Scientists turn sharks into real-time ocean observers with sensors

Researchers from University of Delaware are transforming how oceanographers (scientists who study the earth's oceans) track marine conditions by deploying specialised electronic tags that turn living sharks into mobile, real-time data collection hubs. The research project, led by marine scientist Aaron Carlisle, equips predatory fish with advanced sensors designed to collect water profiles across the US East Coast.Instead of merely tracking animal movements, the tags gather critical data on temperature, salinity and depth – feeding real-time information directly into atmospheric and climate forecast models. The research was published in journal Frontiers in Conservation Science.Researchers decode ocean heat that fuels hurricanesThe primary goal of the tagging initiative is to map the upper layer of the ocean, known to oceanographers as the mixed layer. This upper column of water holds the thermal energy that directly feeds and amplifies hurricane strength.“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,” explained Carlisle, a professor in the university's School of Marine Science and Policy.While oceanographers have deployed sensor tags on marine mammals like elephant seals in polar regions, sharks present a unique advantage for Atlantic storm tracking. They are abundant, widely distributed, and traverse key coastal corridors where major hurricanes develop and gain strength before making landfall.Researchers target migratory species that surface frequently, such as shortfin mako sharks, blue sharks, smooth hammerheads and juvenile great white sharks. Frequent surfacing is critical because the electronic tags must reach the water's surface to transmit cached environmental data up to orbiting satellite networks.Tagging executed like a ‘Pit Crew’The research team conducts offshore expeditions aboard the university’s research vessel, deploying baited lines 30 to 60 kilometres off the Atlantic coast. When a shark is brought alongside the vessel, the team executes the tagging protocol with extreme precision under strict animal welfare guidelines.“The tagging process itself is operated like a pit crew in an auto race,” Carlisle said, emphasising that the procedure typically takes under five minutes. Each animal undergoes a quick health check before being tagged on its dorsal fin. To protect the sharks long-term, the tags are secured using metallic components designed to naturally corrode and shed after a predetermined period.Get the latest technology news and updates. Download the TOI App.