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				“Tarpon research Finally under way” "Tarpon are thought to be migratory, moving from south to north and from salt to brackish or fresh water as part of their spawning cycle. They also travel from deep to shallow water, ostensibly to feed. However, a true species pattern is not clearly known." - Russell Chatham, Sterling Silver Tide magazine By Phil H. Shook Whether a broad-shouldered, silver plated giant looming out of the night to gulp air in front of the Pier House in Key West, a dozen six-footers streaming across a grass flat at Islamorada, or a four-pound chico crashing a popper next to the mangroves in a Venezuelan laguna, few sights are more energizing to salt water anglers than the appearance of tarpon. Interest in the welfare of Megalops atlanticus, the silver king, grew by leaps and bounds last year. It all started in about 1880 when the first tarpon reportedly were taken on rod and reel in Florida waters. Since then, presidents have fished for them, towns have been named after them and tackle has been designed and built to catch them. Anyone who has seriously pursued the tarpon seems to know something about them: They are difficult to hook, but will strike anything from a dead mullet to a three-inch fly. They are not good to eat, but excel as runners and jumpers. They feed in shallow water and spawn in deep water. Or do they feed in deep water and spawn in shallow water? Anecdotal evidence and opinions are as readily available as tarpon fishermen, but up until recently, little if any scientific information was available to back up the assumptions. Over the last three years researchers at the University of South Carolina and officials with the Florida Marine Research Institute have undertaken studies that for the first time will provide comprehensive information on the life cycle of tarpon, supported with scientific evidence. The data, which has been gathered with the aid of the most modern of laboratory equipment and techniques, has been collected from spawning grounds and nurseries in the Carolinas to the east coat of Florida, the Gulf of Mexico, Central and South America. Ned Cyr, a 27 year-old Freeport, Texas native and doctoral candidate in the Marine Science Program at the University of South Carolina, has been working on one tarpon study for two years. He expects to complete the work, which will form his doctoral dissertation, in early 1991. Co-investigators with Cyr in ongoing studies on tarpon are John Mark Dean, a biology and marine science professor at the Belle W. Baruch Institute for Marine Biology and Coastal Research, University of South Carolina, and Roy Crabtree, a tarpon biologist with the Florida Marine Research Institute. For the first time, thse studies provide data on how fast tarpon grow, how old they get, the differences in growth rates between male and female fish, and where and when tarpon reproduce. So what will new data mean to everyone with a stake in tarpon? Cyr and his fellow researchers have a clear view on the importance of such studies. "It is the foundation on which fisheries management is based, the critical information for the management of the (tarpon) stock," he says. "If you are going to spend money to protect tarpon, you need to know what the problems are," Cyr says. "We suspect that fewer juvenile tarpon in south Florida may be making it to the adult stage than did previously," Cyr says. "Now the research question becomes, why is this phenomenon occurring and the management question is, what can we do to reverse the trend." Mike Collins, a South florida fishing guide who is chairman of the Islamorada-based Hawley foundation, whose members are funding a good part of the tarpon research, says initial interest in the study stemmed from concerns about a serious falloff in the population of young tarpon in Florida over the past 10 years. "The tarpon is one of the major sport fish, economically and image-wise in the entire world, and the sum total of research before we started three years ago was 100 pages," Collins says. Billy Pate, the international angler and multiple world record holder for a number of species caught on flyrod, including tarpon, has become a major contributor to tarpon research, both personally and through the Hawley Foundation. Pate says he is most interested in the advances in genetic research that can now be applied to the tarpon study, to determine whether tarpon stocks in geographically diverse areas are related to each other. He says there are many intriguing questions that tarpon research will try to answer. "By analyzing DNA molecules, can we determine whether fish in Islamorada turn up in South Carolina or Homosassa?" And more important, Pate says, "Do our fish spend part of the year in South and Central America?" That could be a concern for future tarpon stocks in the waters of the United States, where the tarpon is not sought as a commercial food fish. "We know they eat them in Costa Rica. We have seen them in the markets in Venezuela and Brazil," Pate says. Pate, who has been on a lifetime quest to land a tarpon of 200 pounds or more on flyrod to top his own world record of 188 pounds on 16-pound tippet, says there are 200-pound fish "around" in countries like Gabon, Venezuela, Mexico and even the United States. "There are a few 300-pounders around took," he says. George Hommell, co-owner of World Wide Sportsman in Islamorada who occastionally guides President Bush on the bonefish flats, is a longtime conservationist who also understands the economic implications of a healthy tarpon population. "Flyfishing is becoming so important to South Florida and the Florida Keys, and the tarpon is the main fish for flyfishing," Hommell says. "If something happened to them it would be disastrous." Pate, Hommell and Terry McKendree, who opened his Safari Caribe operations in Rio Chico, Venezuela to researchers, are among a growing number of anglers, conservationists and outfitters giving their support to the tarpon projects. After collecting larval tarpon off Tampa and Boca Grande, Florida and also researching taxidermist's records and collecting fish from Casa Mar in Costa Rica and Rio Chico, Cyr and his colleagues have arrived at a number of interesting preliminary findings. In ecological terms, Cyr says the tarpon is characterized by large size, slow growth rates, late age of sexual maturity, a long life span, different growth rates for males and females, and annual reproduction. "Species with these life-history characteristics tend to have very stable population sizes over time as long as they are not disturbed," Cyr says. The smallest sexually maturing female examined by the researchers was about 37 pounds and 11.3 years of age. The smallest mature male fish (running milt) was 25 pounds and about seven years old, based on growth curve estimates. Cyr says the late age and large size at sexual maturity are characteristics of fish populations which can easily be affected by overfishing and are generally slow to recover from overfishing. "What we are trying to point out is that tarpon may need to be managed more conservatively than other fish species," he says. Cyr and his colleagues have collected more than 1,000 adult and juvenile tarpon in a monthly sampling program. To estimate the reproductive stages of female tarpon, researchers have taken samples of reproductive organs (ovaries), examining more than 15,000 separate and maturing eggs under the microscope. Based on egg samples examined in the Boca Grande Pass area on Florida's Gulf Coast, researchers suspect that spawning tarpon move into the area beginning in April (a period that corresponds with the beginning of fishing season) but don't remain there long. Cyr said researchers surmise that the Boca Grande fish are migratory, moving into the pass to feed for a short time in the productive estuary waters there, but then they leave to spawn offshore. "These fish appear to spend a very specific portion of their developmental period in the pass, and all of the fish in the pass at any given time are in the same general, pre-spawn developmental stage," Cyr said. He said this also may be the case in other large passes, such as Miami's Government Cut, where large schools of tarpon congregate during the April-June spawning season. Evidence that tarpon are spawning offshore during April through June is supported by the presence far offshore of extremely small tarpon larvae, which have back-calculated spawning months of May, June and July. Crabtree and other researchers at the Florida Marine Research Institute have documented the presence of huge daisy chains of tarpon estimated at up to 500 fish forming off the west coast of Florida in early summer. "We think these huge daisy chains serve as a mechanism for tarpon to aggregate before beginning their offshore migration, so they can arrive at the spawning grounds together," Cyr says. He also notes that large schools of adult tarpon have been observed up to 80 miles offshore in June, presumably heading out to spawn. Cyr says this is based on observations and must be confirmed by catching fish offshore and examining their reproductive organs. "But it seems to fit together well," Cyr says. Studies to date of 206 adult tarpon (based on 20 pounds as the cutoff for an adult fish) indicates an age range of 10 to 51 years, with an average of 22 years. Intriguing to researchers is the finding of a large frequency in the same age class of 17 years. "This could mean either that 1972 was an extremely good year-class for tarpon, or that 17 year old fish at about 73 pounds are simply the most prevalent fish in the sportfishery," Cyr says. "Unfortunately there is no easy way to tell the difference." The researchers also have gathered age and growth rate information by removing otoliths, the ear stones, from tarpon and examining them in the lab. In addition, tissue samples are being collected and frozen in liquid nitrogen. Information from the ongoing study at Florida's Marine Research Institute will be used to determine whether tarpon stocks in North America, Central America and South America are related, or are part of different populations. "If we find that tarpon in Florida, Costa Rica and Venezuela are parts of separate and distinct populations, then overfishing in one area won't have an impact on the others," Cyr says. "But if we find it to be one big population, then what happens in a breeding nursery in Venezuela could affect tarpon stocks in Florida." While sampling efforts have not taken place in Texas waters, Cyr says he tries to relate his overall findings to the Texas stock. "Something occurred that radically altered the habits or the numbers of fish (that once came into Texas waters)," Cyr says. "We are talking about a big group of fish and they stopped coming in." He said you can speculate forever on what might have happened in Texas, but answers will come only after long term data are gathered. March/April 1991