Scientists tagging sharks in Gulf to predict hurricane intensity

Researchers tag sharks, tarpon, tuna and billfish with torpedo shaped sensors which gather data and send it back to satellites. Researchers tag sharks, tarpon, tuna and billfish with torpedo shaped sensors which gather data and send it back to satellites. Photo: Rosenstiel School Of Marine And Atmospheric Science Photo: Rosenstiel School Of Marine And Atmospheric Science Image 1 of / 30 Caption Close Scientists tagging sharks in Gulf to predict hurricane intensity 1 / 30 Back to Gallery

Fifty sharks, tuna, tarpon and billfish are swimming around the Gulf of Mexico right now fitted with satellite-linked tags to help scientists track water temperatures and perhaps one day help improve hurricane forecasting.

The devices were put there by researchers at the University of Miami who have tagged a total of 750 animals in the past 10 years to record water temperature and salinity at different depths.

The fish had merely provided data of interest to biologists, but earlier this year scientists realized the temperature figures coming back from the animals could be crucial to humans living in the path of hurricanes.

Biological sensors

Since the strength of a hurricane depends largely on the amount of warm water it hits as it forms, the idea is that the data from sharks could help weather forecasters plot more accurately just how big a storm may get by telling them how hot the water is.

"The fish act as biological sensors," said marine biologist Jerald Ault. "The fish dive, so they create a vertical picture of what the water temperature looks like."

That vertical picture generates a figure for Ocean Heat Content or OHC, the critical statistic you need to understand when forecasting the strength of a storm, according to Ault.

The tags look like mini torpedos and are clipped to the shark's fin. They were first used in 2001 and over the years scientists realized that the fish were gravitating to water measuring around 79 degrees.

The path of that exact isotherm is what meteorologists study when assessing the potential intensity of a storm.

Ocean hot spots

Meteorologists currently figure out where isotherms are using satellite data from above or by dropping their own sensors right into a storm. Often the picture produced is just a mass of red above the Gulf.

The fish tags give them firsthand access to pinpoint information.

"The data that the tags were providing could provide higher resolution data than the forecasters were getting," Ault said.

The team at UM's Rosenstiel School of Marine and Atmospheric Science admit that it's not a perfect science yet, but they say using animals as data gatherers has great possibilities.

For the sharks, the tags look quite big and cumbersome, although experts at the National Oceanic and Atmospheric Administration say attaching them behind the dorsal fin would feel like little more than an ear piercing.

Marine piercings

"They are usually tagged in the area below the first dorsal fin, it's an area that has very few blood cells and generally not a lot of nerve tissue," said John Carlson from NOAA.

Many of the sharks' routes over the past few years can already be seen using GPS tracking linked to Google Earth at the school's website.

The swimming highways of hammerheads, tiger sharks, makos, bull sharks and more can now be studied. Some, like Arianna, a hammerhead tagged in the Florida Keys, stay close in to the Gulf. Others, like sandbar shark Aldonza, are way out there in the Pacific, tagged off Hawaii. Heff, a shark also tagged in the Keys, made it halfway up the Eastern seaboard last month, spotted off the coast of North Carolina in early April.

Each time they come near or break the surface, the tag is triggered and sends its data back to the satellite.

Tens of millions of data points

Some suggest the idea of living marine meteorologists is somewhat of a stretch, but at UM they say the amount of data they are already getting is pushing them to move forward with the project.

"We've had fish move from Veracruz, Mexico, to the mouth of the Mississippi River in 30 days. Plus, they go back and forth, it's not a straight route, you could get tens of millions of data records," said Ault.

All that leads to a mass of information that one day could save lives, according to UM meteorologists.

"The fish can give a gazillion pieces of information, and that represents a really exciting opportunity," Nick Shay, a professor of meteorology and oceanography at Rosenstiel, told the Sun Sentinal.

To really get going, the researchers need many more tags to produce a whole army of ocean meteorologists.

"The problem is getting the density of tags up," said Ault.