sharks, which can travel across large areas and naturally move through different parts of the water column.
The researchers are interested in shark species whose behavior makes them suitable for transmitting data. Reuters reported that species being considered include shortfin makos, blue sharks, smooth hammerheads and juvenile great white sharks.
The approach also changes the purpose of animal tagging. Instead of using the animals primarily to study their movements, scientists are seeking to use those movements to gather information about the surrounding ocean.
“Animals as ocean observers is an emerging branch of oceanography,” Matt Oliver, a University of Delaware professor, said in the university’s July 2025 article. “Instead of tagging the animals to just figure out where the animals go, it’s using the animals to tell you something about the ocean. Even though we’re going to get fewer profiles from these sharks, the profiles are going to be spread out in space and time. We’re excited about these tags, and we’re excited about what the sharks can tell us about the ocean.”
Complementing underwater gliders
The shark project is being developed alongside existing ocean-observation systems.
Researchers in the Mid-Atlantic already use autonomous underwater gliders to collect CTD measurements. The University of Delaware said the gliders provide vertical profiles showing what the water column looks like as hurricane season approaches.
The university also said the gliders are slow-moving, restricted to particular areas and expensive to deploy and maintain. The researchers believe sharks could provide observations across a wider area through their natural movements.
“The sharks and the tags are significantly cheaper, faster and have more variability in their movement behaviors,” Caroline Wiernicki, a University of Delaware doctoral candidate, said in the university’s 2025 article. “The idea is that these sharks can go out and help collect more data, more efficiently and then send it back for you rather than deploying the glider picket line.”
The shark system is therefore being explored as an additional source of ocean observations rather than a replacement for established monitoring platforms.
Mid-Atlantic’s cold pool
The Mid-Atlantic offers a useful environment for testing the technology because its waters become seasonally stratified.
According to the University of Delaware, colder water moves toward the bottom and forms a “cold pool,” while warmer water occupies the upper part of the water column during spring and early summer. By late July and early August, the separation between the warmer surface water and colder water below can become pronounced.
Researchers want the shark-borne CTD measurements to provide additional information about these conditions.
“For hurricanes, warm water is the gas, and cold water is brakes,” Wiernicki said. “Depending on where that cold pool is relative to the shore, that will impact how strong a hurricane is when it makes landfall or as it approaches our coast.”
The measurements could help scientists better characterize how temperature conditions vary across the region before and during hurricane season.
Getting the tags to transmit
One of the project’s biggest technical challenges is making sure the tags can communicate with researchers.
The equipment must reach high enough above the water to transmit data, while the sharks’ behavior is inherently unpredictable. Researchers cannot direct the animals to particular locations or determine exactly when they will surface.
Oliver described successful transmission as an important early milestone.
“Honestly, the challenge in all of this is getting a tag to report back to you,” Oliver said. “The tag has to get high enough out of the water to transmit, and you have so much variability in animal behavior. Right now, we only have one profile, but the fact that we actually got it to work is a big deal. If we can make this happen on a consistent basis, we can get a lot of high-quality oceanographic data in order to say something quantitatively about the ocean.”
Reuters reported that the tags are attached to sharks’ dorsal fins and are designed to transmit measurements when the animals surface. The tags can eventually detach from the sharks.
Early deployments
As of July 21, 2025, the Delaware researchers had successfully deployed two tags: one on a young white shark and another on a shortfin mako. The tags were produced by a group at the University of St Andrews in Scotland, according to the university.
The white shark continued transmitting after being tagged in May and was tracked near Martha’s Vineyard, Cape Cod and Long Island.
The shortfin mako traveled south toward North Carolina before heading north again, although it transmitted less frequently than the white shark.
The contrasting behavior highlighted a basic limitation of using animals as observation platforms: researchers cannot control where individual sharks travel or when they surface.
At the same time, that freedom of movement is central to the project’s potential value.
“We send the sharks out with a tag and they can collect the data for us and help augment the resources that we have,” Wiernicki said. “Ultimately, the sharks that carry this tag will act as oceanographers and ocean observing platforms to collect high quality oceanographic data and send it back to us in real time.”
A potential new source of hurricane data
The research involves the University of Delaware and the Mid-Atlantic Regional Association Coastal Ocean Observing System, or MARACOOS.
The immediate goal is to determine whether measurements gathered by tagged sharks can provide useful additional information about ocean conditions during hurricane season.
The project does not eliminate the need for satellites, gliders or other ocean-observing systems. Instead, the sharks could add another source of measurements from different locations and depths.
The key test will be whether those observations are reliable and sufficiently useful to improve the information available to hurricane researchers and forecasting models.
For now, the project remains experimental. But if researchers can establish a dependable stream of high-quality measurements, sharks could become an unusual addition to the ocean-observing network.
The broader concept is straightforward: instead of using marine animals only as subjects of scientific research, researchers are exploring whether their natural movements can help collect data about the ocean itself.
For hurricane scientists, that could eventually provide another way to monitor the ocean conditions that influence how powerful a storm becomes before it reaches the U.S. coast.