Tarpon scrub down
By David A. BrownEditor's note: David A. Brown has a B.A. in journalism from the University of South Florida and you can see his work in Florida Sportsman, FLWOutdoors.com, Cabela's Outfitter Journal, TIDE, In-Fisherman, Louisiana Sportsman, The St. Petersburg Times and Saltwater Angler. He also ghost-wrote and published "Fish Smart — Catch More!" for Tampa's cable TV host Capt. Bill Miller (www.billmiller.com) and a couple more publishing projects will be docking soon. He operates a professional writing/marketing agency, Tight Line Communications.
If you've ever wondered how tarpon fare in the catch-and-release experience, studies show that they do just fine. Kathy Guindon, fisheries biologist with Florida's Fish and Wildlife Research Institute in St. Petersburg, said that sonic transmitters attached to tarpon through 2007 have proven that most tarpon survive catch-and-release. That's encouraging, but stats on recapture frequency and fish movement would be equally valuable — if they weren't so scarce.
Enter forensic science — the newest tool for tarpon management.
Guindon heads up the Tarpon Genetic Recapture Study, a joint research project between FWRI and Mote Marine Laboratory in Sarasota. Through this program, DNA samples taken from captured tarpon are analyzed to determine basic details that may provide clues as to what happens after a release.
"Tarpon are hardy fish and the data shows that they do survive after being released," Guindon said. "The next question was: 'If most of these fish survive, 'How many are caught again and where?' We're now looking at this so we can start to see the recapture rates and movement."
The study collects tarpon DNA through dorsal fin clippings taken by FWRI scientists and skin cell samples obtained from abrasive pads rubbed against a tarpon's bony cheek plates. Recreational anglers provide most of the DNA "scrubs."
Officially launched in 2006, the FWRI/Mote partnership is steadily building a database of details on individual tarpon catches — location, date, etc. Comparing DNA samples from past and future catches provides a definitive picture of which fish are recaptured. Such information is vital because the tarpon's highly-migratory ways, plus its extremely challenging nature makes it a difficult species to study.
With the slogan "Any Tarpon, Anywhere, Any Size" the study provides a more angler-inclusive system than conventional dart tagging. Mote biologist Carole Neidig points out that the DNA method opens the study to more fish and, therefore, more data. "Genetic sampling allows you to take DNA from any size tarpon, whereas we wouldn't have used conventional tags for smaller fish. You can go ahead and take that sample and we'll know that fish forever."
Noting that FWRI can work up a tarpon DNA sample for about $3, Neidig said: "It's a lot more reasonable for us to do this than to purchase tags. It's a very cost-effective method and with the anglers helping us collect the samples, that helps drive the cost down even more."
FWRI provides sampling kits with scrub pads, plastic vials with ethanol for preserving the samples, catch data sheets, pencils and zippered plastic bags for returning the samples to official drop-off sites. No refrigeration is necessary and drop-off sites can also provide additional sample kits.
For information on genetic tagging, call (800) 367-4461 or email TarponGenetics@myfwc.com.
