ShrimpBook Efficiency Villalon
Villalon, J., Maugle, P., Laniado, R. (1989) Present Status and Future Options for Improving the Efficiency of Shrimp
Mariculture. In: Olsen, S. and Arriaga, L., editors. A Sustainable Shrimp Mariculture Industry for Ecuador.
Narragansett, RI: Coastal Resources Center, University of Rhode Island
A SUSTAINABLE SHRIMP MARICULTURE
INDUSTRY FOR ECUADOR
Edjttd by Stephen Olsen and Luis Arrlaga
Characteristicsof the
Mariculture Industrv
NOTE TO READER
September 1, 2006
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document with the margins as originally published, do not use page scaling in the printer
set up.
This document is posted to the web site of the
Coastal Resources Center,
Graduate School of Oceanography,
University of Rhode Island
220 South Ferry Road
Narragansett, Rhode Island, USA 02882
Telephone: 401.874.6224
http://www.crc.uri.edu
Citation:
Villalon, J., Maugle, P., Laniado, R. (1989) Present Status and Future Options for Improving
the Efficiency of Shrimp Mariculture. In: Olsen, S. and Arriaga, L., editors. A Sustainable
Shrimp Mariculture Industry for Ecuador. Narragansett, RI: Coastal Resources Center,
University of Rhode Island
Present Status and Future Options for Improving the Efficiency
of Shrimp Mariculture
Estado Actual y OpcionesFuturas para Mejorar la Eficiencia de Ia
Maricultura del Camar6n
Jos6 R. Villal6n, Paul D. Maugle y Rodrigo Laniado
Resumen
En 1986habiam6sde 94.000ha autorizadas
paraconstrucci6n
depiscinascamaroneras,
esiaban
terminadas
unas60.000ha y de 6stass61oun50Voestabanenproduccidnde postlarvas(pls).
La mayoriade los cultivadores
siguenun m6todode manejosemi-exiensivo,
condensidades
de
siembrade 10.000a 50.000pls/ha. Seusael flujo de mareaso el bombeodiarioparael intercambiode agua
en laspiscinas.Los nutrientessonproporcionados
por la producci6nnaturaldel iitoplanctonen los
estanques.
Las empresas
con m6salto gradode infraestructura
y recursosecondmicoiusanel mdtodosemiintensivocondensidades
de siembrade 100.000a 180.000pls/ha.En general,densidades
de siembra
mayoresque50.000juvenilesrequierende fertilizaci6no la dispersi6nde laspls en muchaspiscinaspara
la ventajade la productividadel fitoplancton.Los eitanquespara;semillero"usadosen las
aprovechar
operaciones
simi-intensivas
sonsembrados
conm6sde 2 millonesde pls por hectirea. De aqui son
frasladados
a laspiscinasde crecimientodespuds
quealcancen
pesosde 05 a 1,0gr.
Aproximadamente
del 50 al607odepls "sembradas"
en laspiscinasdel Ecuadorsonobtenidasen el
ambientenatural.El 50Vode pls conesponden
a P. vannamei,selecci6nqueesclbasadaen su capacidad
para
resistiry creceren el ambienterigurosode laspiscinas,antesqueen la disponibilidadde pls. Cuandolai pls
eslSnmezcladas
condetritusy el tiempode ftansporteeslargo,la mortalidaddepls puedellegara un 502o.
!n ggnerallas pls capturadassevendenaunintemediarioquelas transfierea centrosde acopioparala
ltmpieza,.Taego_son
empacadas
y transportadas
hasa los criaderos,usandoparaestoaireybxigeno
comprimidos.La temperatura
no secontrolaen el tanquede transporte.La aclimataci6nde lis pls serealiza
enpiscinasde crecimiento,siendoestaoperaci6nmateriade controversias
considerables.
Los autoresanalizanen detallevariosaspectos
de los sistemas
de manejoen los estanques
"semilleros"y delaspiscinasdeproducci6n,incluyendoel usode alimentosconientradosgranulados
lpellets).
La vigilanciade los pardmetros
ambienales(oxigenodisuelto,pH, temperatura,
salinidad,
.
turbiedad),esefectuada
en laspiscinasconcultivossemi-intensivos
confinesde manejo.Asi, valoresde
oxigenomenoresque3 ppn originala suspensi6n
de alimentosy aumentodel ingresode aguapor bombeo;
temperaturas
menoresque24oCesla referenciapuaaumentarla profundidaddel aguaen laspiscinas;si la
turbiedadesmenorquie32cm o haypH alto, sesuspende
la fetitlacidn.
Se
acepta
ampliamente
que
en
Ecuador
la
convenidn
de 6reasde manglar a pisicinascamaroneras
es
- unade las razonesprincipalesde la declinacidnde la abundanciade pls. Tambidn,loi autoresmencionanque
lugaresparapiscinasen algunas6reasde El Oro compitencon tierrasagricolasy de patoreo.
Entre lasrecomendaciones
planteadaspor los autoresseencuentran:(a) capacitartdcnicos,
habidndoseestimado
queel Ecuadornecesitani-enEe
700y 800t6cnicosparatiboraioriosy paralaspiscinas
ya autorizadas;(b) un prcgramade capacitaci6nparapersonalde los centos de colecci6ny
iara los que
transportanlas pls; (c) proporcionarfacilidadesde mantenimientopuadesarrollodepls; (O)esableclr un
laboratoriode diagndsticoparaaplicaci6nde nivelesadecuados
de alimentaci6n;(e) mejorarlos
conoc-imientos
delos productores;(f) difusi6nde m6todosapropiados
paraaclimataci6ndepls y estanques
"semilleros";G) desanolloderacionesecuatorianas
paramaduraci6n
en los laboratorios.
a9
NOTE TO READER
September 1, 2006
THIS IS A SEARCHABLE PDF DOCUMENT
This document has been created in Adobe Acrobat Professional 6.0 by scanning the best
available original paper copy. The page images may be cropped and blank numbered pages
deleted in order to reduce file size, however the full text and graphics of the original are
preserved. The resulting page images have been processed to recognize characters
(optical character recognition, OCR) so that most of the text of the original, as well as some
words and numbers on tables and graphics are searchable and selectable. To print the
document with the margins as originally published, do not use page scaling in the printer
set up.
This document is posted to the web site of the
Coastal Resources Center,
Graduate School of Oceanography,
University of Rhode Island
220 South Ferry Road
Narragansett, Rhode Island, USA 02882
Telephone: 401.874.6224
http://www.crc.uri.edu
Citation:
Villalon, J., Maugle, P., Laniado, R. (1989) Present Status and Future Options for Improving
the Efficiency of Shrimp Mariculture. In: Olsen, S. and Arriaga, L., editors.
A Sustainable Shrimp Mariculture Industry for Ecuador. Narragansett, RI: Coastal Resources
Center, University of Rhode Island
Historical Developmentof Shrimp Mariculture in Ecuador
The Incasmay havebeenthefirst to farm shrimpin Ecuadorsome400 yearsagoby impounding
waterscontainingpenaeidshrimplarvae. Modernshrimpmariculturebeganin the late 1960sin El Oro
provincein southernEcuadorwhen an ownerof a bananaplantationnoticedthat flood watersimpounded
behinda dike yieldeda bountifulharvestof shrimp. By 1977thereweresome360 hectares(ha)of shrimp
pondsin production(R. Naboa,personalcommunication).In the earlydaysof the industry,investorswere
ableto pay off the costsof pondconstructionwithin two or threeyears. This, combinedwith seemingly
abundantpostlarvaeandtherelativelyhigh pricefor shrimpin theU.S. market,led to therapid
of the shrimpmaricultureindusry. By 1983the shrimpindustryhadexpandedto an estimated
development
89,367ha of (Alvarez,this volume)andproductionpeakedin 1982-83at23,300metrictons(m.t.)of
shrimpreportedlyworthU.S.$218.7million (NationalMarineFisheriesService,1986).
Thereis a feeling amongproducersinterviewedby the authorsthat the shrimpindustryis currently
in the early 1980sis over. Future
undergoinga consolidation.Therapidexpansionexperienced
the producerssay,will not be in the areaof newpondconstructionbut in theacquisitionof
development,
of hatcheries.
not presentlyin useandthedevelopment
concessions
hasrecentlybecomethepredominant"survivalunit" in the
The so-calledintegratedenterprise
andmay
shrimppondswith packingandexportoperations,
Ecuadorianshrimpindustry. It incorporates
havea harcheryin operationor underconstruction.Suchan integatedenterprisemay includeseveralof the
following segments:
.
.
r
.
.
.
.
importhouse(s)in theUnitedStatesandothermarkets
packingplant
gowout ponds(thismay includeseveralcompanies)
feedand/orfertilizerplant
fishingfleet (sourcing)
larval collectionandair and/orgroundransport group(s)
hatchery
Area in Production
In 1986thereweremorethan94,000ha of shrimppondsauthorizedforconstructionand
approximately60,000ha hadbeencompleted(Table 1). Basedon a preliminaryaerial surveyandinterviews
with shrimpproducersin the Guayas-ElOro productionareas,theauthorsestimatethat only half of the
completedpondswerein productionin June-July1986,presumablybecauseof postlawaeshortages.
Pond ManagementTechniques
The nationalcrisisbroughtaboutby thedepletionof wild stockpostlarvae(PL), during 1984-85,
into two distinctcampswith confrastingcultureand
strategies
hasdividedEcuadorianfarm managemont
management
sEategies.
Semi-Extensive
Most farmerspursuea semi-extensive
management
straiegywhich callsfor stockingdensitiesof
10,000to 50,000PL per hectare.Thesefarmersacceptlower productionreturnsalongwith substantial
reductionsin theirproductioncosts.Producers
usingsemi-extensive
systemsmay usethetidesand/ordaily
pumpingto provide waterexchangein gravity drainedflow-throughponds. Nutrientsareprovidedby
naturalphytoplanktonproductionin theponds.
Semi-Intensive
Companieswith a higherdegreeof infrastructureandeconomicresourcesmaximizetheir
productionby utilizing a semi-intensive
method. Here,higherstockingdensitiesof 100,000to 180,000
PL per hectarearemaintained,with correspondingly
higherfixed costs.Themajorityof thesecompanies
pursuewild stockpostlarvaeby payingmorefor catches,or aremeetingtheir stocking
aggressively
demandswith theirown hatcheryproduction.Nurserypondsutilizedin semi-intensive
operationsare
stockedwith up to 2 million PL per hectare.Thejuvenilesaremovedfrom nurserypondsto growout
pondsafterreachingweightsof 0.5 to 1.0grams. Stockingdensitiesat levelshigherthan50,000juvenile
shrimprequirefertilized growoutponds,or postlarvaespreadover manypondsto take advantageol
phytoplanktonproductivityandreducerisks of lossfrom overstocking.Stockingdensityis oftena function
of wild stockpostlarvaeavailability.
Generally,the small farmersor farmerswho do not havea highty developedinfrastructuredo not
sharethetechnologicaladvancement
employedby thelargercompanies.This lack of technologyamongthe
smallerproducersusingsemi-extensive
methodshasresultedin high mortalityat high stockingdensities.
On theotherhand,farmerswho havehigherfixed costsandinfrastructure
development,
havealso
aggressivelypursuedthe advancementof their technologywhich is reflectedin an increasein overall
productionlevels.
Demand for Postlarvae
Pondoperatorsobtainpostlarvaeby oneor moreof severalmethods,including:
.
'
'
.
'
.
.
purchasefrom middle men
collectingPL with personnelfrom the shrimpfarm in estuariescloseto the farm
cgllectingfrom artificial estuaries(semilleros)constn:ctedin mangroveareasbordering
the shrimpfarm
collectingin the intakecanals
collecdngfrom nurseryponds,whenthey aretidally filled during the monthly flood tide
aguaje)
purchasesfrom a hatchery
importsfrom othercountries
Approximately50 percentto 60 percentof thepostlarvaestockedin Ecuadorianpondsarewildcaughtandpurchased
from middlemen. Postlarvae
pricesarebasedon availability,principallyof Penaeus
vannamei.Theseanimalstypicallychangehandstwo to threetimesbetweenthe fishermenandthegrowers'
ponds. A fishermanreceivesapproximately100sucresper 1,000postlarvaefrom middlemen.The
postlarvaearethensoldto thepondownersor to othermiddlemenfor approximately450 to 1,000sucres
per 1,000.
Wild-caughtPenaeus
vannameiaregenerallymoreabundantduringthemontls of December
throughMarch. During thesemonthswell above50 percentof the catchis P. vannameiwith a notable
decrease
in thepresenceof P. occidentalis.The selectionof P. vannameiasthe speciesof choicewasnot
basedon its availability(Klima, 1986andZimmermanet al., 1986)but on its ability to resistand grow in
et al., 1986).
a very rigorouspondenvironment(Snedaker
During the 1985-86stockingseasonthe supplyof postlarvaeremainedhigh throughthe middleof
March 1986(Table2). Producerswho hadamplefundswereableto rapidly stocktheirponds.Many of the
largerpond ownershaveresortedto hiring groupsof fishermenanda middleman!o tansport the postlarvae
andpay them a salarynearly doublewhat they would otherwiseeam. A fishermancanthus eambetween
of overallannualeamings
2,000and5,000sucresin a day,whichmay accountfor a signifrcantpercentage
for theseartisanalfishermen.Sincethecaptureof postlarvaeis determinedby moonphase,tide,water
temperatue,locationandthefisherman'sskill, he may be limited to five to eightdaysof goodfishingper
monrh. A middlemancan sell between500,000to 1 million PL per day,but ttrisactivity is limited by the
which includeequipmentandshort-term
lengthof time thatPL areavailableandhis capitalexpenditures,
operatingloansat interestratesof 25 percentto 50 percentper two monthperiod.
40 percentto 60 percentof theoveralloperatingcostsin a farm operation.
Postlarvaecanrepresent
Severalproducershaveresortedto importingpostlarvaefrom theUnitedStatesandothercounfries,though
therehavebeenproblemswith poorqualityandsizeconsistency.A comparisonof theeffectof wild and
is givenin Table3.
importedseedstockon productioncostestimates
Thereareno dataon the numbersor speciescompositionof thepostlarvaecaughtby the artisanal
fishery,but the Camarade Productoresde Camaronesdel Guayasestimatesthat the fishery hadprovided3 to
4 billion P. vannameiPL eachyearuntil the 1983-84El Nino. Thereis an unmistakabletrendfollowing
lack of wild seedstock. Table4 provides
andsubsequent
theEl Nino towardshortspawningseasons
estimatesfor thenumberof PL utilizedby the indusry in recentyearsandthepotentialPL demand.
Postlarval Transport and Survival
Whenwild-caughtpostlarvaearemixedwith detritus,andthelengthof time from capturepoint to
transporttankis prolonged,PL mortalitiescanbe ashigh as 50 percent.The catchis thensoldto
middlemenwho Eansferthepostlarvaeto collectioncentersfor furthercleaning.Whensufficientnumbers
air and
havebeenaccumulated,thepostlarvaearerepackedandtransportedto nurseryponds. Compressed
andair
oxygenareusedto maintainpostlarvaeduringfransport,with battery(12v)operatedair compressors
stoves.The waterlemperatuein thetransporttanksis not controlled,nor arechemicalsaddedwhichwould
was
inhibit ttreeffectof diseaseor chelatetoxicants.In thepast,thenumberof larvaebeingpurchased
duringtimeswhenwild-stockpostlarvaewere
estimatedby eye. Althoughthistechniqueseemedadequate
abundantandpriceswererelativelylow, economiccompetitioneventuallyforcedfarmersto mathematically
quantifytheir postlarvae.Volumetriccountingtechniquesrapidly becamestandardoperatingprocedure,
althoughthey had inherentcountingerrorsof up to approximately30 percentdependingon container
design,watervolume,larvaedensity,andmixing techniques.As a result,someof themoretechnically
and
advancedproducersnow usea reductioncountingtechniquewith sendardizedwatertemperatures
loweredthemarginof errorto acceptable
This techniquehassuccessfully
mechanicalmixing apparatuses.
levelsof approximately10percent.The improvementof tlte level of confidencein thequantificationof
postlarvaestockedinto pondshasresultedin the development
of a valuabletool for watermanagement
harvestprojectionsandfertilizationprograms.
decisions,feedconversions,
Acclimation of Postlarvae
controversy.Many producers
Postlarvalacclimationto growingpondsis a subjectof considerable
favor limited acclimationprocedures.A technicallyadvancedfarm, EmpacadoraNacional,usesa slow
acclimationprogramcombinedwith controlledecologicalconditionsin theacclimationstation. This
pro$am usesa continuousflow-tlrough systemwhile feedingArtemiasalina,naupliiandsteamedegg
yolk. Acclimationdensitiesof up to 500 five-day-oldpostlarvaeper liter, a rateof two partsper thousand
haveyieldeda 1 percentmortality
salinitychangeper hour,anda 1 degteeCelsiuschangein temperature
previous
period,
rudimentarytechniques.
improvement
over
the
l2-hour
a
significant
a
acclimation
over
The lengttrierprocessalsoallowsfarm biologiststo evaluatetheconditionandbehaviorof thepostlarvae.
252
Nursery Pond Management Systems
Stockinga nurserypondis not generallya problem,providingthepostlarvaedo not comelong
_.
distancesor from environmentalconditionswhichvary greatlyfrom pondconditions.Survivalestimates
aremadefrom samplesof 100animals,which in somecasesareheldin fine-meshed
netsin thenursery
pondsfor 48 to 96 hours.
Amongthemoretechnicallyadvanced
companies,
whichgenerallyemploysemi-intensive
management
0echniques,
muchattentionis paidto ttrepreparationof nurserypondbottomsto produce
nutrient-richwater,sinceit is believedthatfeedingreducesmorhlity duringthe criticalfirst threeweeks.
Producers
prepareboth growoutpondandnurserypondbottomsby allowingthemto completelysundry
andoxidize. Humid areasarehand-tilledandoxidizedwith a saturatedsolutionof hypochloride.Wateris
allowedto half fill the nurseryafterpassingthrougha I mm filter screen.Inflows andeffluentweirsare
thensealedfor five days. Fertilizerat a concentration
of 1.3partsper million (ppm)of nifiogenand0.3
ppm of phosphorus
is appliedin a singledose. Algaeareallowedto grow for two to five daysbeforethe
nunery pondsarecompletelyfilled. Wateris commonlytransparent
to a depthof 30 centimeters
at this
point.Feedfor juvenile shrimpwith 35 percentproteinis added24 hoursprior to stockingatarate of 100
pounds(45kg) per hectare.Thenurserypondsarethenstockedat densitiesof up to 2 million postlarvae
per hectare.The shrimpareharvestedby drainingthepond 50 daysafter stockingwhentheir averageweight
is 1.5grams. Survivalratesashigh as65 percentarecommonlyrecordedusingthesetechniques.
Production Pond Management
Stocking
Growoutpondscanbe stockedin two ways. First,postlarvaecanbe placeddirectlyin 5 o 15
hectareunitsfor a 180to 210 daygrowoutperiod,bypassingtheneedfor nurseryponds.With thesecond
metiod, largerjuvenile shrimpharvestedfrom nurseryponds,asdescribedabove,areplacedin the growout
ponds.
Stockingdensitiesin growoutpondsfarmedby semi-intensive
methodsrangefrom 50,000o
180,000hatchery-reared
postlarvaeper hectare.Feedandfertilizationarecarefullyconrolled andpondsare
treatedasproductionunits. Yieldsrangefrom 1,400to 1,300kg per hectareper yearof wholeshrimp.
Semi-intensive
management
systemsutilizedby integratedenterprises,
generallyemploytraineA
biologistswho rely upona wide rangeof physicalandchemicalinformationwhenmakingmanagement
decisions.Ecologicalparameters
aremonitoredin all ponds.
Accordingto Empacadora
NacionalC.A. (a majorfeedproducer),stockingPL directlyin growout
pondsat densitiesof 160,000PL per hectaremay yield 45 percentsurvivalaftera 180-daygrowouiperiod.
Stockingwith juvenilesat densitiesof 80,000per hectareyields75 percentsurvival atthe22 gramsize,the
targetharvestweight,obtainedin approximately140days.
Shrimpharvestsashigh as3,500poundsper hectareper tumoverwith two tumoversper yearare
commonin semi-intensive
operations.However,semi-extensive
producersoftenrealizea greatermarginof
profit with lower stockingdensities,lowerlevelsof technologyanda reducedmanagemenieffort.
Feeding
In semi-intensive
operations,
theuseof compounded
dry pelletedfeedsis widely accepted.Daily
applicationsare madefrom canoesin a zig-zagfashionover the entirepond surface. Therearetwo basic
feedformulationscurrentlyin use. Oneconsistsof 35 percentproteinand 8 percentfat, andis usedto feed
juvenilesuntil they oblainan averagesizeof 6 grams. Oncethejuvenilesreach6 grams,the feedration
changesto a growoutproductionformulacontaining25 percentproteinand5 percentfat" Feedrationlevels
areadjustedweeklyaccordingto the shrimpweight. Stringentqualitycontrolguidelinesarefollowedin the
feedmanufacturing
process.Local producersstriveto maintainthestabilityof thepelletin thewaterfor
morethan four hoursandmaintaindigestibility greaterthan70 percent. The useof shrimpheadsand other
by-productsin shrimpfeedsarebeingconsidered.
strategieshaverecentlyrecognizeddiseaseSeveralproducenutilizing semi-intensivemanagement
relatedproductionproblems.Use of medicatedfeeds(Table5) could havea significantimpacton production
capacities,providedthe following factorsaretakeninto consideration:
.
.
.
identification of benefis from point specificversusbroad spectrumprophylacticantibiotic
applications
economicfeasibilityat thecommerciallevel
andhealthimpacts
the evaluationof potentialenvironmental
Costs and Profits
lvlanyproducersusing semi-extensivemanagementstrategiesfertilize only during the dry season
when the waterpumpedfrom the estuaryis lessproductive. While theseproducershaveusedlocally
producedshrimpfeeds,they often view the useof feedwith greatdistrust. The feed,in their opinion,breaks
down in the water,makingit little morethanan expensivefertilizerthatdoesnot producesufficient
eitherin quantityor sizeof shrimpto offsetthe additionalcapitaloutlay.
improvement
Excludingthe costof financingthe shrimpfarm operationduringthegrowthperiod,it costsfrom
approach(harvest
U.S. $.70to asmuchas$1.20to producea poundof shrimpusingthe semi-extensive
U.S.$.40moreper poundto usefeeds.Producers
harvests/yr),
andapproximately
rateof L5,000/ha/2.2
receiveberweenU.S. $2.20to $3.50per poundof shrimpdependingon the sizeof the shrimpandtime of
year.
Although therewould appearto be a greaternetprofit to the semi-extensiveproducerif higher
stockingdensitieswere used,neitherthe quality of the feednor the technologycurrentlyavailableseem
adequateto prompt changingtheir methods.However,someproducersareopento alternativefarming
strategiespr-oviOingsufficient quantitiesof PL areavailablefor higherdensitystocking,high quality feedis
availableandadequatelyEainedbiologistsareavailableto operatethe shrimpfarms.
Ecological Monitoring
salinityandwaterturbidityis carriedout
Monitoringof dissolvedoxygen,pH, watertemperature,
and againatzp.m. Althougha
commonly
at
6
a.m.
many
operations;
semi-intensive
twice daily in
routine feitilization programis utilized, resultsfrom waterquatty analysisoverridethe routine scheduleof
fertilization.
arepriority pafirmetersandusedaswarningsin basic
Dissolvedoxygenand watertemperatures
A
low
oxygenreadingof lessthan3 ppm dictatesthe
dissolved
decisions.
biologicalmanagement
of lessthan
of feedingandan increasein theflow of incomingwater. A low watertemperature
suspension
24oCis the basis[o increasewaterdepthin a pond,in an attemptto cushionor reducetherateof changein
watertemperaturein the deeperareasby decreasingpond surfaceareain relation to total volume. In the
dictatesimilarreactions.Afternoon
aftemoon,high dissolvedoxygenand/orhigh watertemperatures
monitoringis alsousedasa guidelinefor fertilization. Waterturbidityreadingsof lessthan32cm and,/or
of routinefertilization. Hydrogensulfides,ammoniaandphosphate
high pHs alsocall for the suspension
in
all ponds.
weekly
areanalyzed
concentrations
Water Quality Management
management
system,whethera nurseryor productionpond,i,s
Eachpondin the semi-intensive
managedfor iti percenrageof watervolumeexchange.Water level readingsover tle effluentweir boardsare
measuredevery2 hoursfor 12 hours. The diurnaltide reflectstwo shiftsin pumpingcapacityso thatwater
overa 24-hourperiodto calculateinflow volume. Oncethepond systemis
level valuescanbe extrapolated
catfbpte{ adjustmentsgre qade daily, basedon ecologicalparameters,stockingdensitiesand shrimp
weight. Generally,productionpondsareinitiatedwith a 6 percentdaily exchangerate,while final water
exchangeratesmay graduallyincreaseover time to 17percentper day. Someof the moreadvanced
producers,using extensivemanagement
practicesalsopump daily at ratesrangingfrom 5 percentto l0
percentof thepondvolume.
Production Capabilities
With stockingdensitiesof 15,000to 30,000PL per hectareand 1.5to 2.2 harvestsper year,many
farmersestimateharvestlevelsat 800to 2,100pounds/hectare/year.
Shouldproducerschangetheir productionstrategyto onewhich incorporateslow stockingdensities
with fewer turnovers(harvess)per year,thenthey would be abletn producelarger-sizedanimalsand
potentiallymorevaluablecrops. For example,onecompany(Langacua,S.A.jusing an extensive
management
strategystocks18,000to 25,000juvenilesper hectare.Theseanimalsgrow n 24 gm size
Q6-30count)in 100-120daysin therainy seasonand 120-140daysin the dry season,
with an overall
survival rate of 90 percent,yielding approximately600 poundsof shrimp2.5 times per year. This
extensivestrategyproduceson the average2,100poundsper hectareper year. Suchan approachseemsto
offset potential lossesdueto inadequatesupplyof postlarvaeand may havethe potentialof stabilizing
overallproduction,makinglevelsof productionachievedin previousyearsobtainableat lower costs,with
fewerpostlarvaeand/orproducers.
Pond Siting, Construction and Utilization
It is widely believedin Ecuadorttrattheconversionof mangroveareasto shrimppondsis a major
reilsonfor the declineof PL abundance.Alvarez (this volume)providesestimatesfor the changesin areaof
mangroves,
salinasandshrimppondsbetween1969and 1984. Basedon remotesensingdata,heestimated
that the total mangroveareain Ecuadorhasdecreased
by 10.6percentduring this period.
CLIRSEN,asreportedby Valdiviezo(1985)utilizing informationobtainedfrom the 1982-83
r-emotesensingstudies,tabulatedmangroves,
shrimppondsandsaltflats in El Oro andGuayasProvinces
(Table6). The locationanddistributionof mangrovein El Oro, is distinctfrom otherprovihces,andmay
be describedasa nrurowbelt lessthan 100meterswide running along ttreperipheryofttre estuary. Shrimp
ponds,agricultureandpasturelandslie inlandfrom this narrowmangrovebelt. In manyareasshrimpponds
were built leavingno mangrovebuffer. Sitesfor shrimppondsin severalareasin El Oro also compete
directly with agriculturalandpasturelands.
Mangrovesin the GuayasProvinceareconcentratedon islandsand asbels of varying widths along
the continent. Shrimppondsin the areaappearto havefrst beenbuilt in salina(salt flat) areasand later
expandedinto surroundingmangroves.
If onewereto prioritizethedamageto themangroveresources
alongtheEcuadoriancoast,the
mostimpactedareawouldbe El Oro,followedperhaps6y Manabi. In the G-uayas,
althoughimpactedby
the shrimpfarm development,
a considerable
mangroveareastill exists. Thepotentialthreatsto mangroves
in the Guayasandto the shrimpindustrymay lie in a combinationof increasedsiltation,reducedwater
circulation,and upstreamchangesin waterquality due to a reductionof freshwaterinputsandincreasein
chemicalintensiveagriculturalpractices.For a moredetaileddiscussionseeTwilley (this volume).
Coastalareasin Esmeraldas,
conlaininglessttran2,000ha of shrimpponds,havebeenlittle
affectedby the industry. Consideringthe copiousamountof rainfall in thisprovince(Twilley, this
volume),the impacton mangroveareasfrom shrimpfarm development
may be limited to a maximumof
5,000hecares,which is a maximumof onequarterof theapparentmangroveareain 1983.
Investment Requirements
During 1984investmentsto developa shrimpfarm rangedfrom 40,000to 600,000sucresper
hectareClable7). If the only access!o thefarm wasby boat,an additionalinvestmentwouldbe required.
255
of a shrimpfarm,
with the development
Beyondthe initial acquisitionandconstructioncostsassociated
largepumpsandpiping aswell aswaterqualityequipmentarebasicrequirements.Much of this equipment
with impors seePerezandRobadue(this
mustbe imported. For discussions
of theproblemsassociated
volume).
Recommendations
Many actionsshouldbe takenat all levelsto helpthe shrimpindustryreacha stablelevel of
relatedto shrimppondimprovements
arediscussed:
development.Herea few measures
1.
The singlemosteffectiveway to stabilizethis industryis to closethe gapbetweenthe
legalandapparent(s/165:1U.S.D.)exchangerates. In theearlymonthsof 1985,exportersreceived108.50
sucresper dollar exported,in additionto a 15percentAbono Tributario for the total dollar value exported,
which is calculatedat s/95:1U.S.D. The abonois like a bond with a one yearmaturity,so exporters
discountit 3l percentof its value. The real benefitis calculatedasfollows: (95 x 0.15)- 0.31 (95 x 0.15)
= s/9.83. Thus,the legalexporterof shrimpreceivess/108.50+ 9.83= s/l 18.33for eachdollarof export
product. This stepwastakenin late 1986.
Therapid gowth of the indusry hasmadeit impossiblefor theuniversitiesand
2.
polytechnicschoolsto provideenoughsuitablyrained technicians.It is estimatedthatEcuadorwill require
presentlyunderconstruction.
to fully utilize hatcheries
an additional700 to 800 trainedhatcherytechnicians
18,000and22,ffi0
between
in
Ecuador,
it
is
estimated
ttrat
With over900 authorizedshrimpfarms
procedures
on shrimpfarms
operating
in
hatcheries
and
ttre
daily
Improvements
are
employed.
technicians
throughan extensionprogam couldhavea directandvisiblebenefitfor theindusfy andEcuador.Sucha
progam couldbe supportedttrrougha grcupof banksandtheDIGEMA-URI CoastalResources
Program.It would focuson pondswhich arenot currentlyin productionaswell ason
Management
requireloansto operateor expandoperations.All new loansto producerscould be usedto
which
operations
groupsin operationtoday. It
procuretechnicalassistance
from oneof the approvedtechnicalassistance
would be the responsibilityof the extensionserviceto examinethe technicalcapabilityof consultantsand
technicalassistantgroups,andissuethema permitto work within the system.Additionally,a diagnostic
laboratorywith supportactivities in the field could be funded,bringing to Ecuadorexpertsin areasof
specificneed.
extensionprogramwouldinclude:
Servicesprovidedby a comprehensive
. periodictrainingcotuses
.
hatcherytechniques
.
waterquality management
. pondproductiontechniques
.
feeddevelopment
.
diagnosisofdiseases
.
informationanddatabasedevelopment
. dissemination
of reliableinformation
. postlarvae
handling,Eansportandacclimation
.
mangroverestoration
.
developmentof an internationalshrimpmarketinglobby
3.
An immediateimprovementin pondproductioncanbe achievedif producerswould focus
their attentionon wild stockandhatchery-producedpostlarvalhandlingand acclimation
mettrods.The efficientuseof postlarvaehasthegreatestimmediatepotentialgain for the
in capture,
produceraswell asconservingthis limited naturalresource.Improvements
Eansport,handlingandacclimationmethodsfor postlawaecanhavean immediateand
visiblepositiveeffect.
4.
A raining programfor postlarvaecollectioncenterandtransportpersonnelalongwith a
certificatefor coursecompletionshouldbe developed.Sucha programwould focuson
postlarvae,andconductroutinespotchecksto
improvingsurvivabilityof harvested
256
confirm adherence
to conectproceduresto help guaranteedelivery of high quality wild
stockpostlarvae.
5.
Postlarvalholdingfacilitiesat farm sitesto furtherdeveloppostlarvae,from PL 5 to PL
21-30shouldbe developed.Thesefacilitieswouldenhancesurvivalof harchery-produced
stockin thepondenvironment.
6.
Stepsshouldbe takento establishan in-countrydiagnosticlaboratorywhich could
monitorpopulationsof shrimpandbe responsible
for theapplicationof appropriatelevels
andtypesof medicatedfeeds.
7.
Stepsshouldbe takento enhance
theknowledgeof producers,
andkeepthemappraised
of
recentadvances
in hands-ontechnology.This might be donethroughroutinenews
releases.
8.
Otherareasthatcouldhavedirect,immediateandvisiblepositiveeffectson theindustry
include:
'
development
anddissemination
of improvedmettrodsfor postlarvalacclimation
.
stockingof nurseryponds
.
thedevelopment
of acclimation,nurseryandgrowoutpondmaintenance
programs.
9.
Pondproducersshouldcoordinatetheir effortswith hatcheryproducersto assue thattheir
respectivepondsareadequatelyprepared0oreceivepostlarvae.
10.
More effort shouldalsobe givenwithin thepondproducers'enterprises
to control
parameters
environmental
!o preventcausesof unduesEess.
11.
Many improvements
to feedscurrentlyusedin Ecuadorcanbe madeusinglocally
availablefeedstuffs. Costeffectivefeedsof adequate
nutritionalvalueshouldbe further
developedusingin-countryfeedstuffsandprocessing
by-productsfor all segments
of the
industry(i.e.larval,maturation,nurseryandgrowoutponddiets).
t2.
An Ecuadorianmaturationdiet for usein harcheriesneedsto be developedbecausepresent
stocksof oystersandothershellfishin Ecuadorwill be gravelyimpactedwhenallihe
hatcheries
presentlyunderconstruction
comeon-line.
257
Table I
EstimatedShrimpPondSurfaceArea(in hectares)
Authorized,Completedandin Use
Province
Authorized
in 19861
Guayas
72,208
El Oro
Manabi
14,496
5,407
Esmeraldas
TOTAL
2,241
94,352
Construction
inlg842
Completedand
Urder
Construction
in 1986
In Use
in 1986
52,9r2
26,484
8,377
1,595
89,368
60,0003
30-40,0004
I R. Hornaet a1.,1986.
2 clnsgN, 1986.
3 R. Homa, O. Crespo,W. Bustamente,
A. Lopez, L986.
4 Aetial observation,P. Maugle,lv{arch1986:conoboratedby the Camerade Productoresde Camaronesdel
Guayas,1986.
Table 2
1985-86PostlarvalCoststo PondOperators*
perthousand
Sucres
1,300
1,900
1,900
1,200
500
May - July 1985
August- September1985
October- November1985
December- January1986
February- March 1986
* From M. Leslie,personalcommunication.
Table 3
Comparisonof ProductionCostEstimatesto a hoducer Using
Method*
Wild StockandImportedSeedStockin anExtensiveManagement
Wild stock
Importedseedstock
Unit sold atU 26-30
@L Cost)
20.00**
3.00
20.00
7.00
Grossmargin
17.00
13.00
- E"pensesrary significantly from onefarm to another,and economicsof scaleareachievedabove120to
150hectares.
** Salesarebasedon an averagepricefor U 26-30. Costsin sucresat 118 sucresper U.S. dollar.
258
Table 4
Two Meansfor EstimatingDemandby Ecuador'sShrimpMariculture
lndusbryfor Postlarvae
Estimated
farm productionl
year
(m.t.)
r977
r978
r979
1980
1981
1982
1983
1984
1985
3.9
5.0
6.2
9.2
tt.2
r6.4
23.3
2r.7
18.7
Postlarvae
required2
(millions)
Areain
cultivation3
Oa)
420.4
539.0
668.4
991.8
I,207.4
r,767.9
2,srt.7
2,339.3
2,015.9
360
1,010
3,150
8,875
26,360
39,120
51,700
59,350
43,r50
Demandfor
postlarvaea
(millions)
55.4
155.5
485.1
1,366.8
4,059.4
6,024.5
7,961.8
9,139.9
6,645.r
I Squ.ceNMFS (1986)EcuadorAj.S.ShrimpImpofis
2 Basedon thefollowing calculationandassumptions
(for 1977):
= lbs.
3.9 metric tonsx2.Zlbslkg x 1,000,000
x 0.70 (tail weight)x 35 shrimplb)/year
x l/0.5 (507osurvival)= 4.20 x 10 8 larvae.
3 So*ce, Dept.EstudiosPesqueros
y Estadisticas,
SubSec.de Pesca
4 Estimatesbasedon the areain cultivationusedthefollowing calculation(for 1983):
(e.g.)51,700ha x 35,000plha x 2.2harvestslyeat
x U0.5 (507osurvival)= 7.96x 10 9 larvae.
Tabte 5
CostEvaluationof SeveralWide SpecrumAntibiotics
asa FeedAdditive
Antibioric
Nitrofurazone
(9.37o)
DosageRecommendations*
(mg. per kg)
Cost**
(per 50 kg bagof feed)
100
500
$0.3s
Oxytetracycline
500
1,000
3.75
7.50
TenamycinFremix
500
1,000
2.30
4.59
(rM-sOD
s0snb)
t.75
* Source:Lightner (seereferences)
t'* ArgentChemicals,1985. This companyhasalsoobtainedaveragegrowthratesof 0.95gramsper
weekfor juvenilesup to 6 gramiize, and 1.25gramsper weekfor shrimpgreaterthan6 gams in size,
at densitiesof up to 70,000juvenilesper hectare.Final feedconversions
rangefrom 2.2 n 3.0:1.0.
Althoughtheseconversionsmay not proveoptimalthey arewell within economicfeasibility.
259
Table 6
in 1983
CoastalLandUsein Ecuador(in hectares)
(Valdiviezo,1985)
Province
ShrimpPonds
Guayas
El Oro
Manabi
Esmeraldas
52,9rr
TOTAL
89,367
Mangroves
Salinas
r2r,463
t7,340
2,520
163
4
24,488
7,873
2L,293
26,483
8,376
1,595
24,028
I75,IT9
Table 7
PondConstructionin SucresCircaFebruary1984
Landconcessions
on the mainland
[,andconcessions
on islands
Privateundeveloped
agriculturallands
on the mainland
Previouslyin use
Landclearing200,000/ha
400,000-600,0001ha
Construction
Undeveloped
120,000/ha
heviously in use
400,000/ha
Undeveloped
80,000-120,000/ha
Low land*
60,000-80,000/ha
High land**
40,000-60,000/ha
120,000/ha
Privateundeveloped
land on islands
*
Below the high tide level.
'ft{' Above the high tide level.
260
References
Alvarez. This volume.
CENDES. 1984. "Analisisdel Sectorcamaronero."Technicalreport:r-231.
y W' Sanchez.1986. "Anatomiay Evolucionde la Actividad
{o*u, R., O. Crespo,G. Contrerase,
Camaronera
en el Ecuador.pp. L47.
W. Bastamante,
andA.Lopez. 1986. "La Exportationde Camarones."Guayaquil,
Io*?, R., O_Crespo,
Ecuador:II CongresoMundialdeAcuacultura.
Klima, E. This volume.
Klima, E. 1986. Reviewof EcuadorianShrimpFisheriesandSuggestions
for Management
andResearch:
r-t2.
Lightner,D.V., et al. 1980. "The Useof Antibiotic FeedAdditivesin Aquacultue." Kyoto, Japan:proc.
UJIVR Conf. on Aquaculture.
NationalMarineFisheriesService(us) 1986. "EcuadorianShrimpupdate." 1-12.
Olsen,S. andP. Maugle. 1986. "StatusandProspectsfor ShrimpMariculturein Ecuador." Paper
presentedat the SecondInternationalSymposiumon Wetlands:1-19.
Perez,E.,D. Robadueand S. Olsen. This volume.
Snedaker,S.,J. Dickinson,M. Brown andE. Lahmann. 1986. "ShrimpPondSiting andManagement
Alternativesin MangroveEcosystems
in Ecuador."Miami, Florida: Final report. USAID GrantDPE5542-G-SS-4022-00.
1-81.
Valdivieso,J. 1985. "EstudioAcnralizadode Manglaros,Camaroneras
y areasSalinas."Presented
at ttreII
CongresoNacionalde Productores
de Camaron:1-10.
262
Mariculture. In: Olsen, S. and Arriaga, L., editors. A Sustainable Shrimp Mariculture Industry for Ecuador.
Narragansett, RI: Coastal Resources Center, University of Rhode Island
A SUSTAINABLE SHRIMP MARICULTURE
INDUSTRY FOR ECUADOR
Edjttd by Stephen Olsen and Luis Arrlaga
Characteristicsof the
Mariculture Industrv
NOTE TO READER
September 1, 2006
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deleted in order to reduce file size, however the full text and graphics of the original are
preserved. The resulting page images have been processed to recognize characters
(optical character recognition, OCR) so that most of the text of the original, as well as some
words and numbers on tables and graphics are searchable and selectable. To print the
document with the margins as originally published, do not use page scaling in the printer
set up.
This document is posted to the web site of the
Coastal Resources Center,
Graduate School of Oceanography,
University of Rhode Island
220 South Ferry Road
Narragansett, Rhode Island, USA 02882
Telephone: 401.874.6224
http://www.crc.uri.edu
Citation:
Villalon, J., Maugle, P., Laniado, R. (1989) Present Status and Future Options for Improving
the Efficiency of Shrimp Mariculture. In: Olsen, S. and Arriaga, L., editors. A Sustainable
Shrimp Mariculture Industry for Ecuador. Narragansett, RI: Coastal Resources Center,
University of Rhode Island
Present Status and Future Options for Improving the Efficiency
of Shrimp Mariculture
Estado Actual y OpcionesFuturas para Mejorar la Eficiencia de Ia
Maricultura del Camar6n
Jos6 R. Villal6n, Paul D. Maugle y Rodrigo Laniado
Resumen
En 1986habiam6sde 94.000ha autorizadas
paraconstrucci6n
depiscinascamaroneras,
esiaban
terminadas
unas60.000ha y de 6stass61oun50Voestabanenproduccidnde postlarvas(pls).
La mayoriade los cultivadores
siguenun m6todode manejosemi-exiensivo,
condensidades
de
siembrade 10.000a 50.000pls/ha. Seusael flujo de mareaso el bombeodiarioparael intercambiode agua
en laspiscinas.Los nutrientessonproporcionados
por la producci6nnaturaldel iitoplanctonen los
estanques.
Las empresas
con m6salto gradode infraestructura
y recursosecondmicoiusanel mdtodosemiintensivocondensidades
de siembrade 100.000a 180.000pls/ha.En general,densidades
de siembra
mayoresque50.000juvenilesrequierende fertilizaci6no la dispersi6nde laspls en muchaspiscinaspara
la ventajade la productividadel fitoplancton.Los eitanquespara;semillero"usadosen las
aprovechar
operaciones
simi-intensivas
sonsembrados
conm6sde 2 millonesde pls por hectirea. De aqui son
frasladados
a laspiscinasde crecimientodespuds
quealcancen
pesosde 05 a 1,0gr.
Aproximadamente
del 50 al607odepls "sembradas"
en laspiscinasdel Ecuadorsonobtenidasen el
ambientenatural.El 50Vode pls conesponden
a P. vannamei,selecci6nqueesclbasadaen su capacidad
para
resistiry creceren el ambienterigurosode laspiscinas,antesqueen la disponibilidadde pls. Cuandolai pls
eslSnmezcladas
condetritusy el tiempode ftansporteeslargo,la mortalidaddepls puedellegara un 502o.
!n ggnerallas pls capturadassevendenaunintemediarioquelas transfierea centrosde acopioparala
ltmpieza,.Taego_son
empacadas
y transportadas
hasa los criaderos,usandoparaestoaireybxigeno
comprimidos.La temperatura
no secontrolaen el tanquede transporte.La aclimataci6nde lis pls serealiza
enpiscinasde crecimiento,siendoestaoperaci6nmateriade controversias
considerables.
Los autoresanalizanen detallevariosaspectos
de los sistemas
de manejoen los estanques
"semilleros"y delaspiscinasdeproducci6n,incluyendoel usode alimentosconientradosgranulados
lpellets).
La vigilanciade los pardmetros
ambienales(oxigenodisuelto,pH, temperatura,
salinidad,
.
turbiedad),esefectuada
en laspiscinasconcultivossemi-intensivos
confinesde manejo.Asi, valoresde
oxigenomenoresque3 ppn originala suspensi6n
de alimentosy aumentodel ingresode aguapor bombeo;
temperaturas
menoresque24oCesla referenciapuaaumentarla profundidaddel aguaen laspiscinas;si la
turbiedadesmenorquie32cm o haypH alto, sesuspende
la fetitlacidn.
Se
acepta
ampliamente
que
en
Ecuador
la
convenidn
de 6reasde manglar a pisicinascamaroneras
es
- unade las razonesprincipalesde la declinacidnde la abundanciade pls. Tambidn,loi autoresmencionanque
lugaresparapiscinasen algunas6reasde El Oro compitencon tierrasagricolasy de patoreo.
Entre lasrecomendaciones
planteadaspor los autoresseencuentran:(a) capacitartdcnicos,
habidndoseestimado
queel Ecuadornecesitani-enEe
700y 800t6cnicosparatiboraioriosy paralaspiscinas
ya autorizadas;(b) un prcgramade capacitaci6nparapersonalde los centos de colecci6ny
iara los que
transportanlas pls; (c) proporcionarfacilidadesde mantenimientopuadesarrollodepls; (O)esableclr un
laboratoriode diagndsticoparaaplicaci6nde nivelesadecuados
de alimentaci6n;(e) mejorarlos
conoc-imientos
delos productores;(f) difusi6nde m6todosapropiados
paraaclimataci6ndepls y estanques
"semilleros";G) desanolloderacionesecuatorianas
paramaduraci6n
en los laboratorios.
a9
NOTE TO READER
September 1, 2006
THIS IS A SEARCHABLE PDF DOCUMENT
This document has been created in Adobe Acrobat Professional 6.0 by scanning the best
available original paper copy. The page images may be cropped and blank numbered pages
deleted in order to reduce file size, however the full text and graphics of the original are
preserved. The resulting page images have been processed to recognize characters
(optical character recognition, OCR) so that most of the text of the original, as well as some
words and numbers on tables and graphics are searchable and selectable. To print the
document with the margins as originally published, do not use page scaling in the printer
set up.
This document is posted to the web site of the
Coastal Resources Center,
Graduate School of Oceanography,
University of Rhode Island
220 South Ferry Road
Narragansett, Rhode Island, USA 02882
Telephone: 401.874.6224
http://www.crc.uri.edu
Citation:
Villalon, J., Maugle, P., Laniado, R. (1989) Present Status and Future Options for Improving
the Efficiency of Shrimp Mariculture. In: Olsen, S. and Arriaga, L., editors.
A Sustainable Shrimp Mariculture Industry for Ecuador. Narragansett, RI: Coastal Resources
Center, University of Rhode Island
Historical Developmentof Shrimp Mariculture in Ecuador
The Incasmay havebeenthefirst to farm shrimpin Ecuadorsome400 yearsagoby impounding
waterscontainingpenaeidshrimplarvae. Modernshrimpmariculturebeganin the late 1960sin El Oro
provincein southernEcuadorwhen an ownerof a bananaplantationnoticedthat flood watersimpounded
behinda dike yieldeda bountifulharvestof shrimp. By 1977thereweresome360 hectares(ha)of shrimp
pondsin production(R. Naboa,personalcommunication).In the earlydaysof the industry,investorswere
ableto pay off the costsof pondconstructionwithin two or threeyears. This, combinedwith seemingly
abundantpostlarvaeandtherelativelyhigh pricefor shrimpin theU.S. market,led to therapid
of the shrimpmaricultureindusry. By 1983the shrimpindustryhadexpandedto an estimated
development
89,367ha of (Alvarez,this volume)andproductionpeakedin 1982-83at23,300metrictons(m.t.)of
shrimpreportedlyworthU.S.$218.7million (NationalMarineFisheriesService,1986).
Thereis a feeling amongproducersinterviewedby the authorsthat the shrimpindustryis currently
in the early 1980sis over. Future
undergoinga consolidation.Therapidexpansionexperienced
the producerssay,will not be in the areaof newpondconstructionbut in theacquisitionof
development,
of hatcheries.
not presentlyin useandthedevelopment
concessions
hasrecentlybecomethepredominant"survivalunit" in the
The so-calledintegratedenterprise
andmay
shrimppondswith packingandexportoperations,
Ecuadorianshrimpindustry. It incorporates
havea harcheryin operationor underconstruction.Suchan integatedenterprisemay includeseveralof the
following segments:
.
.
r
.
.
.
.
importhouse(s)in theUnitedStatesandothermarkets
packingplant
gowout ponds(thismay includeseveralcompanies)
feedand/orfertilizerplant
fishingfleet (sourcing)
larval collectionandair and/orgroundransport group(s)
hatchery
Area in Production
In 1986thereweremorethan94,000ha of shrimppondsauthorizedforconstructionand
approximately60,000ha hadbeencompleted(Table 1). Basedon a preliminaryaerial surveyandinterviews
with shrimpproducersin the Guayas-ElOro productionareas,theauthorsestimatethat only half of the
completedpondswerein productionin June-July1986,presumablybecauseof postlawaeshortages.
Pond ManagementTechniques
The nationalcrisisbroughtaboutby thedepletionof wild stockpostlarvae(PL), during 1984-85,
into two distinctcampswith confrastingcultureand
strategies
hasdividedEcuadorianfarm managemont
management
sEategies.
Semi-Extensive
Most farmerspursuea semi-extensive
management
straiegywhich callsfor stockingdensitiesof
10,000to 50,000PL per hectare.Thesefarmersacceptlower productionreturnsalongwith substantial
reductionsin theirproductioncosts.Producers
usingsemi-extensive
systemsmay usethetidesand/ordaily
pumpingto provide waterexchangein gravity drainedflow-throughponds. Nutrientsareprovidedby
naturalphytoplanktonproductionin theponds.
Semi-Intensive
Companieswith a higherdegreeof infrastructureandeconomicresourcesmaximizetheir
productionby utilizing a semi-intensive
method. Here,higherstockingdensitiesof 100,000to 180,000
PL per hectarearemaintained,with correspondingly
higherfixed costs.Themajorityof thesecompanies
pursuewild stockpostlarvaeby payingmorefor catches,or aremeetingtheir stocking
aggressively
demandswith theirown hatcheryproduction.Nurserypondsutilizedin semi-intensive
operationsare
stockedwith up to 2 million PL per hectare.Thejuvenilesaremovedfrom nurserypondsto growout
pondsafterreachingweightsof 0.5 to 1.0grams. Stockingdensitiesat levelshigherthan50,000juvenile
shrimprequirefertilized growoutponds,or postlarvaespreadover manypondsto take advantageol
phytoplanktonproductivityandreducerisks of lossfrom overstocking.Stockingdensityis oftena function
of wild stockpostlarvaeavailability.
Generally,the small farmersor farmerswho do not havea highty developedinfrastructuredo not
sharethetechnologicaladvancement
employedby thelargercompanies.This lack of technologyamongthe
smallerproducersusingsemi-extensive
methodshasresultedin high mortalityat high stockingdensities.
On theotherhand,farmerswho havehigherfixed costsandinfrastructure
development,
havealso
aggressivelypursuedthe advancementof their technologywhich is reflectedin an increasein overall
productionlevels.
Demand for Postlarvae
Pondoperatorsobtainpostlarvaeby oneor moreof severalmethods,including:
.
'
'
.
'
.
.
purchasefrom middle men
collectingPL with personnelfrom the shrimpfarm in estuariescloseto the farm
cgllectingfrom artificial estuaries(semilleros)constn:ctedin mangroveareasbordering
the shrimpfarm
collectingin the intakecanals
collecdngfrom nurseryponds,whenthey aretidally filled during the monthly flood tide
aguaje)
purchasesfrom a hatchery
importsfrom othercountries
Approximately50 percentto 60 percentof thepostlarvaestockedin Ecuadorianpondsarewildcaughtandpurchased
from middlemen. Postlarvae
pricesarebasedon availability,principallyof Penaeus
vannamei.Theseanimalstypicallychangehandstwo to threetimesbetweenthe fishermenandthegrowers'
ponds. A fishermanreceivesapproximately100sucresper 1,000postlarvaefrom middlemen.The
postlarvaearethensoldto thepondownersor to othermiddlemenfor approximately450 to 1,000sucres
per 1,000.
Wild-caughtPenaeus
vannameiaregenerallymoreabundantduringthemontls of December
throughMarch. During thesemonthswell above50 percentof the catchis P. vannameiwith a notable
decrease
in thepresenceof P. occidentalis.The selectionof P. vannameiasthe speciesof choicewasnot
basedon its availability(Klima, 1986andZimmermanet al., 1986)but on its ability to resistand grow in
et al., 1986).
a very rigorouspondenvironment(Snedaker
During the 1985-86stockingseasonthe supplyof postlarvaeremainedhigh throughthe middleof
March 1986(Table2). Producerswho hadamplefundswereableto rapidly stocktheirponds.Many of the
largerpond ownershaveresortedto hiring groupsof fishermenanda middleman!o tansport the postlarvae
andpay them a salarynearly doublewhat they would otherwiseeam. A fishermancanthus eambetween
of overallannualeamings
2,000and5,000sucresin a day,whichmay accountfor a signifrcantpercentage
for theseartisanalfishermen.Sincethecaptureof postlarvaeis determinedby moonphase,tide,water
temperatue,locationandthefisherman'sskill, he may be limited to five to eightdaysof goodfishingper
monrh. A middlemancan sell between500,000to 1 million PL per day,but ttrisactivity is limited by the
which includeequipmentandshort-term
lengthof time thatPL areavailableandhis capitalexpenditures,
operatingloansat interestratesof 25 percentto 50 percentper two monthperiod.
40 percentto 60 percentof theoveralloperatingcostsin a farm operation.
Postlarvaecanrepresent
Severalproducershaveresortedto importingpostlarvaefrom theUnitedStatesandothercounfries,though
therehavebeenproblemswith poorqualityandsizeconsistency.A comparisonof theeffectof wild and
is givenin Table3.
importedseedstockon productioncostestimates
Thereareno dataon the numbersor speciescompositionof thepostlarvaecaughtby the artisanal
fishery,but the Camarade Productoresde Camaronesdel Guayasestimatesthat the fishery hadprovided3 to
4 billion P. vannameiPL eachyearuntil the 1983-84El Nino. Thereis an unmistakabletrendfollowing
lack of wild seedstock. Table4 provides
andsubsequent
theEl Nino towardshortspawningseasons
estimatesfor thenumberof PL utilizedby the indusry in recentyearsandthepotentialPL demand.
Postlarval Transport and Survival
Whenwild-caughtpostlarvaearemixedwith detritus,andthelengthof time from capturepoint to
transporttankis prolonged,PL mortalitiescanbe ashigh as 50 percent.The catchis thensoldto
middlemenwho Eansferthepostlarvaeto collectioncentersfor furthercleaning.Whensufficientnumbers
air and
havebeenaccumulated,thepostlarvaearerepackedandtransportedto nurseryponds. Compressed
andair
oxygenareusedto maintainpostlarvaeduringfransport,with battery(12v)operatedair compressors
stoves.The waterlemperatuein thetransporttanksis not controlled,nor arechemicalsaddedwhichwould
was
inhibit ttreeffectof diseaseor chelatetoxicants.In thepast,thenumberof larvaebeingpurchased
duringtimeswhenwild-stockpostlarvaewere
estimatedby eye. Althoughthistechniqueseemedadequate
abundantandpriceswererelativelylow, economiccompetitioneventuallyforcedfarmersto mathematically
quantifytheir postlarvae.Volumetriccountingtechniquesrapidly becamestandardoperatingprocedure,
althoughthey had inherentcountingerrorsof up to approximately30 percentdependingon container
design,watervolume,larvaedensity,andmixing techniques.As a result,someof themoretechnically
and
advancedproducersnow usea reductioncountingtechniquewith sendardizedwatertemperatures
loweredthemarginof errorto acceptable
This techniquehassuccessfully
mechanicalmixing apparatuses.
levelsof approximately10percent.The improvementof tlte level of confidencein thequantificationof
postlarvaestockedinto pondshasresultedin the development
of a valuabletool for watermanagement
harvestprojectionsandfertilizationprograms.
decisions,feedconversions,
Acclimation of Postlarvae
controversy.Many producers
Postlarvalacclimationto growingpondsis a subjectof considerable
favor limited acclimationprocedures.A technicallyadvancedfarm, EmpacadoraNacional,usesa slow
acclimationprogramcombinedwith controlledecologicalconditionsin theacclimationstation. This
pro$am usesa continuousflow-tlrough systemwhile feedingArtemiasalina,naupliiandsteamedegg
yolk. Acclimationdensitiesof up to 500 five-day-oldpostlarvaeper liter, a rateof two partsper thousand
haveyieldeda 1 percentmortality
salinitychangeper hour,anda 1 degteeCelsiuschangein temperature
previous
period,
rudimentarytechniques.
improvement
over
the
l2-hour
a
significant
a
acclimation
over
The lengttrierprocessalsoallowsfarm biologiststo evaluatetheconditionandbehaviorof thepostlarvae.
252
Nursery Pond Management Systems
Stockinga nurserypondis not generallya problem,providingthepostlarvaedo not comelong
_.
distancesor from environmentalconditionswhichvary greatlyfrom pondconditions.Survivalestimates
aremadefrom samplesof 100animals,which in somecasesareheldin fine-meshed
netsin thenursery
pondsfor 48 to 96 hours.
Amongthemoretechnicallyadvanced
companies,
whichgenerallyemploysemi-intensive
management
0echniques,
muchattentionis paidto ttrepreparationof nurserypondbottomsto produce
nutrient-richwater,sinceit is believedthatfeedingreducesmorhlity duringthe criticalfirst threeweeks.
Producers
prepareboth growoutpondandnurserypondbottomsby allowingthemto completelysundry
andoxidize. Humid areasarehand-tilledandoxidizedwith a saturatedsolutionof hypochloride.Wateris
allowedto half fill the nurseryafterpassingthrougha I mm filter screen.Inflows andeffluentweirsare
thensealedfor five days. Fertilizerat a concentration
of 1.3partsper million (ppm)of nifiogenand0.3
ppm of phosphorus
is appliedin a singledose. Algaeareallowedto grow for two to five daysbeforethe
nunery pondsarecompletelyfilled. Wateris commonlytransparent
to a depthof 30 centimeters
at this
point.Feedfor juvenile shrimpwith 35 percentproteinis added24 hoursprior to stockingatarate of 100
pounds(45kg) per hectare.Thenurserypondsarethenstockedat densitiesof up to 2 million postlarvae
per hectare.The shrimpareharvestedby drainingthepond 50 daysafter stockingwhentheir averageweight
is 1.5grams. Survivalratesashigh as65 percentarecommonlyrecordedusingthesetechniques.
Production Pond Management
Stocking
Growoutpondscanbe stockedin two ways. First,postlarvaecanbe placeddirectlyin 5 o 15
hectareunitsfor a 180to 210 daygrowoutperiod,bypassingtheneedfor nurseryponds.With thesecond
metiod, largerjuvenile shrimpharvestedfrom nurseryponds,asdescribedabove,areplacedin the growout
ponds.
Stockingdensitiesin growoutpondsfarmedby semi-intensive
methodsrangefrom 50,000o
180,000hatchery-reared
postlarvaeper hectare.Feedandfertilizationarecarefullyconrolled andpondsare
treatedasproductionunits. Yieldsrangefrom 1,400to 1,300kg per hectareper yearof wholeshrimp.
Semi-intensive
management
systemsutilizedby integratedenterprises,
generallyemploytraineA
biologistswho rely upona wide rangeof physicalandchemicalinformationwhenmakingmanagement
decisions.Ecologicalparameters
aremonitoredin all ponds.
Accordingto Empacadora
NacionalC.A. (a majorfeedproducer),stockingPL directlyin growout
pondsat densitiesof 160,000PL per hectaremay yield 45 percentsurvivalaftera 180-daygrowouiperiod.
Stockingwith juvenilesat densitiesof 80,000per hectareyields75 percentsurvival atthe22 gramsize,the
targetharvestweight,obtainedin approximately140days.
Shrimpharvestsashigh as3,500poundsper hectareper tumoverwith two tumoversper yearare
commonin semi-intensive
operations.However,semi-extensive
producersoftenrealizea greatermarginof
profit with lower stockingdensities,lowerlevelsof technologyanda reducedmanagemenieffort.
Feeding
In semi-intensive
operations,
theuseof compounded
dry pelletedfeedsis widely accepted.Daily
applicationsare madefrom canoesin a zig-zagfashionover the entirepond surface. Therearetwo basic
feedformulationscurrentlyin use. Oneconsistsof 35 percentproteinand 8 percentfat, andis usedto feed
juvenilesuntil they oblainan averagesizeof 6 grams. Oncethejuvenilesreach6 grams,the feedration
changesto a growoutproductionformulacontaining25 percentproteinand5 percentfat" Feedrationlevels
areadjustedweeklyaccordingto the shrimpweight. Stringentqualitycontrolguidelinesarefollowedin the
feedmanufacturing
process.Local producersstriveto maintainthestabilityof thepelletin thewaterfor
morethan four hoursandmaintaindigestibility greaterthan70 percent. The useof shrimpheadsand other
by-productsin shrimpfeedsarebeingconsidered.
strategieshaverecentlyrecognizeddiseaseSeveralproducenutilizing semi-intensivemanagement
relatedproductionproblems.Use of medicatedfeeds(Table5) could havea significantimpacton production
capacities,providedthe following factorsaretakeninto consideration:
.
.
.
identification of benefis from point specificversusbroad spectrumprophylacticantibiotic
applications
economicfeasibilityat thecommerciallevel
andhealthimpacts
the evaluationof potentialenvironmental
Costs and Profits
lvlanyproducersusing semi-extensivemanagementstrategiesfertilize only during the dry season
when the waterpumpedfrom the estuaryis lessproductive. While theseproducershaveusedlocally
producedshrimpfeeds,they often view the useof feedwith greatdistrust. The feed,in their opinion,breaks
down in the water,makingit little morethanan expensivefertilizerthatdoesnot producesufficient
eitherin quantityor sizeof shrimpto offsetthe additionalcapitaloutlay.
improvement
Excludingthe costof financingthe shrimpfarm operationduringthegrowthperiod,it costsfrom
approach(harvest
U.S. $.70to asmuchas$1.20to producea poundof shrimpusingthe semi-extensive
U.S.$.40moreper poundto usefeeds.Producers
harvests/yr),
andapproximately
rateof L5,000/ha/2.2
receiveberweenU.S. $2.20to $3.50per poundof shrimpdependingon the sizeof the shrimpandtime of
year.
Although therewould appearto be a greaternetprofit to the semi-extensiveproducerif higher
stockingdensitieswere used,neitherthe quality of the feednor the technologycurrentlyavailableseem
adequateto prompt changingtheir methods.However,someproducersareopento alternativefarming
strategiespr-oviOingsufficient quantitiesof PL areavailablefor higherdensitystocking,high quality feedis
availableandadequatelyEainedbiologistsareavailableto operatethe shrimpfarms.
Ecological Monitoring
salinityandwaterturbidityis carriedout
Monitoringof dissolvedoxygen,pH, watertemperature,
and againatzp.m. Althougha
commonly
at
6
a.m.
many
operations;
semi-intensive
twice daily in
routine feitilization programis utilized, resultsfrom waterquatty analysisoverridethe routine scheduleof
fertilization.
arepriority pafirmetersandusedaswarningsin basic
Dissolvedoxygenand watertemperatures
A
low
oxygenreadingof lessthan3 ppm dictatesthe
dissolved
decisions.
biologicalmanagement
of lessthan
of feedingandan increasein theflow of incomingwater. A low watertemperature
suspension
24oCis the basis[o increasewaterdepthin a pond,in an attemptto cushionor reducetherateof changein
watertemperaturein the deeperareasby decreasingpond surfaceareain relation to total volume. In the
dictatesimilarreactions.Afternoon
aftemoon,high dissolvedoxygenand/orhigh watertemperatures
monitoringis alsousedasa guidelinefor fertilization. Waterturbidityreadingsof lessthan32cm and,/or
of routinefertilization. Hydrogensulfides,ammoniaandphosphate
high pHs alsocall for the suspension
in
all ponds.
weekly
areanalyzed
concentrations
Water Quality Management
management
system,whethera nurseryor productionpond,i,s
Eachpondin the semi-intensive
managedfor iti percenrageof watervolumeexchange.Water level readingsover tle effluentweir boardsare
measuredevery2 hoursfor 12 hours. The diurnaltide reflectstwo shiftsin pumpingcapacityso thatwater
overa 24-hourperiodto calculateinflow volume. Oncethepond systemis
level valuescanbe extrapolated
catfbpte{ adjustmentsgre qade daily, basedon ecologicalparameters,stockingdensitiesand shrimp
weight. Generally,productionpondsareinitiatedwith a 6 percentdaily exchangerate,while final water
exchangeratesmay graduallyincreaseover time to 17percentper day. Someof the moreadvanced
producers,using extensivemanagement
practicesalsopump daily at ratesrangingfrom 5 percentto l0
percentof thepondvolume.
Production Capabilities
With stockingdensitiesof 15,000to 30,000PL per hectareand 1.5to 2.2 harvestsper year,many
farmersestimateharvestlevelsat 800to 2,100pounds/hectare/year.
Shouldproducerschangetheir productionstrategyto onewhich incorporateslow stockingdensities
with fewer turnovers(harvess)per year,thenthey would be abletn producelarger-sizedanimalsand
potentiallymorevaluablecrops. For example,onecompany(Langacua,S.A.jusing an extensive
management
strategystocks18,000to 25,000juvenilesper hectare.Theseanimalsgrow n 24 gm size
Q6-30count)in 100-120daysin therainy seasonand 120-140daysin the dry season,
with an overall
survival rate of 90 percent,yielding approximately600 poundsof shrimp2.5 times per year. This
extensivestrategyproduceson the average2,100poundsper hectareper year. Suchan approachseemsto
offset potential lossesdueto inadequatesupplyof postlarvaeand may havethe potentialof stabilizing
overallproduction,makinglevelsof productionachievedin previousyearsobtainableat lower costs,with
fewerpostlarvaeand/orproducers.
Pond Siting, Construction and Utilization
It is widely believedin Ecuadorttrattheconversionof mangroveareasto shrimppondsis a major
reilsonfor the declineof PL abundance.Alvarez (this volume)providesestimatesfor the changesin areaof
mangroves,
salinasandshrimppondsbetween1969and 1984. Basedon remotesensingdata,heestimated
that the total mangroveareain Ecuadorhasdecreased
by 10.6percentduring this period.
CLIRSEN,asreportedby Valdiviezo(1985)utilizing informationobtainedfrom the 1982-83
r-emotesensingstudies,tabulatedmangroves,
shrimppondsandsaltflats in El Oro andGuayasProvinces
(Table6). The locationanddistributionof mangrovein El Oro, is distinctfrom otherprovihces,andmay
be describedasa nrurowbelt lessthan 100meterswide running along ttreperipheryofttre estuary. Shrimp
ponds,agricultureandpasturelandslie inlandfrom this narrowmangrovebelt. In manyareasshrimpponds
were built leavingno mangrovebuffer. Sitesfor shrimppondsin severalareasin El Oro also compete
directly with agriculturalandpasturelands.
Mangrovesin the GuayasProvinceareconcentratedon islandsand asbels of varying widths along
the continent. Shrimppondsin the areaappearto havefrst beenbuilt in salina(salt flat) areasand later
expandedinto surroundingmangroves.
If onewereto prioritizethedamageto themangroveresources
alongtheEcuadoriancoast,the
mostimpactedareawouldbe El Oro,followedperhaps6y Manabi. In the G-uayas,
althoughimpactedby
the shrimpfarm development,
a considerable
mangroveareastill exists. Thepotentialthreatsto mangroves
in the Guayasandto the shrimpindustrymay lie in a combinationof increasedsiltation,reducedwater
circulation,and upstreamchangesin waterquality due to a reductionof freshwaterinputsandincreasein
chemicalintensiveagriculturalpractices.For a moredetaileddiscussionseeTwilley (this volume).
Coastalareasin Esmeraldas,
conlaininglessttran2,000ha of shrimpponds,havebeenlittle
affectedby the industry. Consideringthe copiousamountof rainfall in thisprovince(Twilley, this
volume),the impacton mangroveareasfrom shrimpfarm development
may be limited to a maximumof
5,000hecares,which is a maximumof onequarterof theapparentmangroveareain 1983.
Investment Requirements
During 1984investmentsto developa shrimpfarm rangedfrom 40,000to 600,000sucresper
hectareClable7). If the only access!o thefarm wasby boat,an additionalinvestmentwouldbe required.
255
of a shrimpfarm,
with the development
Beyondthe initial acquisitionandconstructioncostsassociated
largepumpsandpiping aswell aswaterqualityequipmentarebasicrequirements.Much of this equipment
with impors seePerezandRobadue(this
mustbe imported. For discussions
of theproblemsassociated
volume).
Recommendations
Many actionsshouldbe takenat all levelsto helpthe shrimpindustryreacha stablelevel of
relatedto shrimppondimprovements
arediscussed:
development.Herea few measures
1.
The singlemosteffectiveway to stabilizethis industryis to closethe gapbetweenthe
legalandapparent(s/165:1U.S.D.)exchangerates. In theearlymonthsof 1985,exportersreceived108.50
sucresper dollar exported,in additionto a 15percentAbono Tributario for the total dollar value exported,
which is calculatedat s/95:1U.S.D. The abonois like a bond with a one yearmaturity,so exporters
discountit 3l percentof its value. The real benefitis calculatedasfollows: (95 x 0.15)- 0.31 (95 x 0.15)
= s/9.83. Thus,the legalexporterof shrimpreceivess/108.50+ 9.83= s/l 18.33for eachdollarof export
product. This stepwastakenin late 1986.
Therapid gowth of the indusry hasmadeit impossiblefor theuniversitiesand
2.
polytechnicschoolsto provideenoughsuitablyrained technicians.It is estimatedthatEcuadorwill require
presentlyunderconstruction.
to fully utilize hatcheries
an additional700 to 800 trainedhatcherytechnicians
18,000and22,ffi0
between
in
Ecuador,
it
is
estimated
ttrat
With over900 authorizedshrimpfarms
procedures
on shrimpfarms
operating
in
hatcheries
and
ttre
daily
Improvements
are
employed.
technicians
throughan extensionprogam couldhavea directandvisiblebenefitfor theindusfy andEcuador.Sucha
progam couldbe supportedttrrougha grcupof banksandtheDIGEMA-URI CoastalResources
Program.It would focuson pondswhich arenot currentlyin productionaswell ason
Management
requireloansto operateor expandoperations.All new loansto producerscould be usedto
which
operations
groupsin operationtoday. It
procuretechnicalassistance
from oneof the approvedtechnicalassistance
would be the responsibilityof the extensionserviceto examinethe technicalcapabilityof consultantsand
technicalassistantgroups,andissuethema permitto work within the system.Additionally,a diagnostic
laboratorywith supportactivities in the field could be funded,bringing to Ecuadorexpertsin areasof
specificneed.
extensionprogramwouldinclude:
Servicesprovidedby a comprehensive
. periodictrainingcotuses
.
hatcherytechniques
.
waterquality management
. pondproductiontechniques
.
feeddevelopment
.
diagnosisofdiseases
.
informationanddatabasedevelopment
. dissemination
of reliableinformation
. postlarvae
handling,Eansportandacclimation
.
mangroverestoration
.
developmentof an internationalshrimpmarketinglobby
3.
An immediateimprovementin pondproductioncanbe achievedif producerswould focus
their attentionon wild stockandhatchery-producedpostlarvalhandlingand acclimation
mettrods.The efficientuseof postlarvaehasthegreatestimmediatepotentialgain for the
in capture,
produceraswell asconservingthis limited naturalresource.Improvements
Eansport,handlingandacclimationmethodsfor postlawaecanhavean immediateand
visiblepositiveeffect.
4.
A raining programfor postlarvaecollectioncenterandtransportpersonnelalongwith a
certificatefor coursecompletionshouldbe developed.Sucha programwould focuson
postlarvae,andconductroutinespotchecksto
improvingsurvivabilityof harvested
256
confirm adherence
to conectproceduresto help guaranteedelivery of high quality wild
stockpostlarvae.
5.
Postlarvalholdingfacilitiesat farm sitesto furtherdeveloppostlarvae,from PL 5 to PL
21-30shouldbe developed.Thesefacilitieswouldenhancesurvivalof harchery-produced
stockin thepondenvironment.
6.
Stepsshouldbe takento establishan in-countrydiagnosticlaboratorywhich could
monitorpopulationsof shrimpandbe responsible
for theapplicationof appropriatelevels
andtypesof medicatedfeeds.
7.
Stepsshouldbe takento enhance
theknowledgeof producers,
andkeepthemappraised
of
recentadvances
in hands-ontechnology.This might be donethroughroutinenews
releases.
8.
Otherareasthatcouldhavedirect,immediateandvisiblepositiveeffectson theindustry
include:
'
development
anddissemination
of improvedmettrodsfor postlarvalacclimation
.
stockingof nurseryponds
.
thedevelopment
of acclimation,nurseryandgrowoutpondmaintenance
programs.
9.
Pondproducersshouldcoordinatetheir effortswith hatcheryproducersto assue thattheir
respectivepondsareadequatelyprepared0oreceivepostlarvae.
10.
More effort shouldalsobe givenwithin thepondproducers'enterprises
to control
parameters
environmental
!o preventcausesof unduesEess.
11.
Many improvements
to feedscurrentlyusedin Ecuadorcanbe madeusinglocally
availablefeedstuffs. Costeffectivefeedsof adequate
nutritionalvalueshouldbe further
developedusingin-countryfeedstuffsandprocessing
by-productsfor all segments
of the
industry(i.e.larval,maturation,nurseryandgrowoutponddiets).
t2.
An Ecuadorianmaturationdiet for usein harcheriesneedsto be developedbecausepresent
stocksof oystersandothershellfishin Ecuadorwill be gravelyimpactedwhenallihe
hatcheries
presentlyunderconstruction
comeon-line.
257
Table I
EstimatedShrimpPondSurfaceArea(in hectares)
Authorized,Completedandin Use
Province
Authorized
in 19861
Guayas
72,208
El Oro
Manabi
14,496
5,407
Esmeraldas
TOTAL
2,241
94,352
Construction
inlg842
Completedand
Urder
Construction
in 1986
In Use
in 1986
52,9r2
26,484
8,377
1,595
89,368
60,0003
30-40,0004
I R. Hornaet a1.,1986.
2 clnsgN, 1986.
3 R. Homa, O. Crespo,W. Bustamente,
A. Lopez, L986.
4 Aetial observation,P. Maugle,lv{arch1986:conoboratedby the Camerade Productoresde Camaronesdel
Guayas,1986.
Table 2
1985-86PostlarvalCoststo PondOperators*
perthousand
Sucres
1,300
1,900
1,900
1,200
500
May - July 1985
August- September1985
October- November1985
December- January1986
February- March 1986
* From M. Leslie,personalcommunication.
Table 3
Comparisonof ProductionCostEstimatesto a hoducer Using
Method*
Wild StockandImportedSeedStockin anExtensiveManagement
Wild stock
Importedseedstock
Unit sold atU 26-30
@L Cost)
20.00**
3.00
20.00
7.00
Grossmargin
17.00
13.00
- E"pensesrary significantly from onefarm to another,and economicsof scaleareachievedabove120to
150hectares.
** Salesarebasedon an averagepricefor U 26-30. Costsin sucresat 118 sucresper U.S. dollar.
258
Table 4
Two Meansfor EstimatingDemandby Ecuador'sShrimpMariculture
lndusbryfor Postlarvae
Estimated
farm productionl
year
(m.t.)
r977
r978
r979
1980
1981
1982
1983
1984
1985
3.9
5.0
6.2
9.2
tt.2
r6.4
23.3
2r.7
18.7
Postlarvae
required2
(millions)
Areain
cultivation3
Oa)
420.4
539.0
668.4
991.8
I,207.4
r,767.9
2,srt.7
2,339.3
2,015.9
360
1,010
3,150
8,875
26,360
39,120
51,700
59,350
43,r50
Demandfor
postlarvaea
(millions)
55.4
155.5
485.1
1,366.8
4,059.4
6,024.5
7,961.8
9,139.9
6,645.r
I Squ.ceNMFS (1986)EcuadorAj.S.ShrimpImpofis
2 Basedon thefollowing calculationandassumptions
(for 1977):
= lbs.
3.9 metric tonsx2.Zlbslkg x 1,000,000
x 0.70 (tail weight)x 35 shrimplb)/year
x l/0.5 (507osurvival)= 4.20 x 10 8 larvae.
3 So*ce, Dept.EstudiosPesqueros
y Estadisticas,
SubSec.de Pesca
4 Estimatesbasedon the areain cultivationusedthefollowing calculation(for 1983):
(e.g.)51,700ha x 35,000plha x 2.2harvestslyeat
x U0.5 (507osurvival)= 7.96x 10 9 larvae.
Tabte 5
CostEvaluationof SeveralWide SpecrumAntibiotics
asa FeedAdditive
Antibioric
Nitrofurazone
(9.37o)
DosageRecommendations*
(mg. per kg)
Cost**
(per 50 kg bagof feed)
100
500
$0.3s
Oxytetracycline
500
1,000
3.75
7.50
TenamycinFremix
500
1,000
2.30
4.59
(rM-sOD
s0snb)
t.75
* Source:Lightner (seereferences)
t'* ArgentChemicals,1985. This companyhasalsoobtainedaveragegrowthratesof 0.95gramsper
weekfor juvenilesup to 6 gramiize, and 1.25gramsper weekfor shrimpgreaterthan6 gams in size,
at densitiesof up to 70,000juvenilesper hectare.Final feedconversions
rangefrom 2.2 n 3.0:1.0.
Althoughtheseconversionsmay not proveoptimalthey arewell within economicfeasibility.
259
Table 6
in 1983
CoastalLandUsein Ecuador(in hectares)
(Valdiviezo,1985)
Province
ShrimpPonds
Guayas
El Oro
Manabi
Esmeraldas
52,9rr
TOTAL
89,367
Mangroves
Salinas
r2r,463
t7,340
2,520
163
4
24,488
7,873
2L,293
26,483
8,376
1,595
24,028
I75,IT9
Table 7
PondConstructionin SucresCircaFebruary1984
Landconcessions
on the mainland
[,andconcessions
on islands
Privateundeveloped
agriculturallands
on the mainland
Previouslyin use
Landclearing200,000/ha
400,000-600,0001ha
Construction
Undeveloped
120,000/ha
heviously in use
400,000/ha
Undeveloped
80,000-120,000/ha
Low land*
60,000-80,000/ha
High land**
40,000-60,000/ha
120,000/ha
Privateundeveloped
land on islands
*
Below the high tide level.
'ft{' Above the high tide level.
260
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{o*u, R., O. Crespo,G. Contrerase,
Camaronera
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W. Bastamante,
andA.Lopez. 1986. "La Exportationde Camarones."Guayaquil,
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Ecuador:II CongresoMundialdeAcuacultura.
Klima, E. This volume.
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r-t2.
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262