Group: Super Administrators
Joined: Jan. 2004
||Posted: Oct. 28 2007,08:21
A fascinating read...
|Fishermen have plenty of theories on why fish do what they do.|
Dr. Jerry Ault has facts.
Ault is a professor of marine biology and fisheries at the University of Miami's Rosenstiel School of Marine & Atmospheric Science in Virginia Key. Among his current research projects is tagging bonefish and tarpon.
Those tags tell a much different story than the anglers who pursue those species.
For example, some fishing guides claim there is a Biscayne Bay population of bonefish and a Keys population, and that bonefish stay where they are.
Over the past 10 years, Ault enlisted the aid of 114 flats guides who tagged 5,593 bonefish. The 167 tagged bonefish that were recaptured provided some fascinating information, like the bonefish that was caught again after traveling 110 miles in 10 days.
"The one that kind of blew our socks off was tagged in Bear Cut, near the school," Ault said, "and 321 days later, it showed up off Andros Island [in the Bahamas]."
Ault shared his findings Wednesday night before a capacity crowd at Lauderdale Yacht Club in Fort Lauderdale. His presentation entitled "The Future of Sport Fishing in South Florida" was part of the Dr. William W. Dolan lecture series.
A dentist and sailor who was a member of LYC, and who had several patients who worked at Rosenstiel, Dolan was fascinated by their research. After his death, Dolan's widow, Jean, funded the free lecture series in her husband's memory.
Ault, whose book Biology and Management of the World Tarpon and Bonefish Fisheries was recently published by CRC Press, said that there is a lack of information about bonefish and tarpon. Using standard tags and pop-up archival tags or PATs, has provided Ault and his students with ground-breaking dat.
For example, the Keys and Biscayne Bay don't have many small bonefish. Ault's explanation was that when bonefish spawn, their larvae drift up to St. Lucie Inlet and even as far north at Daytona Beach. There the young bonefish feed on sand fleas. Eventually they swim south and enter the fishery in South Florida at 10-12 inches in length.
The PATs showed that bonefish respond to cold fronts by leaving the flats and heading offshore for deeper water. After the front passes, the fish move back.
Ault also has conducted an annual one-day census to count how many bonefish exist in South Florida. He said the number is about 300,000. When you consider that bonefishing in the Keys has an economic value of $1 billion — for things such as guide fees, gas, fishing tackle, meals and hotel rooms — each bonefish is worth about $3,500 a year and $75,000 over its lifetime.
Speaking of money, Ault pointed out that sport fishing dwarfs commercial fishing in South Florida. He said commercial fishing is worth $534 million a year and provides 9,787 jobs. Seafood processing is worth $583 million and has 3,108 jobs. Recreational fishing is worth $10.1 billion — yes, billion — and accounts for nearly 60,000 jobs.
"Recreational fishing is bigger than Florida's citrus industry," Ault said.
Anglers know that tarpon migrate. The PATs that record data on water temperature, depth and salinity, then detach and transmit the data to a satellite, revealed just how far.
In the United States, tarpon range from North Carolina to Texas. Tagged tarpon have gone to Cuba and one showed up in Venezuela. One tarpon traveled from Savannah, Ga., to Sebastian Inlet to feed on mullet. Another went from Veracruz, Mexico, to Louisiana, covering 2,000 kilometers in 30 days.
PATs also showed that tarpon prefer water temperatures of 79 degrees and although they tend to stay shallow, one fish dove 475 feet. During a full moon, Ault said tarpon are active and eating all night. And, like bonefish, tarpon are affected by cold fronts.
One fish with a PAT zig-zagged down the Atlantic coast "kind of like a drunk walking down the street" as it searched for warm water.
Credit: Ft L Sun Sentinel
Edited by Capn Jimbo on Oct. 28 2007,08:24
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