Scientists at the University of Delaware in the US state of Delaware are investigating whether sharks can be used as observational systems to collect ocean data and improve forecasts of hurricane intensity.
Researchers at the University of Delaware are fitting sharks with sensors that measure ocean temperature, electrical conductivity and depth. Electrical conductivity is related to the amount of salt in the water.
According to Aaron Carlisle, a professor at the university’s School of Marine Science and Policy and the study’s lead researcher, animal-mounted sensors have been successfully used in ocean research for years, particularly in areas where scientific observations are limited.
Researchers say sharks are suitable for the study because they are relatively abundant, inhabit large areas of the ocean and are easier to access than many protected marine mammals.
Until now, shark tagging has mainly been used to track their movements and habitats. In the new research, however, scientists are selecting sharks that can collect useful data for hurricane forecasting and regularly come close enough to the ocean surface for their tags to transmit information via satellites.
Initial analyses in the North Atlantic identified shortfin mako sharks, blue sharks, smooth hammerheads and juvenile great white sharks as suitable species for the research.
According to Carlisle, scientists are particularly focused on heat in the upper layer of the ocean, known as the “mixed layer.”
He explained that this layer plays an important role in hurricane intensity because a warmer mixed layer can contribute to stronger hurricanes.
Caroline Wiernicki, a doctoral student at the University of Delaware, said the shark-tagging process begins in early May, when several migratory shark species return closer to shore after spending the winter in remote areas of the Atlantic Ocean.
Researchers travel by boat to waters around 50 to 65 kilometers offshore, where baited lines are deployed and they typically wait two to three hours for a shark to approach.
A tag is attached to the shark’s dorsal fin. When the shark swims near the surface, the tag connects with a network of satellite receivers and transmits data.
Carlisle said the tagging process is completed rapidly, much like a “pit crew” during a motor race, and usually takes less than five minutes. Shark tagging is carried out under institutional animal-care oversight to minimize its impact on the animals.
The tags are attached using materials that gradually break down and detach over time. Each shark is also examined for its health before being released back into the ocean, as stress or injury could alter its natural behavior and potentially affect the data collected.
Wiernicki said sharks are portrayed as extremely frightening animals in movies, whereas in reality they are relatively calm creatures.
According to researchers, if the project succeeds, data collected from sharks could help improve forecasts of hurricane intensity along the US East Coast.
The information could provide more reliable forecasts to coastal communities from North Carolina to Massachusetts, helping them prepare for hurricanes and strengthen coastal protection.
Carlisle said sharks are remarkable animals that are exceptionally well adapted to the ocean and that there is much that humans can learn from them. If it can be proven that sharks can also benefit humans, he said, it would be a win-win situation for both.
