A University of Miami professor has dedicated the past 10 years of his life to the study of a large fish that has launched a cult-like following all over the globe. The tarpon is not only one of the oldest fish in the ocean, it generates billions of dollars in sport fishing tourism.

University of Miami professor of marine science Jerry Ault and his team have been fishing for tarpon since five in the morning, here in the Florida Keys.  Tarpon is an anglers'  dream: big, fast, strong and able to jump over three and a half meters high in the air. 

The passion for the sport lies in the tarpon's  elusiveness.

This is a powerful animal that puts up a big fight.

After 30 minutes of back-breaking work, this team is finally able to bring a tarpon close to the boat.  

But this team is here not just for the sport.  They study tarpon and bonefish. 

They measure their catch: 1.6 meters long; 62 centimeters in circumference. It weighs around 60 kilograms.  They then take a DNA sample and implant a satellite tag on its back.

For the next few months, the tag will constantly record the fish's  environment for location, depth, salinity and water temperature. Professor Ault explains what will happen in a few months.

"The tag separates from the fish, it raises to the surface, it connects to the Argos satellite network, uplinks the data and then I get an e-mail that is basically ET is phoning home," he explained.

Until now, very little research had been done on the tarpon. 

But as the fish's numbers began to dwindle over the past few years, the demand for more information about the fish has increased.

Because billions of dollars are at stake with the loss of the tarpon population, Professor Ault found several organizations willing to shell out some cash for research.

"Currently in Florida, commercial fisheries generate about a billion dollars a year in economic revenue," he added. "Recreational fisheries are estimated by the state of Florida to generate about $10 billion a year revenue.  Recreational fishery in Florida is now more valuable than the citrus industry."

This group of anglers were taking a break at a local restaurant.  They have been coming for decades to the Florida Keys to fish tarpon.  Anay Brackett is a fly fishing guide from Georgia.  He has been coming for the past 42 years.

"I fish all around the world and there is no question about it, tarpon is the most spectacular game fish in the ocean," he noted.  "It is extremely exciting."

Professor Ault also dives into one of the most popular destinations for tarpon today: the shadowy depths under bridges.  He documents their number and size.  He says many factors are now threatening one of the strongest and oldest animals in the ocean.  That includes removing bait shrimp - one of the tarpon's favorite foods.

"Today they take of the order of half a billion pounds of shrimp, immature, that are being removed," Ault explained.  "We introduced pollution, through land base run off, we degraded the habitats, so is a combination of things."

Through his satellite tagging and research Jerry Ault has found out some valuable information that may one day help the tarpon from decreasing in population.

He has found that tarpon can travel great distances to find their ideal water temperature of 26 degrees centigrade.  From Florida, they can travel nearly 2,000 kilometers north on the U.S. Coast, or south into the the Gulf of Mexico, Central and South America.

"Unfortunately when it crosses into the U.S. border it is catch-and-consume and so for fishes that live the lifetime of a tarpon, 80 years, they are very vulnerable to any level of exploitation," he said.

Margaret Miller, a coral researcher at the National Marine Fishery Service in Florida, says the raising temperature of the oceans could endanger many species, including the tarpon.

"That is going to disrupt the cues that the animals use, the timing likely where they are queued to begin migrations and this is likely to affect a broad range of species as well," she noted.

And so, after a decade observing the tarpon Jerry Ault feels he has just begin to understand a fish that survived the extinction of dinosaurs, but whose future is now threatened by human activity.