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“The production system on our farm is fairly typical of commercial catfish operations in this area," says Kevin Shirk of the 103.5-acres he and his wife, Edith, have near Brooksville, Miss. "Unlike some farms here, however, catfish is our only enterprise. We attempt to do a superior job of managing our operation, which we feel gives us a competitive advantage. Since we started operation in 1997, we've not had a year that we didn't show a profit."
KEVIN SHIRK and his wife, Edith, operate a catfish farm in Noxubee County, Miss. They have 103.5 acres in 10 ponds, with a consistently high level of production.
Constant oxygen monitoring
The most common problem they encounter in daily pond management, Kevin says, is keeping the dissolved oxygen level high enough at night to keep fish from feeling stress.
“We manage this with aeration. We monitor oxygen levels with a Campbell Scientific automated control and monitoring system that checks parts per million of dissolved oxygen every 20 seconds and transmits the information to my cell phone. Each aerator can be set, controlled, and monitored individually, and it will turn aerators on and off at set points we choose.
“Our 10 horsepower electric floating paddlewheel aerators are from Aerway Mfg., and we use two to six of these per pond, depending on acreage and availability of power. Most of our ponds have the maximum load allowed by our power supplier, 4 County Electric Power Association.
“Five horsepower per acre is our highest aeration level, 3.85 horsepower per acre our lowest. Even in ponds with 5 horsepower per acre, production has increased when aeration is increased. So, we’ll continue adding aerators as time and availability permit.”
They have been buying used aerators from farms quitting production, Kevin says, “but we’re no longer able to find good used aerators, so we’ve been buying new ones from Aerway Mfg.”
Tractor backup aerators are used every night during production season. They have 13 diesel power units and tractor aerators.
“We’ve been starting the backup aerators at about 2 to 2.5 parts per million of dissolved oxygen,” he says, “compared to the industry norm of starting when fish pack behind the aerators.
“Our goal is to never see a fish until they’re seined at harvest. If I see fish packed behind the aerators, I know there’s some reason they aren’t comfortable and that I’m losing production because they aren’t eating and growing as they should.”
Diseases can also be troublesome, Kevin says, and in 2010 and 2011 outbreaks of Aromonos hydrophila resulted in significant losses.
“In 2009, it caused major losses in the Alabama catfish industry, and since then seems to have been spreading westward. It happens with great rapidity: one day you may have 25 dead fish, the next day 2,500, the next day 25,000.
“It just explodes, and when it hits it seems there’s nothing you can do. It is the only part of catfish production today for which I have no solution. Medicated feed seems to help, but by the time you can start feeding you’ll have thousands of dead fish.
“In 2010, we lost 100,000 pounds of fish to the disease and last year 250,000 pounds. Fortunately, catfish prices offset the losses, but still it’s the kind of financial blow you don’t like to have.
“The potential for major losses to the industry is scary. Right now, other than catfish imports, it’s our biggest challenge. Scientists at the Delta Research and Extension Center at Stoneville are working on it, and we hope a solution can quickly be found.”
Charlie Hogue, Warm Water Pond Management, is the Shirks’ consultant, and Craig Miller tests ponds weekly for water quality.