Dr. Les Torrans - NC Aquaculture Development Conference

Refinements in PondAquacultureLes TorransNat’l l Warmwater Aquaculture CenterUSDA ARS Catfish Genetics Res. UnitP.O. Box 38, Stoneville, MS 38776Cell: 662-390390-38823882E-mail:LTorrans@ars.usda.gov

Life Requires OxygenAnd the more,the merrier!!!

6:208:2010:2012:2014:2016:2018:2020:2022:200:202:204:20121086420TimeD.O. (mg/L)

Production without aeration• 30 lbs·acre -1·day -1 max. safefeeding rate (Swingle, 1959).• 1600-1800 lbs/acre averagecommercial production (Reportto the Fish Farmers, 1970).

Aeration vs. Feed

300Torrans, E.L., 2005*Feeding Rate (lbs·acre -1·day -1 )25020015010050Alabama BMP’s, 2002Hollerman, W.D. and C.E. Boyd, 1980Hollerman, W.D. and C.E. Boyd, 19800Swingle, 1959; Tucker et al., 19790.0 2.0 4.0 6.0Available Aeration (HP/Acre)* 2005. North American Journal of Aquaculture 67(4):275-288.

What D.O. concentrationdo catfish need?

How does morning D.O.concentration effect feedconsumption, growth, and FCR?

©2003 Les Torrans

Delta-Western Research CenterIndianola, MS

Minimum Daily D.O., 20021412Low OxygenHigh OxygenAve. Temp3530Min. Daily D.O. (mg/L)1086425201510Mean Daily Temp. (C)250MAR MAR APR MAY JUN JUL AUG SEP OCTDate0

Daily Feed, 2002600Low OxygenHigh OxygenAve. Daily Temp. (C)3530Mean Daily Feed (lbs/acre)400200252015105Mean Daily Temp. (C)0Mar Apr May Jun Jul Aug Sep OctDate0

Torrans - Catfish Oxygen Studies100Feed Consumed (% Control)503/4/5-yearcrop(60 lbs/100)1.17 lbs1.7 lbsDelta Western 2001-2002USDA 2001-2002USDA Fingerlings 2003DW 2004USDA 200400 1 2 3 4 5Minimum D.O. (mg/L)

Torrans - Catfish Oxygen Studies100Feed Consumed (% Control)5000 1 2 3 4 5Minimum D.O. (mg/L)

Torrans - Catfish Oxygen Studies100Feed Consumed (% Control)5000 1 2 3 4 5Minimum D.O. (mg/L)

Torrans - Catfish Oxygen Studies100Feed Consumed (% Control)50How can we maintain ahigher D.O.???00 1 2 3 4 5Minimum D.O. (mg/L)

Torrans - Catfish Oxygen Studies100Feed Consumed (% Control)50How can we maintain ahigher D.O.???1) Add more aerators; raiseD.O. in entire pond.00 1 2 3 4 5Minimum D.O. (mg/L)

Where does the O go?2Water Column (Plankton) 60%Sediment (Bacteria) 20%Fish (at 6000lbs/ac) 20%

Torrans - Catfish Oxygen Studies100Feed Consumed (% Control)50How can we maintain ahigher D.O.???1) Add more aerators; raiseD.O. in entire pond.00 1 2 3 4 5Minimum D.O. (mg/L)

Torrans - Catfish Oxygen Studies100Feed Consumed (% Control)50How can we maintain ahigher D.O.???1) Add more aerators; raiseD.O. in entire pond.2) Develop “New” aerators.00 1 2 3 4 5Minimum D.O. (mg/L)

Roland Schmidt, Aerway Mfg. Co.,“Gen-Air”

DO 2 E Corp.

P.A.S. / Wilfley-WeberSubterranian Stratamix Aerator(Dr. Craig Tucker, NWAC)

U-Tube designed and built incollaboration with John Carradine“Big John Aerators”(Southern Machine Welding, Inc.)

5-HP 3-phasemotorDiffuser in mouth of“down” tube5-HP 3-phaseblower

Torrans - Catfish Oxygen Studies100Feed Consumed (% Control)50How can we maintain ahigher D.O.???1) Add more aerators; raiseD.O. in entire pond.2) Develop “New” aerators.00 1 2 3 4 5Minimum D.O. (mg/L)

Torrans - Catfish Oxygen Studies100Feed Consumed (% Control)500How can we maintain ahigher D.O.???1) Add more aerators; raiseD.O. in entire pond.2) Develop “New” aerators.3) Use new techniques withexisting aerators.0 1 2 3 4 5Minimum D.O. (mg/L)

Current Method:Maximize Circulation• Improves distribution of oxygen• Minimizes organic matter accumulation• Reduces density of algal blooms• Shifts composition of algal blooms• Reduces off-flavor• Improves survival• Increases production(From SRAC Publication No. 4602)

Aerators placed in parallel on the center of the long levee of a 15-acre pond. This may provide the most efficient (practical) pondcirculation (George Selden – UAPB).

“Standard” Paddlewheel Placement(Maximize Circulation)

“Standard” Paddlewheel Placement(Maximize Circulation)

“New” Paddlewheel Placement(Minimize Circulation)300 ft600 ftHigher D.O. where fish are?Fish eat more feed?Higher Production?Reduced Energy Costs?More Profit?Impact on water quality?751300 ft75 ft??? Low D.O. Concentration High ???

Paul D. DeesDillard & Co, Inc.

Experimental Design• Ten 17-acre ponds• Three 10-hp paddlewheels per pond• Single-batch system (clean harvest)• Brought into study in pairs• Standard farm management practices• Water quality sampled twice/month

Water QualityParameterNewSystemOldSystemNPNitrite (mg/L)0.0960.075208N.S.TAN (mg/L)1.141.03188N.S.TSS (mg/L)136992070.0001Volatile Solids (mg/L)68.756.62070.035Fixed Solids (mg/L)68.444.92070.0002Chlorophyll a (mg/L)632587205N.S.

Dissolved OxygenMonthMayJuneJulyAugSeptMeanNew System+0.09 mg/L+0.25 mg/L+0+0.05 mg/L+0.57 mg/L+0.19 mg/L

ProductionParameterNet Yield(lbs/acre/year)Feed(lbs/acre/year)FCRNew System+185-15-0.07

AerationTractorsType(days/yr)NewSystem14.0OldSystem19.1Electric Aerators(Hp-hr·ac -1·yr -1 )8491109

• 550 acre Mississippi delta farm• Electric Rates (per kW-hr)increased by 15% in 2006• Total farm electric bill dropped$1000• Feed input increased by 200tons (727 lbs/acre)

PrecisionAeration:Apply OxygenDirectly to the Fish.

The Sock-SaverSaver

Photo courtesy ofSteven Asmus

Total Cost: $8300

Sock-Saver II: the Redneck VersionCharlie HogueJohn NorrisRobert CunninghamPhotograph courtesy of Charlie Hogue Jr.

Total Cost: $2300Photograph courtesy of Charlie Hogue Jr.

Oxygen Consumption of ChannelCatfish Eggs and Fry: Implications forHatchery Management

Established CatfishSpawning Techniques:3-6 year-old brooders1000-1500 lbs/acre2-5:1 ♀:♂ ratioone can/1-3 malesMove brooders annuallyFeed 32% protein feedSupplement with foragefish (fathead minnows, tilapia,threadfin shad, brim, silversides)

Eight tanks, O 2(232%)SupersaturatedEight tanks, Air(94%) Saturation

Effect of Dissolved Oxygen onCatfish Eggs and FryMean D.O.(% Saturation)Hours to HatchSurvival to Swim-Up(per cent)Low DO7.4 (94%)14272.5High DO18.4 (232%)14888.9

ProbePCV ProbeHolderEggPlatformSpin Bar266 mL WideMouth JarWaterBathMagneticStir Plate

D.O. Conc. (mg/L)10.09.08.07.06.05.04.03.02.01.00.0∆ D.O./∆ T0 20 40 60 80 100Time (min)

1200“Standard”Metabolic Rate1100Limiting OxygenLevel1000900800700600500∆ mg O2/kg-h1251007550250400% Oxygen Saturation

1200Horsepower1100Limiting OxygenLevel1000900800700600500∆ mg O2/kg-h1251007550250400% Oxygen Saturation

1200Horsepower1100RestrictorPlate Size1000900800700600500∆ mg O2/kg-h1251007550250400% Oxygen Saturation

1600Metabolic Rate14001200mg O2/kg-hr10008006004002000EggsSac FrySwim-Up Fry0 5 10 15 20 25Age (days post-spawn)

1600Metabolic Rate14001200mg O2/kg-hr10008006004002000EggsSac FrySwim-Up Fry0 5 10 15 20 25Age (days post-spawn)

1600Metabolic Rate14001200mg O2/kg-hr10008006004002000EggsSac FrySwim-Up Fry0 5 10 15 20 25Age (days post-spawn)

1600Metabolic Rate14001200mg O2/kg-hr10008006004002000EggsSac FrySwim-Up Fry0 5 10 15 20 25Age (days post-spawn)

Incipient Limiting Oxygen LevelO2 Saturation (%)10090807060504030201000 5 10 15 20 25 30Age (days post-spawn)

Incipient Limiting Oxygen LevelO2 Saturation (%)10090807060504030201000 5 10 15 20 25 30Age (days post-spawn)

Incipient Limiting Oxygen LevelO2 Saturation (%)10090807060504030201000 5 10 15 20 25 30Age (days post-spawn)

Incipient Limiting Oxygen LevelO2 Saturation (%)10090807060504030201000 5 10 15 20 25 30Age (days post-spawn)

65Drop in DO Inside Spawn (mg/L)432y = 0.0408xR 2 = 0.8526100 20 40 60 80 100 120 140 160Time Since Spawn (hours)

Incipient Limiting Oxygen LevelO2 Saturation (%)10090807060504030201000 5 10 15 20 25 30Age (days post-spawn)

Effect of Dissolved Oxygen onCatfish Eggs and FryMean D.O.(% Saturation)Hours to HatchSurvival to Swim-Up(per cent)Low DO7.4 (94%)14272.5High DO18.4 (232%)14888.9

Commercial Implications• Of 26 commercial hatcheriessurveyed, only 7 maintained a D.O.saturation >96%; 6 were below 80%.• Raising the D.O. concentration tosaturation on the last day ofincubation could increase swim-up frysurvival across the 1.8 billion-fryindustry by 150-300 million/year.

Recent Developments

After 15 years of continuous use

Sedimentation and Oxygen LossOld Pond New Pond• Depth 2 ft, DO 10 ppm• Plankton 0.60 mg/l/h• Sediment 500 mg/m2• 5.5 Hours till DO=2• Depth 6 ft, DO 10 ppm• Plankton 0.60 mg/l/h• Sediment 500 mg/m2• 7.8 Hours till DO=22.3 hours aeration saved per night!J.A. Steeby. 2004.

Environmental Management System• Research to reduce the discharge ofpotential pollutants• Consisted of four farm practicesimplemented together• Four year study in large ponds• Continuous production• Measured effluent dischargevolume and quality, wateraddition, and productionC. Tucker. 2005.

Research ProtocolEMS• Pond water-levelmanagement• Feed limit of 100lbs/A per day• 28% protein feed• Max fish density of7,500 fish/ANon-EMS• No pond water-levelmanagement• No feed limit• 32% protein feed• 10,000 fish/A addedeach springC. Tucker. 2005.

Results (after 3 years)• Average concentration of nitrogen,phosphorus, solids, and organic matterin effluents were not different.• Overall discharge of these componentswas reduced by 70% in ponds with thepond water-level management.C. Tucker. 2005.

Pond Water-level Management Scheme12-inchdrop8-inchstorage4-inchfillC. Tucker. 2005.

Results (after 3 years)ParameterTotal Overflow (inches)Non-EMS151EMS60Avg. AnnualGroundwater (inches)Avg. AnnualProduction (lbs/A)205,0697 a5,100aNo water added in 2001C. Tucker. 2005.

BlueHybridChannel

Channel x Blue Catfish Hybrids• Since late 1960s• Requires hormoneinduced strip-spawning• Fry production costly• Production advantages• Consistent, high survival• Improved diseaseresistance• Better feed conversion• Faster growth• Higher meat yield

Producing Hybrid CatfishFry: Workshop ManualGoogle “TCNWAC”,go to “publications”

• Limited production• Advantages• Can be pond-spawned• More resistant to ESC, PGD• Desirable for pay lakes• Easy to seine• More uniform growth• Disadvantages ?• Late maturity• Harvest issues• Tolerance of low DO andhandling stress ?• Processing issuesBlue Catfish

Multiple-batchProductionFingerlingsGrowout PondModularProductionFingerlings Stockers (6(6 mo)Growout Pond (7 mo)

Why Switch?• Economics of multiple-batch systemsbecome less profitable with processors’desire for increased size of harvestedproduct (1.5 to 2.0 lb)• Insufficient control of stock inventory• Increased disease losses• Better water quality in foodfish pondsdue to lower stocking rates

Aquaflor ® Approved• Approved by FDA onOctober 2005•1 st aquatic VeterinaryFeed Directive (VFD)drug• VFD drugs = Newanimal medicated feedsapproved after 1996P.S Gaunt. 2003.

Using Aquaflor ®• For use in Catfish feeds only• Used in floating feed• 10-day treatment• 12-day withdrawalP.S Gaunt. 2003.

Aquaflor ® Websitehttp://www.aquaflor-usa.com

AQUAVAC-ESC®Vaccine

AQUAVAC-COLCOLVaccine

Intervet, Inc. Websitehttp://www. intervetusa.com

Life cycle of Bolbophorus sp.Mature wormsEggs hatchand infest snailSnailexcretescercariaeMetacercariae encyst catfishCercariaepenetratefish

Impact on Production• Severe infections – high mortality rates• Infection is direct cause of mortality• Moderate infections• Poor feed consumption/conversion• High rate of bacterial infections (ESC)• Light infections -hard to detect• Poor feedconsumptionand conversionD.J. Wise. 2005.

The “Seine-itizer”

Daniel Petre, Prairie Welding and Supply, Macon, MS

In-Pond (“Heikes(Heikes”) ) Grader• Easily incorporated into standard harvestprocedure• Adjustable grader-bar spacing• Able to grade fingerlingsand foodfish• 9,000 lbs foodfish/min• Increased weight of fishwithin processor specsby 12.5%D. Heikes. . 2004.

“Zipper” SockOld SockZipper SockRearDimensions = 4x4 ftRearDimensions = 12x4 ft

ORGANIC PRODUCTION OFCHANNEL CATFISHMenghe H. Li, Edwin H. Robinson, CharlesC. Mischke, Eugene L. Torrans, and BrianG. Bosworth(at Delta-Western Research Center)2006. North American Journal ofAquaculture 68:53-62

ltorrans@ars.usda.gov662-390-3882