US Scientists Turn to Sharks for Help With Hurricane Prediction

Scientists at the University of Delaware are using sharks as underwater helpers to gather information about the ocean. They are attaching small electronic devices to sharks swimming off the US East Coast. The goal is to collect data that could one day help predict how powerful a hurricane will be before it reaches shore.

The devices are called CTD tags. They measure three things: how salty the water is, how warm it is, and how deep the shark swims. Each time a tagged shark swims near the surface, the tag sends that information up to satellites in orbit. Scientists can then use that data to study ocean conditions in near real time.

Warm ocean water is what gives hurricanes their energy. The top layer of the ocean, called the mixed layer, is especially important. '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,' said Aaron Carlisle, a professor at the university's School of Marine Science and Policy.

Sharks make good data collectors for a few reasons. They are found in large numbers across wide stretches of the ocean. They are also easier to work with than many protected marine mammals, like whales or seals. In the past, scientists used sensors on elephant seals in polar regions, but sharks open up new areas that were hard to study before.

Not every shark species works for this project. Researchers look for sharks that swim near the surface often enough for their tags to send signals to satellites. Good candidates include shortfin mako sharks, blue sharks, smooth hammerhead sharks, and young great white sharks. These species all move through the North Atlantic, which is where many hurricanes form and travel.

The tagging process starts in early May, when certain shark species migrate closer to the coast. Researchers travel 50 to 65 kilometers offshore on a research vessel and drop baited lines into the water. They usually wait two to three hours for a shark to bite, said Caroline Wiernicki, a doctoral student in marine science at the university.

Once a shark is caught, the tagging team works quickly — like a pit crew at a car race, according to Carlisle. The whole process takes less than five minutes. A health check is done on each shark before it is released, because a stressed animal might not behave normally, which could make the data less reliable.

The tags are designed to be safe for the sharks. They are made with materials that slowly break down in saltwater, so the tag eventually falls off on its own. The project follows strict animal care rules to make sure the sharks are not harmed. Researchers want healthy, active sharks so the data they collect is as accurate as possible.

If the project is successful, it could make a real difference for people living on the East Coast. Better hurricane forecasts could help communities from North Carolina to Massachusetts prepare more effectively. As storms grow stronger over time, having more accurate warnings could help save lives and reduce damage.

Carlisle said most people only know sharks from scary movies and stories. But in reality, he said, 'they are amazing animals perfectly adapted to the ocean, and we can learn a huge amount from them.' He added that if sharks can be shown to help people stay safe, 'it's a win-win situation.'