Sagana Fish Farmby D. Liti and J. MungutiMoi University and Sagana FishFarm, Kenya

Recent History

I mprovement of Sagana FishFarm has been at the center of

aquaculture development inKenya since 1993. Rehabilitation of thefarm started then, under the sponsor-ship of a project funded by the BelgianGovernment. Renovation of old pondsas well as construction of new onestook place through 1996. In 1997, thePD/A CRSP project was initiated atSagana. Farm operations under bothprojects were partly funded by theGovernment of Kenya. Sagana nowhas 109 ponds, 65 ponds of whichwere constructed specifically forresearch purposes, with the balancebeing used for spawning, fingerlingproduction, and growout of fish.

The Farm as a Training CenterSagana is a busy station characterizedby many visits from farmers,government officers, students fromprimary, secondary, and universityinstitutions, and local as well asinternational scientists. Last yearSagana hosted Jonathan Munguti, aKenyan, and Richard Nyamwihura, aTanzanian, for four months duringtheir M.S. research periods. Both wereparticipating in an internationalacademic program in limnology andwetland ecosystems, and their staywas sponsored and Austrian Academyof Sciences and The Netherlands’International Institute for Infrastruc-tural, Hydraulic and Environmental

Sustainable Aquaculture

for a Secure Future

POND DYNAMICS/AQUACULTURE COLLABORATIVE RESEARCH SUPPORT PROGRAM NEWSLETTER

Volume 17, Number 4/Fall 2002 pdacrsp.orst.edu ISSN 1062-4996

CRSP Activities in the Africa RegionWe devote much of this issue to the PD/A CRSP in Africa. An overview of currentinvestigations and collaborating partners appears on the following page, withadditional information on these available at the CRSP website (see Publicationssection “Tenth Work Plan”). See p. 10 for a story on a new InterCRSP Njoro Riverwatershed management project.

Use of Local Technology toPromote AquacultureDevelopment in Sagana,Kenyaby D. Liti and J. MungutiMoi University and Sagana FishFarm, Kenya

Sagana and the CRSP

PD/A CRSP activities at SaganaFish Farm have greatlyenhanced the reputation and

visibility of Sagana’s research insustainable aquaculture.

In the current PD/A CRSP workplan, research at Sagana is aimed atimproving production of fish proteinand fish seed. Two investigations areunderway: 1) Evaluation of Growthand Reproductive Performance ofThree Strains of Nile Tilapia,Oreochromis niloticus, Found in Kenyafor Use in Aquaculture; and 2)Development of Economically FeasibleFeeds for Semi-Intensive Culture ofTilapia, Oreochromis niloticus, UsingLocally Available Agricultural By-Products.

…continued on p. 4

Aquaculture ponds at Sagana Fish Farm, Kenya.

Mw

an

gi

Mb

ug

ua

…continued on p. 4

2

included. This will include informa-tion on prices, product forms, marketchannels, volume requirements forvarious market channels, andpotential target market segments.Economic planning tools such as theseunder development in Kenya willassist existing and prospective tilapiafarmers to increase the likelihood ofdeveloping successful businesses

Techniques for the Production ofClarias gariepinus Fingerlings as

Baitfish for the Lake Victoria NilePerch Longline Fishery

Moi University, KenyaFisheries Department, KenyaAuburn University, USOregon State University, US

Regional Enterprise Budget andBusiness Plan Development; and

Economic and Risk Analysis of TilapiaProduction in Kenya

Moi University, KenyaUniversity of Arkansas at PineBluff, US

Kenyan Regional EnterpriseBudget and Business PlanDevelopmentby Carole Engle, University ofArkansas at Pine Bluff, and MucaiMuchiri, Moi University

T here is a great deal of interestin the development ofsuccessful aquaculture

businesses in the East Africa region.Researchers at the University ofArkansas at Pine Bluff and MoiUniversity, Eldoret, Kenya, arecollaborating in the development ofenterprise budgets for both tilapiamonoculture and tilapia–Clarias spp.polyculture. Budgets will bedeveloped for cash systems based onon-farm inputs and for commercialsystems based on purchased feeds andfertilizers. The enterprise budgetsdeveloped will be published fordistribution with instructions tofarmers on how these can be adaptedto their particular situation and farm.

From the enterprise budgets, proforma financial statements (includingannual cost and returns, estimate oftotal required capital, balance sheets,income statements, and cash flowbudgets) will be developed for the

production systems and average farmsizes selected. The financial statementswill be published with instructionscontaining a spreadsheet for farmersto enter farm-specific data as needed.

A summary of marketinginformation will be prepared for eachof the production systems/scenariosproposed. Fundamental marketinformation required to present themarket plan component will be

2002 Portfolio of PD/A CRSP Investigations and Collaborating Partners in Africa

Development of EconomicallyFeasible Feeds for Semi-

Intensive Culture of Tilapia,Oreochromis niloticus, Using LocallyAvailable Agricultural By-Products

Moi University, KenyaFisheries Department, KenyaAuburn University, US

Aquaculture Training forKenyan Fisheries Officers and

University Students

Moi University, KenyaFisheries Department, KenyaAuburn University, USOregon State University, US

Evaluation of Growth andReproductive Performance of

Three Strains of Nile TilapiaOreochromis niloticus Found in Kenyafor Use in Aquaculture

Moi University, KenyaFisheries Department, KenyaAuburn University, US

Reaction of Liming Materials inPond Bottom Soils, South Africa

University of Stellenbosch, SouthAfricaAuburn University, US

Kev

in F

itz

sim

mo

ns

Aquaculture facilities at Moi University, Eldoret, Kenya.

continued on p. 11...

Aquanews ~ Fall 2002

3

Kenya’s Director ofFisheries Department Visitsthe USBy Steve Sempier

N ancy Gitonga, Director of theKenya Department ofFisheries, recently returned

home after spending several weeks inthe United States. Highlights of hertrip included attending an AmericanFisheries Society (AFS) conference,visiting with United States Agency forInternational Development (USAID)officials, and touring several USuniversities and fish farms.

Gitonga gave a well-received posterpresentation at the 132nd AnnualMeeting of the American FisheriesSociety. The poster focused onaquaculture development in Kenya.Gitonga attended the meeting, whichtook place from 18 to 22 August 2002in Baltimore, Maryland. During the

meeting she met many current andpotential future PD/A CRSP colla-borators. In addition, she attendednumerous presentations that address-ed fisheries issues and challenges thatalso face Kenyan fisheries.

After the AFS meeting, Gitongatraveled to Washington, DC. AtUSAID, she gave a presentation titled,“The Role of Aquaculture in FisheriesDevelopment in Kenya.” The USAIDofficials who attended the 23 August2002 presentation expressed greatinterest in the subject.

In addition to Gitonga’s time inBaltimore and Washington, she spent

time at The OhioState Universityin Columbus andat the Universityof Arkansas atPine Bluff. Thesevisits allowedGitonga to spendtime at USuniversities thatare collaboratingwith the CRSPand expand theKenya Depart-ment of Fisheriesnetwork. While inArkansas, Giton-ga also visitedseveral aquacul-ture farms thatcultured a varietyof species. Shenoted the similar-ities and differ-ences betweenthese farms andfarms in Kenya.Those tours mayopen up moredoors for oppor-tunities in Kenya.

Gitonga’sCRSP-sponsoredtrip was a success

as she was able to both build uponand strengthen her network of UScontacts in the fisheries andaquaculture field. In addition, she wasable to share concerns and successesrelated to aquaculture in Kenya andfoster interest in pursuing aquacultureresearch in this region of Africa.

Kenya Fisheries Department Director Nancy Gitonga at AFS meetingin Baltimore earlier this year.

Stev

e Se

mp

ier

Optimizing Lime Use inAquaculture Ponds–CRSP Work in South Africa

R esearchers Claude Boyd andWes Wood, both from AuburnUniversity, are collaborating

with Danie Brink, University ofStellenbosch, South Africa, in aninvestigation that seeks tomaximize the effectiveness of limeapplied to aquaculture ponds.

Lime is used to increase alkalinity inaquaculture ponds, which in turnencourages the growth of the plant lifeupon which certain types of fish,including tilapia, feed.

The experiment involves treatingponds in a variety of ways.Specifically, treatments include:1) applying agricultural limestoneover pond water surface afterfilling; 2) applying agriculturallimestone over pond bottom beforefilling; 3) applying agriculturallimestone over pond bottomfollowed by tilling of soil beforefilling; and 4) control (noagricultural limestone added).

To obtain values for alkalinity andhardness, researchers collect weeklywater samples. Soil cores are collectedon a monthly basis and divided into2 cm-long segments; these will beanalyzed for pH and exchangeableacidity.

These experiments are beingduplicated in Jaguariuna, Brazil.When this work is complete, data willbe available for coarse textured (SouthAfrica) and fine textured (Brazil) soilsregarding the influence of limeapplication method on neutralizationof acidity in ponds.

These data will allow the scientiststo formulate recommendations onappropriate application methods tomaximize effectiveness of lime appliedto aquaculture ponds. Beneficiaries ofresults obtained in this research effortinclude not only farmers near CRSPsites, but those in neighboringcountries as well.

Auburn University and theUniversity of Stellenbosch have co-signed a Memorandum ofUnderstanding and an AcademicInterchange Agreement.

4

Sagana Investigations

Evaluation of Growth andReproductive PerformanceThree Nile tilapia strains from LakeVictoria, Lake Turkana, and Saganaare being evaluated to determine thebest strain that can be recommendedto farmers. Although the strainexperiment is in its initial stages, thereare indications that the Lake Victoriastrain may have the best performancein terms of growth.

Development of EconomicallyFeasible FeedsSingle ingredients of agricultural by-products—wheat bran, maize bran,and rice bran—have been evaluatedand recommended to farmers. Wheatand maize bran have proved throughprevious experiments to be better feedsupplements for Nile tilapia than ricebran. The latter performed poorly due

…from p. 1

Use of Local Technology to Promote Aquaculture Development in Sagana, Kenyaby D. Liti and J. Munguti

to adulteration by the suppliers. Infact, rice performed only marginallyover the fertilizer treatments despitehaving the same cost per unit weightas the other two brans.

In addition to the singleingredients, locally availablecommercial feedshave also beenevaluated as feedsupplements forNile tilapia.Research at Saganahas established thatdiets formulated forpigs perform aswell as thecommercial dietsformulated fortilapia. Moreover,as pig diets arecheaper than tilapiadiets, their useincreases

Engineering. Collaborating East Afri-can host institutions were Egertonand Moi Universities in Kenya, Ma-kerere University in Uganda, and theUniversity of Dar es Salaam in Tan-zania. Sagana played akey role in this programas a site for the research,as well as providingguidance to the students.

Support to theCommunitySince the late 1990s,Sagana has emerged as acenter of excellence inaquaculture, not only inKenya but also through-out East and CentralAfrica. Research activitieshave contributed a greatdeal in providing farmerswith quality seeds,knowledge about fishfeeds, and advice on the

economic use of fertilizers andfertilization rates. These, together withprovision of quality protein, haveplayed a key role in uplifting theliving standards of the local people.Protein malnutrition, mainly among

Sagana Fish Farm…from p. 1

The Sagana feed mill.

Mw

an

gi

Mb

ug

ua

children, has been reduced to a greatextent. The farm is also a source ofinspiration to those farmers whowanted to venture in small-scalecommercial fish farming. Theintroduction of communal fish

farming, mainly bywomen groups in theCentral and Easternprovinces of Kenya, hasimmensely improvedtheir income. Publicawareness and change ofattitudes towards fishfarming and fishconsumption, especiallyto those communitiesliving away from capturefishery areas, and whichpreviously did not appre-ciate fish farming, havesuccessfully been achiev-ed. This has been donethrough extension ser-vices and frequent organi-zation of field days.

Students’ Short-term Experiments at SaganaYield Tangible Benifits

In parallel with longer-term research investigations,side experiments are conducted at Sagana byundergraduate students in fulfillment of their seniorprojects. Results from these experiments have beenquite interesting. In one instance, ponds weretreated with lime and common salt to simulate thewell known productive soda lakes, of which LakeTurkana in Kenya is an example. The student projectdemonstrated that treatment of limed earthen pondswith common salt lead to a remarkable increase infish growth.

profitability.Analysis of commercial feeds con-

ducted at the Sagana laboratory hasshown that some commercial feeds donot meet the specifications given bythe manufacturers. Moreover, thefeeds are unreasonably expensive.

Aquanews ~ Fall 2002

5

Mw

an

gi

Mb

ug

ua

The pelleter resembles a meat mincer and is driven by a single phase 1.5 hp motor. It wasdeveloped in collaboration with the engineering company East African Foundry Works in

Nairobi. The first of its kind to be made by local artisans, it has a capacity to produceapproximately 30 kg pellets of feed per hour. J. Kariuki, Sagana, is pictured.

Aquaculture in Kenyaby D. Liti and J. Munguti

K enya’s aquaculture is based onwarm water, cold water, andmarine culture. The industry is

supported by three major aquaculturefarms: Sagana, Ngomeni, and Kiganjo.These provide fish seed, fish food, training,research, and extension services. Tilapiaculture in Kenya is carried out basically ata subsistence level and is widespreadthroughout the country. Trout farming isnot as prevalent, being currently confinedto a few commercial farms near Mt. Kenya,while shrimp farming has not taken offdespite the funding of the Ngomeni projectby the United Nations Food andAgriculture Organization and the UnitedNations Development Programme.

At the community level, interest inaquaculture is just beginning to emergewith many farmers making inquiries onwhether the industry can generateadequate profits to improve their economicbases.

Major constraints that have contributedto the slow development of aquaculture inKenya include inadequate knowledge ofhow to raise aquacultural animals, lack ofquality fish seed, lack of cheap and highquality diets, and inadequate extensionservices. Another major problem is the lackof locally made—and thus affordable—equipment.

Mw

an

gi

Mb

ug

ua

The mixer has a capacity of 1.5 m3 and can mix 50 kg of feed at a time. It is manually driven byusing a well designed handle. It can also be adapted to be operated by a gasoline engine or

electrical power. J. Kariuki, Sagana, demonstrates.

Jua-Kali

T he feed experiment (opposite top left) has taken aninteresting direction by delving into so-calledappropriate technology. Two important pieces of

equipment, a pelleter and a mixer, have been successfullydeveloped. The two were developed with the help of aninformal sector, locally known as Jua-Kali, and are designed tomeet local needs for easy service and maintenance.

Jua-Kali is a local name which literallymeans “hot sun,” and is given to enterprisesthat work with metal and wood materials.The industry, though small in scale, plays animportant role in the livelihoods of manyKenyans. The Jua-Kali sector makes good,inexpensive tools and equipment from scrapmetal and with limited resources. Thehistory of the Jua-Kali in agriculturedevelopment in Kenya is well known and iswell represented in the production ofagricultural tools and equipment.

Most of the Jua-Kali equipment in theagricultural sector meets the designs andspecifications of the sector. Up until now theaquaculture sector has not benefited muchfrom the industry. The turnaround cameearlier in this current work plan, when Jua-Kali was engaged to develop a pelleter andmixer. The two have attracted the attentionof farmers with two of them placing ordersfor the pelleter and many others venturinginto making their own mixers.

by D. Liti and J. Munguti

6

away for free as well. Thus,although the farmers did not

invest much inthe way of realcapital, they stilldid a lot of workand never reapedany financialbenefit. TheCRSP on-farmtrials made itpossible for thisfarmer toconvince hisneighbors thathis aquacultureponds were nowa bonafide busi-ness venture.

Farmers Appreciative ofLessons Learnedduring On-farm Trialsby Karen Veverica,Auburn University

O n-farm testing is a logicalstep in transferring research-based technologies to the

farm, as it allows farmers to assesstheir costs and benefits under localconditions as well as to receiveinstruction and training in basic pondmanagement skills. It also allowsproject personnel to work with and

train the fisheries extension officers,complementing the experience theextension officers gain through formaltraining activities.

In a collaboration among OregonState University, Auburn University,Moi University, and Sagana Fish Farm,on-farm trials were conducted inCentral, Eastern, Rift Valley, andWestern Provinces, Kenya.

Although the technical advice wasuseful and important, participants’attitudes towards business is whatmade these trials so successful. Theonly services provided by the CRSPproject were transport of fingerlings,visits to offer technical advice, andhelp with sampling.

Farmers were required to purchaseall of their own inputs, includingfingerlings. This was a difficult pill toswallow for many farmers. Nonethe-less, as a result of having a personal

investment at stake, at the end of thetrials, many farmers presented theirdata as expenses and revenues ratherthan just the weight of fish harvested.

One farmer stated that his fatherhad never earned a single shillingfrom his aquaculture ponds in morethan 10 years. However, because ofthese trials, in just one harvest the sonended up with 10,000 KSh in hispocket. He went on to explain thatover the years, with the manyextension projects promoting fishfarming and providing farmers withinputs at no cost, everyone always

thought of aquaculture more as ahobby than a serious business enter-prise.

As a result, neighbors—that is,potential customers—figured theharvested fish should be given

Ponds at a small-scale aquaculture farm, Kenya.

Ch

ar

les

Ng

ug

iFOLLOWING THE FINAL MEETING OF

FARMERS FOR THE ON-FARM TRIALS INWESTERN KENYA, PARTICIPANT

MR. MORRIS ROBERT OMUHAYA

RETURNED HOME AND WROTE LETTERS

TO PROJECT STAFF MEMBERS JUDITH

AMADIVA AND KAREN VEVERICA

EXPRESSING HIS APPRECIATION FOR

WHAT HE LEARNED DURING THE ON-FARM TRIALS.

HE WROTE:

I have improved on my fish

farming enterprise through your

good advice and lectures. I’ve

now stocked my ponds for the

next season and I’m going to

improve on pond inputs so that

I get [even better] profits than

[those] I got in the on-farm

trials...

My son is going to sit in this

year’s O-level exams just

because of these fish ponds

which have become my only

financial resource.

Ch

ar

les

Ng

ug

i

Pond harvest during on-farm trials.

Aquanews ~ Fall 2002

7

Aquaculture Experts Convene inNairobi

T he PD/A CRSP convened the third and last ofa series of regional expert panel meetings inJuly 2002 in Nairobi, Kenya.

Africa Expert Panel members were selected basedon their area of expertise and disciplinary focus,region, and gender. Expert Panel members,among them three women, includedbiologists, social scientists, and engineers.Individuals hailed from Egypt, BurkinaFaso, Nigeria, Ghana, South Africa,Kenya, Malawi, and Congo. As panelmembers their objective was toparticipate as representatives of theregion as a whole rather than ofsubregions.

The panel meeting took place on8 July. After the meeting, many of thepanelists participatedin a tour of theSagana Fish Farm,just northeast ofNairo-bi, and of MoiUniversity inEldoret, which isseveral hundredmiles to thenorthwest.

The PD/A CRSPscurrent grantextends through July31, 2003. In 2001, thePD/A CRSPconvened a ProposalPlanning ExecutiveCommit-tee (PPEC), whose objective is to coordinate andlead the planning effort for the next continuation proposalto USAID. The first phase of information gathering was astakeholder meeting held in Honduras in August 2001.

The second phase of information gathering involvedthree expert panel meetings for the Latin America andCaribbean Region, Asia Region, and Africa Region. Eachpanel had 10 experts, as well as a chair and a facilitatorfrom PPEC. Panel members came to the meeting havingpreviously reviewed a broad selection of relevantliterature.

Panelists were asked to consider, “What are the issuesthat constrain small-holder fish farms from becoming moresuccessful in the [relevant] region?”) and “What are theresearchable priorities arising from these constraints?”Based on the constraints and researchable prioritiesidentified in each of the three panels, the PPEC developed asynthesized set of global researchable priorities both for afive-year proposal and for the Request for Proposals for theEleventh Work Plan. (Proposals submitted in response tothat RFP are currently undergoing panel peer reviews.)

The Expert Panel meetings for the Latin America and theCaribbean Region and for the Asia Region took placerespectively in San Diego, California, in February, andBeijing in April.

Panel members visited Sagana Fish Farm and Moi University after theExpert Panel Meeting in Nairobi. Above they tour ponds at Sagana.

Gw

yn

New

co

mb

e

Africa Region Expert PanelMembers, from top left:

Mucai Muchiri Aboubacar Toguyeni

J.F. BaroillerStella Williams

Fatma HafezPierre Justin Kouka

Kwamena QuagrainieDaniel JamuDanie Brink

Nancy Gitonga

Kev

in F

itz

sim

mo

ns

Kev

in F

itz

sim

mo

ns

Gw

yn

New

co

mb

e

8

Churo is a PromisingCandidateApplesnails (Pomaceaspp.)—and among themP. maculata, or churo, as itis known in Peru—are thelargest known freshwatergastropods, reachinglengths of 155 mm anddiameters of 135 mm(Pain, 1960). This aquaticorganism lives in thefloodplain of the Amazonregion (Cobos, 1998),preferring the zone wherewater mixes in the majorand minor rivers(hardness from 35 to 256mg l-1) as well as in theirtributaries (Villacorta,1976). It is a species ofperiodic reproduction(Cobos, 1998), depositingits eggs in clustersoutside the water on hardsurfaces (e.g., trees,shrubs, wood debris),most frequently in theflooding months (rainyseason). The number ofeggs produced per female at eachspawn varies according to body size,ranging from 233 to 1,425 eggs(Cobos, 1998; Rojas and Mori, 1976;Villacorta, 1976). Ontogenicdevelopment takes from twelve tosixteen days (Alcántara et al., 1996)and hatching rate is 87% (Cobos,

…continued on p. 11

Culture of Mollusks toImprove Human ProteinIntake in the AmazonRegionby Fernando Alcantara andSalvador Tello, Instituto deInvestigaciones de la AmazoniaPeruana, and Christopher C.Kohler, Susan T. Kohler, andWilliam Camargo N., SouthernIllinois University, Carbondale

Mollusks Offer an Alternative toFish-based Aquaculture

T he Amazon River regioncontains a high biodiversity ofaquatic organisms hence an

excellent potential for commercialaquaculture. The sustainability andexpansion of aquaculture inAmazonia will be fostered byestablishing new species forcultivation. Invertebrates, inparticular, have received minimalattention in this regard. Severalspecies of mollusks (gastropods andbivalves) have been exploitedirregularly by the ever-decliningcommercial fishing industry in theAmazonian region. Currently,research is underway by the Institutode Investigaciones de la AmazoniaPeruana (IIAP) in Iquitos andPucallpa, Peru, to develop simpletechnologies to culture aquatic andgiant terrestrial gastropods as analternative form of polyculture orintegrated aquaculture.

1998). Churo is omnivorous, feedingeither on fresh or partiallydecomposed organic matter,including floating macrophytes (e.g.,water lettuce or huama–Pistiastratiotes, duckweed–Lemna minor),rooted plants (e.g., gramalote–Paspalum spp.), tree leaves (e.g.,renaco–Ficus guianensis, cetico–Cecropia spp., tangarana–Paniculatatachigalia, catahua–Hura crepitans andquinilla–Vochysia lomatophylla) andshrubs (e.g., ñejilla–Bactris sp. andwater chestnut or rayabalsa–Montrichardia spp.) in the naturalenvironment (Cobos, 1998).

Churo is a hardy species thatreadily adapts to controlledenvironments and reproduces incaptivity. The egg-layingcharacteristics facilitate egg collectionunder culture conditions. In Iquitos,churo culture is conducted by IIAP inaquaria or in cement tanks slightlyfilled with water (15 cm depth). Theseare covered with a lid made of awooden frame layered with a fineAdult Pomacea bridgesi.

[Image courtesy of <www.applesnail.net>.]

Stij

n G

hes

qu

ier

e

Ro

ger

Ha

rr

is

Pomacea eggs on tree trunk near Iquitos, Peru.[Image courtesy <www.junglephotos.com>.]

Aquanews ~ Fall 2002

9

highly prized favorite among theconsumer of the Amazonian region.

A drastic population decrease in A.gigas is the result of intense capturepressure that the species has beenunder in its natural habitat.According to Guerra (1996), statisticson landings in the Department ofLoreto, Peru, show that during highseason A. gigas comprised 10% of the

Arapaima Pond Culture bythe Small-Scale FishProducers of the PeruvianAmazonby Fernando Alcantara andSalvador Tello, Instituto deInvestigaciones de la AmazoniaPeruana, and Christopher C.Kohler, Susan T. Kohler, andWilliam Camargo N., SouthernIllinois University, Carbondale

K nown as paiche in Peru andpirarucu in Brazil andColombia, Arapaima gigas

(Osteoglossidae) is one of the majorscaled fishes in the Amazon andOrinoco watershed systems (Luling,1969). It lives in lagoons and in thelarge rivers of the vast Amazonregion in water with slightly acid pHthat is typically black in color (owingto the presence of abundantdecomposing plant material). In itsnatural environment, A. gigas reacheslengths from two to three meters andcan weigh up to 200 kg (Saint-Paul,1986), feeding mainly on live fish(Fontenele, 1942; Sánchez, 1961). Themeat lacks intermuscular bones orspines, and each fish has a dressoutyield of 57% (Imbirirba, 1986). Thefillet is of excellent quality and is a

…continued on p. 14

Ped

ro

Ic

om

edes

Biologist Palmira Padilla from IIAP (right) handing one of the six Arapaimajuveniles given to a beneficiary.

IIAP/CRSP Extensionist Carlos Chávez holding an Arapaima juvenile.

Ped

ro

Ic

om

edes

total fish capture from 1980 to 1992but declined thereafter. The fishingpressure has placed the species at riskfrom a conservation and sustainableusage perspective; in fact, A. gigas islisted as endangered by theConvention on International Trade ofWild Fauna and Flora Species.

A. gigas has been able to reproducenaturally in medium-size ponds(Alcántara, 1990) and large waterenclosures, feeding on small culturedforage fish (Bard et al., 1975;Alcántara & Guerra, 1992; Rebaza,1998; Imbiriba, 2001) and cultivatedwith simple technologies that canreadily be incorporated by the privatesector. Furthermore, A. gigas undercultivation conditions accepts altern-ative foods, such as chicken embryos,pelletized feed (De Souza et al. 1986;Aldea, 2002; Village, 2002 unpublish-ed; Sagratzki-Cavero et al., in press)and, in extreme conditions, bread andcrackers (Rebaza et al., 1999).

Earlier this year, a nongovern-mental organization (NGO) that hasbeen working in the area of Iquitos,Peru, took cultured A. gigas productsto the International Fair of Bremen,Germany, where the NGO deter-mined demand in that market alonefor A. gigas fillet to be around 60tonnes per month.

10

T he Pond Dynamics/Aquaculture CRSP and theGlobal Livestock CRSP have

joined together to support acollaborative initiative for problemmodel assessment and human capacitybuilding for the rehabilitation of theRiver Njoro watershed in Kenya. Themultidisciplinary team is composed offaculty members from EgertonUniversity, the University ofWyoming, the University of Californiaat Davis and Moi University, as well aspartners from other Kenyaninstitutions such as the KenyaDepartment of Fisheries and KenyaWildlife Service.

The team is composed of fourprincipal groups: watershed charac-terization, stakeholder involvement,ecology, and socio-economics, whichwill integrate stakeholder interestswith scientific research and consultwith various stakeholders in thewatershed on matters such as waterquantity and water quality. Awatershed assessment will lead to thepreparation of a problem model thatwill in turn facilitate the team togenerate a full project proposal forintegrated sustainable management of

Assessment and Initial Capacity Building for the Rehabilitation of the RiverNjoro Watershed, Kenya (SUMAWA)by Susan Johnson,Global Livestock CRSP,University of Califormia, Davis

EdOp Net a Window onOpportunities

The team for the joint PD/A CRSP and Global Livestock CRSP project(SUMAWA) recently presented a poster entitled “Integrated Stakeholder

Participation and Watershed Assessment in the River Njoro Watershed, Kenya”at the GL-CRSP Program Conference. Pictured, from right, Ole KamuaroOlolitisatti, Maasai Environment Resource Coalition, William Shivoga

and Francis Lelo, Egerton University, SUMAWA project leaders.

Susa

n J

oh

nso

n

Susa

n J

oh

nso

n

SUMAWA team member Prof. Aboud, Dean of the Faculty of EnvironmentalStudies and Natural Resources, Egerton University, is pictured with Adam

Wolf of the GL-CRSP Livestock Development and Rangeland Science projectin Central Asia, and Getachew Gebru and Solomon Desta, GL-CRSP

Pastoral Risk Management (PARIMA) project in Ethiopia and Kenya. Prof.Aboud is also a team member on the PARIMA project.

watershed re-sources throughstakeholderparticipation atthe watershedscale.

SUMAWAprojectparticipantsmet inWashington DCrecently.Among themwere MoiUniversityprofessorsMucai Muchiriand GodfreyMonor. Muchiriis also a PD/ACRSP principalinvestigator.

After the meeting in Washington,Muchiri and Monor visited Oregonover the course of several days. Theirvisit, hosted by the PD/A CRSP,included meetings with staff at theOregon Department of EnvironmentalQuality in Portland. At Oregon StateUniversity they met with CRSPDirector Hillary Egna, Fisheries andWildlife Department Head Dan Edge,and CRSP Kenya Project OSUPrincipal Investigator Jim Bowman.

E dOp Net has come a long waysince the first issue in October1996. With a mailing list of over

500 subscribers and over 1,200 visitsper month to the website, EdOp Nethas grown into a preferred resourcefor PD/A CRSP participants andothers interested in current education-al and employment opportunities inaquaculture. At the time of publishingthere were approximately 100opportunities posted on the website. Ifyou know of any educational oremployment opportunities in theaquaculture field, let us know.

EdOp Net is a great way to findnew graduate assistants, postdocs,interns, or people with generalexperience in aquaculture, and itallows you to reach potentialapplicants from around the world. Tosubscribe electronically to EdOp Netor to post anopportunity, emailIan Courter at<courteri@onid.orst.edu>; you canalso see listings onour website,<pdacrsp.orst.edu/edops/edop.html>.

Aquanews ~ Fall 2002

11

metallic mesh to provide a suitablesurface for oviposition. Two weekslater, the eggs hatch and the juvenilesfall into the water. At this time theyare fed lettuce (Lactuca sativa,Villacorta, 1976; Sáenz, 2001), eggplant(Solanum melongena), squash or zapallo(Cucurbita pepo) and taro or pituca(Colocasia esculenta). In a six-monthculture period, they reach a weight of35 g and a length of 6.5 cm, with anaverage food conversion ratio (FCR) of2.9. Further, Alcántara and Nakagawa(1996) conducted nutritionexperiments using artificial feeds,obtaining variable yields between 8.1to 31.8 kg m-2 in seven months ofculture, with individuals averagingweights from 39 to 98 g.

The market size (proportional to

K enyan Jon Rauni began workwith the Pond Dynamics/Aquaculture CRSP in

February 2002. Just two months laterhe began working on his mastersdegree in aquaculture at MoiUniversity, Kenya. Rauni’s interest inpursuing his masters is attributed tohis relationship with N.K. Kinyajui,who served as Sagana Fish Farm Headof Station at the time. After workingwith Rauni, Kinyajui advised him todevelop his expertise in aquaculture.Rauni then applied for a CRSPscholarship through Moi University.After his application was accepted,Rauni dove into a rigorous schedule,balancing course work and thesisresearch under the supervision of PD/A CRSP Host Country PrincipalInvestigator, Charles C. Ngugi.

As a youngster, Rauni grew upfishing near his hometown, Meru,located on the slopes of Mount Kenyain the Samburu Region. His love forfishing kindled his interest inaquaculture. It is fitting that Rauni’sCRSP research project is on Clarias,because he boasts a five hundred gramClarias as his most prized catch whilefishing. Clarias, a type of catfish, isAfrica’s most widely distributed fish.

Rauni expects his thesis project,titled “Clarias Fingerlings as BaitFish,” will take him about two years tocomplete. He is working with Ngugi,Jim Bowman, and Baraza Wangila toexplore the issues surrounding Clariasculture. Their research focuses onmaximizing Clarias fingerlingproduction through alteration ofshading regime, stocking density, andgrow-out period. A recent increase indemand for Clarias fingerlings stemsfrom longliners in popular fishingareas such as the Winam Gulf. Clariasis the preferred bait for longlining inKenya, with an estimated demandbetween 5,000 and 50,000 fingerlingsper fishing day. This amounts to ademand of 1.5 to 15 million Clariasfingerlings per year. Clarias is anaturally abundant species, dwellingmost often under floating shorelinevegetation. However, capturing thefingerlings can be destructive to nativecichlid populations. Due to theimportance of the cichlid fishery inKenya, beach seining and fishing withmosquito nets have been banned inKenya. Rauni and his colleagues feelthat successful aquaculturalproduction of Clarias is just what theKenya freshwater fishery needs,

Graduate Student Profile: Jon Rauniby Ian Courter

providing an inexpensive supply ofbait fish without damaging wild fishpopulations.

When asked what makes Kenya anexcellent place to developaquaculture, Rauni replied, “Anabundant water supply, cheapagricultural products, and an idealtropical climate. Kenya has a longhistory of aquaculture and now hasSagana and Moi University as goodresearch and training centers.”

What does the future hold? Aftergraduation Rauni hopes to continueresearch and further his education,particularly with respect to Clarias, afish which he has become increasinglyfond of. He believes that Clarias is animportant species because of itswidespread distribution throughoutAfrica, marketability, and potential asa biological control species.

Rauni recognizes the increasingimportance of aquaculture worldwide,but he also knows when it’s time totake a break from the hecticatmosphere of graduate school. Whennot in class or conducting aquaculturestudies, Rauni finds himself fishing orrelaxing to the melodious music ofCharlie Pride and other country stylefavorites.

...from p. 8

...continued on p. 15

through adequate business planningand monitoring.

The proposed activity will produceenterprise budgets and pro formafinancial statements for business plansthat can be used as guides forprospective and existing fish farmers.A sound business plan is required byfinancial institutions before extendingcredit to any new enterprise. Theinformation developed in this projectwill not only provide farmers with theappropriate tools to show profitability,but it will also help lending institu-tions to better assess the viability ofaquaculture projects and reduce therate of failure in loan repayment.Furthermore, this effort will identifythe gaps in the existing database on fishfarming in Kenya and the region.

...from p. 2

Mollusks in AmazoniaKenyan Budget Development

culture period) can be reducedconsiderably to fit the requirements ofinternational markets. Marketing theproduct as escargot (in Europe), forexample, reduces the market size ofthe snails to only 4 cm in length,requiring only 2- to 3-months growth.

Another possibility is to use a value-added method such as canning, whichIIAP and Southern Illinois UniversityCarbondale under PD/A CRSPsponsorship have successfullyproduced using brine as thepreservation media. This product isreadily consumed by the locals toprepare cebiche de churo, a traditionaldish. An economic study performedby IIAP determined profit margins of58, 62 and 93%, at low (1,000 m-2),

12

Graduates’ Corner

Congratulations to CRSP-sponsored graduate students Enos Mac’Were, Bethuel Omolo, and Robert Carpenter on completionof their degrees. In March 2002, Enos Mac’Were earned a Master of Science degree from the Fisheries Department of theFaculty of Forest Resources and Wildlife Management at Moi University, Kenya. His major professor was Charles Ngugi.Bethuel Omolo earned a Master of Science degree from the Department of Fisheries and Allied Aquacultures at AuburnUniversity. A CRSP-sponsored graduate student profiled in the Summer 2000 issue of Aquanews, he defended his thesis inNovember 2001. Ron Phelps was his major professor. Rob Carpenter, also advised by Ron Phelps, earned a Master of Sciencedegree from the Department of Fisheries and Allied Aquacultures at Auburn University in August 2002.

...continued on p. 14

COMPARISON OF TILAPIA AND CLARIAS POLYCULTURE YIELDS AND ECONOMIC BENEFITS RESULTING FROM ALOCALLY AVAILABLE ANIMAL FEED (PIG FINISHER PELLET), AGRICULTURAL BY-PRODUCT (RICE BRAN), AND A

PELLETED TEST DIET IN FERTILIZED PONDS

(abstract of Enos Mac’Were’s M.S. thesis)

Oreochromis niloticus and Clarias gariepinus were reared for 180 days in fertilized ponds receiving different feeds to

compare growth and financial analysis. Supplemental feeds tested were a readily available agricultural by-product (rice

bran), commercially available animal diet (pig finisher pellet), and a pelleted test diet. Test diet was formulated to

contain 20% crude protein (CP). The two pellets were compared to rice bran.

Twelve 800-m2 ponds, with four replicates for each of three feeds and fertilizer regimes were limed at 2.5 ton

ha-1 just prior to filling with water. Each pond was stocked with 1550 tilapia and 50 Clarias averaging 89 g and

330 g respectively. Fish were fed twice a day at 10 A.M. and 4 P.M. at estimated 2% body weight. Each pond

was fertilized at 5 kg P ha-1 wk-1 and 20 kg N ha-1 wk-1 from diammonium phosphate (DAP) and urea.

Water quality parameters were not significantly different (p>0.05) among treatments except total alkalinity in

which TDP was higher than RB, and both dawn and afternoon pH and dissolved oxygen where ponds receiving

RB and PFP had highest and lowest (p<0.05) values respectively.

All three feeds contained much lower protein than expected. Rice bran (RB) had 5% CP content against

expected 10%. Pig finisher pellet (PFP) advertised to contain 14% had 10% while test diet pellet (TDP) had only

11%.

RB had significantly lower values (P<0.05) in fish growth rate, gross and net fish yields, net annualized

production and with higher values on apparent feed conversion ratio compared to both PFP and TDP. However,

Image of Clarias gariepinus courtesy of FishBase (<www.fishbase.org>),reproduced with permission from Dr. Guy Teugels, Royal Museum for Central Africa, Tervuren, Belgium.

Aquanews ~ Fall 2002

13

Graduates’ Corner (cont.)

SEX DETERMINATION AND INHERITANCE OF SEX RATIO IN FAMILIES OF OREOCHROMIS NILOTICUS

Abstract of Robert Harper Carpenter’s M.S. thesis

Inheritance of sex ratio was studied using three strains of Oreochromis niloticus progeny sets from nine individual

pair spawns, designated as families, from April to October of 2000. Five males were placed in hapas with half

the females from their family and were allowed to spawn during the summer months. Ten sets of progeny from

each family, eight from Family VI, were collected after at least sixty days of grow-out. Sex ratios of all 88 progeny

groups were determined by microscopic examination of gonads. Sex ratio of each spawn was compared to that of

the parent family, family mean, and population mean using Chi-square tests. Of the nine families, four produced

progeny where 100% of the ten sets were significantly different from the parent ratio (P < 0.05). Of the other

five families, four had 40 to 90% of the progeny sets different from the parent while Family VIII only reported

10% of the sets to be significantly different. Results of progeny sets when compared to the family mean, mean

proportion of males for all that families spawns, revealed three families where 10% of the progeny sets were

significantly different. The remaining families revealed 20 to 50% of progeny sets different from the family mean.

Similar differences were found when comparing each spawn to the population mean. Calculations for heritability

of sex ratio revealed an h2 value of 0.09 with an R2 value of 0.04. Results suggest sex ratio is not an inherited

trait.

A temperature study was also performed on spawns from three families to determine the effect of environment

on sex determination. Spawns were separated into equal groups at swim-up and one group was reared in

temperature controlled aquaria at 35±1 °C for 30 days and the other at ambient temperature averaging 29±1 °C.High temperature skewed the sex ratio to male in two of the three families tested giving evidence that there was

an environmental component in sex determination. This effect, however, is not always expressed.

FEED CONVERSION EFFICIENCY IN CHANNEL CATFISH

(ICTALURUS PUNCTATUS) AS A FUNCTION OF SIZE

(abstract of Bethuel Oduor Omolo’s M.S. thesis)

Research was conducted in 0.04-ha ponds at Auburn University Fisheries Research Station to study changes in

feed conversion efficiency by channel catfish after reaching a minimum market weight of 250 g and assess the

implications for economically optimum harvest weight. Fish from five nominal weight classes (250, 500, 1000,

1500, and 2000 g) were stocked in two randomly selected ponds per weight class and fed a 32% protein,

floating feed once daily to apparent satiety. In order to maintain similar water quality in all ponds, the stocking

densities were such that, based on existing bioenergetic models, predicted average daily feed consumption at water

temperatures of 29°C would be near 50 kg/ha in all ponds. All observed mortalities were counted and weighed.

Ponds were harvested when cumulative feed consumption exceeded 150% of initial fish biomass or 1600 kg/ha

(average rearing time 86 d).

After harvest, fish were restocked to produce two additional replications of the 500-, 1000-, and 2000-g

nominal weight classes, following the same feeding criteria. Four of the 16 ponds failed one or both inclusion

criteria for further analysis (survival > 70% and fish recovery > 95% of initial stock). In the remaining 12

ponds, average water temperature was 27 C, fish weights were not related (each P >0.10; r2 <0.20) to dissolved

oxygen concentration at dawn (5.9 mg/L), survival (95%), recovery of stocked fish (99%), feeding rate (31 kg/ha-

d), and standing crop of fish at harvest (3341 kg/ha). Feed conversion ratios (FCR, feed/gain) ranged from 1.47

to 3.54 and were related to fish weight (P<0.01, r2=0.63). The relationship between FCR and average weight was

described by the equation FCR=1.41 + 0.54Wkg. This relationship suggested that at current feed and fingerling

...continued on p. 15

14

there were no significant differences (p>0.05) in survival rate

and stocking size of fish among treatments.

Relative profitability analysis using partial and full

enterprise budgets revealed that PFP was the best feed

followed by RB at normal selling price of Kshs 90 kg-1

fish. At higher prices of Kshs 120 kg-1 and if price varies

by size in favour of bigger fish PFP would still be a

better choice followed by TDP while RB would be least

profitable. RB and PFP had significantly lower (P<0.05)

break-even prices on total cost than TDP. RB recorded least

operational cost.

This study assessed relative profitability of the

three nutrient regimes and gave full enterprise

budget for the most profitable one. It should

therefore be a valuable contribution to development

of management practices involving nutritionally

incomplete feeds. In addition, the development of

cost-effective tilapia feed may increase the profitability

of fish farming in the region and stimulate

commercial aquaculture enterprises.

…from p. 12

Comparison of Tilapia and Clarias

Arapaima Culture ProgramTwo years ago IIAP and TerraNuova, an Italian NGO, joinedtogether to initiate an A. gigascultivation program that includesseveral small-scale producerponds.

In this article we report theprogress of the program, as well asthe methodology used.

Objectives of the program are to:

• Develop the natural (non-induced) production of A. gigas(paiche) fingerlings frombroodstock in the ponds of thesmall-scale fish producers alongthe Iquitos-Nauta Road in Loreto.

• Augment the supply of A. gigasfillets by producing diversevalue-added products aimed atthe growing international market.

• Enhance fingerling supply.• Diminish A. gigas fishing pres-

sure in its natural habitat.• Contribute to A. gigas conserva-

tion.• Assist with the diversification of

productive activities and livingconditions of the PeruvianAmazon inhabitants.

The program anticipates thefollowing results:

• Provide six A. gigas juveniles toeach of 93 small-scale producers(currently 31 producers receivedsix juveniles each) along the

Activities and Methodology

Breeding A. gigas juvenilesThe A. gigas juveniles (25 cm averagetotal length) are coming from thenatural reproduction of pond-raisedbroodstock held in IIAP Quistacochaand Pucallpa facilities, Peru.

Identification of BeneficiariesThe beneficiaries of the program wereidentified based on the followingcriteria: 1) Readiness and suitability oftheir pond(s); 2) Degree to which A.gigas broodstock security could be

~ Iquitos, Loreto ~

Fernando Alcántara, Palmira Padilla, Rosa Ismiño, and CRSPextensionists Luciano Rodríguez and Carlos Chávez

~ Pucallpa, Ucayali ~

Mariano Rebaza, Carmela Rebaza, and Sonia Deza

~ Tarapoto, San Martin ~

Humberto Guerra, Gilberto Ascón, and Jorge Iberico

~ Southern Illinois University Carbondale ~

Christopher C. Kohler, Susan T. Kohler, and William Camargo

ARAPAIMA Culture Program Collaborators

Iquitos-Nauta Road, as an initialphase of the program.

• Incorporate A. gigas culture as aproductive activity in the Amazonregion.

• Create awareness among theAmazon inhabitants in general (e.g.,fish producers, fishermen) in thepractice of A. gigas cultivation.

• Increase the diversity of A. gigasproducts offered.

• Decrease A. gigas fishing pressure inits natural habitats.

• Develop a broodstock batch man-aged by the small-scale producers toincrease fingerling supply.

Arapaima Pond Culture

…from p. 9

continued on p. 16...

Aquanews ~ Fall 2002

15

…from p. 11

medium (5,000 m-2), and high (10,000m-2) stocking densities, respectively.Thus, the culture and processing ofchuro offers excellent potential toproduce animal protein at a very lowproduction cost.

Other potential candidates thatdeserve research effort are theAmazonian soft-shell clams(Anodontites spp.) locally namedtumba-cuchara, which possess very fastgrowth of visceral mass compared tothe shell, which is surprisingly verythin (Fig. 3). This bivalve has beenreported to grow up to 10 cm in lessthan seven months in fishponds(stocked with paiche–Arapaima gigas)at high densities at IIAP, Pucallpa (M.Rebaza, personal communication),Lago de Sauce, Tarapoto (Campos,

Mollusks in Amazonia

Half-grown bivalve locally named “tumba-cuchara,” Anodontites sp. (13.4 mm length, and 8 monthsold), found in a recently drained fish culture pond at IIAP Pucallpa.

Wil

lia

m C

am

ar

go

References

Alcántara, B.F. and N. Nakagawa,1996. Cultivo preliminar delchuro Pomacea maculata. Perry1810. (Gasterópoda, Am-pullariidae). Folia Amazónica,8(2): 29-33.

Alcántara, B.F., N. Nakagawa, andE. Zamora, 1996. Característicasdel desove del churo Pomaceamaculata, en ambientecontrolado. Folia Amazónica,8(2): 7-11.

Amazon Alliance. 2000. Peru:Indigenous March Planned toInitiate Government Dialogue.July, 2000. <http://www.amaz-onalliance.org/update/2000/upd_jul00_en.htm>.

Cobos, M., 1998. Bioecología delchuro Pomacea maculata, en elCaño Liverpool. Río Marañón.Tesis para optar el títuloprofesional de Biólogo.Facultad de Ciencias Biológicas.Universidad Nacional de laAmazonía Peruana, Iquitos,Peru. 92 pp.

Pain, T., 1960. Pomacea.(Ampullaridae). On the Ama-zon River System. J. Conch.24(12):421-32.

Rojas, J. and L.L. Mori, 1976.Aspectos bioecológicos delchuro Ampullaria canaliculataD’Orbigni. Centro deInvestigaciones de RecursosNaturales Amazónicos, Iquitos,Peru. 29 pp.

Sáenz, B.O., 2001. Dietas deorigen vegetal y composicióncorporal del “churo” Pomaceasp., en Iquitos – Perú. Tesispara optar el título profesionalde Biólogo. Facultad deCiencias Biológicas.Universidad Nacional de laAmazonía Peruana, Iquitos,Perú. 61 pp.

Villacorta, M., 1976. Algunasconsideraciones bio-ecológicasdel churo Pomacea maculata. Tesispara optar el título profesional deBiólogo. Facultad de CienciasBiológicas. Universidad Nacionalde la Amazonía Peruana, Iquitos,Perú.

prices ($215/metric ton and $60/1000, respectively), feed plus fingerling costs

(others factors held constant) per metric ton of net fish yield is lowest if fish are

harvested at a weight of 1000 g. If fingerling prices remain at current rates ($60/

1000) but feed prices increased by 85% to $401/metric ton, the smaller weight

class of catfish (250–500 g) became the economically superior size class due to the

least cost of input requirement to obtain a net fish yield of one ton. When feed

prices held at current rates but fingerling prices raised, the next larger size class

(1000-1500 g) became economically superior only after fingerling prices are

increased by 133% to $140/1000.

…from p. 13

Feed Conversion Efficiency

personal communication), and otherlocalities of the Peruvian Amazon. Thenatural habitat of these bivalves is alsovery diverse. They are present inwhite (high silt) and black (hightannin) waters, in meanders, and inwaters with considerable flow rates.The soft-shell clams have beenreported in the Amazon, Itaya, andTapiche Rivers, near Iquitos, and areprobably widely distributedthroughout the entire Amazon region.Surprisingly, they are rarely present inthe largest local markets (Iquitos andManaus, Brazil), and little informationis available regarding theirconsumption by the riverside people.Some regional Peruvian dishes,however, incorporate this bivalve indiverse combinations such as cebiche(marinated clams and/or fish), picante(hot sauce) with rice, and picante withyucca. Accordingly, this resource

could become another importantalternative to diversify aquaculture ina resources-rich region where,unfortunately, some inhabitants aremalnourished (Amazon Alliance,2000) because of lack of knowledge ofall the alternatives available.

16

guaranteed; and 3) Interest of theproducer to conduct A. gigascultivation.

Forage fish (prey) culture and A. gigasstockingThe small-scale producer ponds arefertilized and initially stocked a fewweeks before stocking with A. gigasjuveniles, with bujurqui (Cichlasomaamazonarum) and/or mojarra(Gymnocorymbus thayeri andTetragonopterus sp.) at stockingdensities from 20,000 to 30,000 fish/pond, to secure a forage base.

MonitoringThe monitoring of the performance ofthe A. gigas is conducted by two CRSPextensionists who carry out periodicvisits to the A. gigas producers tomonitor growth, sanitary state,survival, and yield (kg ha-1 yr-1). Themonitoring will be conducted for ayear, and the data will be collectedand analyzed to determine A. gigasperformance in culture ponds.

References

Alcántara, F., 1990. Observacionessobre comportamientoreproductivo de paiche,Arapaima gigas, en cautiverio.Folia Amazónica, 2: 4.

Alcántara, F., and H. Guerra, 1992.Cultivo de paiche, Arapaimagigas, utilizando bujurqui,Cichlassoma bimaculatum, comopresa. Folia Amazónica, 4 (1):129–139.

Aldea, M., 2002. Cultivo de paicheArapaima gigas con dietasartificiales en jaulas flotantes.B.S. thesis, UniversidadNacional de la AmazoniaPeruana, Iquitos, Perú.

Bard, J., P. De Kimpe, J. Lemasson,and P. Lessent, 1975. Manual depiscicultura destinado a laAmérica tropical. Centre Tech-nique Forestier Tropical. Minis-terio de Asuntos Extranjeros,Francia. Revisado por ChristianBerger. Second ed. 104 pp.

De Souza, J.E., J.M. Junqueira, andP.S. Ceccarelli, 1986.Monocultivo de pacu, Colossomamitrei em gaiolas. Síntese dosTrabalhos Realizados con

Especies do Género Colossoma.Centro de Pesquisa eTreinamento em Aquicultura.Ministerio de Agricultura.Superintendencia doDesenvolvimento da PescaCentro de Investigaçao para oDesenvolvimento. 23pp.

Fontenele, O., 1942. Contribuiçãopara o conhecimento da biologiade pirarucu Arapaima gigas(Cuvier), em cativeiro:(Actinoptrygii, Osteoglossidae).DNOCS. Coletânea de trabalhosTécnicos. Série I-C.

Guerra, H., 1996. Notas sobre elpaiche en la Amazonía Peruana.Instituto de Investigaciones dela Amazonia Peruana, Iquitos,Peru. Informe interno. 3 pp.

Imbiriba, E.P., 2001. Potencial deCriação de pirarucu emcativeiro. Acta Amazonica 31(2):299–316.

Luling, K.H., 1969. Daslaichverhalten der vewetreterder familie Osteoglossidae(Versuch einer Ubersicht). Bonn.Zool. Beitr., 20(1/3): 228–243.

Rebaza, M., 1998. Crianza dePaiche, Arapaima gigas, en

cautiverio, Centro Regional deInvestigaciones de Ucayali,Instituto de Investigaciones dela Amazonia Peruana, Iquitos,Peru. Informe Interno, 5 pp.

Rebaza, M.A., F. Alcántara, andG.M. Valdivieso, 1999. Manualde Piscicultura del paicheArapaima gigas. Editorial ManatíGráfico S.A. Caracas-Venezuela.72 pp.

Sanchez, J., 1961. El paiche.Aspectos de su historia natural,ecología y aprovechamiento.Servicio de Pesquería delMinisterio de Pesquería. Lima,Peru. 48 pp.

Saint-Paul, U., 1986. Potential foraquaculture of South Americanfreshwater fishes; a review.Aquaculture 54: 205–240.

Sagratzki-Cavero, B.A., M. Pereira-Filho, R. Roubach, R.D. Ituassú,A. Lima Gandra, and R.Crescêncio, In press. Stockingdensity effect on growth homo-geneity of juvenile pirarucu inconfined environments.Pesquisas AgropecuáriaBrasileira. In Portuguese withEnglish abstract.

Jaime Boria, a beneficiary (center), expressing appreciation for one of the six Arapaima juveniles providedto him by the IIAP-CRSP.

Ped

ro

Ic

om

edes

Arapaima Pond Culture…from p. 14

Aquanews ~ Fall 2002

17

CRSP Research Report 02-185

RECYCLING POND MUD NUTRIENTS IN INTEGRATED

LOTUS–FISH CULTURE

Yang Yi and C. Kwei LinAquaculture and Aquatic Resources ManagementAgricultural and Aquatic Systems and Engineering ProgramSchool of Environment, Resources and DevelopmentAsian Institute of TechnologyPO Box 4, Klong LuangPathum Thani 12120, Thailand

James S. DianaSchool of Natural Resources and EnvironmentUniversity of MichiganAnn Arbor, MI 48109-1115, USA

An experiment was conducted in nine 200-m2 fertilizedearthen ponds at the Asian Institute of Technology,Thailand, during January–September 2000. This experi-ment was designed to assess the recovery of nutrients frompond mud by lotus (Nelumbo nucifera), to assess pond mudcharacteristics after lotus–fish co-culture, and to comparefish growth with and without lotus integration. There werethree treatments in triplicate: (A) lotus–tilapia co-culture;(B) tilapia alone; (C) lotus alone. Seedlings (0.39 ± 0.09 kg)of Thai lotus variety were transplanted to ponds of the

treatments with lotus (treatments A and C) at a density of25 seedlings pond–1, while sex-reversed all-male Nile tilapia(Oreochromis niloticus) fingerlings (8.6–10.3 g) were stockedat two fish per square meter in ponds of the treatmentswith tilapia (treatments A and B) when the water depth hadbeen increased to 50 cm due to increasing lotus height.Ponds stocked with tilapia (treatments A and B) werefertilized weekly with urea and triple super phosphate(TSP) at a rate of 4 kg nitrogen (N) and 1 kg phosphorus(P)/ha/day after tilapia stocking. There was no fertilizationin ponds of the lotus alone treatment. Lotus co-culturedwith tilapia or cultured alone in ponds was able toeffectively remove nutrients from old pond mud. Annualnutrient losses from mud in a 1-ha pond was about 2.4 tonN, and 1 ton P, among which about 300 kg N and43 kg P were incorporated in lotus biomass. There were nosignificant differences in lotus growth performance betweenthe lotus–tilapia and lotus alone treatments, while Niletilapia cultured alone grew significantly better than whenco-cultured with lotus. The present experiment hasdemonstrated the effectiveness of nutrient removal fromold pond mud by lotus and the feasibility of rotation andco-culture of lotus and Nile tilapia. Both systems canrecycle nutrients effectively within ponds and areenvironmentally friendly culture systems.

This abstract was based on the original paper, which waspublished in Aquaculture, 212 (2002):213–226.

This Notice of Publication announces recently published work carried out under PD/A CRSP sponsorship. Toreceive a full copy of a report, please contact the author(s) directly unless it is otherwise noted.

Notice of Publication

PD/A CRSP Publishes Pond Soil Manual

C ongratulations are due to Dr. Claude E. Boyd and his co-authors, C.W. Wood andTaworn Thunjai, for the successful completion of their manual, Aquaculture Pond Bottom

Soil Quality Management, published in July 2002 by the PD/A CRSP, Corvallis.The 41-page manual offers a succinct yet comprehensive guide to all aspects of managing

pond soils, from initial excavation to ongoing care of soils in mature pond systems. Anintroduction to chemical and physical soil characteristics is followed by practical details onpond soil treatments. Traditional methods such as liming and tilling are covered, while moremodern approaches such as disinfection are also included. The book’s final section on soilanalysis provides technicians straightforward practical methods to sampling soils and toanalysis for pH and lime requirements.

This book will prove invaluable to managers of aquaculture facilities where earthenponds are used. Students and researchers will also benefit by gaining useful insights intomethods for maintaining productive pond systems.

Request copies by email from harrirog@onid.orst.edu or from:PublicationsPond Dynamics/Aquaculture CRSPOregon State University418 Snell HallCorvallis OR 97331-1643 USA

18

practical and economic aspects ofoyster farming. The group savored thelocal product raw, with a fiery hotsauce.

Next was a visit to the Oregon CoastAquarium, renowned for its displaysof marine life.

At Hatfield Marine Science Center(HMSC), the group met with CarolDelancy of the Marine MammalProgram who spoke on currentresearch issues. Dr. Chris Langdon, aprofessor in OSUs Fisheries andWildlife Department and a PrincipalInvestigator for the CRSPs OSU Kenyaproject, discussed the Center’sMolluscan Broodstock Program. Next,the group sampled dulse (Palmariapalmata), a rhodophyta (seaweed) thatis cultured as abalone food. They werethen shown the clownfish broodstocksystem that is being used to testmicroparticulate diets.

With the increasing pressure onglobal food resources and thepotential of aquaculture to meet thedemand, such cultural exchangeswill become ever more valuable.Effective communication betweenaquaculture practitioners andexperts from widely varyingbackgrounds is essential to ensuringthat technological advances remainfocused on providing the mostefficient means of raising fish.

PD/A CRSP HostsDelegation From Chinaby Roger Harris

C hina’s aquaculture traditionstretches back two thousandyears or more. Yet the Chinese

feel they have much to learn from therapid developments in aquaculturetechnology in other parts of the world.

As part of a US Department ofAgriculture-sponsored fact-findingmission to the US, seven delegatesfrom the People’s Republic of Chinawere hosted by the PD/A CRSP atOregon State University, 30-31 October2002.

The group began at theEnvironmental Protection Agencyfacility on the OSU campus.Discussions focused on the legal andenvironmental aspects of aquaculture,especially with regard to theregulation of potentially hazardouschemicals such as fungicides andmasculinizing hormones.

During a tour of the OSU FoodToxicology Nutrition Laboratory, Dr.Dave Williams, Director, explainedhow intensive culture of rainbow troutwas providing material forinvestigation of environmentalcarcinogens.

Nearby is the Salmon DiseaseLaboratory where Rob Chitwooddescribed pathogens affectinghatchery-raised fish in Oregon. Thedelegates showed a keen interest innovel technologies to applyantibiotics through medicated feed.The group was also fascinated withthe sturgeon being raised at thelaboratory for research into caviarproduction.

After lunch, the group met on theOSU campus with Dr. Hillary Egna,Director of the PD/A CRSP, and alsowith Dr. John Bolte, Interim Dean ofOSUs Bioengineering Department. Dr.Bolte developed the POND© softwarepackage, designed to facilitatedecision-making by aquaculturists.Mr. Zeng Hui, Vice Director ofGuangxi Fishery Research Institute,had previously corresponded with Dr.Bolte on the prospects of convertingthe software to a Chinese languageinterface. Dr. Egna helped facilitate an

agreement for the Guangxi FisheryResearch Institute to begin the processof converting the software, and OSUsBioengineering Department to train astudent from China in the C++programming language needed tocompile the program.

In the Political Science Departmentthe group met with Professor BillLunch, Head of Department and well-known commentator. Also presentwere Professor Pat Corcoran,Professor Brent Steel, and AssistantProfessor Hua-yu Li, who is alsoChinese. Professor Lunch replied tonumerous questions from the visitors,including a technical but illuminatingdiscussion on the USs stricter limitsfor contaminants in fish food productsfrom China compared to westerncountries.

The final visit of the day was back atthe Salmon Disease Laboratory wherethe group met with Professor MichaelKent. Dr. Kent enjoyed showing thegroup the facilities for pathologicalwork on fish, including the well-equipped histology lab.

The PD/A CRSP then hosted thegroup for a second day, this time tovisit various locales in Newport on theOregon coast.

First stop was the Oregon OysterFarm, where owner and manager LiuXin introduced the group to the

At the OSU Food Toxicology Nutrition Laboratory, Dr. Dave Williams (DirectorNIEHS Marine/Freshwater Biomedical Sciences Center), explains aspects of the

laboratory’s operations. (Pictured: Li Xiaozheng, Chen Hong, Huang Zhen, Wan Xun,Xiong Fengming, Zeng Hui, Wang Guoli, Dave Williams.)

Ro

ger

Ha

rr

is

Aquanews ~ Fall 2002

19

Workshops and Short Courses

Upcoming Conferences and Expositions

Date Topic/Title Event Location Contact Information

November28–December1, 2002

Feria de la Pesca 2002 Montevideo, Uruguay Gloria Scelza; Centro de Informacion Tecnica,Infopesca, Uruguay; Fax: 598-2-903-0501; Email:pesca2002@latu.org.uy; Website: <www.latu.org.uy>

December10–14, 2002

Symposium On Intensive UseOf Groundwater

Valencia ConferenceCenter, Valencia, Spain

Margarida Valverde; Phone: 34-934-582-600;Fax: 34-964-590-106; Email: gerencia@fcihs.org; Website:<www.fcihs.org/SINEX.HTM>

December17–20, 2002

Sixth Indian Fisheries Forum Mumbai, India S. Ayyappan; Convenor, Sixth Indian Fisheries Forum,Central Institute of Fisheries Education, India; Phone:91-22-636-1446/7/8; Fax: 91-22-636-1573

February18–21, 2003

Aquaculture America 2003 InternationalConvention Center,Louisville, Kentucky

Conference Manager; 2423 Fallbrook Place, Escondido,CA 92027; Fax: 760-432-4275; Email:worldaqua@aol.com; Website: <www.was.org>

February20–22, 2003

Asian Fisheries, Aquacultureand Seafood

Bangkok, Thailand Baird Publications, Australia; Fax: 61-3-9645-0475;Email: marinfo@baird.com.au; Website:<www.baird.com.au>

March19–22, 2003

AquaSur 2003 Club de DeportesNauticos Reloncavi

Sue Hill; Heighway Events, England; Fax: 44-0-20-7017-4537; Email: sue.hill@informa.com; Website:<www.heighwayevents.com>

April20–23, 2003

Middle East Aquaculture andFishing Show 2003

UAE, Dubai Abdulla A. Abulhoul; Mediac, Dubai, UAE; Fax: 9714-2691296; Email: mediac@emirates.net.ae

May19–23, 2003

World Aquaculture 2003 Salvado, Brazil Conference Manager; 2423 Fallbrook Place, Escondido,CA 92027; Phone: 760-432-4270 Fax: 760-432-4275;Email: worldaqua@aol.com

Date Title/Topic/Site Contacts

November 29–30,2002

Epidemiology and Risk Assessment/Gold CoastInternational Hotel, Australia

Chris Baldock; Phone: 61-7-3255-1712; Email:chris@ausvet.com.au

November 29–30,2002

Epidemiology-Biosecurity Workshop/Gold Coast,Australia

Rochelle Manderson; Email: daa5@ozaccom.com.au

December2–6, 2002

Asia-Pacific Regional Molluscan Health ManagementTraining Program Phase II/Gold Coast InternationalHotel, Australia

Rob Allard; Phone: 61-7-3840-7723

December3, 2002

Basic Principles of Aquaculture/Iloilo, PhilippinesNutrition

L. Torres Jr.; SEAFDEC Aquaculture Department,Phone: 63-33-336-2937; Fax: 63-33-336-2891; Email:pltorres@aqd.seafdec.org.ph;Website: <www.aqd.seafdec.org.ph/4647.html>

January26–31, 2003

Practical Course On Feed/Texas A&M University,College Station, Texas

Mian N Riaz; Food and Protein R&D Center; Fax: 979-458-0019; Email: mnriaz@tamu.edu;Website: <www.tamu.edu/extrusion>

January26–31, 2003

Feeds & Pet Food Extrusion/Texas A&M University,College Station, Texas

Mian N. Riaz; Email: mnriaz@tamu.eduWebsite: <www.tamu.edu/extrusion>

February19–21, 2003

Speaking for the Salmon workshop/Vancouver, BC The World Summit on Salmon;Website: <www.sfu.ca/cstudies/science/salmon.htm>

April23–29, 2003

14th International Pectinid Workshop/St. Petersburg,Florida

Beth Miller-Tipton; Email: bmiller-tipton@mail.ifas.ufl.edu

Pond Dynamics/Aquaculture CRSPOregon State University418 Snell HallCorvallis OR 97331-1643

CRSP CONTACT INFORMATION

CRSP publications can be accessed electronically at<pdacrsp.orst.edu/pubs/publications.html>; print copies can beordered online, by sending an email to <courteri@onid.orst.edu>,or by writing to:

Pond Dynamics/Aquaculture CRSPOregon State University418 Snell HallCorvallis, OR 97331-1643

Contact information for other inquiries:

Assistant Director of ResearchSteve Sempier sempiers@onid.orst.edu

Director, Information ManagementDanielle Clair claird@ucs.orst.edu

I have discovered Aquanews online and no longer need toreceive it on paper.

My address has changed, and I have made correctionsto the label. (Please mail label to address above.)�

�

�

Program Director: Dr. Hillary S. EgnaAquanews Editor: Danielle Z. ClairStaff: Ian Courter and Roger Harris

Aquanews is published quarterly by the InformationManagement & Networking Component of the PondDynamics/Aquaculture Collaborative ResearchSupport Program, Oregon State University, 418 SnellHall, Corvallis OR 97331-1643.<pdacrsp.orst.edu>

The contents of this newsletter are copyrighted bythe Pond Dynamics/Aquaculture CRSP. Copyright2002. All rights reserved including mechanical andelectronic reproduction.

Mention of trade names or commercial products doesnot constitute endorsement or recommendation foruse on the part of USAID or the PD/A CRSP.

The Pond Dynamics/Aquaculture CollaborativeResearch Support Program is funded in part by theUS Agency for International Development underCRSP Grant No. LAG-G-00-96-90015-00 and byparticipating US and host country institutions.

Oregon State University is an Affirmative Action/Equal Opportunity Employer.

PRSRT STDUS POSTAGE

PAIDCORVALLIS ORPERMIT NO 200

I wish to discontinue receiving this publication.