Mystic ― In August 1976, 14-year-old Jon Dodd was one of several people involved in catching a 10-foot blue shark off the shore of Sandy Point in Stonington.

The experience, for the teen who had been fascinated by sharks since he was a young child, was memorialized on the front page of The Day and played a major part in Dodd’s future.

Today, Dodd, who still spends his summers in Stonington, is the founder and executive director of the Atlantic Shark Institute, an organization dedicated to shark research in Wakefield, R.I.

His organization is looking at data coming from a new seal research collaboration between Mystic Aquarium and the Rhode Island Department of Environmental Management to further the understanding and conservation of great white sharks, classified as vulnerable by the International Union for Conservation of Nature.

The project will use photography, drones and seals tagged with satellite and acoustic trackers to determine the current number of seals near the North Light lighthouse on Block Island to determine if the population is growing. It will also look at behavior of rehabilitated and released seals.

Dodd said last week that shark conservation is vital. Over 100 million sharks are killed each year through overfishing, being accidentally caught by fishermen in nets or on hooks, and by shark finning. The latter is the practice of removing a shark's fins, which can demand a high price for use in shark fin soup in parts of the world, and tossing its body back into the ocean where it usually dies.

“What we say is: ‘Shark health is ocean health, and ocean health is our health,’ ” he said, explaining that as an apex predator, sharks keep the food chain in balance.

When shark populations decline, there is nothing to keep other predators, like seals, in check, and those populations can explode, ultimately decimating each subsequent lower-level life form down to the fish that eat algae and plankton and keep reefs clean and healthy.

In early February, the aquarium and the DEM’s Division of Marine Fisheries kicked off the one-year research project, funded by a $150,000 United States Fish and Wildlife Pittman-Robertson grant, when the aquarium tagged and released a gray seal named Scarlet, with both satellite and acoustic trackers. Last month, a gray seal named Jeffrey Morgan was also tagged and released.

The satellite trackers allow researchers to monitor seal locations in real time for around three months, until it falls off. The acoustic trackers last far longer and send out signals that are picked up by acoustic receivers deployed by states, researchers and government entities along the coast of the United States and farther out in the oceans. Rhode Island has 43 acoustic receivers that it deploys seasonally in Rhode Island waters.

Whenever a seal comes within a half to one kilometer of a receiver, it will pick up the signal, allowing researchers to note the location of a seal. Tracking the seals will help researchers find a baseline number of seal residents on Block Island to monitor population growth, which anecdotally has been growing in recent years.

DEM Department of Marine Fisheries Chief Conor McManus, said drone photos taken early last week showed more than 600 seals, up from approximately 270 last year. It is unclear whether the seals are permanent residents or just passing through the area, but the research will shed light on changing population and migratory trends as well as inform how policy makers manage commercial fishing in areas where seal populations are increasing.

Sarah Callan, program manager for the aquarium’s Marine Animal Rescue Program, said the data can also inform research into how climate change and rising water temperatures may impact seals, sharks and other sea life.

The aquarium has tagged five seals to date and hopes to tag up to 25 seals as part of the research to study seal behavior, changing ocean conditions and seal populations.

For Dodd, the research has significant implications for understanding great white shark behavior and conservation of a species critical to the ocean environment.

He said recent studies estimate that 800 great whites come to the waters off Cape Cod each year where there are thousands of seals. More than three hundred of the sharks have been tagged with acoustic trackers to date, allowing the institute along with other agencies and researchers to track their movements and study population trends using the same acoustic receivers used to track the seals the aquarium releases.

“Each of these releases is adding exponentially to the data set and the information about seal movements,” Dodd said.

He explained it is important to find out what the seals are doing because seals, while prey for adult great whites, are also predators that compete for some of the same food sharks eat.

Currently, he said, the sharks detected around Block Island are “just passing through,” and there for just a period of hours before disappearing, but the Atlantic Shark Institute wants to know the point at which a seal population gets large enough to gain permanent great white residents. He said he is unaware of any previous studies that have attempted to determine that.

Dodd said the data may lead to other potential answers about how shark populations impact seal populations and seal behavior.

“We’re intrigued by the white sharks we’re detecting, the growing seal population, our new ability to track the movements of both, when that might result in a resident, if it ever does, and if that happens, what happens then,” he said.