Aquaculture System (1).ppt

aquaculture system

2. •Aquacultureispracticedinawidevarietyofsystems
dependingondifferentconditionsrelatedto
geography,economy,technicaldevelopmentetc..
•Ontheotherhand,aquaculturesystemscanbe
classifiedaccordingtothelevelsinputs.
Intensive
Semi-intensiveExtensive
Tanks and
Cages
PondsPonds
Ponds,
Enclosures and
Reservoirs
Culture
based
fisheries
Fish seeds,
feed &
environment
control
Fish seeds,
fertilizers, feed
& aeration
Fish seeds,
fertilizers &
feed
Fish seeds &
fertilizers
Fish seeds

3. ExtensiveCultureSystems
1.Culturebasedfisheries:
•Mostprimitiveform.
•Usuallywithcommonownership
(public).
•lowestlevelofinputs.
•Lowlevelofproduction/area(50-
150Kg/acre.
•limitedornocontrolonthe
activities.
•Usuallyinlakes,coastallagoons
orrivers.
•productionisafunctionofnatural
productivity.
•Canbewithasingleormultiple
mixtureofspecies.
•harvestingperiodislong(usually
morethan8monthsayear),with
seasonalseedsupply.

4. Although culture-based aquaculture and extensive
aquaculture may be taken lightly and considered as
simple and primitive techniques, still its success is in
fact based on high levels of scientific knowledge. Such
knowledge is required to get the best out of the
production system (the water body) and the cultured
species.
Carrying capacity and productivity of water
bodies
Inculturebasedfisheriesandextensiveaquaculturein
naturalwaterbodies,and(tosomeextent)thesemi-
intensivecultureunits;thecalculationofprimary
productivityandnaturalfoodpopulationstructureare
veryimportantfactorsforplanningcultureandstocking
programs.

5. Calculationofprimaryproductivity:
Primaryproductivityisthecapacityofanecosystemto
buildup,attheexpenseofexternalenergy(radiantand
chemical),primaryorganiccompounds ofhigh
chemicalpotentialfortransformationandflowto
higherlevelsystems.
Inmostaquaticecosystemstheelaborationofbiomass
byphotosynthesisofplanktonicalgaeformsthebase
onwhichthemajorenergypathwaysaredependant.
Accordingly,fishyieldfromwaterbodiesisstrongly
correlatedwithprimaryproduction.
Photosynthesiswhichisthefundamentalprocess
involvedinprimaryproductivitycanbeexpressedin
thefollowingequation:
6CO
2+6H
2O —light C
6H
12O
6+6O
2

6. Usingthisequation,primaryproductivitycanbe
estimatedeitherbymeasuringcarbonuptake,oroxygen
production.
Measuringoxygenproductionistechnicallymucheasier
toconductinthefield.
Thetechniqueisbasedonmeasuringtheincreasein
oxygenbyphotosynthesisandoxygenuptakeby
respirationofmicroorganismsinwatersamplesfrom
differentdepths.
Oxygenismeasuredatthesamplingtime(C
1)atdifferent
depths,andtwotransparentbottles(250ml)arefilledat
thesametimebywaterfromthesamepoint.Oneofthe
twobottlesiswrappedinaluminumfoil(darkbottle)and
hangedatthesamplingdepthwiththetransparentone.

7. Thebottlesarelefthangedinthewaterbodyfor6
hours.
Oxygenisthenmeasuredinboththedark(C
2)and
transparentbottles(C
3).
(C
1-C
2)=oxygenuptakebyrespiration.
(C
3-C
1)=oxygenproductionbyphotosynthesis.
(C
1-C
2)+(C
3-C
1)=totaloxygenproducedincluding
thatconsumedbyrespiration.
Each1mgofoxygenproducedisequivalentto0.312
mgofcarbon.
Each1mgcarbonequals2.3dryorganicmatter
(consideredasfeedforsecondaryproducers(mainly
filterfeedingfishandsomezooplanktons)).

8. 20%oftheprimaryproductivityconsumedis
producedintheformofsecondaryproductivity
biomass(pelagicfish,filterfeeders,zooplanktons)
availabletobeconsumedbypredators(toreacha
biomassofabout10%ofthesecondary
productivity).

9. 2.Pondsandenclosures:
•Largeponds(25-100acres),
usuallyshallowandwithsimple
structures.
•Fertilizersaresometimesusedto
improvenaturalproductivity.
•Enclosuresincoastallagoonsor
onprotectedshores.
•Usuallywithmixedspecies.
•Harvestinginashorterseason(3-
4months)andusuallysize
selective.
•Usuallywithprivateownership.
•Productionislowtomedium(100-
350Kg/acre).

10. Semi-intensive
Ponds:•Mediumsizeponds(10-25acres)
withhigherdykes.
•Usually applies poly-culture
approach.
•Productionofnaturalfoodis
enhancedbyorganicandsometimes
mineralfertilizers.
•Stocksfeedsonnaturalfoodand
somesupplementaryfeedaddedto
supportproductivity.
•Goodcontroloninletsandoutlets
throughsluices.
•Higherlevelsofproduction/area
(0.5-1.5tons/acre/year).
•Totalharvestattheendofthe
seasonusuallybydrainingponds.

11. Modern semi-intensive ponds:
•Smallerponds(5-10acres)withgood
dykesandwelldesignedstructures.
•Usuallyappliespoly-cultureapproach
withhighstockingrates.
•Naturalfoodisoflessimportance
andbalancedmanufacturedfeedisthe
mainsourceoffoodforstockedfish.
•Higherratesofpondswaterrenewal
tokeepahealthyenvironment.
•Requires higher levels of
management.
•Dependsonstockingwithlarger
fingerlings.
•Highproduction/area(2-4tons/acre)
andusuallytwoproductioncyclesare
appliedeachyear.

12. Intensive ponds:
•Smallponds(0.5-1acre)withgood
dykesandotherinfrastructures.
•Waterdepthisover1.5meters.
•Highratesofwaterrenewal(5-
10%/day).
•Highstockingdensity.
•Highfeedingrateswithbalance
manufacturedfeed.
•Oxygenlevelsenhancedthrough
aerationespeciallyatnight.
•Basically monoculture, but
polyculturecanbeapplied.
•Highlevelsofenvironment
managementandcontrolofdisease.
•Highproduction(upto24
tons/acre).
•Twoproductioncycleseachyear.
•Requireslargersizefishseeds.

13. Intensive in Tanks:
•Highlevelsoftechnologyandits
success relylargelyon
engineeringanddesign.
•Possibility of artificial
environmentcontrolforveryhigh
stockingandproductiondensity
andcontinuousproduction.
•Highlydependantonenergy
supply.
•Requires highly skilled
management andhighquality
inputs(feed,seed,etc..).
•Suitableforexpensivefish,but
canbedesignedforfeasible
productionofotherfish.
•Usuallymonoculture.
•Canapplywaterrecycling
technology.

14. Intensiveincages
•Highstockingdensity.
•Lowcostofinfrastructure.
•Requires highly skilled
managementandhighqualityinputs
(feed,seed,etc..).
•Usuallymonoculture.
•Nocontrolontheenvironment.
•Productionisseasonaland
numberofcyclesdependsonlength
ofgrowingseason.
•Canbeappliedinanykindofwater
(fresh,brackishormarine)andall
culturespecies.
•Largelydependant on site
selection.
•Diseasecontrolandtreatmentis
difficult.
•Highreturnoninvestment.