Ponds, ponds, ponds...Ponds, ponds, ponds...

Lecture 5

Dr. Craig S. Kasper

FAS 1012C: Introduction to Aquaculture

Lecture 5

Dr. Craig S. Kasper

FAS 1012C: Introduction to Aquaculture

AcknowledgementAcknowledgement

• Appreciation and sincere thanks are given to Dr. Joe Fox (TAMUCC) who kindly donated material for this presentation!!

• Please visit his website!(http://www.sci.tamucc.edu/pals/maric/Index/WEBPAGE/mari1.htm)(http://www.sci.tamucc.edu/pals/maric/Index/WEBPAGE/mari1.htm)

• Appreciation and sincere thanks are given to Dr. Joe Fox (TAMUCC) who kindly donated material for this presentation!!

• Please visit his website!(http://www.sci.tamucc.edu/pals/maric/Index/WEBPAGE/mari1.htm)(http://www.sci.tamucc.edu/pals/maric/Index/WEBPAGE/mari1.htm)

IntroductionIntroduction

• Ponds were used as one of the first forms of aquaculture.

• Dates back to ancient China.

• Already had the water...just add fish, feed, and presto!

• Pond production has come along way since then!

• Ponds were used as one of the first forms of aquaculture.

• Dates back to ancient China.

• Already had the water...just add fish, feed, and presto!

• Pond production has come along way since then!

POND DESIGN CRITERIA (Ideal)POND DESIGN CRITERIA (Ideal)

• Screened inflow gates at shallow end of pond• Screened harvest gates at deep end• Slope to harvest basin (0.5-1.0%)• Water depth 1.25 2.00 M• Feeding tray piers• Rounded or square corners, steps or ramps for

entry• Primary dikes (levees) wide enough to

accommodate vehicles

• Screened inflow gates at shallow end of pond• Screened harvest gates at deep end• Slope to harvest basin (0.5-1.0%)• Water depth 1.25 2.00 M• Feeding tray piers• Rounded or square corners, steps or ramps for

entry• Primary dikes (levees) wide enough to

accommodate vehicles

GENERAL DESIGN, INTENSIVE POND

HARVESTHARVESTGATEGATE

HARVESTHARVESTBOXBOX

FILTERFILTERBAGBAG

HARVESTHARVESTBASINBASIN

SLOPE 1SLOPE 1

SLOPE 2SLOPE 2

SLOPE 3SLOPE 3

LeveeLevee

Leve

eLe

vee

Leve

eLe

vee

LeveeLevee

DIS

TR

IBU

TIO

N C

AN

AL

DIS

TR

IBU

TIO

N C

AN

AL

INFLOWINFLOWGATEGATE

PRIMARYPRIMARYFILTERFILTER

PADDLEWHEEL AERATORPADDLEWHEEL AERATOR

RE

CIR

C C

AN

AL

RE

CIR

C C

AN

AL

LeveeLevee

Le

ve

eL

ev

ee

Le

ve

eL

ev

ee

LeveeLevee

Pond LeveeworkCONSTRUCTION CRITERIA

Pond LeveeworkCONSTRUCTION CRITERIA

• Levees are typically constructed by D6- (Catepillar) sized bulldozers

• Construction is first undertaken on ponds nearest the sedimentation basins and pump station

• Bulldozers push earth up to create general form of the levee walls

• Follow stakes set along the length of the pond

• Smaller dozers used to put on finishing touches

• Levees are typically constructed by D6- (Catepillar) sized bulldozers

• Construction is first undertaken on ponds nearest the sedimentation basins and pump station

• Bulldozers push earth up to create general form of the levee walls

• Follow stakes set along the length of the pond

• Smaller dozers used to put on finishing touches

Pond LeveeworkDESIGN CRITERIA

Pond LeveeworkDESIGN CRITERIA

• Heights determined by pond bottom elevation, tidal amplitude

• Perimeter levee often required for protection in flood areas

• Levees trapezoidal with slopes 1:2 for high clay, 1:3-4 low clay

• Levee crown width varies with use

• Width of crown: 5 m (driving), 3m (walking)

• Crown is sloped to reduce puddles on levee top

• Once formed, levees are sprigged with grass to reduce erosion

• Heights determined by pond bottom elevation, tidal amplitude

• Perimeter levee often required for protection in flood areas

• Levees trapezoidal with slopes 1:2 for high clay, 1:3-4 low clay

• Levee crown width varies with use

• Width of crown: 5 m (driving), 3m (walking)

• Crown is sloped to reduce puddles on levee top

• Once formed, levees are sprigged with grass to reduce erosion

Pond LeveeworkCONSTRUCTION CRITERIA

Pond LeveeworkCONSTRUCTION CRITERIA

• Erosion is the main problem in maintaining levee slopes

• Source: both rainfall and wave action

• Solution: plants and vegetation (local grasses or Salicornia sp.) as soon as possible

• Pond sides receiving wind could be reinforced with rocks (contracted service)

• Tops of levees definitely need layer of rocks, especially if high clay content

• Erosion is the main problem in maintaining levee slopes

• Source: both rainfall and wave action

• Solution: plants and vegetation (local grasses or Salicornia sp.) as soon as possible

• Pond sides receiving wind could be reinforced with rocks (contracted service)

• Tops of levees definitely need layer of rocks, especially if high clay content

WIDTH=4 TO 5 M

PONDSIDE

4.0

CANALSIDE

2.0M1.5M

CUT-OFFTRENCH

Typical Cross-section of Pond Levee

Typical Cross-section of Pond Levee

2.0M

3.0

Preventing LeaksPreventing Leaks

• Minimize amount of loss due to seepage- Proper compaction- Core trenching- Vertical plastic membranes- Vegetative coverage

• Remove burrowing animals (turtles, muskrat)

(.243 Winchester works great!)

• Optimal clay content

• Construction during dry season

• Minimize amount of loss due to seepage- Proper compaction- Core trenching- Vertical plastic membranes- Vegetative coverage

• Remove burrowing animals (turtles, muskrat)

(.243 Winchester works great!)

• Optimal clay content

• Construction during dry season

Pond BottomCONSTRUCTION CRITERIA

Pond BottomCONSTRUCTION CRITERIA

• If detailed pond bottom slopes are required, usually accomplished by scrapers

• Small 4-6 m3 earthmovers towed by 4X4 tractors, laser-guided

• Bottom slope from upper end to lower end of pond usually 1m:250-500m or 0.4-0.2% for large ponds

• In simple ponds, follows natural slope to estuary

• Must insure at least 20 cm height of harvest gate above high tide elevation (varies considerably by site)

• If detailed pond bottom slopes are required, usually accomplished by scrapers

• Small 4-6 m3 earthmovers towed by 4X4 tractors, laser-guided

• Bottom slope from upper end to lower end of pond usually 1m:250-500m or 0.4-0.2% for large ponds

• In simple ponds, follows natural slope to estuary

• Must insure at least 20 cm height of harvest gate above high tide elevation (varies considerably by site)

POND BOTTOM DESIGNSPOND BOTTOM DESIGNS

crown

canal

canal

canal

canal

plateau

plateau

POND BOTTOM ELEVATIONPOND BOTTOM ELEVATION

• Primary design criterion

• Based upon tidal amplitude (or drainage)

• Above the freshwater table

• Above mean high tide

• Determines canal/levee height

• Pond should be drainable at all times

• Primary design criterion

• Based upon tidal amplitude (or drainage)

• Above the freshwater table

• Above mean high tide

• Determines canal/levee height

• Pond should be drainable at all times

Pond Bottom vs. TidePond Bottom vs. TideWHERE SHOULD YOU WHERE SHOULD YOU BE????BE????

WATER CONTROL STRUCTURESINFLOW GATES

WATER CONTROL STRUCTURESINFLOW GATES

• Used for control of pond water exchange• Concrete structures with screen/bag filters on both

sides of Levee• Dual primary screens for pre-filtration (1/4" to

1/2“)• Secondary filtration screen bag eliminates potential

predators (250-500 µM)• Flashboards for controlling flow rate of water

entering pond• Multiple gates in larger ponds

• Used for control of pond water exchange• Concrete structures with screen/bag filters on both

sides of Levee• Dual primary screens for pre-filtration (1/4" to

1/2“)• Secondary filtration screen bag eliminates potential

predators (250-500 µM)• Flashboards for controlling flow rate of water

entering pond• Multiple gates in larger ponds

CONCRETEAPRON

PRIMARYFILTER

LeveeCROWN

LeveeSLOPE

LeveeSLOPE

FLASHBOARDS

WINGWALL

BAGFILTER

CORRUGATEDPLASTICTUBES

PLAN VIEW OF TYPICAL INFLOW GATE

TOP OF LeveeCANALSIDE POND

SIDE

BAGFILTER

ATTACHMENTSLOT

FLASHBOARDS

FILTER SLOT

PRIMARYFILTER

CULVERTPIPE

CROSS SECTION OF TYPICAL INFLOW GATE

WATER CONTROL STRUCTURES

HARVEST GATE

WATER CONTROL STRUCTURES

HARVEST GATE• Concrete w/harvest basin in pond

• Number/size of gates depends on speed

of harvest required

• Screen to retain shrimp, mesh according to size

• Use of flashboards

• Canal side often modified

for harvest pump

• Concrete w/harvest basin in pond

• Number/size of gates depends on speed

of harvest required

• Screen to retain shrimp, mesh according to size

• Use of flashboards

• Canal side often modified

for harvest pump

LeveeCROWN

LeveeSLOPE

LeveeSLOPE

HARVESTBASIN

WINGWALL

FILTERSCREEN FLASH

BOARD

CULVERT TUBES

PUMP BOX

NET SLOT

DRAINAGECANAL

PLAN VIEW OF HARVEST GATE

Harvest Gate: inflowHarvest Gate: inflow

Harvest Gate: outflowHarvest Gate: outflow

Harvest Gates: outflowHarvest Gates: outflow

Harvest Gates: multipleHarvest Gates: multiple

Gate ConstructionGate Construction

POND AERATION/OXYGENATIONPOND AERATION/OXYGENATION

• level determined by oxygen demand

• pumping vs. artificial aeration

• used for oxygenation and solids mobilization

• efficiency of devices varies

• paddlewheels: 2.13 kg O2/kwh

• propeller/aspirator: 1.58

• diffusors: 0.97

• level determined by oxygen demand

• pumping vs. artificial aeration

• used for oxygenation and solids mobilization

• efficiency of devices varies

• paddlewheels: 2.13 kg O2/kwh

• propeller/aspirator: 1.58

• diffusors: 0.97

Typical AeratorsTypical Aerators

air injectorair injector

paddlewheelpaddlewheel

Multiple Aeration UnitsMultiple Aeration Units

Estimating Oxygen RequirementEstimating Oxygen RequirementEstimating Oxygen RequirementEstimating Oxygen Requirement

• During paddlewheel aeration and high density culture O2 requirement usually estimated on the basis of feed application to pond

• 1 kg of feed = 0.2 kg O2 consumed via respiration• 300 kg feed = 60 kg O2 consumed/day

• Caveat: Some O2 consumed by shrimp/fish, but more by primary productivity

• During paddlewheel aeration and high density culture O2 requirement usually estimated on the basis of feed application to pond

• 1 kg of feed = 0.2 kg O2 consumed via respiration• 300 kg feed = 60 kg O2 consumed/day

• Caveat: Some O2 consumed by shrimp/fish, but more by primary productivity

Estimating Paddlewheel Requirements

Estimating Paddlewheel Requirements

Biomass density (kg/ha)

Hp (flow-through)

Hp (limited water exchange)

< 1,000 None None

1,000 – 2,000 2-4 4-8

2,000 – 4,000 4-8 8-16

4,000 – 8,000 8-10 16-20

Above 8,000 Above 10 Above 20

Additional Paddlewheel GuidelinesAdditional Paddlewheel Guidelines

• Use high quality switch boxes and adequate guage wire

• Orient paddlewheels to reduce “dead” spots in ponds (locate in corners); don’t change orientation during a run

• More paddlewheels (e.g., 1.0 hp units) = fewer dead spots but more $$$ (units & parts)

• Stainless steel = less corrosion!

• Pay attention to electrical demand and quality of electricity (less motor repair)

• Use high quality switch boxes and adequate guage wire

• Orient paddlewheels to reduce “dead” spots in ponds (locate in corners); don’t change orientation during a run

• More paddlewheels (e.g., 1.0 hp units) = fewer dead spots but more $$$ (units & parts)

• Stainless steel = less corrosion!

• Pay attention to electrical demand and quality of electricity (less motor repair)

ELECTRICAL SUPPLYELECTRICAL SUPPLY

• More tecnology = more demand!

• Semi-intensive ponds need electricity for ice production, living accomodations, perimeter lighting, laboratory, fry acclimation facility

• Usually provided by diesel generators (more dependable and, therefore, cheaper in the long run)

• Intensive and super-intensive operations have large energy demand (aeration is about 90% of demand)

• More tecnology = more demand!

• Semi-intensive ponds need electricity for ice production, living accomodations, perimeter lighting, laboratory, fry acclimation facility

• Usually provided by diesel generators (more dependable and, therefore, cheaper in the long run)

• Intensive and super-intensive operations have large energy demand (aeration is about 90% of demand)

Electrical DistributionElectrical Distribution

• Distribution via high tension line with 20-50 kVA Distribution via high tension line with 20-50 kVA step-down transformers situated throughout the step-down transformers situated throughout the farmfarm

• Demand could be as high as 50 kVA per haDemand could be as high as 50 kVA per ha

• 300 ha intensive farm could have 3,000 one hp 300 ha intensive farm could have 3,000 one hp paddlewheels = 2.5 megawatt demandpaddlewheels = 2.5 megawatt demand

• Electrical distribution system could cost well over Electrical distribution system could cost well over $1 million$1 million

• Distribution via high tension line with 20-50 kVA Distribution via high tension line with 20-50 kVA step-down transformers situated throughout the step-down transformers situated throughout the farmfarm

• Demand could be as high as 50 kVA per haDemand could be as high as 50 kVA per ha

• 300 ha intensive farm could have 3,000 one hp 300 ha intensive farm could have 3,000 one hp paddlewheels = 2.5 megawatt demandpaddlewheels = 2.5 megawatt demand

• Electrical distribution system could cost well over Electrical distribution system could cost well over $1 million$1 million

ARTIFICIAL SUBSTRATES(POND LINERS)

ARTIFICIAL SUBSTRATES(POND LINERS)

• Used in areas where soil quality is poor (percolation/toxicity)

• Also used to reduce effluent solids via erosion of pond bottom and drainage canal

• Cost now $0.25/m2• Long-term viability and uv resistance• Use at least 30 mil thickness• Don’t install yourself!!

(unless very good at it!)

• Used in areas where soil quality is poor (percolation/toxicity)

• Also used to reduce effluent solids via erosion of pond bottom and drainage canal

• Cost now $0.25/m2• Long-term viability and uv resistance• Use at least 30 mil thickness• Don’t install yourself!!

(unless very good at it!)

Soil-Cement LinersSoil-Cement Liners• Made from 1:6-8 mixture

of cement and sand• Pond raked down to 3”• Cement added to achieve

ratio• Watered and smoothed

via 3,000 lb roller compactor

• Rate: 1ha/wk

• Made from 1:6-8 mixture of cement and sand

• Pond raked down to 3”• Cement added to achieve

ratio• Watered and smoothed

via 3,000 lb roller compactor

• Rate: 1ha/wk

Stocking DensitiesStocking Densities

• Species dependent:

-catfish (3500-5000 fish/acre w/aeration)

-tilapia... similar

-prawn-start with 16,000/acre if substraight present

-flounder-not density, but “bottom coverage,” usually tolerate 200% bottom coverage if adequate water flow.

• Species dependent:

-catfish (3500-5000 fish/acre w/aeration)

-tilapia... similar

-prawn-start with 16,000/acre if substraight present

-flounder-not density, but “bottom coverage,” usually tolerate 200% bottom coverage if adequate water flow.