Sharks as Ocean Sensors: A Revolutionary Approach to Hurricane Forecasting
The Intersection of Nature and Technology
In a fascinating fusion of marine biology and meteorology, scientists at the University of Delaware are turning to one of the ocean’s top predators—sharks—to enhance hurricane forecasting. This innovative research involves tagging sharks with sensors that gather crucial data on ocean conditions, offering a fresh perspective on how to predict hurricanes more accurately as they approach the U.S. East Coast.
Understanding the Role of Ocean Conditions in Hurricanes
Hurricanes draw energy from the ocean, particularly from the heat stored in the upper layers of water. Understanding the conditions beneath the surface can significantly improve forecasts of hurricane intensity. However, data from these layers is often scarce, especially in the challenging environment of the Mid-Atlantic Bight, where currents and temperatures can be unpredictable.
Sharks as Mobile Data Collectors
The concept behind this research is to convert sharks into natural, mobile ocean-observing platforms. While traditional methods of ocean data collection, such as satellites and surface buoys, are useful, they fall short in capturing the complexities of underwater conditions. Other systems like underwater gliders and Argo floats can be expensive and logistically challenging to deploy.
Sharks, with their natural migratory behavior and ability to travel through various depths, provide a unique solution. This innovative approach allows researchers to collect valuable data from areas difficult to monitor regularly.
How the Data Collection Works
The sensors, known as CTD (Conductivity, Temperature, Depth) tags, are attached to sharks and monitor temperature, depth, and electrical conductivity, which is closely related to salinity. As the sharks swim and dive, they acquire measurements at different depths. When the sharks surface, the tags send the collected data and GPS location to satellites.
This method is not entirely new; animal-borne sensors have been successfully used for years on species like elephant seals in remote polar regions. However, sharks present a more feasible option for researchers due to their widespread distribution and easier access compared to many marine mammals.
Selecting the Right Shark Species
Not all sharks are suited for this kind of data collection. After analyzing more than 20 years of satellite-tagged data from various shark species, researchers determined that shortfin makos and blue sharks are the most appropriate candidates. These species are particularly promising due to their frequent surface-swimming behavior, which allows the tags to establish communication with satellites regularly.
Shortfin makos, for instance, surface nearly twice daily, providing ample opportunities for data transmission. However, sharks also present unique challenges compared to other tagged animals. Unlike seals, sharks can remain submerged for extended periods, complicating the frequency of satellite connections.
Overcoming Technical Challenges
The initial phase of the project faced several technical difficulties. In 2023, the first versions of the CTD tags tested on blue sharks struggled to transmit data consistently, primarily due to improper placement and exposure issues. In response, researchers redesigned the tag housing and mounting system to better accommodate the varying dorsal fin shapes of different shark species.
By May 2025, researchers successfully attached the redesigned tags to two shortfin makos; one shark transmitted valuable CTD profiles and surface positions, marking a significant milestone in the project.
Timing the Tagging Process
To maximize data collection, researchers aim to tag sharks during the months leading up to hurricane season. Shortfin makos and blue sharks migrate to the Mid-Atlantic in May after wintering in deeper offshore waters. Understanding their movements during summer is crucial, as blue sharks tend to move north to cooler waters, while shortfin makos linger longer in the Mid-Atlantic.
The tagging process is conducted about 30 to 40 miles offshore, involving baited lines and careful monitoring to entice sharks. Once a suitable shark takes the bait, researchers quickly attach the tag, adhering to strict protocols to ensure the animal’s health and wellbeing during the procedure.
Data Processing and Future Applications
The research team plans to deploy additional CTD tags during the summer, focusing on enhancing the coverage of their data collection efforts. Collaborating with organizations like MARACOOS (Mid-Atlantic Regional Association Coastal Ocean Observing System), the collected data will be integrated into OceansMap for analysis.
Once through quality-control procedures, this information will be routed to advanced global networks like the Global Telecommunication System and the Global Ocean Observing System, laying the groundwork for incorporating marine animals into a more comprehensive real-time data collection system.
The ultimate objective of this remarkable initiative is to enable scientists to refine hurricane intensity forecasts, offering a lifeline for coastal communities at risk as storms begin to approach.
As this innovative research unfolds, it not only highlights the adaptability of scientific methods but also emphasizes the crucial relationship between nature and technology in addressing pressing environmental challenges.