days. It likely wintered in south Florida and then migrated up the Atlantic coast rather than back into the Gulf. Another fish was at large for eight years between tagging and recapture. “The problem with the dart tags is that we don’t know what happens between Point A and Point B,” Franks says. “We have no idea what that fish did in between. That’s why we want to tag more with the microwave telem- etry satellite tags. They provide daily tracking and movement for as many as four months. They can also tell us the water temperatures and depths the fish stayed in. So far we have tagged five fish with the satellite tags, although we haven’t had a chance to analyze the data yet. We do know at least one fish migrated from Mississippi west through Louisiana and then into Mexico’s Yucatan waters.”
ON THE RUN
Cobia primarily eat fish, although they appreciate variety as well. Croakers, menhaden and spiny box- fish are favorite food. So are hardhead catfish, based on stomach samples — although it is unclear as to whether catfish is on the menu by choice or because so many anglers use them as bait. Cobia also love eels and crabs, and they will water column.
feed throughout the
There may be two distinct groups of cobia within the Gulf — an eastern and western segment. And there is also another possibility that some migrate in a circular pattern every year.
Cobia show up off Florida Pan- handle beaches every spring and mosey up the Atlantic coast, making fre- quent layovers in South Carolina’s Port Royal Sound and along the Outer Banks before spending vacation time around the Chesapeake Bay Bridge. But where do they go afterwards? Are
TIDE
they true snowbirds that winter in Miami Beach and the Keys? Or do they hang out in deep water offshore and wait until St. Patrick’s Day? That is the big mystery that is slowly becoming clearer thanks to tagging studies. One of the longest-running programs is administered by the University of Southern Mississippi’s Department of Marine Resources Gulf Research Lab- oratory and is funded by the U.S. Fish and Wildlife Service Sportfish Restor- ation Program.
“Several colleagues with the South
Carolina Department of Natural Re- sources, the North Carolina Division of Marine Fisheries and Virginia Institute of Marine Science have done various cobia tagging studies,” explains Jim Franks, a biologist with USM’s pro- gram since 1988. “Read Hendon has been running our program for the last several years. It’s been a big factor in determining what we do know to date about cobia migration.” “A lot depends of how long the fish has been at large since it was tagged,” Hendon adds. “Thousands of anglers have participated in the program, and that really adds to our overall data base.”
Hendon says the long-distance
record was for a fish tagged in April 1994 near Pensacola, Florida. It was recaptured again in July 1995 off Hardeville, South Carolina, a distance of 1,280 miles over a period of 479
www.joincca.org Based on the traditional nylon dart
tag returns, Franks and Hendon say there are five possible explanations of cobia travel. The first and most proba- ble is, the fish winter in south Florida and then migrate up the Florida penin- sula into the Gulf or Atlantic Ocean. There may be a small subset that stays south all year around the reefs and wrecks. Another group may be resi- dent fish that stay in deep, warmer water all the time, or only migrate occasionally.
If so, these fish probably
stick close to oil and gas rigs or other offshore structure. Franks suspects there may be two distinct groups of cobia within the Gulf — an eastern and western segment. And there is also another possibility that some migrate in a circular pattern every year.
“The only way to know for sure is with more satellite tags,” Hendon explains. “We suspect some of the fish off southwest Louisiana and Texas con- tinue swimming into Mexican waters. But with the tag instructions in English and the amount of commercial fishing in those waters we don’t know for cer- tain. Obviously there is still much to be learned and it’s all tied to the number of anglers who fish for cobia and vol- unteer to tag those they release.” Those who want to help with the tagging efforts can contact Hendon at
read.hendon@usm.edu or call 228-872- 4202 to receive a free tag kit.
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