Page 1 December, 2008

SOUTHERN REGIONALAQUACULTURE CENTER

For the Period Through August 31, 2008TWENTY-FIRST ANNUAL SUMMARY OF PROJECTS

ARKANSASLOUISIANAMISSISSIPPI

KENTUCKYVIRGINIA

OKLAHOMA

TEXASALABAMAGEORGIA

NORTH CAROLINASOUTH CAROLINAVIRGIN ISLANDS

FLORIDATENNESSEE

PUERTO RICOPR VIVIVIVIVI

Most of the $1 billion dollardomestic aquacultureindustry is located in thesoutheastern United States,where important crops ofcatfish, crawfish, bait andornamental fish, trout, andbivalve molluscan shellfishare produced. The USDA-CSREES Southern RegionalAquaculture Center (SRAC)supports this critical sectorof southern agriculture byproviding research andeducation funds to addresskey issues faced by theindustry.

WHAT IS SRAC? . . . SRAC is one of five Regional Aquaculture Centersestablished by Congress and administered through the USDA CooperativeState Research, Education, and Extension Service. The thirteen states andtwo territories included in the Southern Region are listed in the masthead,above. Mississippi State University serves as the Host Institution forSRAC, and the Administrative Center is located at the Thad CochranNational Warmwater Aquaculture Center, Stoneville, Mississippi.

SRAC is a mechanism for identifying and solving problems. Priorityresearch and education needs for the Southern Region are identified bythe Industry Advisory Council, which consists of aquaculture industryrepresentatives from throughout the region, and the Technical Committee,which consists of research and extension scientists. The two groupsrecommend project areas to the SRAC Board of Directors, which selectsprojects with the highest priority for development and funding. The bestscientific talent in the region is then brought together to address theproblem.

IMPACT . . . In the past year, four research projects funded at nearly$2 million were in progress. The Center’s “Publications” project is in its

thirteenth year of funding and has produced more than 200 publications with contributions from 186 authorsfrom throughout the region. All publications are available at the SRAC web site (see box below).

Over the years, SRAC projects have identified many new technologies that benefit the aquaculture industry. Inone current project, two modifications of traditional pond aquaculture systems show considerable potential forincreasing production efficiency. The Clemson University Partitioned Aquaculture System (PAS) is particularlywell-suited for production of channel catfish fingerlings, with fishgrowing to more than a quarter of a pound in one summer of growth.Meanwhile, a modification of the PAS, called the “split-pond system” hasconsistently produced 15,000 to 18,000 pounds of food-sized catfish peracre in tests at Mississippi State University. These two systems maybecome attractive alternatives to traditional aquaculture ponds.

This report summarizes these projects and others currently funded bySRAC.

For further information on theSouthern Regional AquacultureCenter, fact sheets and reportsof the results of SRAC projects,visit the SRAC web site at http://www.msstate.edu/dept/srac.

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Publications, Videos andComputer Software

OUR RESPONSE . . .

THE CHALLENGE . . .

Aquaculture produces over 50% ofthe world’s seafood supply and isone of the most rapidly expandingagricultural industries in theworld. Most domestic aquacultureoccurs in the southeast,where more than 100species of fish, shellfish,aquatic reptiles, andplants are cultured forfood or ornamentalpurposes. The totalfarm value of southeast-ern aquaculture is overone billion dollars peryear, with a totaleconomic impactexceeding five billiondollars. Aquaculture isa relatively young,unique industry, and theneed for information tosustain growth anddevelopment has increaseddramatically over the past 30years.

Extension and research scientistsin the southeastern United Statesinitiated this project to produceeducational materials to supportregional aquaculture. The SRACpublication project uses a region-wide pool of experts to developmaterials for distribution throughthe nationwide network of educa-tors, Extension Specialists, andCounty Agents and the World WideWeb. This process makes efficientuse of personnel and funds at theState level, and results in timely,high-quality educational materials.

Each publication contains under-standable, factual information thatprovides guidance for producers,processors, consumers, students,or investors. Subject matterincludes biology and life history ofspecific culture species, culturetechniques and systems, nutrition,

water quality and waste manage-ment, disease treatment, consumereducation, marketing, and muchmore.

The Southern Regional Aquacul-ture Center has now published 188fact sheets, 5 project reports, 19research reports, and 20 videos.These publications provideessential information for aquacul-ture producers, lending agencies,and consumers of aquacultureproducts. Educators in highschools and colleges use SRACpublications in classroomsthroughout the United States andthe world. From September 2007

through August 2008, more than37,800 unique visitors used theSRAC web site and accessed over249,600 pages.

One of the most popular series ofSRAC publications is “SpeciesProfiles,” which provides detailed

technical informationon the biology andculture of marine andfreshwater fish withcommercial potential.Among the speciesincluded in the seriesare grouper, largemouthbass, hybrid sunfish,cobia, pompano,southern flounder,queen conch, andsturgeon.

Eight fact sheets werecompleted this year,with seven in progress.The remaining eight

VHS videos produced by SRACwere converted to DVD formatthis year. This year’s publicationswere developed by 14 scientistsassociated with the followinginstitutions and agencies:

• Mississippi State University• Texas A&M University• University of Arkansas at Pine

Bluff• USDA/APHIS/Wildlife

Services, National WildlifeResearch Center

Copies of all fact sheets areavailable on the Internet at http://www.msstate.edu/dept/srac orhttp://srac.tamu.edu.

PRINCIPALACCOMPLISHMENTS . . .

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Innovative Technologies and Methodologiesfor Commercial-scale Pond Aquaculture

OUR RESPONSE . . .

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THE CHALLENGE . . .

Aquaculture operations in thesouthern region of the UnitedStates are finding it difficult tomaintain profitability. Productioncosts are increasing, but pricesreceived for fish, shrimp, andother cultured aquatic animals arenot keeping pace. Problems areespecially troublesome forchannel catfish farming, themajor aquaculture activity in theregion. Increasing profitability ofchannel catfish farming is a long-term, complex, multifacetedproblem. Nevertheless, methodsfor reducing production costswould provide an immediateimprovement in profitability.

Eleven research scientists fromseven institutions are collaboratingin a 4-year project to investigatenew technologies and methodolo-

gies to improve the efficiency andenhance the profitability ofaquaculture in the SouthernRegion. The scientists representthe following institutions:

• Auburn University• Clemson University

• Louisiana State University• Mississippi State University• University of Arkansas at Pine

Bluff• USDA-ARS (Pine Bluff, AR)• USDA (Stoneville, MS)

Several possible methods forimproving efficiency and profitabil-ity of aquaculture are underinvestigation:

• Evaluation of new productionsystems and improvements inexisting production systemsfor channel catfish;

• Improvement in equipmentused for mechanical aerationand for fish harvesting inchannel catfish culture;

• Evaluation of energy, mater-ial, and economic efficiency ofproduction systems.

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PRINCIPALACCOMPLISHMENTS . . .

Several variations of the parti-tioned aquaculture system (PAS)concept are being evaluated forpossible commercialization. ThePAS concept is based on physi-cally dividing a pond into sectionsfor holding fish and treating wasteproduced during culture. The twosections are connected by largevolumes of water flowing betweenthe two systems. Research atClemson University showed thatthe PAS has promise for accelerat-ing the growth of channel catfishfingerlings. During 4 years ofexperimentation, the system hasproduced fingerlings of over aquarter pound in less than 5months at a final carrying capacityequal to 4,000 pounds/acre. Thesystem appears to have potentialfor commercial use. A lessintensive approach, the split-pondsystem, can be built by modifyingexisting earthen ponds. Annual

catfish production in the split-pond system has ranged from17,000 to almost 20,000 kg/ha.This system also appears to havecommercial potential.

Maintenance of water quality inmost pond aquaculture systemsdepends on plant growth (auto-trophy). However, undersuper-intensive culture conditions,autotrophy cannot provide

adequate waste treatment and issupplemented by microbial-based(heterotrophic) processes. Aheterotrophic, biofloc system forchannel catfish production wastested by USDA scientists at PineBluff, Arkansas. Stocking rates of2.9, 5.7, and 8.5 fish/m2 resulted inlinear increases in fish biomasswith a net yield of 3.7 kg/m3 at thehighest stocking rate. This produc-tion is equivalent to about 50,000pounds/acre in pond systems.

At Stoneville, Mississippi, USDAscientists tested a motor-poweredU-tube aerator and confirmed thatthe device is highly efficient inmoving water, but the oxygentransfer rate must be improvedthrough design modifications.Considerable progress also hasbeen made by researchers at theDelta Research and ExtensionCenter towards a development ofan electrically-enhanced seine.

Innovative Technologies and Methodologies forCommercial-scale Pond Aquaculture(continued from page 3)

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Feed Formulation and Feeding Strategiesfor Bait and Ornamental Fish

THE CHALLENGE . . .

OUR RESPONSE . . .

PRINCIPALACCOMPLISHMENTS . . .

Commercial production of baitfishand tropical ornamental fishrepresents economically valuablecomponents of the U.S. aquacul-ture industry. Market sizes of baitand ornamental fishes are rela-tively small and specific sizes areneeded for specific purposes, sothat repeated grading and handlingduring production are oftenrequired. After harvest, fish mustwithstand the additional demandsof distribution and sales, and mustsurvive for extended periods.Significant losses occur when fishare transported on trucks from theproduction facilities to distributionsites. A combination of handlingstress and suboptimal environmen-tal conditions can result in highmortality when fish are transferredbetween facilities. Therefore,effective management practicesthat enhance stress resistance andprolong survival of bait andornamental fishes are criticallyneeded.

Six scientists from four institu-tions are collaborating to developdiets and feeding practices thatenhance stress resistance andprolong survival of bait andornamental fishes. Scientistsparticipating in this projectrepresentthe following institutions:

• Texas A&M University• University of Florida• University of Arkansas at Pine

Bluff• University of Georgia

The project addresses the followingobjectives: 1) manipulation of dietcomposition and feeding strategy foreconomical production of “jumbo”golden shiners; 2) manipulation ofdiet composi-tion and feedingstrategy to increase immuno-competence and resistance to stressin bait and ornamental fish duringproduction, transport and livedisplay; and 3) determination of therelative contribution of natural foodsand prepared diets to growth,response to low dissolved oxygen,and other health indices for bait andornamental fish in differentproduction systems.

The overall goal of this project isto assess changes in diet composi-tion and feeding strategies on thegrowth, health, and body composi-tion of freshwater baitfish andornamental fish.

Feeds and feeding for “jumbo”golden shiners. There is an unmet

demand for large baitfish (“jum-bos”) and there is currently nogood way to produce these fish inone year. The first task was todetermine the best stockingdensity for juvenile golden shinersto maximize the production ofjumbos (larger than 12g) within asingle growing season. In this trial,golden shiner juveniles werestocked at four densities andgrown for 105 days while beingfed once daily with a commercial42% protein feed. Average fishweight decreased with increasingfish density, but gross yield (totalpounds of fish produced) in-creased with density. Survival wasnot different among treatments.Fish stocked at 30,000/acreresulted in about 54% jumbos byweight. Stocking juvenile goldenshiners in late July resulted inlower single-season yields ofjumbos compared to directstocking of hatchery fry at lowdensities. Direct stocking of fry inearly May resulted in higher yieldof jumbos in a single season.

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However, the extra production ofjumbos must be balanced againstother uses for the ponds.

A second trial evaluated the effectsof diet composition and feedingfrequency on the growth andproduction of golden shiners.Juvenile golden shiners werestocked into earthen ponds at30,000 fish/acre. Fish were fedeither once or twice daily with acontrol diet or an experimental diet,with the intent of matching theperformance of fish fed the controldiet but at a lower cost. The dietswere similar in total protein (42%)but the experimental diet containedno fish meal. At harvest, there wasno difference in yield, averageweight, or survival due to diet orfeeding frequency. Feeding a dietwith fish meal did not improveyields over a comparable dietformulated with poultry by-products, and feeding twice a dayinstead of once a day provided nobenefits.

Feeds and feeding to enhancehealth of bait and ornamental

fish. Multiple feeding trials withdietary additives that may stimu-late fish health have beencompleted at Texas A&M Univer-sity (TAMU) and the University ofArkansas at Pine Bluff (UAPB).Methodological problems hinderedprogress initially, but overall therehave been few pronounced effectsof these feed additives on generalperformance (growth, survival,feed conversion) of golden shinersand goldfish in tanks. Bettermethods of measuring immuneand stress responses of smallfishes must be developed to assessthese diet additives fully. Wedeveloped a promising techniqueto measure cortisol (a stresshormone) in the whole body of thefish instead of the blood. Thisprocedure has been validated ingolden shiners and partiallyvalidated in goldfish. The tech-nique has been published and isbeing implemented to measurestress from industry-relevantsources such as handling andtransport. Golden shiners obtainedfrom a study conducted duringyear 1 in which fish were sub-

jected to normal harvesting,handling and distribution practiceswere analyzed for whole-bodycortisol as well as zinc and ascor-bic acid (vitamin C) as potentialindicators of stressful conditions.The whole-body cortisol assay wasthe most sensitive measure ofstress in golden shiners; whereas,whole-body zinc and ascorbic acidwere not readily altered by thevarious harvesting, grading andtransportation stressors.

The most promising feed additivetested is a prebiotic (GroBiotic®-A). This is a non-living productcontaining indigestible carbohy-drates from dairy and yeast sourcesthat stimulate “good bacteria” inthe gut. Prebiotics can enhance fishperformance under stress, such asexposure to pathogens. It isapparent now that GroBiotic®-A ismore effective in protecting goldenshiners against specific pathogens(such as the bacterium that causescolumnaris disease), rather thanenhancing the general immuneresponse. Although goldfish havealso been exposed to bacterialpathogens following feeding trialswith GroBiotic®-A, so far theresults have been inconclusive.Differences in diet compositionand physical form of the diets usedin different trials might contributeto differences in results betweenfish species. However, we haveestablished that GroBiotic®-A iseffective both in cold-pelletedsinking pellets, and in extruded,floating pellets.

The effects of diets with 4 or 10%lipid (fat) and diets with or without

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fish meal on performance ofgolden shiners in tanks have alsobeen examined. Previous studiesshowed some beneficial effects ofhigh lipid levels in diets for goldenshiner and goldfish. However, intank studies with golden shinersthere were no differences ingrowth, survival, or whole-bodylipid of fish fed diets with 4 or10% lipid. In general, feedconversion of golden shiners fed10% lipid diets was higher thanthat of those fed 4% lipid diets,except for fish fed diets withGroBiotic®-A. It is likely thatgolden shiners did not respond tohigher dietary lipid in this studybecause they were larger at thebeginning of the trial (larger fishgrow more slowly), and the dietswere lower in protein than previ-ous studies. Therefore, moreprotein may have been used forenergy instead of tissue growth,and the benefits of extra lipid werenot realized in aquaria. Goldfish inaquaria fed diets with or withoutthe same prebiotic and 4 or 10%added lipid also showed nodifferences in growth, survival, orfeed conversion. There were nomajor differences in performanceof golden shiners fed diets with orwithout fish meal, consistent withprevious studies. Exclusion of fishmeal from production diets forgolden shiners and goldfish wouldreduce feed cost and addressenvironmental concerns over fishmeal shortages.

A bacterial challenge on groups ofgolden shiners fed the standarddiet (4% poultry fat), a 10%poultry fat diet, or a diet with both10% poultry fat and 2%Grobiotic®-A was performed.

Golden shiners fed the diet withGrobiotic®-A had higher survivalthan fish fed the other diets whenexposed to the bacteria that causecolumnaris disease. This is asignificant pathogen of goldenshiners and other bait and orna-mental fish. We also attempted touse a low dissolved-oxygen stresstest to assess diet effects, butconditions were not lethal soresults were inconclusive. Inseparate trials, TAMU found thatGroBiotic®-A reduced the cortisolresponse of goldfish to crowdingstress, which might be beneficial.Theoretically, the prebioticfunctions by stimulating the goodbacteria in the gut, which canstimulate the immune response.However, no differences in gutbacteria were detected in fish feddiets with or without prebiotic,and the mechanism of action stillhas not been demonstrated inbaitfish.

At the University of Georgia,

whole-cooked soybeans are beingcompared to soybean meal in dietsfor golden shiners, feeder goldfishand fathead minnows. Duringinitial trials in aquaria, it wasnecessary to increase the salinityof the water to 3 parts per thou-sand using artificial sea salts to getsignificant improvement insurvival of golden shiners from acommercial source or from abreeding population establishedonsite. Golden shiners fromcommercial ponds in Arkansaswere transported to Georgia andheld in vats for later distribution toarea bait shops. However, theywere not able to survive in aquariaas well as golden shiners fromponds at the research location inTifton, Georgia. Survival ofcommercial golden shiners was0% after 14 days in aquaria versus97% survival for Tifton-rearedgolden shiners after 56 days infresh water. Fathead minnows

Feed Formulation and Feeding Strategies for Bait andOrnamental Fish (continued from page 6)

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Feed Formulation and Feeding Strategies for Bait andOrnamental Fish (continued from page7)

obtained from the same commer-cial source did not show signs ofdisease and survived at the rate of95% for 56 days in aquaria in freshwater.

Golden shiners from Tifton pondswere used in the aquarium feedingtrial to assess responses to acomplete diet or whole-cookedsoybeans. Weight gain for goldenshiners fed to satiation for 56 dayswas similar for the two diets.Results were similar for fatheadminnow fed the same diets inaquaria.

Golden shiners in ponds fedroasted full-fat soybean meal or anutritionally complete diet showedsimilar growth. Consumption ofnatural food appeared to provideessential nutrients that are notpresent in the simple soybean mealdiet.

The economics of feeding forbaitfish changed over the course ofthis project. Roasted soybeansobtained for $500.00 per ton arecurrently available for $630.00 perton FOB Missouri. While 48%protein soybean meal is availablefor $342.00 per ton, complete feedcosts range from $360.00 to$640.00 per ton, depending onquantity and location. At on-the-farm prices of $11.00 to $12.00 perbushel, soybean roasting would putfeed value between $407.00 and$444.00 per ton for whole roastedsoybeans. Roasting costs another$25.00 to $40.00 per ton. There-fore, baitfish producers who alsoraised soybeans could consider on-farm roasting to reduce dependenceon the feed milling industry duringperiods of price uncertainty.

Contribution of natural foods togrowth and health of bait andornamental fish. It is difficult toseparate the effects of prepareddiets and natural foods in outdoorsystems (pools, ponds) on perfor-mance of fish, but most commer-cial production of bait andornamental fishes is in outdoorsystems. Multiple studies wereconducted to determine the bestdiets to use in ponds where baitand ornamental fish will haveaccess to both food sources.

At TAMU, two separate feedingtrials with goldfish examined theeffects of GroBiotic®-A in thepresence or absence of naturalfoods. Fish were fed a commer-cially prepared control diet or adiet with GroBiotic®-A in both arecirculating system with wellwater, and an outdoor system witha continuous supply of pond water.Significantly improved feedefficiency was noted in bothfeeding trials for goldfish fedGroBiotic®-A when compared tothe control diet. Weight gain andsurvival were not different by diet,although goldfish had bettersurvival in the system with naturalfoods (pond water). A bacterialchallenge with Aeromonas wasinconclusive with respect to dieteffects.

At UAPB, a 10-week feeding trialwith golden shiner in outdoorpools was conducted using dietswith or without GroBiotic®-A,with or without fish meal, or with4 or 10% lipid from poultry fat.Weight gain and feed conversiondid not differ by diet. There wereslight differences in conditionfactor and survival that were not

consistently associated with dietvariables. Whole-body lipid wassignificantly higher in fish fed the10% poultry fat diets compared tothose fed the 4% poultry fat diets,regardless of other diet variables.

After harvest, shiners fed thecontrol diet or diet with 2%GroBiotic®-A were acclimated toindoor tanks and challenged withthe bacteria that cause columnarisdisease (trial 1). In trial 2, shinersfrom the same treatments weresubjected to confinement stress orleft unmolested, then exposed tothe bacteria. Mortality was notsignificantly different for thecontrol diet, GroBiotic®-A diet, orGroBiotic®-A diet with stresstreatments. Mortality for thecontrol diet with stress treatmentwas significantly higher than theother treatments. Prebioticsupplementation in golden shinerfeeds prior to a stressful eventcould significantly reduce associ-ated mortality from columnarisdisease.

The performance of juvenilegolden shiners in ponds fed acontrol diet or the same formulawith 2% Grobiotic®-A wasevaluated. Fish were fed tosatiation twice daily with custom-made 35% protein diets extrudedas 1.5-mm pellets. The formulawas similar to a commercialcatfish diet. Due to small initialfish size and the relatively lowstocking density, growth was veryrapid and the study was harvestedafter 7 weeks to avoid reproduc-tion. At harvest there were nodifferences in average fish weight,

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net yield, or feed conversion ratiobetween treatments.

A bacterial challenge was per-formed as described for the pooltrial with groups of fish from eachpond divided into stressed orunstressed groups prior to bacte-rial exposure. Results weresimilar, and survival of stressedfish fed the diet with 2%Grobiotic®-A was higher than thatof stressed fish fed the controldiet, while no diet effect wasapparent in unstressed fish. Apartial budget analysis based onthe results of the challengeindicates that the increased cost offeed containing 2% Grobiotic®-Awould be fully justified based onincreased survival of goldenshiners exposed to stress andpathogens. However, as commer-cial implementation was exploredfurther we discovered that thepreviously quoted price for theprebiotic was contingent onpurchase of a large quantity ofproduct. The minimum quantitythat our local feed mill would haveto purchase would be in excess ofthe amount that the small baitfishindustry could use. Therefore, the

economics of prebiotic use inbaitfish diets need further evalua-tion.

A 10 week feeding trial withgoldfish in pools was conductedusing the 4- and 10% poultry fatdiets with or without 2%Grobiotic®-A. Weight gain andcondition index of goldfish feddiets with 10% poultry fat, 2%GroBiotic®-A plus 4% poultry fator 2% GroBiotic®-A plus 10%poultry fat were higher than thoseof fish fed the control diet with 4%poultry fat and no prebiotic. Feedconversion and survival did notdiffer among diets. After the trial,goldfish were moved to indoortanks for a bacterial (columnaris)challenge (in progress). Thischallenge includes groups of fishfrom each diet that were stressed(crowding) or unstressed prior tobacterial exposure.

The University of Florida con-ducted pond and tank trials on fivespecies of ornamental fish –Brachydanio rerio (zebra danios),Xiphophorus helleri (swordtails),Hypostomus sp. (commonplecostomus), Cichlasoma meeki,

Firemouth Cichlid, andMoenkhausia sanctaefilomenae,Red-eye Tetra. The work wasdesigned to address the basicquestion of whether farmsproducing small, ornamentalspecies are feeding the fish, orfeeding the pond when they use acommercial diet. When the workwas proposed there was a com-mercial source of inexpensive,unprocessed meal diets, so thisstudy compared the effects of theunprocessed diet with a processed(i.e. pelleted and reground) dieton ornamental fish growth andsurvival. Two fertilizationregimes were also added to thetests to determine the ability ofthese species to utilize naturalfoods. Therefore, each pond trialtested 4 treatments: 1) cottonseedmeal; 2) liquid fertilizer; 3) anunprocessed, 33%-protein mealdiet; and 4) a processed, 33%-protein diet. A tank trial was alsoconducted with each species tocompare growth and survivalusing the two diets in the absenceof natural foods.

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Feed Formulation and Feeding Strategies for Bait andOrnamental Fish (continued from page 9)

There was a significant differencein the growth and survival ofzebra danios produced in pondsreceiving treatments of liquidfertilizer, cottonseed meal, anunprocessed meal diet, and aprocessed diet. Growth of zebradanios was best on the processeddiet, followed by the unprocesseddiet, then cottonseed meal, withlowest growth in the liquidfertilizer treatment. Nevertheless,the liquid fertilizer treatmentalone produced many market-sized fish with minimal costs. Intanks trials, zebra danios fed theprocessed diet out-performedthose fed an unprocessed diet.

Survival of swordtails in all pondstudies was greater than 100% dueto reproduction. Treatment effectson overall production were thesame as for zebra danios, withhighest production for fish fed theprocessed diet, followed by theunprocessed diet, then cottonseedmeal, with lowest growth in theliquid fertilizer treatment. Atharvest, the average size of a“small” graded fish was not yetsaleable (less than 1.5 inches) butall “large” graded fish weresaleable. Profit made by selling allsaleable fish was higher from theprocessed diet, unprocessed diet,or cottonseed meal treatment thanfrom ponds treated only withliquid fertilizer. Profits were alsohigher for the processed diettreatment than for the cottonseed-meal treatment. Growth andsurvival of swordtails in tankswere similar for fish fed theprocessed or unprocessed diet.

In pond studies with Plecostomus,production was highest for fish

fed the unprocessed diet, followedin order by the processed diet,cottonseed meal, and liquidfertilizer treatments. Pondsreceiving the unprocessed diet hadthe largest number of large fishand the best production andsurvival. Investment return for theunprocessed diet treatment wastwice that of the processed dietand cottonseed meal treatments.Ponds treated with liquid fertilizerperformed very poorly and did notproduce enough sellable fish tocover the costs of the treatment.Percent survival varied dramati-cally, with liquid fertilizerproducing only 10% survivalcompared to 65% survival for theunprocessed diet. In tanks, growthand survival of Plecostomas fedprocessed or unprocessed dietswere similar.

Firemouth Meeki cichlids in pondsgrew best on the processed diets,followed in order by the un-processed diet, liquid fertilizer andcottonseed meal treatments.Interestingly, liquid fertilizer aloneproduced the highest number offish. Firemouth Meeki cichlidsreadily spawn in ponds, andreproduction and survival ofoffspring was best in the liquid-fertilized ponds, but fish size wassignificantly smaller than in theponds treated with either diet. Intanks, there was no difference ingrowth or survival of FiremouthMeeki cichlids fed the processedor unprocessed diet.

Production of Red Eye Tetras inponds was best when fed theprocessed diet, followed by theunprocessed diet, cottonseed meal,and liquid fertilizer treatments.

Tank studies using Red Eye Tetrasshowed no significant differencein growth or survival of fish fedthe processed or unprocessed diet.

Overall, the ornamental fish studydemonstrated that pond fertiliza-tion alone produces a significantnumber of fish at a relatively lowcost, but the size of the fish issignificantly smaller compared toother treatments. There also was ageneral trend toward increasinggrowth and survival in ponds withprocessing of the diet, but not forall species. Selection of an organicfertilizer such as cottonseed mealor an inorganic fertilizer such asthe liquid used in this study, alsoproduced different yields, butagain there was variation in therelative trend between species.Firemouth Meeki cichlid showed adramatic increase in survival andtotal yield with an inorganicfertilizer versus cottonseed meal.

The original objectives of thisproject have largely been met orexceeded, as additional lines ofresearch have been generated thatwill continue past the completionof the project. Results indicate thatthere is good potential to improveproduction efficiency, productquality, and marketability of baitand ornamental fishes throughchanges in diet composition andfeeding strategy. Based on thecollective data generated from thisproject, several producers of baitand ornamental species havealtered their stocking densities andfeeding regimes. Further imple-mentation of the results isexpected when preliminaryestimates of economic feasibilitycan be confirmed.

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THE CHALLENGE . . .

DEVELOPMENT AND EVALUATIONOF POND INVENTORY METHODS

OUR RESPONSE . . .

Maintaining accurate inventoryrecords in large earthen-pondaquaculture systems has alwaysbeen problematic. Accuratebiomass, headcount and sizedistribution information is criticalfor production management,business planning, accounting andoperation financing. With produc-tion costs rising and profit marginsshrinking for many aquacultureenterprises, the development ofmore accurate inventory estima-tion techniques would helpprovide crucial business planninginformation.

Nine research scientists from fiveinstitutions are participating in atwo-year project to develop newmethods and techniques forestimating inventory biomass,headcount, and size distribution ofaquatic animals raised in earthenpond systems. The scientistsparticipating in this projectrepresent the following institu-tions:

• Louisiana State University• Mississippi State University• University of Arkansas at Pine

Bluff• University of Florida• University of Mississippi

Various inventory techniques andmethodologies tailored to differentproduction facilities are underinvestigation. The primaryobjectives include efforts to:

• Determine the most accurateand reliable way to estimateornamental fish inventoriesin ponds;

• Determine the most accurateand reliable way to estimatecrawfish inventories inponds;

• Modify the Aquascanner Cat-fish SONAR system to sizeindividual catfish collectedfrom ponds;

• Develop and evaluate severaldown-looking and low fre-quency side-scan sonar tech-nologies to determine num-bers of channel catfish inponds;

• Develop and evaluate a cat-fish trawl and portable com-puting technologies to esti-mate inventory numbers incatfish ponds.

PRINCIPALACCOMPLISHMENTS . . .

Work at the University of Floridafocuses on quantifying discrepan-cies between producer estimates ofornamental fish larvae and actualnumbers of fish stocked intoproduction facilities. Largesystematic errors were identified,which has resulted in improvedmethods for estimation of numberat stocking and improved recordkeeping procedures to improveinventory tracking over theproduction cycle for ornamentalfish produced in ponds.

Research at Louisiana StateUniversity showed that crawfishsampling by test traps generallywas a good indication of potentialyield in crawfish test ponds and

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ECONOMIC FORECASTING ANDPOLICY ANALYSIS MODELS FORCATFISH AND TROUT

THE CHALLENGE . . .

OUR RESPONSE . . .

PRINCIPALACCOMPLISHMENTS . . .

The U.S. aquaculture industry isfacing challenging economicconditions. Increasing quantities ofimports have made it difficult topass rapid increases in feed andother costs on to consumers. Othersegments of the agriculture andfood sectors in the U.S. rely uponeconomic models to anticipate theeffects of changing economicconditions on farm prices andquantities produced and to assessthe effects of new policy initiatives.No such economic models exist forU.S. aquaculture industries.

Nine research and extensionscientists from five institutions havejoined in a two-year project todevelop models that will provideguidance to the catfish and trout

industries on the effects of varioustypes of changes in the economy.The scientists represent the follow-ing institutions:

· Louisiana State University· Mississippi State University· North Carolina State Univer-

sity· University of Arkansas at Pine

Bluff · University of Florida

The following types of economicmodels are under development:

· U.S. demand and supply of cat-fish and trout;

· International trade effects onthe catfish and trout industries;

· Potential effects of variouspolicy alternatives and externaleconomic shocks on the catfishand trout industries.

Economic models have been devel-oped of demand and supply of U.S.catfish at both the farm and whole-sale levels. The variables withsignificant effects on U.S. catfishsupply and demand were identifiedfor both the farm and wholesalelevels. Other models have beendeveloped that evaluate effects ofinternational trade on the U.S. cat-fish and trout industries. The vari-ables from the international modelswith significant effects on domesticcatfish prices were identified. Thisproject will now move to combinethe most important variables fromthe domestic supply and demandmodels with those from the interna-tional trade models to begin to as-sess effects of various policyalternatives and external economicshocks.

Research at Auburn University hasdeveloped indicators of resourceuse efficiency in catfish farmingand other types of aquaculture.These indicators have been usedby several environmental NGOs indeveloping aquaculture eco-labelcertification standards. Energyuse for production and processingof catfish is about 9.059 kW · hr/kg of live fish. Grow-out ofchannel catfish and production of

feed for use in grow-out accountsfor about 50% and 25% of energyuse, respectively.

Findings from research at theUniversity of Arkansas at PineBluff were used to construct acommercial-size barrier system ata commercial fish farm in Arkan-sas. The barrier system has beenstocked, and production data willbe available at the end of 2008.

Cash flow budgets developed at theUniversity of Arkansas at Pine Bluffare being used by several banks formaking decisions about loans tocatfish farmers. These budgetsshow that lending limits result infarmers removing ponds fromproduction. Also, as cash flow isrestricted, smaller farms switch tostocking smaller fingerlings, andlarger farms switch to stockingfingerlings instead of stockers.

Innovative Technologies and Methodologies forCommercial-scale Pond Aquaculture(continued from page 4)

Page 13

that simulated population recruit-ment was poorly correlated tocrawfish yield in the pondsstudied. The most accurate pondinventory methodology, and thebest indicator of potential yield inthis study, was the simple passivedrop sampler. Additional researchwill determine how well thesefindings apply to large scalecommercial operations andwhether these methods areaccurate enough to have practicalapplications.

The Aquascanner Catfish SONARsystem has been modified byUniversity of Mississippireseachers to determine the size ofindividual catfish collected fromponds. An acoustic backscatter

system has been built to measurethe target strength of individualfish from a harvested population.That information can then beprocessed to predict the popula-tion weight distribution of the fishharvested.

First year research at MississippiState University focused onobtaining and testing the inventorypotential of a commercial side-imaging sonar unit. “Screen SnapShots” obtained with the side scanlobes of the unit in commercialcatfish ponds indicate that thistechnology can be used to imagefish.

Researchers at the University ofArkansas at Pine Bluff have

modified a commercially avail-able “otter style” trawl for thepurpose of collecting a largesample of catfish in levee-styleproduction ponds. Early resultssuggest that the catfish samplingtrawl may capture large stockersand food-size fish more effec-tively than it does fingerlings.Nevertheless, the trawl may stillremain a viable sampling tech-nique to assess the sizedistribution of catfish populationsafter these biases are quantified.Also, considerable progress hasbeen made in the development ofa sample data collection systembased on a hand-held “PDA”computer platform.

Development and Evaluation of Pond Inventory Methods(continued from page 11)

Southern Regional Aquaculture CenterCraig S. Tucker, Director

P.O. Box 197Stoneville, MS 38776Phone: 662-686-3285

Fax: 662-686-3320E-mail: srac@drec.msstate.edu

http://www.msstate.edu/dept/srac

In cooperation with the U.S. Department of Agriculture, CooperativeState Research, Education, and Extension Service