DEARING - Each time George Atnip sees a trophy striper caught at Thurmond Lake, it brings forth a tinge of pride - and a smile.
"I know there's at least a 50 percent chance I've seen that fish before," said Atnip, who manages the Georgia Wildlife Resources Division's McDuffie Fish Hatchery.
The public isn't always aware that the largest fish species found in the 70,000-acre reservoir doesn't simply appear there.
Striped bass, and their smaller, more plentiful cousin - the hybrid bass - cannot reproduce on their own and must be stocked each season.
Atnip is part of an unusual team of biologists, technicians and others scattered across the state who help maintain the lake's fishery. Across the river, South Carolina's Department of Natural Resources also maintains stocking programs for both species.
The landlocked striper's life cycle begins in coastal rivers and estuaries, where biologists capture large females each spring. They are taken to Georgia's hatchery in Richmond Hill, where eggs are stripped from the females and incubated until they hatch.
The millions of fry are kept in tanks and small holding areas for several days before being trucked out to holding ponds at various state hatcheries, including Atnip's operation in Dearing.
"While they're here, in our ponds, we supplementally feed them a small commercial diet," Atnip said. "We also make sure there are absolutely no other fish in these special holding ponds that would eat them."
After about 27 days, the fry grow to inch-long fingerlings - and are ready to be released into Thurmond Lake.
"Once we remove them from our holding pond, they are taken to a fish holding house to be inventoried," Atnip said. "We take a sample weight, then weigh the entire batch to get more exact estimates."
This year, more than 2.5 million stripers are scheduled to be released into reservoirs statewide - including 286,140 fish into Thurmond Lake, which also will receive a similar number of hybrid bass.
Typically, the fingerlings are stocked in May, and usually around boat ramps. Once released, the fish have a tough first year.
"By the time fall rolls around, they're up to eight or 10 inches, but until then, they are subject to a lot of predators and there is high mortality," said Ed Bettross, a Georgia fisheries biologist.
Mortality from larger fish, birds - even carnivorous insects called back paddlers - could be as high as 50 percent, but no one really knows for sure.
The survivors, however, make a rapid ascension from prey to predator.
"The growth rate will vary from lake to lake, but they grow very fast," Bettross said. "We try to match the stocking rate to the forage base. Part of the reason we put them in there in the first place is to help control forage fish - blueback herring, threadfin shad and gizzard shad."
Both stripers and hybrids serve as a management tool - helping to keep baitfish from overpopulating, and also eating enough of them to force remaining shad and herring to spawn more often - keeping the mean baitfish size smaller.
Having smaller, younger baitfish offers more forage opportunities for smaller gamefish such as crappie and largemouth bass, which thrive on small herring and shad but could not eat larger ones.
Stripers grow at different rates, but a recent experiment at Thurmond Lake helped shed new light on growth rates for that reservoir.
"In 2002 we had a tagging program in which about 500 stripers and hybrids were captured, tagged and released," Bettross said. "This spring, a fish tagged three years ago - at 14 pounds and five years old - was caught three years later, weighing 30 pounds."
Biologists who examined the fish calculated it had gained 16 pounds in three years - and gone from a thimble-sized fingerling to a trophy striper in just over eight years.
"Of course, that's just from one fish, and others might grow faster or more slowly," he said. "But it shows how important it is to remind people that we need to know when someone catches a tagged fish."
Georgia's stocking program for Thurmond Lake stripers began almost 40 years ago, with annual releases each year since the mid-1970s.
Reach Rob Pavey at 868-1222, ext. 119 or rob.pavey@augustachronicle.com.
Scientific name: Morone Saxatilis
Common names: rockfish, lineside, striper
Favorite foods: blueback herring, threadfin shad
Average life span: 15 years (record is 31 years)
Thurmond Lake record: 55 pounds, 12 ounces
Georgia record: 63 pounds, 1967, Oconee River
IGFA world record: 781 pounds, 1982, Atlantic City, N.J.
Maturity: Males mature in two years; females at six years.
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