Sharks Equipped with Sensors Provide New Clues for Hurricane Forecasting
July 28, 2025
Emily Davenport, MARACOOS Communications Manager
New research explores how sharks can help collect vital ocean data to improve hurricane intensity forecasts.
In the Mid-Atlantic, researchers at the University of Delaware’s School of Marine Science and Policy are taking an innovative approach to filling critical ocean data gaps—sharks. Specifically, tagging Shortfin Mako and Blue sharks with sensors that measure conductivity, temperature, and depth (CTD) to turn the sharks into mobile ocean observing platforms (OOPs). The data collected by these animals will help improve hurricane intensity forecasting models across the Mid-Atlantic Bight (MAB).
This shark-based strategy is part of a larger effort to explore how biological platforms can complement and enhance traditional ocean observing systems. While satellites and surface buoys provide critical information about the ocean’s surface, understanding what’s happening below—especially in dynamic nearshore and mid-shelf waters—requires subsurface data. Traditionally, this data has come from expensive tools like gliders, ship-based CTD surveys, or Argo floats in the open ocean. But sharks, which naturally travel through a range of ocean depths and environments, offer a unique opportunity to gather subsurface measurements—like temperature and salinity—across regions that are costly, difficult, or even impossible to reach consistently with traditional methods. By equipping sharks with sensors, researchers are filling key data gaps, as well as improving our ability to model complex ocean processes and forecast weather events, all at a fraction of the cost.
Can Sharks Help With Hurricane Predictions?
The overarching research question driving this effort asks: Can sharks serve as effective ocean observing platforms in the Mid-Atlantic Bight (MAB) during hurricane season to augment more traditional sensor data used in predicting hurricane intensity?
Answering this question could be a game-changer for ocean observing. The Mid-Atlantic Bight is a region where ocean conditions—especially temperature stratification—can strongly influence the behavior of tropical storms. Yet, the shallow coastal areas in this region remain under-sampled due to limitations in current ocean observing infrastructure.
“Increasing the quantity and quality of ocean data in the Mid-Atlantic, especially in nearshore and shelf environments, is critical for improving hurricane forecasts,” said Matt Oliver, Patricia and Charles Robertson Distinguished Professor of Marine Science and Policy. “Traditional sensors often miss these areas. That’s where sharks can help.”
Why Makos and Blue Sharks?
Sharks, particularly species like Makos and Blues, are ideal candidates because of their regular diving and surfacing behavior. The project began by analyzing satellite-tag data from over 20 years of shark movements in the Pacific and Atlantic oceans. Out of the 11 shark species the team looked at, Shortfin Makos and Blue sharks ranked highest for surfacing frequency and transmission quality.
“We wanted to identify species that reliably came to the surface and stayed there long enough to establish a strong satellite connection,” said Caroline Wiernicki, PhD student at the University of Delaware. “The performance of the CTD tag is tied directly to how often and predictably the animal breaks the water’s surface.”
Shortfin Makos came out on top. These fast-swimming open water sharks surface almost twice daily on average, making them excellent candidates for CTD tag deployment. This behavior allows the CTD tag to collect a vertical profile of water column data as the shark comes up from depth. Once the shark surfaces again, the tag transmits that data—along with precise GPS coordinates—via satellite to researchers on land.
How the Tags Work: Collecting and Sending Data Successfully
Unlike air-breathing seals, which have long been used to carry similar tags in places like the Southern Ocean, sharks pose a greater challenge. Seals naturally surface to breathe, giving their tags frequent and extended opportunities to transmit data via satellite. Sharks, on the other hand, don’t breathe air and may spend long periods below the surface, limiting transmission windows and making data recovery far more difficult.
This means researchers must rely on a different set of dynamics, such as how often a shark dives and has its dorsal fin break the surface, to understand how to best program the tags to transmit collected data to satellites. When the shark surfaces, the tag breaks the water and connects with overhead satellites, sending the collected profile and establishing GPS coordinates. The entire system depends on the shark surfacing frequently enough and long enough for successful data transmission.
“The engineering challenge was designing a mounting system that would reliably keep the tag’s antenna out of the water during surfacing events,” explained Aaron Carlisle, associate professor in the School of Marine Science and Policy (SMSP) at the University of Delaware. “We learned from our first deployments and redesigned the tag housing to accommodate different fin shapes.”
That early iteration, tested on two Blue sharks in 2023, failed to consistently transmit data due to issues with tag placement and antenna exposure. The revised mount—rigid and contoured to fit the leading edge of the dorsal fin—was deployed on two Shortfin Makos in May 2025. The result: successful data transmissions, including CTD profiles and surface positions from one of the two tagged sharks.
Understanding Shark Behavior to Improve Data Collection
Seasonal migration patterns influence how much and what kind of data these sharks can collect. Makos and Blues both arrive in the Mid-Atlantic in May, but their behaviors diverge through the summer. Blue sharks shift northward toward cooler waters, while Makos often stay in the Mid-Atlantic Bight through early fall before moving offshore.
Because the CTD data is most valuable during the months leading up to and during hurricane season, the team aims to tag sharks as soon as they arrive and across a broad range of locations in the Mid-Atlantic, to maximize geographic coverage.
What’s Next: Scaling Up Shark-Based Ocean Observations
The team plans to deploy at least two more CTD tags this summer, continuing to focus on tagging Makos and Blues. As more data come in, they will collaborate with MARACOOS to integrate profiles into OceansMap and apply IOOS QARTOD quality control procedures before sending data to the GTS and ultimately to the Global Ocean Observing System (GOOS).
“This is a long-term vision,” Aaron Carlisle says. “We’re working toward a global system where tagged marine animals, including sharks, are routinely contributing real-time ocean data. But getting there isn’t easy—this is a completely new way of collecting information. It’s taken a lot of trial and error to figure out how to get the technology to function effectively on them. Each round of tagging teaches us something new—early tags failed, so we adjusted; the next round worked better but brought new hurdles. That iterative process is just part of breaking new ground.”
Watch an interview with Dr. Aaron Carlisle on Fox Weather’s YouTube channel:
This research was featured in:
–
As one of eleven certified U.S. IOOS regional associations, MARACOOS is dedicated to delivering high-quality ocean and coastal data to stakeholders, partners, and the public. OceansMap provides free and open access to critical data products that support decision-making in the Mid-Atlantic region, spanning from Cape Cod, MA, to Cape Hatteras, NC.
No responses yet