Quarter 1 Module 3. Fishpond
An accurate preparation prior to the construction of a fishpond is the key to a successful aquaculture business venture. The preparation of the needed resources helps in mobilizing aquaculture activities thus saving time, effort and money. Aquaculture preparation involves identifying the needed resources, preparing of program of works and making a layout plan for a fishpond.
Content Standard
1. The learner demonstrates understanding of the underlying
Performance Standard
1. The learner independently and accurately draws the layout plan of a
concepts in drawing the layout plan of a fishpond. 2. The learner demonstrates
fishpond. 2. The learner independently evaluates a suitable site for a fishpond.
understanding of the underlying concepts in evaluating a suitable site for fishpond.
Lesson 1. Draw the Layout Plan of a Fishpond
Introduction The fishpond is a common fixture in the Philippine rural setting and perhaps second only to the rice fields in terms of providing livelihood and income for farmers (PCAMRD, 1998).
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Quarter 1 Fishponds or earthen ponds are found in almost all parts of the country and are used in the breeding, nursery and grow out of various food fishes. These earthen structures serve as an important factor in the increased production of the country’s most important cultured freshwater fish, the tilapia (PCAMRD, 1998). This module will provide you with basic skills in drawing the layout plan of a fishpond. This will also help you familiarize with the different pond compartments and accessory units of a fishpond system and guide you to evaluate a site for fishpond construction. Specific Objectives At the end of the lesson, you are expected to: 1. draw the layout plan of a fishpond system using a particular scale. 2. specify facilities, equipment, tools and materials in the proposals based on survey results. 3. determine the number of water pumps to be installed and the location of the ground water. 4. plan and layout other pond facilities.
Pre-Assessment
Directions: Match Column A with Column B. Write the letter of your choice in your test notebook. COLUMN A 1. Nursery Pond 2. Transition Pond 3. Rearing Pond
COLUMN B a.
It is for confining breeders.
b. It is used for confining and catching fry, fingerlings, and fish of marketable size. c. It supplies water to the different compartments 41
Quarter 1
4. Breeding Pond
5. Catching Pond
6. Head Pond
7. Feed Pond
8. Water Supply Canal
9. Main Gate 10. Secondary Gate 11. Tertiary Gate
12. Perimeter Dike
13. Secondary Dike
14. Tertiary Dike
15. Hatching Pond
d. It is intended for producing food such as “lablab” (plankton) and “lumot”. e. It is a pond compartment intended for the rearing of fish fry to fingerlings. f. It is a structure that controls the water in the entire pond system. g. It surrounds the entire pond system to ensure protection and safety of the stocks. h. It
divides
the
pond
system
into
several
compartments. i.
It controls the incoming and outgoing water in the different pond units.
j.
It is for storing reserve water.
k. It is intended for raising fingerlings up to a marketable size. l.
It is intended for depositing eggs until they are hatched.
m. It controls the incoming and outgoing water in the smaller compartments of the pond system. n. It
is
intended
for
the
acclimatization
of
fingerlings. o. It
subdivides
compartments
42
the
pond
into
smaller
Quarter 1
SCALING A scale is the ratio of the distance on the map or drawing and distance on the ground. It is widely used by engineers, architects, professors and all other fields. Formula: Scale: Map or Drawing Distance (m) Ground Distance (m) Example of a scale is 1:10m, 1:100m, 1:1000m, etc. Problem Solving To determine the ratio of drawing with the following ground measurements of 125m long and 80m wide is to do the ratio and proportion formula, thus; 1m (map) = 1000m (ground)
X map 125m (ground)
1000m X = (1m) (125) X = 125 m2 1000m X = 0.125m or 12.5cm Or do the division and multiplication process, thus
a. 1 1000
x
125 m
0.001
x
125 m = 0.125 m or 12.5 cm
b. 1
x 125 m = 1000
125 m = 0.125 m or 12.5 cm 1000
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Quarter 1 The Fishpond Layout A fishpond is an artificial body of water consisting of dikes, gates, pipes and canals to facilitate water supply management. In view of the high cost of fishpond development, improved types and the specifications of pond designs must be considered. These depend on the nature and quality of water supply and the species of fish to be cultivated. Below is a sample layout of a conventional fishpond system with the following specifications:
Area = 10,000 m2 Nursery Pond (NP) = 1% of the total production area Transition Pond (TP) = 9% of the production area Figure 1. Conventional Fishpond System
Rearing Pond (RP) = 80% of the production area Catching Pond (CP) = At least 2% of the NP NP = 10,000 x 1%
TP = 10, 000 x 9%
RP = 10 000 x 80%
= 10,000 x 0.01
= 10, 000 x 0.09
= 10 000 x 0.80
= 100 x 0.02
= 100 m2
= 900 m2
= 8 000 m2
= 2 m2
44
CP = 100 x 2%
Quarter 1 The Compartment Units of a Fishpond System
Figure 2. Transition Pond
Figure 3. Rearing Pond
Figure 4. Catching Pond
Figure 5. Water Supply Canal
Photos Taken at Malolos Marine Fisheries School and Laboratory, Barangay Balite, City of Malolos, Bulacan Photos Credited to Eliseo T. Caseres
The Function of the Fishpond Compartments/Units 1. Nursery pond (NP). This is where the fish fry are reared to fingerlings. The most suitable place for this is a site where it can be easily supplied with fresh water and can be readily drained even during low tide. The size of the NP depends primarily on the targeted yearly production of fingerlings.
45
Quarter 1
2. Transition pond (TP). This is used for the storage or acclimatization of fingerlings located adjacent to the nursery pond for effective and easy transfer of fry. Its pond bottom is constructed 0.20 m lower than that of the nursery pond. 3. Rearing pond (RP). It is used for raising fingerlings up to marketable size. It is the largest compartment in the pond system. 4. Breeding pond. It is used for confining the breeders. 5. Hatching pond. It is used for depositing eggs until these are hatched. 6. Catching pond (CP). It is used for confining and catching fry, fingerlings and fish of marketable size. It is constructed adjacent to the secondary gate inside the pond. 7. Head pond. It is used for storing reserve water. 8. Feed pond. It is used for producing food such as “lab-lab” and “lumot”. In fishpond areas where natural foods do not grow well and supplementary feeding is necessary, one of the RPs or NPs could be utilized as a feed pond. It should be a separate compartment ideally located near the pond where supplementary feeding is intended.
Common Accessory Units of a Fishpond and their Functions 1. Main gate. A wooden or concrete structure that controls water in the pond system 2. Secondary gate. Controls the incoming and outgoing water in the different pond units 3. Tertiary gates or pipes. Controls the incoming and outgoing water in the smaller compartments of the pond system. 4. Main/perimeter dike.
Surrounds the entire pond system to ensure
protection and safety of the stocks. It is composed of the biggest and
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Quarter 1 highest blocks of earth and is usually provided with strong basal foundation and puddle trench. 5. Secondary dike. Subdivides the pond system into several compartments with or without basal foundation and puddle trench. 6. Tertiary dike. Subdivides the pond system into smaller compartments and serves as partition in the nursery pond.
Figure 6. Main gate
Figure 7. Secondary gate
Figure 8. Tertiary gate
Figure 9. Main/Perimeter Dike
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Quarter 1
Figure 10. Secondary Dike
Figure 11. Tertiary Dike
Photos taken at Malolos Marine Fisheries School and Laboratory, Barangay Balite, City of Malolos, Bulacan Photos credited to Eliseo T. Caseres
Other Pond Support Structures a. Water supply canals (SC). These canals serve the purpose of supplying and draining water to and from the pond. The main water supply canal starts from the main gate and usually transverse the central portion of the fish farms. The floor slopes towards the gate floor. A 10-15 ha pond is provided with SC having a width of at least 3 m. b. Drainage Canals (DC). These are support structures usually constructed in the outer sides of the pond parallel or perpendicular to the SC. These are recommended in the intensive culture, especially of shrimps, to effect flow-through system and better water management. c. Pumps. These are machines used in pumping water into and out of the ponds. These are very necessary during the dry season when the water level is low and the salinity of brackish water ponds become too high. There must be at least 2 water pumps for every hectare of fishpond available for use, one as back up pump to the one commonly used.
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Quarter 1 Types of Improved Fishpond Layouts
1. Conventional. It consists of one main gate and long water supply canal. This
supplies
the
different compartments.
Figure 12. Conventional type fishpond
2. Radiating. It has one main gate, wide and short supply canal, and secondary gates in the different compartments. Figure 13. Radiating type fishpond 3. Progressive. It consists of one main gate, long supply canal and a secondary gate provided to different compartments of progressively increasing areas.
Figure 14. Progressive type fishpond
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Quarter 1 4. Specialized. It has one main gate and one or two
drainage
There
is
gates.
also
a
compartment with two secondary gates and a large
supply
and
Figure 15. Specialized type fishpond
catching canal/pond.
Advantages of the Improved Types of Layout 1. Easy control of pond water. 2. Easy eradication of fish pest and predator. 3. Easy means of cropping. 4. Cultivation of the pond bottom can be done when desired. 5. Artificial feeding can be conducted easily when resorted to after the natural food of fish has been consumed. 6. High productivity.
Marginal Information of the Map The following should appear in a map for a fishpond. 1. Sheet Name or Title. It is the name of the map. This should be placed on top of the map. 2. Sheet Number. It should be placed on the upper right – hand corner of the map. 3. Scale. It should be placed at the center, below the map. 4. Legend. It should be placed on the lower right – hand corner of the map. 5. Edition Note. It should be placed on the lower left – hand corner of the map. 50
Quarter 1
Layout Specifications for Brackish Water Fishpond Systems
1. Conventional Pond System. The NP comprises
about
production
area
1%
of
(TPA).
the
total
The
TP
comprises about 9% of the TPA. The RP comprises about 80% of the TPA. The CP intended for a NP and TP must be at least 2% of the compartment’s watered area and 1 to 1½ if it is intended for the Figure 16.Conventional pond system RP.
2. Modular Pond System. The NP comprises about 4% of the TPA. The TP covers only 6% of the TPA. The RP is
divided
into
three
Production Process Stages (PPS). The main idea is to transfer the fingerlings to the next larger module. The ratio of the area of the three
Figure 17. Modular Pond System
stages of PPS is 1:2:4 for upper PPS and 1:3:9 for lower PPS.
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Quarter 1 3. Multiple Stock/Harvest System. There will be at least two NP’s comprising 6% of the total production area. A fish holding canal (FHC), which holds fingerlings when the rearing ponds are being prepared, covers at least 1% of each RP’s area. It is connected to the RP in such a way that each RP will have a separate FHC. The RP covers
Figure 18. Multiple Stock /Harvest
up to 94% of the TPA including FHC.
System
The general practice is to stock at different times different sizes and group of fingerlings and harvest the bigger ones selectively with the use of the gill net.
Dikes and Gates 1. Dikes Types of Dikes a. Primary, main or perimeter dike - It is the widest among the types of dikes with the most gradual slope. - It is the dike that should be provided with the freeboard of 0.3 – 1.0 meter after shrinkage and settlement. - The dike is usually provided with puddle trench measuring 30 cm in width and 50 cm in height dug up along the central path of such a dike. Freeboard – is the additional height of the structure, e.g. main dike, above high water level to prevent over flow.
52
Quarter 1
Figure 19. Perimeter/Main Dike
b. Partition Dikes b.1 Secondary Dike. This is smaller than the main dike with gradual slope and which encloses the nursery pond, transition pond, and rearing pond. b.2 Tertiary dike. It is the smallest and lowest in height which encloses the catching pond and fry acclimation pond. 4. Gates a. Primary/Main Gate - It is the largest and tallest gate in the entire pond system.
Figure 20. Parts of a Concrete Main Gate 53
Quarter 1
b. Secondary Gate. It is a gate situated on the partition dikes.It is made of either concrete hollow blocks, reinforced concrete mix, or wood. c. Tertiary gate. It is a gate installed in the catching ponds. It is the smallest gate with opening width of 0.5 – 0.8 m.
Figure 21. Parts of a Wooden Secondary Gate
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Quarter 1
I. Directions: Prepare a portfolio or compilation of plates of the different layouts fishpond, main gate and main dike . Drawing
Title
No.
Date
1
Conventional Type of Fishpond
2
Radiating Type of Fishpond
3
Progressive Type of Fishpond
4
Specialized Type of Fishpond
5
Conventional Fishpond Layout
6
Modular Pond System
7
Multiple Stock/Harvest System
8
Layout of a Main Dike
9
Layout of a Main Gate
Rating
Note: Your drawing doesn’t necessarily be scaled.
Directions: In two or three sentences, answer the given questions below. Write your answers in your test notebook. 1. Why is it important to properly design and layout the fishpond? 2. Why is it important to use a scale in drawing the layout of a fishpond? 3. If you were to choose among the designs of fishpond, what type or design would you choose? Why?
55
Quarter 1
Directions: Make a miniature fishpond using the materials listed below. Write the specifications or designs of your layout. I. Materials: Moulding Clay
Plywood (1m x 1m)
Scissors
Cutter
Glue
Marker
Card board
Tooth pick/bamboo sticks
Used net
Ruler
Pencil
pallet
II. Specific Instructions: 1. First, layout a one hectare fishpond using your pencil and a ruler on a 1 m x 1 m plywood . Decide on the design that you are going to use, shape, scale, number of compartments, and others. 2. Next, mold a clay using the cutter and pallette into the shape of a perimeter dike, secondary dike and a tetiary dike. Then place them on the layout following their specific markings. 3. Then, make the accessory units of your fishpond such as the main gate, secondary gate and tertiary gate using the other materials. 4. Finally,
write
necessary
the
legends
below your layout using your marker.
Figure 22. Constructing a Fishpond Scale Model
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Quarter 1 Post Assessment Directions: Match Column A with Column B. Write the letter of your choice in your test notebook. COLUMN A 1. Nursery Pond 2. Transition Pond 3. Rearing Pond 4. Breeding Pond
5. Catching Pond
6. Head Pond
7. Feed Pond
8. Water Supply Canal
9. Main Gate 10. Secondary Gate 11. Tertiary Gate
12. Perimeter Dike
13. Secondary Dike
14. Tertiary Dike 15. Hatching Pond
COLUMN B a. It is for confining breeders. b. It is used for confining and catching fry, fingerlings, and fish of marketable size. c. It supplies water to the different compartments d. It is intended for producing fish food such as “lab-lab” (plankton) and “lumot”. e. It is a pond compartment intended for the rearing of fish fry to fingerlings. f. A structure that controls the water in the entire pond system. g. It surrounds the entire pond system to ensure protection and safety of the stocks. h. It
divides
the
pond
system
into
several
compartments. i.
It controls the incoming and outgoing water in the different pond units.
j.
It is for storing reserve water.
k. It is intended for raising fingerlings up to marketable size. l.
It is intended for depositing eggs until they are hatched.
m. It controls the incoming and outgoing water in the smaller compartments of the pond system. n. It
is
intended
for
the
acclimatization
of
fingerlings. o. It subdivides compartments. 57
the
pond
into
smaller
Quarter 1 Glossary
Accessory - an object or device not essential in itself but adding to the beauty, convenience, or effectiveness of something else Acclimatization – is the process of adjusting the fish to its new environment Basal - relating to, situated at, or forming the base Brackish water – that type of water which is somewhat salty and range from 15 – 35 ppt in salinity; a mixture of fresh and salt water Breeders – are mature fish species capable of producing their own young Compartment – an enclosed space or area that is usually part of something larger and is often used to hold a specific thing Conventional – usual or traditional Fingerling – a stage in the life cycle of the fish measuring 6 – 13 cm depending on the species Fry - a stage at which a fish has just been hatched usually with sizes from 1 – 2.5 cm Hectare – a metric unit of land area equivalent to 10, 000 m2 Layout – the design or arrangement of something; the way something is laid out. Specification - a detailed description of work to be done or materials to be used in a project: an instruction that says exactly how to do or make something Stock – refers to animal such as fish or shrimp that is being cultured
58
Quarter 1
Resources
Coursepack: Republic of the Philippines, Department of Education. Public Technical Vocational High School. Competency- based learning material. Third Year: Aquaculture NC II.
Toledo, C. 2009. AQUA203: Aquaculture Engineering. Lecture Manual. Pangasinan State University, Binmaley Campus.
Website: Philippine Council for Aquatic and Marine Research and Development. Pond Construction and Maintenance for Tilapia Breeding. PCAMRD Currents, 3 (2):8p, August 1998. Retrieved from: http//dti.gov.phuploadsDownloadableFilesPond%20Tilapia.pdf Retrieval Date: February 24, 2014 Retrieval Time: 8:49 PM
Meriam- Webster Online Dictionary. http://www.merriam-webster.com/
Others: Department of Education. Bureau of Secondary Education. Technical Vocational Unit. Competency-Based Curriculum Aquaculture NC II. 2012. 34p.
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Quarter 1 Lesson 2: Evaluate the Suitable Site for Fishpond
Introduction Aside from good management practices, an ideal site for fishpond construction ensures success in the aquaculture business. Just like humans, fishes need a desirable place for them to grow well. A good source of clean, safe and sufficient water is necessary since fishes are primarily dependent on it. The water parameters should also be within the optimum tolerable range of the fish. Other factors like type of soil, topography, accessibility, vegetation, and socio-economic consideration are also crucial matters in the success of an aquaculture venture.
Specific Objectives
At the end of the lesson, you are expected to: 1. assess the suitability of the site for fishpond construction. 2. analyze the type of soil in the area. 3. determine the adequacy of water in the area using the flow rate meter. 4. analyze the water parameters in the area.
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Quarter 1 Pre-Assessment
MULTIPLE CHOICE: Directions. Choose the correct answer from the options given. Write the letter only in your test notebook. 1. What is the foremost factor to consider in selecting the suitable site for fishpond construction? a. Topography b. Accessibility c. Type of Soil d. Water supply 2. What is the ideal type of soil for fishpond construction? a. Silty b. Sandy c. Clayey d. Loamy 3. What is the most ideal source of water for a freshwater fishpond? a. River b. Spring c. Irrigation d. Rain/run-off 4. It is an instrument used to measure the temperature of the water. a. pH Meter b. Soil tester c. Thermometer d. Refractometer
61
Quarter 1
5. What is the ideal pH range for the growth and survival of a fish? a. 4.0 – 5.0 b. 5.1 – 6.4 c. 6.5 – 9.0 d. 11.0 - 14.0 6. The plants that cover the site for fishpond construction are known as ______. a. Trees b. Vines c. Shrubs d. Vegetation 7. What type of soil has a granular appearance? a. Mud b. Clay c. Loam d. Sand 8. Which of the following types of container is not ideal for storing water samples? a. Polyethylene bags b. Hard rubber container c. Empty or used bottles d. Chemical-resistant glass 9. Which of the following is a socio-economic criterion for selecting a suitable site for fishpond? a. Wind protection b. Soil characteristics c. Protection from flood d. Availability of cheap labor
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Quarter 1 10. Bio-assay is a simple and practical way to know if the water is safe for the fish. Which of the following is an example of it? a. Nasal testing b. Observing the clearness of the water c. Tasting the water for any toxic chemicals d. Getting a pail of water from the water source. Put some fish and observe if it can survive for 12-24 hours.
Factors to Consider in Selecting Fishpond Site 1. Water Supply. Water supply is the foremost factor to consider in selecting a fishpond site. The site must have adequate water supply throughout the year and be free from pesticide contamination and pollution. Sources of water can be a surface runoff, stream, creek or irrigation for freshwater fish culture, and brackish water and sea water for salt water fish production.
Limnological Analysis of Pond Site a. Flow Rate. The expected time is determined when the fishpond is filled with the required amount of water. Flow rate meters are used to measure linear, non-linear mass or volumetric flow of liquids or gases.
Figure 23. Flow Rate Meter
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Quarter 1
b. Water Quality Analysis. The collection of a water sample is considered important. This is best taken by obtaining a sample of the water column from top to bottom at the middle of rivers, streams, lakes, and irrigation canals. Types of Water Containers for Water Sample The following are suitable containers for keeping water samples prior to water quality analysis in the laboratory.
Chemically resistant-glass
Polyethylene bags
Hard rubber container
Figure 24. Chemical Resistant Glass
Figure 25. Polyehtylene bottle
Figure 26. Brown/Amber bottles
How to Handle and Store Samples Keeping the water samples in storage at 40C is the best way to preserve them to obtain reliable results. 64
Quarter 1 Types of Samples a. Grab or catch sample. A single sample taken neither at set time nor flow. b. Composite sample. A combination of individual samples of water taken at selected interval. c. Integrated sample. A mixture of grab samples collected from different points simultaneously. A simple bio assay can be done using the following techniques:
Place two or three samples of fish Place a hapa or a scoop net with 3-5 samples of fish that you will that you will culture in a pail full of culture at least 25-50 m from the water from the source to be tested water source. for at least one-half day.
The water is safe to use when the fish samples remain alive after half a day. Ocular inspection or nasal testing to determine the presence of toxic substances is generally ineffective. The maintenance of good water ensures a healthy fish population because good water quality
affects the growth and
reproduction of fish. If the water quality is beyond tolerable limits, fish health is adversely affected.
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Quarter 1 b. Water Temperature. All fishes have tolerable limits to water temeperature. When water temperature goes beyond or below the temperature tolerance limit of the fish, the effects are as follows:
abnormal metabolism resulting in poor growth, abnormal activities or stress
poor response to feeds
very poor feed conversion ratio
An ordinary thermometer or an equivalent device can be used to measure water temperature.
Figure 29. A thermometer
c. Hydrogen Ion Concentration (pH). pH is the acidity or alkalinity of water. If the pH is between 0 and 6 the water is acidic, and if the pH is 7.0, it is neutral. Alkaline water has a pH of 8-14. The ideal pH range for freshwater fish culture is 6.5 - 8.9.
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Quarter 1 The effect of various pH on fish is shown in the table below: pH Range
Effect
0 – 4.0
Fish die because of acidity
4.1 – 5.0
No reproduction
5.1 – 6.4
Slow growth
6.5 – 9.0
Fish thrives well and grows fast
9.1 - 14
Fish dies due to alkalinity
Measure the pH with the use of a litmus paper, pH comparator, portable pH meter or a Hack kit. Acidic water is sour ; alkaline water is bitter. Acidic water is common in swamps and bogs in stagnant areas. The application of agricultural lime corrects pH in a pond.
Figure 30. pH meter
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Quarter 1 d. Ammonia. This is a substance highly toxic to fish. The symptoms of ammonia toxicity in fish are the following:
spongy appearance of gill filaments
presence of bloody gills
excessive production of slime
distended operculum
poor growth of fish
One of the most common causes of high ammonia level in a pond is the heavy application of manure. The composition of organic matter and the over growth of plankton increase the ammonia level in the pond water. 2. Soil Type The soil is a very important factor in the fishpond. It is the material used for diking and it also serves as the base. It absorbs and releases nutrients needed by the plants and phytoplanktons that serve as natural food of fish and shrimps. Furthermore, the quality of pond water is directly affected by the quality of the soil in the fishpond. Types of Soil The textural properties of soil determine the sustability of the soil for fishpond purposes. Clay, clay-loam, silt-clay-loam, loam, and sandy-clay-loam are the types of soil most preferred for fishpond construction. The mineral particles of the soil are clay, silt, and sand while the organic particles are the plant and animal matters at various stages of decomposition. Soils have assigned textural classes depending on the varying proportions of sand, silt, and clay. Each textural class exhibits varying colors which are based on their chemical composition, amount of organic matters present, and the degree of decomposition. 68
Quarter 1 The US Department of Agriculture Classification System has classified soil as follows: General Terms Common
Texture
Basic Soil Textural
Names 1. Sandy Soil
Class Name Coarse
Sandy Sandy loam
2. Loamy Soil
Moderately Coarse
Sandy loam Fine Sandy loam
Medium to Moderately Fine
Very Fine Sandy Loam Loam Silt Loam Silt
3. Clayey Soil
Fine
Sandy Clay Silt Clay Clay Clay Loam Sandy Clay Loam Silt Clay Loam
Clay or sandy clay may be best for dike construction but not as good as clay loam in terms of growing natural food. Sandy clay loam is the best type for diking purposes. A high percentage of clay is desired because it has the largest surface exposed to chemical and physical reactions. Chemical and physical reactions stimulate the growth of plankton and helpful bacteria. A sandy loam soil is more porous than silty loam thus, it has a lesser capacity to hold nutrients.
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Quarter 1 Relationship of Soil Classes and Sustainability for Dike Material Class Clay Sandy
Relative Permeability Impervious
Characteristic Compaction Sustainability Compressibility Characteristic Dike Material Medium Fair to Good Excellent
Impervious
Clay
Low
Good
SemiLoamy
impervious
High
to Impervious SemiSilty
impervious
Medium to high
to Impervious
Fair to very poor
Good to very poor
Good
Fair
Poor
Sandy
Pervious
Negligible
Good
Poor
Peaty
-
-
-
Very poor
Field Determination of Soil Textural Class The determination of the soil class is made in the field mainly by feeling the soil with the fingers. While this requires skill and experience, accuracy can be achieved by frequently checking it against established laboratory results. The following are the definitions of the basic soil textural classes using the manual testing in the field; Sand. A type of loose and single-grained. The individual grains can readily be seen or felt. Squeezed when dry, it will form a cast which readily falls apart, but if squeezed when moist, a cast can be formed that will need careful handling so it will not break apart.
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Quarter 1 Loam. A loam is a soil having a relatively even mixture of different grades of sand and of silt and clay. It is mellow with a somewhat gritty feel, yet fairly smooth and slightly plastic. Squeezed when dry, it will form a cast that will bear careful handling, while the cast formed by squeezing the moist soil can be handled quite freely without breaking. Silt loam. A silt loam is a soil having a moderate amount of the fine grains of sand and only a small amount of clay, over half of the particles being of the size called “silt”. When dry it may appear cloddy but the lumps can be readily ran together and puddled. Either dry or moist, it will form cast that can be freely handled without breaking, but when moistened and squeezed between the fingers, it will not form a “ribbon” but will give a broken appearance. Clay loam. A clay loam is a fine-textured soil which usually breaks into clods of lumps that are hard when dry. When the moist soil is pinched between thumb and fingers, it will form a thin “ribbon” which will break readily, barely sustaining its own weight. The moist soil is plastic and will form a cast that will bear much handling. When kneaded in the hand it does not crumble readily but tends to work into a heavy compact mass. Clay. It is a fine-textured soil that usually forms very hard lumps or clods when dry and is quite plastic and usually sticky when wet. When the moist soil is pinched out between the thumb and fingers, it will form a long, flexible “ribbon”. Some fine clays that are very high in colloids are friable and lack plasticity in all conditions of moisture. Such definitions are suggestive only. An accurate method of determining textural classes of the soil is by mechanical analysis. In this analysis, the relative amounts of sand, silt, and clay fractions are determined and by plotting the results in the triangular chart, the textural classification of the soil can be known. A very rapid method of mechanical analysis is one
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Quarter 1 devised by Bouyoucos using a graduated cylinder, hydrometer and thermometer. 3. Topography Choose a flat terrain for easier excavation and levelling. If the topography is too undulating, the construction cost increases greatly and further excavation work also removes the fertile portion of the pond bottom. Avoid sites that are frequently flooded. The right topography also provides easy in water management and control of fish predators and competitors. b. Wind direction. Wind plays a role in fishpond design. Strong wind generates wave action that weakens the sides of the dike. To minimize this, position the longer pond dimensions parallel to the direction of the prevailing wind to lessen the side of the dike exposed to wave action. 4. Protection from flood If the fishpond site is prone to flooding, construct a diversion canal along the perimeter dike to divert runoff water during heavy downpour; construct a larger and higher perimeter dike to prevent the entrance of flood water. 5. Vegetation. All kinds and types of plants may cover the proposed fishpond site. This will be the basis for construction estimate and development cost. If possible, avoid thickly-vegetated areas. 6. Accessibility or nearness to market Fish is a perishable commodity, hence the farther the site from the market, the greater the possibility that the fish will become stale, which will result in a lower price. 7. Socio-Economic Consideration Cheap labor and construction materials must be accessible in the locality. As much as possible, the site should also be accessible to 72
Quarter 1 sufficient sources of fry or fingerlings for ready stocking. The program of operation will be hampered if fish seeds are not available when needed. Moreover, peace and order situation in the locality should be considered when putting up a fishpond project. The availability of sources of capital like financial institutions must also be considered.
Directions: Below are pictures with descriptions of the possible site for a fishpond. With the knowledge you gained from this lesson, assess the suitability of the site and give some recommendations for the construction of fishpond.
Figure 32. Meycauayan – Obando River
Figure 31. A 0.5 hectare vacant lot
10 meters away from the proposed site
Figure 33. Municipal road 5 meters away from the proposed site
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Quarter 1 A. Location of the Site: Barangay Ubihan, City of Meycauayan, Bulacan B. Area of the Site: 0.5 Hectare C. Other Descriptions of the Site:
5 meters away from the municipal road
Prone to flooding during high tides
Possible source of water is from a river
Type of soil is sandy clay
80% of the people are fishermen and fishpond caretakers
D. Assessment and Recommendations: Water Supply ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ Soil Type ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ Vegetation ______________________________________________________________ ______________________________________________________________ ______________________________________________________________
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Quarter 1 Accessibility _____________________________________________________________ _____________________________________________________________ ______________________________________________________________ Flood Hazard _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Socio-economic Consideration ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ E. General Assessment: Is the site suited for fishpond construction? Why? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________
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Directions: In your test notebook, answer the questions below. 1. What are the factors that you have to consider in selecting a suitable site for fishpond? 2. What is the best alternative you should consider if you encounter sites with low volume water supply or small/narrow tidal difference? 3. Knowing the flood history of the site, what modifications will you do so that the fishpond that you will construct will be safe from flood waters?
Directions: Conduct a field visit in your locality. Take pictures of the possible site and assess its suitability in terms of fishpond construction. Fill up the Assessment Sheet below based from your observation. Location of the Site: Area of the Site: Possible Source of Water: Other Factors:
Assessment (Put a check (/) mark under the appropriate column) Very Ideal
Ideal
a. Type of Soil b. Topography c. Vegetation 76
Not Ideal
Quarter 1 d. Accessibility e. Flood Hazard f. Socio-economic
Evaluation Criteria: *Very Ideal – indicates that the site is perfect for the particular indicator *Ideal – indicates that the site is not so ideal for the particular indicator but can be resolved through some modifications *Not Ideal – indicates that the site is not good for the particular indicator General Assessment/Recommendation: ______________________________________________________________ ______________________________________________________________ Post-Assessment MULTIPLE CHOICE: Directions. Choose the correct answer from the given options. Write only the letter in your test notebook. 1. What is the most important factor to consider in selecting the suitable site for fishpond construction? a. Topography b. Accessibility c. Type of Soil d. Water supply 2. What is the ideal type of soil for fishpond construction? a. Silty b. Sandy 77
Quarter 1 c. Clayey d. Loamy 3. What is the most ideal source of water for a freshwater fishpond? a. River b. Spring c. Irrigation d. Rain/run-off 4. It is an instrument used to measure the temperature of the water. a. pH Meter b. Soil tester c. Thermometer d. Refractometer 5. What is the ideal pH range for the growth and survival of a fish? a. 4.0 – 5.0 b. 5.1 – 6.4 c. 6.5 – 9.0 d. 11.0 - 14.0 6. The plants that cover the site for fishpond construction are known as ___. a. Trees b. Vines c. Shrubs d. Vegetation 7. What type of soil has a granular appearance? a. Mud b. Clay c. Loam d. Sand
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Quarter 1 8. Which of the following types of container is best recommended for storing water samples? a. Polyethylene bags b. Hard rubber container c. Empty or used bottles d. Chemical-resistant glass 9. Which of the following is a socio-economic factor to be considered in selecting a suitable site for fishpond? a. Wind protection b. Soil characteristics c. Protection from flood d. Availability of cheap labor 10. Bio-assay is a simple and practical way to know if the water is safe for the fish. Which of the following is an example of it? a. Nasal testing b. Observing the clearness of the water c. Tasting the water for any toxic chemicals d. Getting a pail of water from the water source and observing if fish can survive for 12-24 hours.
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Quarter 1 Glossary
Bio-assay. The determination of the relative strength of a substance (as a drug) by comparing its effect on a test organism with that of a standard preparation Bog. A wet spongy ground; especially a poorly drained usually acid area rich in accumulated plant material, frequently surrounding a body of open water and having a characteristic flora. Excavation. The act of digging Impervious. Not allowing entrance or passage; impenetrable Limnology. The scientific study of bodies of freshwater (as lakes and rivers) Linear.
Relating to, resembling, or having a graph that is a line and
especially a straight line Swamp. Land that is always wet and often partly covered with water Topography. The physical or natural features of a place Undulating. Having a wavy surface, edge, or marking
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Resources
Coursepack: Republic of the Philippines, Department of Education. Public Technical Vocational High School. Competency- based learning material. Third Year:Aquaculture NC II.
Toledo, C. 2009. AQUA203: Aquaculture engineering. Lecture manual. Pangasinan State University, Binmaley Campus.
Lecture Notes: BFAR Region III and Philippine Federation of Aquaculturist, Inc. 1983. Seminar on prawn and tilapia culture.
Fontanilla, R. and Pediangco, C. Soil conditioning. DA-Aquaculture Development Project, Ilo-ilo City
Website: Meriam- Webster Online Dictionary. http://www.merriam-webster.com/
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