Generalized and specific definition of pond and the types relating their size, use, construction method were illustrated. Besides the culture system of fish and aquatic organisms and their types were also described.
Generalized and specific definition of pond and the types relating their size, use, construction method were illustrated. Besides the culture system of fish and aquatic organisms and their types were also described.
Carps form the mainstay of aquaculture in India contributing over 85% of the total aquaculture production There are 61,259 species of vertebrates recognized world; over 30,700 are fish species of which 8,411 ore fresh water while 11,650 are marine. In India 2,163 spp. are fin fishes have been recorded from upland cold water (157; 7.26%) warm water of the plain (54; 20.99%), Brackish water (182; 8.41%) and marine environment (1,370; 63.43%). Some of these species are cultured at commercial level which covering a lot varieties of fin fishes The three Indian major carps, namely Catla (Catla catla), Rohu (Labeo rohita) and Mrigal (Cirrhinus mrigal) contribute the bulk of production to the extent of 75 to85 percent of the total fresh water fish production, the three exotic carp such as Silver carp (Hypophthalmichthys molitrix) and Common carp (Cyprinus carpio ), Grass carp (Ctenopharyngodon idella )form the second important group to incorporate several other medium and minor carp and into the carp poly culture system several method were used because of their region specific consumer preference and higher market demand.
History
Carp culture in India was restricted only to a homestead backyard pond activity in west Bengal and Odisha until late 1950 s with seed from riverine sources as the only input resulting low level of production the technological breakthrough breeding of carp through hypophysation in 1957 freshwater aquaculture of the country the country till 1984 virtually laid the foundation of scientific carp farming in the country.
Important characteristics of Indian major carps:-
Indian major carp grow fast and can reproduce even in artificial ponds. They feed upon phytoplankton, zooplankton, decaying organic matter, aquatic plant etc. stomach is absent in the alimentary canal of the major carps. Three types of Indian major carps are cultured in
Fertilized fish eggs are known as Fish seeds. In simple words, they are the baby fishes used for seeding new Ponds in fisheries. Fish seed transportation is a process by which transfer of fish seed from the hatchery or place of collection to the rearing ponds.
The transfer of fish seed from the hatchery or place of collection to the rearing pond is called transport of fish seed. The seed fish include fry and fingerlings.
Feed formulation is the major part of aquaculture.The main objective of feed formulation is to utilize the knowledge of nutrient requirements, locally available feed ingredients and digestive capacity of fish for the development of a nutritionally balanced mixture of feed stuff…
Carps form the mainstay of aquaculture in India contributing over 85% of the total aquaculture production There are 61,259 species of vertebrates recognized world; over 30,700 are fish species of which 8,411 ore fresh water while 11,650 are marine. In India 2,163 spp. are fin fishes have been recorded from upland cold water (157; 7.26%) warm water of the plain (54; 20.99%), Brackish water (182; 8.41%) and marine environment (1,370; 63.43%). Some of these species are cultured at commercial level which covering a lot varieties of fin fishes The three Indian major carps, namely Catla (Catla catla), Rohu (Labeo rohita) and Mrigal (Cirrhinus mrigal) contribute the bulk of production to the extent of 75 to85 percent of the total fresh water fish production, the three exotic carp such as Silver carp (Hypophthalmichthys molitrix) and Common carp (Cyprinus carpio ), Grass carp (Ctenopharyngodon idella )form the second important group to incorporate several other medium and minor carp and into the carp poly culture system several method were used because of their region specific consumer preference and higher market demand.
History
Carp culture in India was restricted only to a homestead backyard pond activity in west Bengal and Odisha until late 1950 s with seed from riverine sources as the only input resulting low level of production the technological breakthrough breeding of carp through hypophysation in 1957 freshwater aquaculture of the country the country till 1984 virtually laid the foundation of scientific carp farming in the country.
Important characteristics of Indian major carps:-
Indian major carp grow fast and can reproduce even in artificial ponds. They feed upon phytoplankton, zooplankton, decaying organic matter, aquatic plant etc. stomach is absent in the alimentary canal of the major carps. Three types of Indian major carps are cultured in
Fertilized fish eggs are known as Fish seeds. In simple words, they are the baby fishes used for seeding new Ponds in fisheries. Fish seed transportation is a process by which transfer of fish seed from the hatchery or place of collection to the rearing ponds.
The transfer of fish seed from the hatchery or place of collection to the rearing pond is called transport of fish seed. The seed fish include fry and fingerlings.
Feed formulation is the major part of aquaculture.The main objective of feed formulation is to utilize the knowledge of nutrient requirements, locally available feed ingredients and digestive capacity of fish for the development of a nutritionally balanced mixture of feed stuff…
Introduction to water treatment, objectives for water treatment, water pollution and its effects on human health, BIS values for drinking water, Types of intake Structures.
Techniques of rain water harvesting in urban and rural areasIEI GSC
Rainwater harvesting (RWH)is the process of arresting and storing rain water for efficient application and conservation. This is an effective way of utilising large quantum of water which otherwise goes as surface runoff. RWH has 2 components: 1)Rain water collection for storage
2)Recharging groundwater The talk cum presentation shall demonstrate several ways & methods to harvest rainwater in urban as well as rural areas
Water treatment is any process that improves the quality of water to make it appropriate for a specific end-use. The end use may be drinking, industrial water supply, irrigation, river flow maintenance, water recreation or many other uses, including being safely returned to the environment. Water treatment removes contaminants and undesirable components, or reduces their concentration so that the water becomes fit for its desired end-use. This treatment is crucial to human health and allows humans to benefit from both drinking and irrigation use.
Information on water deficiency and excessive surplus consumption of Water , History of water supply ,Components of water supply and Institutes working in Nepal in Drinking water field
1.Hydrological Cycle
2.Hydrology
3.Sources of water
4.Watershed development
5.Uses or requirement of water
6.Need for conservation of water
7.Dams
8.Weir & Barrage
9.Rainwater Harvesting
10.Flood control Measures
Impacts of Climate Change in Coastal Aquaculture in Bangladesh : A Seminar Paperihn FreeStyle Corp.
Climate change is a change in the statistical distribution of weather over periods of time that range from decades to millions of years. It can be a change in the average weather or a change in the distribution of weather events around an average. Climate change may be limited to a specific region, or may occur across the whole Earth. Climate change may be qualified as anthropogenic climate change, more generally known as "global warming" or "anthropogenic global warming”. Climate change has both direct and indirect impacts on fish stocks which are exploited commercially. Direct effects act on physiology and behavior and alter growth, reproductive capacity, mortality and distribution. Indirect effects alter the productivity, structure and composition of the marine ecosystems on which fish depend for food. However, even though the year-on-year rate of anthropogenic climate change may seem slow, this is very rapid compared with previous natural change and the accumulative value produces a significant difference from the "natural" state quite quickly. Climate change impacts such as more frequent and severe floods and droughts will affect the food and water security of many people.
Bangladesh is thought to be one of the most vulnerable countries of the world to climate change and sea level rise (CCSLR). IPCC estimates predict that due to the impact of climate change, sea level in Bangladesh may rise by 14 cm by 2025, 32cm by 2050 and 88 cm by 2100. There are a number of environmental issues and problems that are hindering development of Bangladesh. Salinity is a current problem, which is expected to exacerbate by climate change and sea level rise. Salinity intrusion due to reduction of freshwater flow from upstream, salinization of groundwater and fluctuation of soil salinity are major concern of Bangladesh. Cyclones and tidal surge is adding to the problem. Tidal surge brings in saline water inside the polders in the coastal area. Due to drainage congestion, the area remains waterlogged, increasing the salinity (Abedin, 2010).
Bangladesh in general is highly vulnerable to predicted climate changes that are already occurring and are expected to continue over the next century. Bangladesh is recognized worldwide as one of the most vulnerable to the impact of global warming and climate change.
Impacts of Climate Change in Coastal Aquaculture in Bangladeshihn FreeStyle Corp.
Climate change is a change in the statistical distribution of weather over periods of time that range from decades to millions of years. It can be a change in the average weather or a change in the distribution of weather events around an average. Climate change may be limited to a specific region, or may occur across the whole Earth. Climate change may be qualified as anthropogenic climate change, more generally known as "global warming" or "anthropogenic global warming”. Climate change has both direct and indirect impacts on fish stocks which are exploited commercially. Direct effects act on physiology and behavior and alter growth, reproductive capacity, mortality and distribution. Indirect effects alter the productivity, structure and composition of the marine ecosystems on which fish depend for food. However, even though the year-on-year rate of anthropogenic climate change may seem slow, this is very rapid compared with previous natural change and the accumulative value produces a significant difference from the "natural" state quite quickly. Climate change impacts such as more frequent and severe floods and droughts will affect the food and water security of many people.
Bangladesh is thought to be one of the most vulnerable countries of the world to climate change and sea level rise (CCSLR). IPCC estimates predict that due to the impact of climate change, sea level in Bangladesh may rise by 14 cm by 2025, 32cm by 2050 and 88 cm by 2100. There are a number of environmental issues and problems that are hindering development of Bangladesh. Salinity is a current problem, which is expected to exacerbate by climate change and sea level rise. Salinity intrusion due to reduction of freshwater flow from upstream, salinization of groundwater and fluctuation of soil salinity are major concern of Bangladesh. Cyclones and tidal surge is adding to the problem. Tidal surge brings in saline water inside the polders in the coastal area. Due to drainage congestion, the area remains waterlogged, increasing the salinity (Abedin, 2010).
Bangladesh in general is highly vulnerable to predicted climate changes that are already occurring and are expected to continue over the next century. Bangladesh is recognized worldwide as one of the most vulnerable to the impact of global warming and climate change.
The term “sustainability” or also “sustainable development”, often used as nothing more than a catch-phrase, has much more to offer. It is a concept to guarantee a livable environment for all people in the long term, encompassing at least three fundamental components of sustainable development, preservation of a functional environment, economic welfare and social equity. Accordingly, also in the field of aquaculture, aiming for sustainability requires not only the achievement of environmental objectives, but also to provide clear economic advantages for aquaculture farmers in the long term. However, the term “sustainability” is often diluted and weakened , being used by politicians, entrepreneurs and the public, in a general way on numerous occasions, very often in a superficial or misleading way and with an incorrect definition, just to exploit the positive , connotations of the term.
Marine Resources: Physical and biological resources, marine energyihn FreeStyle Corp.
Marine resources are physical and biological entities that are found in seas and oceans that are beneficial to man. They include fish, coral reefs and crabs, fungi, etc. A lot of conservation effort is required to protect these resources from human destruction activities like pollution and over fishing. Marine natural resources include both biological and physical sources. Biological sources include anything attributed to life forms whereas physical sources are considered to be those things that are not part of life processes. In a few instances some resources are both biological and physical. In considering the outlook of our oceans it is important to first identify the main natural resources and their status.
Rotifers are popularly called as wheel animalcules. They are an important group of live food organisms for use in aqua hatcheries. Brachionus, which is the most known form of all rotifers, serve as an ideal starter diet for early larval stages of many fish and prawn species in marine as well as freshwater. Species of the genus Brachionus (Brachionidae: Rotifera) are well represented in different water bodies worldwide (Pejler, 1977). Depending on the mouth size of the cultured organisms, small (50 to 110 micron length) or large (100 to 200 micron length) rotifers are used. There are about 2,500 species of rotifers have been known from global freshwater, brackish water, and seawater. B. plicatilis is the species used most commonly to feed fish larvae in hatcheries around the world. It is a euryhaline species, small and slow swimming, with good nutritional value. It is well suited to mass culture because it is prolific and tolerates a wide variety of environmental conditions. The rotifer, B. plicatilis and B. rotundiformis, have been indispensable as a live food for mass larval rearing of many aquatic organisms (Maruyama et al., 1997). By way of significant developments in larval rearing technology of fishes, demand for the rotifer is further increasing.
A rice-fish system is an integrated rice field or rice field/pond complex, where fish are grown concurrently or alternately with rice. Fish may be deliberately stocked (fish culture), or may enter fields naturally from surrounding water ways when flooding occurs (rice field fisheries), or a bit of both. Fish yields can range widely from of 1.5 to 174 kg/ha/season depending on the type of rice fish system, the species present, and the management employed.
In a country like Bangladesh where land is scarce, effort should be taken to increase production through integration of various production system like animal-cum-fish or rice-cum-fish culture for efficient utilization of available meagre resources and maximization of production of diversified products, from a minimum area, which will increase the income of the farmers and would enhance food production. A multi-commodity farming system presents more advantages to a mono-cropping system. But the commodity-integration must fit into the particular farmer's capability, resources and need as well as the social, economic and environmental factors around him.
Goat cum Fish Farming - Present Status and Prospect in Bangladeshihn FreeStyle Corp.
In a country like Bangladesh where land is scarce, effort should be taken to increase production through integration of various production system like animal-cum-fish or rice-cum-fish culture for efficient utilization of available meagre resources and maximization of production of diversified products, from a minimum area, which will increase the income of the farmers and would enhance food production. A multi-commodity farming system presents more advantages to a mono-cropping system. But the commodity-integration must fit into the particular farmer's capability, resources and need as well as the social, economic and environmental factors around him.
Growth Performance of Catla (Catla catla) Fed Diets Containing Different Leve...ihn FreeStyle Corp.
Carp culture has attained commercial culture status.
Feed has become the most important component.
Fish meal induce good growth but it is expensive.
Due to the scarcity of fish meal ; alternative protein sources is gaining importance.
Spirulina platensis (blue green algae) ; A Cyanobacterium.
Spirulina as the replacement of fish meal.
How to write a project proposal ? (*For bd students only)ihn FreeStyle Corp.
Stinging catfish (Heteropneustes fossilis) is one of the commercially farmed fish in Bangladesh and it has gained rapid popularity because of its fast growth and high yields. The species is important for its nutritional and medicinal value. However, the absence of a readily available starter feed in commercial hatcheries remains a major problem in its production. Fish larvae rely on the yolk sac for its nutritional requirements during early stages of growth. Then larvae require live foods such as Artemia nauplii, yeast, unicellular algae, rotifers, copepods, cladocerans as the most appropriate starter foods because the larvae have difficulty in assimilating dry prepared diets due to their incomplete development of the digestive system (Arimoro, 2006; Olurin et al. 2012). These live foods offer an appropriate size ingestible by a wide range of larval fish species and are rich carriers of digestive enzymes (Kolkvoski, 2001). Live foods also affect the fatty acid profile of larvae (Kainz, 2004; Das, 2006; Tocher, 2010). However, information on appropriate live foods for the larviculture of stinging catfish are scarcely available.
What is the stocking density of fish in semi intensive cultureihn FreeStyle Corp.
Stocking Density: Stocking density also known as per-unit stocking amount or stocking rate, refers to the quantity of fry or fingerlings per unit of water area.
Poly Culture: The concept of poly culture of fish is based on the concept of total utilization of different trophic and spatial niches of a pond in order to obtain maximum fish production per unit area. Different compatible species of fish of different trophic and spatial niches are raised together in the same pond to utilize all sorts of natural food available in the pond.
Semi Intensive Culture: Semi-intensive culture systems depend largely on natural food which is increased over baseline levels by fertilization and/or use of supplementary feed to complement natural food.
The increased production of marine fish has come primarily through the motorization of traditional craft, the introduction of new craft and the introduction and popularization of new’ types of synthetic gear, which have replaced the traditional gear. In almost every country, this process has been either instituted or actively supported by the governments in the form of generous subsidies and credit schemes. Blue Economy could play an important role in the economic upliftment of the country in the context of poverty alleviation, ensuring food and nutrition security, combating climate change impacts. Blue Economy requires a balanced approach between conservation, development and utilization of marine and coastal eco-systems, all oceanic resources and services with a view to enhancing their value and generates decent employment, secure productive marine economy and healthy marine eco-systems.
Fisheries and aquatic resources are economically, ecologically, culturally and aesthetically important to the nation. From the global perspectives, the main issues facing by the international fishing community generally are over fishing, overcapacity, by-catch management as well as environmental degradation. The combined effect of these factors that have made 60-70% of the major world fisheries resources are in urgent need of management action to restrict the increase in fishing capacity and to rehabilitate damaged resources (FAO,1991). In Bangladesh, fisheries is one of the major subsectors of agriculture, which play a dominant role in nutrition, employment, earning foreign currency and other areas of economy. Many of our open waterbody are polluted with various pollutants and harmful chemicals. Water Resources Planning Organization (WARPO) has prepared the National Water Management Plan (NWMP) for Bangladesh in December 2001. The goal of the NWMP is to implement the National Water Policy (NWPo) and contribute to national economic development through rational management of open water resources, in a way that protects the natural environment and improves the quality of life for the people of Bangladesh. Open water fisheries are major aquatic common property resources in Bangladesh covering over four million hectares. Around ten percent of the population of 120 million depend for their livelihoods on fisheries.
Hygiene standards and procedures usually described as Good Hygienic Practices (GHP) or Good Manufacturing Practices (GMP), have been in place for many years and constituted an essential tool in traditional food control. These concepts are still essential in a modern food control system by providing the basic environmental and operating conditions for production of safe food and thus being a requisite or foundation for HACCP in an overall food safety management program. What is new is the concept of formalizing the prerequisite program alongside HACCP and the legal requirement in some countries (USA) of documented monitoring of certain sanitation areas.
Non-Infectious Disease
Not caused by pathogens
Cannot be transmitted to other species
Malnutrition, Avitaminoses, Heavy Metals etc. are responsible
Risk factors:
Genetics
Life-style
Environmental factors
Genetic Risk Factors
Determined by genes
Familial Disease Tendency
Disease runs in species
Recessive gene disorders
Down syndrome
Born with extra chromosome
Sex-linked disorders
Linked to x chromosome (female)
Can be recessive in females
Color blindness, hemophilia, & muscular dystrophy
A popular food fish in South Asia. Five types of ilish can be found worldwide.
Yearly ilish caught are 5,000,000 tons. Among them, 50%-60% are caught by Bangladesh.
About 450,000 people are directly involved with the catching for livelihood; around four to five million people are indirectly involved with the trade.
Ideally, surimi should be made from low-value, white-fleshed fish with excellent gelling ability and which are abundant and available year-round. At present, Alaskan pollack accounts for a large proportion of the surimi supply. Other species, such as sardine, mackerel, barracuda, striped mullet have been successfully used for surimi production.
Any aquatic invertebrate animals having a cutaneous or calcareous shell surrounding there body and belonging to the phylum Mollusca, the class Crustacea (phylum Arthropoda), or phylum Echinodermata is known as shellfish. The term is often used for the edible species of the groups, especially those that are fished or raised commercially. The most commercially important shellfish are:
• Mollusk: Oysters, mussels, scallops and clams
• Crustacean: Shrimp, prawn, lobster, crab and crayfish
• Echinoderm: sea urchins and sea cucumbers
Shellfish hatchery is a place where shellfish seeds are produced in a controlled way. Hatchery management is a branch of science which deals with the activities including from collection of brood shellfish to seed production. Culturing of shellfish has occurred since ancient times. Although controlled rearing of young shell has long existed, hatchery production is a more recent advancement. Producing seed under controlled conditions in a hatchery will disconnect its production from environmental factors and provide a reliable supply of seed. Oysters, mussels and mud crabs are the most important groups of shellfish after shrimp and prawn. These are popular among the western countries and becoming more popular all over the world. So hatchery management of oyster, mussel and crab is crucial.
The homeotherms are otherwise known as warm blooded animals. Their body temperature remains constant irrespective of change in environmental temperature e.g. birds and mammals. The poikilotherms are otherwise known as cold blooded animals. Their body temperature fluctuates according to change of the temperature in the surroundings e.g. fishes, amphibians, reptiles and invertebrates.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
5. 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
5
6. 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
6
7. 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
7
8. 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
9. 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
10. 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.
10
11. 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)
11
12. 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
13. Two kinds of pond may found:
1. Series Pond: Cost effective, Easily maintain.
2. Parallel Pond: Difficult to maintain, Contamination occur.
13
15. • 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
16. 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.
16
17. 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.
17
Figure: Dike
20. Using good soil that contains enough clay
Building a central clayey core when using pervious soil material;
Applying good construction practices
20
Figure; Impermeability of dike.
21. The freeboard should never be under water.
It varies from 0.25 cm for very small diversion ponds to 1 m for barrage ponds.
21
Free Board
Water depth
Figure: Pond Dike Height.
22. 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.
22
23. 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.
23
24. 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
24
Figure: Sluices gate
Fig: Simple Drain
26. 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..
26
27. 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
27
28. 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.
28
29. Pond is the basic thing for aquaculture.
Successful aquaculture depends on good pond
construction .
We need to construct pond properly for better profit.
29