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Bangabandhu Sheikh Mujibur Rahman Agricultural

University

Salna, Gazipur-1706

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Pond is an earthen embankment.

Pond is used for (growing fish, rearing fish, Spawning,

Breeding).

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Average depth 1.2 mWater

Figure: A Pond

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Figure: A complete pond.

There are 6 types of pond. These are-

a. Nursery Pond

b. Rearing Pond

c. Stocking Pond

d. Marketing P0nd

e. Brood Stock Pond

f. Quarantine Pond

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Short Description.

a. Nursery Pond: The smallest and shallowest of

ponds for fish culture is a nursery pond. This is

about 0.02-0.05 ha. The water is about 1 m

deep.

b. Rearing Pond: A rearing pond is larger than a

nursery pond. It is 0.08-0.2 ha. The water is

about 1.5-2.0 m deep. Nursery and rearing

ponds can be seasonal.

Fig.: Nursery Pond

Fig.: Rearing Pond

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c. Stocking Pond:

A stocking pond is much larger, often 0.2-2.0 ha. It should be

2.0-3.5 m deep. This pond might be perennial or seasonal.

d. Marketing Pond:

• A marketing pond, which is small but quite deep.

• These ponds can be 0.05-0.10 ha in size with a water level

of 3-4 m in summer.

• Used to keep fish caught from a stocking pond for

sale.

Fig. Stocking pond.

Fig. Marketing pond

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e. Brood Stock Pond:

Brood stock ponds (0.2-0.4 ha) are perennial and have a water depth

of 2 m in the summer.

f. Quarantine Pond:

i. Small (0.02 ha) but perennial (1.5 m deep) quarantine pond

for a time to verify that they are not infected.

ii. This pond is used to treat diseased fish from other ponds.

Fig. Brood stock pond.

Fig. Quarantine pond. 8

Importance Of Site Selection:

Good site selection is a pre-requisite in pond construction.

Improper site selection may lead to:

I. Difficulties in holding water in the pond.

II. High seepage.

III.Dike erosion.

IV.Low productivity of the pond

V. Inability to drain water completely, and

VI.Difficulties in harvesting. 9

A. Space Availability And Topography:

Space of 200 m2 to construct a pond.

Better to select flat land with a slight gradient.

Sites with slight gradients (0.5 to 3 percent is better)

Avoid areas with large undulations and rocks and with large

trees.

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B. Water Supply And Water Quality:

Water Supply:

The source of water should have adequate amount of water

Streams, large rivers, small rivers, lakes and reservoirs can

be used.

Water Quality:

Temperature (25 to 300 C)

Dissolved oxygen (5-9ppm)

pH (6.5-8.5)

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C. Soil Quality:

Physical quality:

Pond soil should have enough clay to hold water

100% clay may crack pond dike for exposing sunlight

Chemical quality:

Pond soil should not be acidic.

Acidic-soils make the pond water acidic.

Acidic-water retards growth of fish

Acidic water causes stress situation & disease.12

Two kinds of pond may found:

1. Series Pond: Cost effective, Easily maintain.

2. Parallel Pond: Difficult to maintain, Contamination occur.

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Series Pond

Parallel Pond

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Front SideBack Side

• Strong wind generates waves and the waves break on the dikes

• It will to erode the sides of the dikes.

Figure: Selection of Pond Site( By Using Compass)15

Pond bottom should be flat and sloping towards the outlet or

drainage gate with a gentle gradient.

Keep a gentle slope of the pond bottom of about 0.5% to 1.0%

from the water inlet to water outlet.

The canals or ditches should be 0.25 - 0.5 m X 0.25 – 0.5 m.

Fig. Pond Bottom.

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Any pond dike should have three basic qualities.

1. Able to resist the water pressure.

2. It should be impervious, the water seepage through the dike

being kept to a minimum.

3. High enough to keep the pond water from ever running over

its top.

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Figure: Dike

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Figure: Pond Dike

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Figure: An ideal pond

Using good soil that contains enough clay

Building a central clayey core when using pervious soil material;

Applying good construction practices

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Figure; Impermeability of dike.

The freeboard should never be under water.

It varies from 0.25 cm for very small diversion ponds to 1 m for barrage ponds.

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Free Board

Water depth

Figure: Pond Dike Height.

The foundations of the dike should be prepared. This may include:

Treating the surface of the foundations;

Excavating and backfilling the cut-off trench;

Excavating and backfilling an existing stream channel.

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Dikes should be protected against erosion by planting or seeding a grass.

Using temporary protection from rain, such as hay or other suitable

materials.

Should not plant large trees on or near dikes. Root may destroy pond

dike.

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Outlet is making for the complete draining of the pond and harvesting of the fish

whenever necessary.

There are four main types,

a. Simple cuts through the dike

b. Simple pipelines and siphons

c. Sluices gate

d. Monks

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Figure: Sluices gate

Fig: Simple Drain

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Figure: Pond Outlet

A means for getting the water to the outside of the pond.

Water can be drained from the top, bottom or intermediate levels of the pond;

Any reasonable excess of water is carried away;

The outlet can be easily cleaned and serviced;

The construction cost and maintenance are relatively low..

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The most common structure is the open canal, which we will consider in detail

first.

Then we will look at other common structures, including:

Simple aqueducts to transport water above ground level

Short pipelines to transport water above or under another structure

such as a water canal or an access road

Simple siphons to transport water over an obstacle such as a pond dike

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Pond-bottom drains are ditches that are dug on the bottom of the pond to

help the water flow out and to direct the fish toward the pond outlet when

harvesting.

However, it is better to build bottom drains:

When the bottom slope is insufficient;

In large ponds more than 75 m long;

In barrage ponds with an uneven bottom relief.

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Pond is the basic thing for aquaculture.

Successful aquaculture depends on good pond

construction .

We need to construct pond properly for better profit.

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