What is the Tarpon Genetic Recapture Study?
The Florida Fish and Wildlife Conservation Commission's (FWC) Fish and Wildlife Research Institute (FWRI) encourages anglers from throughout the state to genetically sample a tarpon, regardless of size, prior to release for identification purposes. We will evaluate our genetic samples from tarpon over time to estimate recapture rates and to examine the interconnectivity of tarpon among Florida’s estuaries, meaning a study to determine if tarpon travel between different offshore areas of the state. A small sample of skin cells collected from the outer jaw of the captured tarpon provides enough DNA to determine whether the fish was previously caught. For more information or instructions on how to collect skin cells from a tarpon, see our instruction page. A tarpon DNA sampling kit is available by e-mailing us at tarpongenetics@MyFWC.com or calling us toll free at 1-800-367-4461.

Why the need to identify an individual fish?
Tagging and marking a fish is a common tool in fishery science that has been used to obtain much information regarding fish species and their movements, migrations (including travel paths), speed, homing tendencies, spawning habitat, reproductive biology, survival rates, growth rates, site fidelity (or a specific place where a species of fish repeatedly return for reproductive purposes), stock identification, abundance, and more.
There are many methods used to mark an individual fish: internal, external, chemical, physical, and biological. There are also considerations regarding a project’s objectives that should be addressed to be sure the best method of marking or available tags are used to properly answer the question or hypothesis being tested in a project. In our current Genetic Recapture Study, we use DNA fingerprinting techniques to determine migration, movement, and recapture rates of individual tarpon. DNA is a permanent way to biologically mark an individual tarpon, and the information lasts forever.

Why is FWRI scraping the tarpon’s jaw for skin cells when they fin-clipped tarpon in 2006?
While fin-clipping is a common, relatively harmless method of obtaining DNA samples from fish, a series of trials during the 2006 tarpon season revealed a simpler but equally effective method. This new technique will be implemented in 2007. Because of the size, demeanor, and strength of some tarpon (both large and small), fin-clipping presented logistical challenges to anglers that are not encountered when handling smaller fish species. Our new technique requires less handling of the fish and in most cases can be performed by a single person while the tarpon is still in the water. While controlling the fish by holding the leader or lower jaw with one hand, the free hand can be used to scrape the outer jaw of the tarpon using an abrasive pad that the FWRI provides, thereby gathering a small sample of skin cells. This method is not a typical or common approach among other species, but is especially useful and preferable when dealing with such large, powerful fish. Mote Marine Laboratory, which works with us on a similar genetic recapture program for redfish that uses fin clips, is assisting the FWC in sampling tarpon DNA as well. Fin clips from tarpon will still be accepted.

Is fin clipping fish common in fishery science?
Fin-clipping fish has been used as a tool in fisheries research for a long time. It is a simple and quick way to externally mark a fish. Fin-clipping is easily carried out with a pair of scissors. Literature shows that partial clips of dorsal fins can be used as short term marks without adverse effects on survival or metabolism (Wydoski and Emery, 1983). The fins will regenerate, or grow back. However, permanent loss or damage can occur if a fin is removed to the point of where it is attached to the bone. References on studies evaluating the effects of fin clips date back to the 1940s. For tarpon, the elongated dorsal threadfin or dorsal filament is an ideal tissue to sample by taking only the tip (a half-inch) of the fin for DNA analysis. In reality, a clip of any fin of the tarpon would work. Today, fin clips are commonly used as part of Project Tampa Bay, which is a genetic study on redfish stocks and the effects of hatchery fish being introduced to wild stocks in the population.

Does fin clipping the threadfin of tarpon for genetic analysis hurt the fish? What is a threadfin used for?
A fin of a fish is used for swimming and direction, lift, thrust, drag, etc. We are aware of no scientifically credible theories as to what the threadfin of a tarpon may be used for, but many theories exist. Someone could learn of several just by talking with anglers who have been out on the water. To our best understanding the threadfin is just an elongated fin ray with no apparent function. Clipping the tip of the threadfin fin is like clipping a fingernail. The fin will regenerate itself.

Is removing a tarpon scale better than fin clipping for DNA samples?
No. The conservative approach is not to remove scales from fish. Scale removal has the potential to be much worse than removing a small area of superficial skin. If you must take a scale, you can do it without terminally harming the fish, but there is risk involved. After the scale is removed, take care to use a wet hand to rub the slime back over the area where the scale was removed. The slime coat of a fish is there for protection against disease. Without it, you open the exposed tissue to bacterial infection which could lead to bigger problems for the fish. Tarpon often lose scales during a fight, but the FWC does not promote pulling scales off tarpon. Scales can be used for DNA analysis but for various reasons, FWC biologists collectively believe that the skin cell sample is an ideal tool for DNA analysis.

What do I do with the DNA samples that I take for the Tarpon Genetic Recapture Study? Can I drop them off somewhere?
Please mail your tarpon DNA samples to:

FWC-FWRI
Attn: Tarpon Genetics
100 Eighth Ave. SE
St. Petersburg, FL 33701

or, you may drop your samples at one of our convenient collection locations around the state.

If you would like to provide a drop-off location, please e-mail tarpongenetics@MyFWC.com

Where can I learn more about tarpon?
Visit the Tarpon Section for more information.