BGD/89/012
By
Dr. Md. Arshad Hossain
National Consultant on Pen Culture
FISHERIES RESEARCH INSTITUTE, MYMENSINGH
GOVERNMENT OF PEOPLES REPUBLIC OF BANGLADESH
UNITED NATIONS DEVELOPMENT PROGRAMME
FAO - FOOD AND AGRICULTURAL ORGANIZATION OF THE UNITED NATIONS
This electronic document has been scanned using optical character recognition (OCR) software and careful manual recorrection. Even if the quality of digitalisation is high, the FAO declines all responsibility for any discrepancies that may exist between the present document and its original printed version.
2. DESIGN, CONSTRUCTION AND INITIATION OF PEN CULTURE EXPERIMENT IN OX-BOW LAKE
3. SURVEY
AND IDENTIFICATION OF POTENTIAL PEN SITES
3.1 Present status of pen culture in Bangladesh
3.2 Possible sites for pen culture in Bangladesh
3.2.1 Criteria for selection of site
3.2.1.1 Water depth
3.2.1.2 Soil type
3.2.1.3 Pollution
3.2.1.4 Aquatic vegetation3.2.2.1 Irrigation canals
3.2.2.2 Oxbow lakes (Baors)
3.2.2.3 Dead rivers
4. ASSISTANCE TO THE
PEN CULTURE PROJECT
4.1 Training programme
4.2 Preparation of a extension pamphlet
4.3 Strengthening of limnology laboratory at FRI
Appendix - I: Design of net pen walls
Appendix - II: Women's training programme on fish culture in pen
Appendix - III: Preparation of extension pamphlet
Appendix - IV: Pilot scale pen culture demonstration project in DND canal
Appendix - V: Abbreviations used
The consultant expresses his sincere gradititute to Dr. M. A. Mazid, Director, Fisheries Research Institute for his kind cooperation.
The consultant expresses his deep respect to Dr. V.R.P. Sinha, Senior Specialist of the FAO/UNDP project "Assistance to Fisheries Research Institute" for his supervision and guidance.
Sincere thanks are due to Dr. G.C. Halder CSO, Riverine Station for his cooperation and help during consultant's work.
During the consultancy work, many persons from different government and non-government organisations such as DOF, BFDC, BWDB and BRAC provided valuable technical information and supporting materials. The consultant is very much grateful to them.
Finally, thanks are due to all scientists of Riverine Station for their help and cooperation.
|
November, 1994 |
Dr. Md. Arshad Hossain |
This report deals with the consultancy assignment of Dr. Md. Arshad Hossain, National Consultant on Pen Culture during 15 June -14 September, 1994 at the Fisheries Research Institute (FRI) under its FAO/UNDP project "Assistance to Fisheries Research Institute" (BGD/89/012). The main objective of the project is the strengthening of the Fisheries Research Institute by establishing a strong organisational frame work, formulating a national research programme relevant to the development of fisheries sector and creating a high degree of technical and management capability in research management, planning, coordination, preparation and implementation of research.
- Design, construct and initiate pen culture experiment in ox-bow lakes;- Assist the counter-part scientists in setting, constructing the pen with locally available material and also in the management of pen culture of carps, catfishes and prawns;
- Prepare the draft material for extension pamphlet;
- Assist in such other activities which would be required from time to time for the successful implementation of the project on "Assistance to the Fisheries Research Institute";
- Prepare a terminal report of the work done.
An attempt was made to survey the possible pen sites including the ox-bow lakes. FRI has already initiated the pen culture experiment in the Chandpur Irrigation Project (CIP) canal where the available manpower were fully involved. Therefore, the consultant udertook to survey the possible pen sites and the scientists were appraised about the specific modifications needed for ox-bow lakes. Pen culture in canal and ox-bow lakes are basically the same.
The ox-bow lakes are the remaining parts of dead rivers, generally horse-shoe shaped. They were created by the delta-building activities of the Ganges and tectonic forces, thousands of years ago. In Bangladesh, ox-bow lakes are mainly found in the south-west part of the country. Generally they are connected with the river system through a small channel in the dry season and have larger connections with other waterbodies during monsoon. Many of the ox-bow lakes form the natural drainage system of the area. The rain water from the surrounding area is collected in the lake through a number of inlet canals as well as by underground seepage.
The chemical characteristics of the water in general is favourable for fish production. The transparency of the water is high (1.5-2.5m) due to heavy infestation of aquatic weed (floating and submerged) which reduces the algal growth. Floating weed (mainly water hyacinth) occupy 20% to 80% of the water. The ox-bow lakes were at one time quite deep, and they formerly covered* large areas. Over the years, due to siltation and heavy organic fill and decaying organic vegetation the ox-bow lakes have become shallower and narrower. The water depth of these lakes varies from less than 1 m to up to 15 meters, depending on the amount of siltation that has ocurred. The water level fluctuates from 1.0 to 2.0 m between rainy and dry season.
Juveniles of various fish species especially carps, catfish, murrels and featherbacks enter these lakes and thus predatory fishes like Wallago attu, Notopterus chitala, and Channa marulius are very common in these waters. In addition to their natural stock, pond reared fry/fingerlings of Indian major carp such as catla (Catla catla), rohu (Labeo rohita), and mrigal (Cirrhina mrigala) are stocked in certain lakes annually in October/November by the Fisheries Department to develop lake fisheries there.
On the basis of the record of the catches available from Joydia, Baluhar, Bergovindapur and Fatepur baor it appears that catla ranges from 1.3 to 2.7 kg whereas rohu and mrigal from 0.42 to 2. 7 and 0.46 to 0.66 kg respectively. It was not certain whether these fishes were one year in the lake or two years or more. But, it was quite reasonable to consider on the basis of the studies made by Department of Fisheries that catla, rohu and mrigal could attain 1 kg, 0.75 kg and 0.5 kg respectively in such productive lakes. Corresponding to these carps, silver carp and common carp could easily attain 1.5, 0.5 kg respectively in one year rearing in lakes. The grass carp could be still faster especially because of Hydrilla. (Sinha, personal communication). Mrigal showed better percentage of retrieval when compared to catla and rohu.
The oxygen level, pH of water and other physico-chemical parameters were quite suitable for carp culture. However, higher productivity gave rise to serious infestation of water hyacinth and submerged weed like Hydrill. Ranges of certain chemical parameters of soil collected from three different ox-bow lakes such as Baluhar baor, Joydia and Fatepur baor were: pH 7.6-8.0; available nitrogen 46.74-59.90 mg/100g; available phosphorus 1.6 -2.0 mg/100g; organic carbon 2.66-3.48% and total nitrogen 0.39-0.55%.
Table 1. Certain chemical parameters of the soil collected from different ox-bow lakes (Sinha, Personal Communication)
|
Ox-bow lake |
pH |
Available N2(mg/100g) |
Available P2O5(mg/100g) |
Organic carbon (%) |
Total N2(%) |
|
Joydia baor |
8.0 |
50.18 |
2.0 |
3.48 |
0.55 |
|
Baluhar baor |
8.0 |
59.90 |
2.1 |
3.96 |
0.49 |
|
Bergovindapur |
7.9 |
58.24 |
1.6 |
2.85 |
0.39 |
|
Morjad baor |
7.6 |
46.74 |
2.0 |
2.66 |
0.41 |
Design:
Simple designs of net pen wall and bamboo fence, including the schematic diagramme of various types of pen suitable for different ox-bow lakes were indicated to the counterpart scientists as shown in appendix-I.
Bamboo screen fencing is suitable in narrow and shallow waters of ox-bow lakes. The height of a pen wall depends on the maximum water level during the culture period. About 0.5 m of the pen wall should be above the maximum water level to prevent jumping out of fish. A portion of the pen wall should go into the bottom mud to keep the pen wall secured in position. Normally, the pen wall should be about 30 cm inside the bottom mud. Bamboo screen fencing is made with bamboo splits (10-15 mm width) interwoven with coconut coir (3 mm) or HDPE (high density polyethylene). Pen wall can be constructed in several pieces each piece having a frame work consisting of a few rows of horizontal struts, and two vertical struts along the two sides. Vertical bamboo bracers at intervals of 4 m or more should be provided depending on the bottom condition, water current, wind velocity etc.
For net pen wall the mesh size of netting should not be more than 10 mm. HDPE knotless webbing is best for net pen wall. If material of appropriate height is not available, sticking of two or more width of material will be required. HDPE rope of 4-5 mm and 3-4 mm thickness should be tied to the bottom and head line of the net respectively. Loops at interval of 3-4 m in the foot rope is needed for tying with bamboo groove which is driven into the mud. This arrangement is to ensure tucking of about 30 cm of the net into the mud. Steps for installation of the net pen is more or less similar to bamboo screen fencing.
The management of pen culture in ox-bow lakes may be similar to that practiced in irrigation canals. However, since the ecology of ox-bow lakes are quite different from the canals, the scientists were given proper emphasis to follow the modifications while undertaking pen culture in ox-bow lakes:
1) Eradication or removal of aquatic weeds such as water hyacinth and Hydrilla should be done properly before installing the pen otherwise the clogging of pen wall might be a serious problem.2) Another important aspect which needs consideration is the presence of predatory fish which could not be totally eradicated by any known technology or netting. Therefore large sized fingerlings need to be stocked.
3) Due to the presence of higher organic matter, species combination may be changed and more bottom dwelling species like common or mirror carp and mrigal should be introduced.
4) The introduction of Chinese carp such as grass carp and silver carp is essential since Indian major carp like rohu, catla, and mrigal do not consume aquatic weeds nor these fish consume phytoplankton like silver carp, whereas common carp is essential to rake up the bottom mud to make available the nutrients present in the bottom.
5) Presence of submerged weed might sometimes cause serious oxygen depletion. The weed need to be controlled by introducing grass carp (Ctenopharyngodon idella).
6) Since the ox-bow lakes are high in organic matter, excessive supplemental feeding with less oxygen content may create serious problem.
7) Because of soft bottom, the net wall should be sufficiently driven into the mud to ensure tucking of at least 30 cm of the net wall into the mud.
3.1 Present status of pen culture in Bangladesh
3.2 Possible sites for pen culture in Bangladesh
The consultant undertook to survey the possible pen culture sites in Bangladesh along with the FRI scientists. Field visits were made to different places to collect field data and to asses physical observation of the sites.
Although the concept of pen and cage culture for commercial production of fish was included in the national development programme in 1977, the actual implementation of the project started very late. During 1981, under ADB assisted Aquaculture Development Project, experimental pen culture activities were undertaken by Department of Fisheries (DOF) in few places in Bangladesh viz. Bahadurpur baor in Jessore, Nabagonga river and Saganna baor in Jenidah and Dhanmondi and Gulshan lakes in Dhaka city.
High density polyethelene (HDPE) or nylon netting and bamboo patta (split bamboo woven together) as fencing material for the pen were used in all the experimental/demonstrationpen culture installations. Carp polyculture of 5 species viz. silver carp (Hypophthalmicthys molitrix), catla (Catla catla), rohu (Labeo rohita), mrigal (Cirrhinus mrigala) and grass carp (Ctenopharyngodon idella) at the rate of 30,000/ha and 38,600/ha were stocked in Bahadurpur baor and Dhanmondi lake respectively. Mustard oilcake and rice bran were used as supplemental feed. A total of 1890 Kg fish was produced after 8 months from 0.5 ha pen in Bahadurpur baor and 1195 kg from 0.25 ha pen in Dhanmondi lake after 6 months of culture period.
The reported economic analysis showed a net loss of Tk. 3,729/- for the operation in Bahadurpur baor and a profit of Tk. 3,564/- for Dhanmondi lake (Karim, 1988). Several causes such as water pollution due to jute retting, heavy clogging of pen walls, low pen height, inadequate settlement of the bottom line etc. were attributed for the loss of fish, either because of mortality or escaping from pens in Bahadurpur baor.
Pen culture of fish in dead rivers has also been tried by Bangladesh Rural Advancement Comittee (BRAC), a leading NGO in the country. BRAC in 1994 under its Rural Development Programme undertook a fish culture programme in the Kobadak river in Jhikorgacha thana in Jessore district. BRAC organised fishermen group and provided financial assistance for fish culture in the river. Three sections of the river covering areas 31, 40 and 32 acres were leased to three fishermen groups. The sections were partitioned by using split bamboo woven together. Large sized fingerlings of 100-150 g size were stocked in January and harvested during April-May 1994. Out of three culture groups only one group earned profit and two other lost. However, the cost analysis did not consider depreciation for pen materials. The loss was reportedly attributed to the escape of fish and because of some poaching.
In recent years, Fisheries Research Institute, Riverine Station, Chandpur has undertaken an experimental research project on pen culture of fish in the Chandpur Irrigation Project (CIP) canal to develop a socially acceptable and economically viable pen culture technology. During 1st phase the experiment was carried out for a period of six months from April to October, 1991. Six pens each of 0.5 ha size were constructed in a row with knotless HDPE netting material of 10.5 m.m mesh in the inner side and with split bamboo fence (50 m.m mesh) in the outer side. The fences were supported by bamboo frame and posts. The water depth in pens ranged between 1.5-3.0 m during the culture period.
Tria polyculture of carps (Major and Chinese) were conducted in six pens and fishes were stocked at the rate of 35, 70 and 105 g/m2 respectively in three treatment groups with two replicates. The species combination was rohu 30%, mrigal 35%, catla 5%, kalibaush (Labeo kalbasu) 5%, silver carp 15% and common carp 10%. The fish were fed with a non pelleted supplemental feed at the rate of 1% of the body weight daily. The feed included fish meal, mustard oilcake, rice bran, wheat bran, wheat flour and molasses in the ratio of 15:40:20:20:3:2. Gross total production obtained were 1.28, 1.14 and 1.48 mt/ha/crop respectively with 34, 17 and 17% retrieval rates. The production included the wild fish as well. The retrieval rate was very poor which was reportedly due to sudden flooding and poaching.
In the 2nd trial, the stocking density and species combination were changed. Fishes were stocked at the rate of 10,000, 15000 and 20,000/ha (each treatment having two replicates). The species composition was rohu 30%, mrigal 20%, catla 10%, silver carp 10% and common carp 30%. The fish were fed non-pelleted supplemental feed at the rate of 1% body weight daily. After 6 months of rearing average size reached by catla, common carp and silver carp was 1.01, 0.90 and 0.55 kg. respectively, while rohu and mrigal attained an average size of 0.31 and 0.35 kg. respectively. In spite of low retrieval rate which ranged between 27 to 36% in different pens, production rate of 1.27, 1.69 and 2.69 mt/ha/crop were obtained.
During the current year (1994) FRI is carrying out pen culture experiments with polyculture of carp and catfish at two stocking densities of 25,000/ha and 30,000/ha. The species included are rohu, mrigal, silver carp, common carp and pangas (Pangasius sutchi). The stocking rate for pangas is only 2%.
Attempts have also been made to include grass carp and tilapia as stocking species in separate pens. One pen was stocked (20,000/ha) with grass carp, rohu, mrigal and silver carp and another pen was stocked with only tilapia at the rate of 10,000/ha.
The results of the pen culture experiments done by FRI at CIP canal are very encouraging. Encouraged by the success of FRI some local fish farmers became interested and they have already started fish culture using pens in the CIP canal. DOF has also allocated 50 ha of the CIP canal to the interested fish farmers group for fish culture using pen culture technology. There are excellent opportunities in Bangladesh to engage thousands of unemployed rural people on long-term basis in aquaculture in existing large number of potential waterbodies which were hitherto completely neglected. Various types of waterbodies, seasonal or perennial could be made productive by applying pen culture techniques.
3.2.1 Criteria for selection of site
3.2.2 Suitable waterbodies
3.2.1.1 Water depth
3.2.1.2 Soil type
3.2.1.3 Pollution
3.2.1.4 Aquatic vegetation
Selection of a waterbody for pen culture must be judged against requirement of species to be cultured and period and duration of the culture which vary from one geographical region to another. Waterways constitute the most important mode of transportation in rural Bangladesh. Therefore, care should be taken in selecting areas to avoid or to reduce conflict with navigation in the waterways. Similarly, the pen sites should be protected from frequent cyclonic storm, strong current and wave action. The site or the penned area should be out of danger from the normal yearly flooding during monsoon.
The depth of water should be at least 60 cm otherwise during summer water temperature may go up beyond the tolerance limit of fish. In a running water system excessive temperature rise is a less likely problem. However, if a penned area includes shallow and substantial area of deep water, fish may take shelter in deeper water during day time and graze in the shallow water during night time. Water depth of 1.5 to 2.5 m is ideal for fish growth. Greater depth not only impedes fish growth but also involves higher investment cost for pen wall.
Soil type is important both for the installation of pen wall and productivity of the pen site as well. Soil rich in organic matter may be a good source of nutrient and benthic fauna which are essential for the growth of bottom feeding fishes. Soft muddy bottom is preferable to hard sandy bottom. Fixing the bottom line of the pen or driving the poles into sandy or very hard bottom would be a problem. At the same time, the bottom should not be too slushy which will make the pen wall or poles vulnerable to water current and wind action. The foot line of the pen wall must be tucked into the mud or it should at least be in close contact with bottom so that the cultured fish do not escape or fish from outside do not enter into the pen.
The wide spread use of pesticides and their presence in water, are of particular concern for fish production. Sources of solid wastes which may remain suspended in water and damage or clog pen walls installed 'in river system are sugar mills, tanneries, jute mills, paper and pulp mills, shrimp and frog leg processing plants. Other sources of pollution may be from sewage, domestic wastes, decomposed aquatic vegetation and large-scale jute retting.
Although aquatic vegetation provides food and shelter to fish, dense vegetation may severely interfere with fish movement and may cause oxygen deficiency. In such waterbody pen installation and fish harvesting becomes very difficult. Drifting patches of water hyacinth may clog the pens.
Other factors like water quality, availability of natural food e.g. plankton and benthic organisms should be given special consideration. Presence of animals like crabs, snails etc. may either damage the pen wall or may harm the stocked fish.
3.2.2.1 Irrigation canals
3.2.2.2 Oxbow lakes (Baors)
3.2.2.3 Dead rivers
Although various types of waterbodies have the potential for pen culture, intensive year round investigations are needed to evaluate their suitability. However, in the present assignment, efforts were made to collect maximum information so far available. The following types of waterbodies are found suitable for pen fish culture in Bangladesh.
Pen culture is feasible in canals with a high eutrophic status. The canals may be blocked off at intervals by barriers to form a series of pens. This system may best be utilized for polyculture, as this has been shown to be the best technique to make full use of the natural resources in an extensive or semi-intensive system.
Of the various FCDI projects in Bangladesh, Dhaka-Narayangonj-Demra (DND) and Chandpur Irrigation Project (CIP) canals were found most suitable for pen culture.
3.2.2.1.1 DND Canal:
DND canal was constructed under the DND Irrigation Project in 1960s. It was constructed by digging earth along the length of canal and the earth materials were spread over the both sides making roads on either sides. As a result the canal became deeper which holds water throughout the year. Since the total irrigation area has now been turned into an urban area, the canal is of little value for irrigation. The canal has turned into a lake and it is therefore, occasionally called DND lake. It is about 14 Km long starting from Jatrabari via Demra up to Narayangonj. The canal is about 150 feet wide and 8-12 feet deep. There are some aquatic vegetations viz. duck weed (Lemna minor), water cabbage (Pistia stratiotes) and Najas sp. Since 1991 the canal is being managed by BFDC. The present production is very low (<1 mt/ha) which is reportedly attributed to poaching and low level of management. However, no food and fertilizers are applied although annual stocking of Indian major carp is followed. Because of problem in 16 management and low production, BFDC has recently requested Fisheries Research Institute to initiate a Demonstration Pen Culture Project in DND canal for better management and increased fish production. A pilot scale adaptive research project proposal has been prepared by the consultant for FRI (Appendix-I).
2.2.2.1.2 CIP canal:
The Chandpur Irrigation Project (CIP) has 67 mile long embankment which encloses the project area. The borrow pit canal was excavated inside the flood control embankment which is used as main irrigation canal. The project area comprised of different types of waterbodies which are shown in Table 1. The borrow pit canal in CIP passes through six thanas of Chandpur and Lakhsmipur districts.
Table 2. Areas of different types of waterbody inside the CIP
|
Types of waterbody |
Total area (ha) |
|
Borrow pit canal |
220.90 |
|
Dakatia river |
555.10 |
|
Dead portion of Dakatia |
202.43 |
|
Link canals |
809.72 |
|
Ditches. |
202.43 |
|
Ponds (2500 Nos) |
809.72 |
|
Total |
2800.30 |
The physico-chemical parameters of water and soil samples of a pen culture site at CIP reportedly are as follows:
Table 3. Values of physico-chemical parameters of water and soil of a pen site during the period of April to October, 1991.1
|
Parameters |
Water |
Parameters |
Soil |
|
Temperature (0°C) |
28 - 29 |
Type |
Sandy |
|
Dissolved O2 (mg/l) |
4.5 - 4.6 |
Colour |
Blackish |
|
Carbondioxide (mg/l) |
8.0 - 12.8 |
pH |
6.0-6.5 |
|
Hardness (mg/l) |
100 - 120 |
Available phosphate |
1.0-2.5 |
|
Alkalinity (mg/l) |
49 - 60 |
(mg/100g) |
|
|
Ammonia (mg/l) |
0.08 - 0.12 |
Available potassium |
3.0-8.0 |
|
pH |
7.0 - 7.5 |
(mg/100g) |
|
|
|
|
Exchangeable calcium % |
0.15-0.25 |
|
|
|
Ammonia Nitrogen |
10-25 |
|
|
|
(mg/100g) |
|
1 Progress Report (1990-91) Fisheries Research Institute, Riverine Station.
According to the water level record the water is routinely drawn down in the project area in November. The borrow pits become shallow for fish culture at that time. Pen culture should therefore, be cycled from December-January. Stocking may be accomplished during December-January and fish could be harvested during October-November when the water level is low. Most of the predators can be removed by repeated netting during the low water period. Net pen fences can easily be fixed in places during this low water period. Restocking in December will allow the nurseries to grow seed up to 6 inch size which can escape predators and grow to marketable size within a culture period of 8-10 months.
An extensive visual observation of the borrow pit canal at CIP was made on aquatic vegetation, water depth, obstruction and general suitability for pen culture. The following water areas of borrow pit canal and dead rivers in the CIP area were identified as suitable for pen culture (Table 3).
Table 4. Water areas of borrow pit canal and dead rivers in CIP area suitable for pen culture.
|
SL. |
Name of the borrow-pit. |
Length |
Area |
Depth |
|
No |
(Km) |
(ha) |
(m) |
|
|
1. |
Ramdasdi-Krishnapur khal |
11.26 |
28.17 |
2 - 3 |
|
2. |
Ramdasdi-Bahuria khal |
4.80 |
19.32 |
1.5 - 3 |
|
3. |
Katakhali khal |
1.00 |
2.53 |
2 - 3 |
|
4. |
Kalikhola-Haimcher khal |
4.30 |
10.83 |
2 - 3 |
|
5. |
Haidergonj-Hazimara khal |
8.00 |
20.12 |
2 - 3 |
|
6. |
Hazimara-Dalal-Bazar khal |
13.00 |
32.27 |
2 - 3 |
|
7. |
Chowdhury Bazar-Brammapara khal |
5.00 |
25.55 |
1.5- 3 |
|
8. |
Krishnapur-Dumuria khal |
11.00 |
27.64 |
1.5 - 3 |
|
9. |
Hazimara dead river |
4.80 |
12.07 |
1.5- 3 |
|
10. |
Dead portion of Dakatia river |
- |
202.43 |
2- 3 |
* Depth recorded during monsoon
However, some parts of the canal and dead portion of Dakatia river need to be cleared off the aquatic weeds viz. water hyacinth, Hydrilla etc. before any pen culture is introduced. Again some parts of the canal however, may need minor reexcavation for making the canal bottom uniform and also to raise the height of canal bank along the field to prevent escape of fish during heavy h rainfall.
3.2.2.1.3 Other Irrigation canals:
There are many flood control drainage and irrigation projects in Bangladesh. Redding and Midlen (1991) reported about 5,245 km of primary and 20,980 km of secondary irrigation canals in Bangladesh. Much of the irrigated area is supplied from main irrigation canal with small low lift pumps, and water is distributed through quaternary channels. During monsoon many irrigation channels are utilized for flood control drainage channel and hence get high flows. Within the FCDI projects many original canals remain dead due to the embankment constructed surrounding the project area. Some of the canals are used as irrigation canals and some others are lying idle and hold sufficient water throughout the year. These canals can be used for pen fish culture. DOF has undertaken an Integrated Fisheries Development Project (IFDP) in Flood Control, Drainage and Irrigation Project area and other waterbodies. The project included 18 FCDI projects in which the land and water areas available from Bangladesh Water Development Board (BWDB) and from other agencies will be developed for aquaculture using 50,000 MT wheat allocated for this purpose under food for works programme. Visit were made to some of these FCDI projects namely, Meghna-Dhanagoda, Muhuri, Naryangonj-Narshindi, and Rupgonj irrigation projects to find out the suitability of the irrigation canals for pen fish culture.
Out of 4 FCDI projects visited the following irrigation canals in Meghna-Dhonogoda and Muhuri projects were found suitable for pen culture with some development works need to be done such as raising of embankment to prevent fish escape during heavy rainfall. Some of the khals need to be cleared off aquatic weed like water hyacinth. The irrigation canals suitable for pen culture in Meghna-Dhonogoda and Muhuri Irrigation Projects are shown in Table 4 and 5 respectively.
Table 5. Water areas in different canals inside the Meghna-Dhanagoda FCDI project suitable for pen culture.
|
Name of canals |
Area (ha) |
Depth of water (feet) |
|
1. Gazipur |
24.78 |
5 - 6 |
|
2. Uddhamdi-Islampur |
60.88 |
8 - 10 |
|
3. Eklashpur |
12.33 |
6 - 8 |
|
4. Sikirchar |
22.27 |
8 - 10 |
|
5. Kalipur |
14.29 |
8 - 10 |
|
6. Beltali-Sadullapur |
30.50 |
6 - 8 |
|
7. Lakhsmipur |
20.69 |
6 - 8 |
* Depth during monsoon
Table 6. Irrigation canals inside Muhuri Irrigation Project suitable for pen fish culture.
|
Name of khal |
Area (ha) |
Depth (feet) |
|
Gatia khal |
10.35 |
5 - 6 |
|
Chhagalnaiya khal |
6.90 |
4 - 6 |
|
Khaatakhali khal |
14.95 |
5 - 7 |
|
Gazari khal |
9.20 |
4 - 6 |
|
Kumira khal |
12.53 |
5 - 6 |
* Depth during monsoon
The ox-bow lakes (baors) were originally connected to river systems but in the course of time parts of the rivers became closed due to sedimentation or changes in the meandering course of the rivers. These oxbow lakes or baors, were at one time deep and they formerly covered large areas. Over the years, due to siltation and heavy organic fill from water hyacinth and other aquatic vegetation, the ox-bow lakes have become shallower and narrower and do not retain connection with the mainstream rivers. Majority of the baors are owned and administered by the Government through the Ministry of Land Administration and Land Reform and leased to private parties. The private lease holders practice limited s-supplemental stocking of the waters but they rarely stock the desired number, size and combination of fish for maximum sustainable yield. Bangladesh fishery resource survey found that there are 79 baors with a total area of approximately 4,800 ha.
From the water quality data available for few baors (Table 7) it seems that the waterbodies are more or less suitable for fish culture although the transparency of the lakes are high. IFAD financed ox-bow lake project demonstrated that fish yield in ox-bow lakes can be increased from 100 Kg to 950 Kg/ha/yr through appropriate culture based management. Based on the success of first phase Baor Development Project a second phase project for development of 30 baors in the greater district of Jessore, Kustia and Faridpur has been going on. In this project fishermen with the assistance of a NGO (BRAC) develop, operate and manage the baors to receive 100% benefit of the production.
Table 7. Various environmental parameters of four baors during dry season.
|
Baor |
Transparency (inch) |
pH |
DO2 ppm |
Nitrate |
Phosphate |
CO2 ppm |
Chloride ppm |
Total hardness ppm |
Conductivity |
|
Baluhar Baor |
55 |
8.1 |
15.2 |
<0.1 |
<0.1 |
8 |
32 |
110 |
340 |
|
Kharincha Baor |
44 |
8.0 |
12.0 |
<0.1 |
<0.1 |
10 |
37 |
220 |
650 |
|
Kannadaha Baor |
21.2 |
8.2 |
11.6 |
<0.1 |
<0.1 |
4 |
26 |
165 |
360 |
|
Shimulia Baor |
51 |
7.2 |
8.0 |
<0.1 |
<0.1 |
6.5 |
38.5 |
105 |
350 |
1 BCAS, 1989
Due to construction of flood control structures, some rivers have turned into closed or semi-closed waterbodies. For example, Dakatia river under Chandpur Irrigation Project, Ichamati river under Pabna Irrigation Project, Kumar river under Ganges-Kobadak Project. Although within the FCDI projects Dakatia river in CIP is still being used for navigational purposes and therefore is not suitable for penculture. However, some rivers in the district of Jessore namely Mukheswari, Betna, Kabodak and Bhairab are suitable for pen fish culture.
3.2.2.3.1 Mukheswari river:
It is a small dead river near Benapole in Jessore district. It is about 30 km long and 60 - 70 feet wide. It becomes almost dry during dry season but holds sufficient water during monsoon. Presently fish culture is being practiced by partitioning different segments of the river by bamboo fences. Usually fences are set in a narrow portion or under a bridge on the river. This river is suitable for fish culture for 6-8 months.
3.2.2.3.2 Betna river:
Betna river originates from kodla river and passes through Sarsa thana of Jessore district. The river is about 200 feet wide and 5-6 feet deep. A total river area of about 1400 acres starting from kodla to Bagasra is suitable for pen culture.
BRAC has a plan to culture fish in Betna river and selected 20 different sections of the river covering an area of about 520 acres. BRAC will organise fishermen group and provide loan and technical assistance. In this connection formal application has been submitted to government for long term lease of the waterbody for a period of 10 years.
3.2.2.3.3 Kabodak river:
It originates from Taherpur of Chowgacha thana and flows through Jhikoregacha thana of Jessore district. The river is about 300 feet wide and 5-6 feet deep. The average area of the river suitable for fish culture is about 872 acres.
BRAC has already initiated a fish culture programme through fishermen group formation in the kabodak river. The river is partitioned by using split bamboo patta and large sized fingerlings are released in January and are harvested in April-May. There is low level of navigation by boats in the river.
3.2.2.3.4 Bhairab river:
It originates from Tengamari border of Meher pur district and passes through Jessore town. The river is almost a dead river due to heavy siltation and minimal water flow. It is about 100 mile long and 300 feet wide. The river is shallow and the average depth is only 4-5 feet which needs reexcavation before any fish culture is undertaken.
DOF under its Baor Development project has selected five sections of the river which cover about 24 miles for fish culture. Already one section of the river has been reexcavated and culture is being practiced by sectioning it through net partitions. The whole river has a potential for pen culture once it is developed by reexcavation and cleared off the water hyacinth.
4.1 Training programme
4.2 Preparation of a extension pamphlet
4.3 Strengthening of limnology laboratory at FRI
Being encouraged by the success of pen culture experiment of FRI in the CIP canal, the local people become very much interested in fish culture. A women training programme on "Fish Culture in Pen" was organised by Riverine Station of FRI uder its FAO/UNDP project BGD/89/012. The project assisted in formulating and organising the training programme. The training programme was implemented by the FRI scientists with the assistance of the consultant. The aim of the training was to initiate pilot scale adaptive research on pen culture technology and involve the rural women in fish culture activities. A total of 25 women who live by the side of CIP canal embankments were selected for a 10 day long training programme from 19th to 28th June, 1994. The training included both theoretical and practical aspects of pen culture. The main topics included-
- Selection of pen site and pen material,
- Construction and installation of pen,
- Removal of carnivorous fishes,
- Preparation of pen for stocking,
- Selection of species,
- Stocking density,
- Supplemental feed and feeding rate,
- Monitoring of fish growth and disease,
- Fish harvesting, preservation and marketing.
A detailed programme of the training conducted is shown appendix -II. Two pens (each 0.5 ha) were constructed and installed in the CIP canal involving the trainees during the training period. Pens were stocked with catla, rohu, common carp and sharputi fingerlings at the rate of 20,000/ha. The fish in the pen will be given supplemental feed composed of rice bran and wheat bran at the rate of 2% of body weight of fish. Pen materials and fingerlings were supplied by Riverine Station, FRI. The trinees will continue the pen culture under the guidance of FRI scientists.
Encouraged by the success of the pen culture experiment by FRI, people from Valuka, Mymensingh become interested in pen culture and were assisted by FRI. This will serve as a demonstration to popularize the- pen culture technology. The consultant assisted the counter part scientist in initiating the demonstration of pen culture with the involvement of local people at Valuka in Mymensingh.
FRI has recently an extension leaflet on "Fish culture in Pen". The consultant prepared a draft of the pamphlet on pen culture and is expected to be published by FRI shortly. A draft is enclosed in appendix -III.
Although the pen culture experiments by FRI were promising, the monitoring of water quality and productivity of water needed to be done properly. The existing limnology laboratory at RS, Chandpur was strengthened by installing the equipment available at stores of RS. Some of the existing equipment in the laboratory were repaired and installed. Reagents and chemicals were indented for the laboratory. Procedure for collection of plankton and benthos by plankton net and Ekman dredge respectively were also shown. A practical demonstration on how to separate and identify benthos were also made to the counterpart scientific officers.
- To reduce the initial cost of production, pen sites should be selected where 2-3 sides are closed with embankments/roads leaving only one or two sides to be controlled by putting fences or netting materials.- Pilot scale study on the suitability of irrigation canals for fish production (species suitable for canals, factors limiting fish production in canals and economics of production) should be undertaken.
- In view of the massive fingerlings requirements and lack of sufficient nurseries, the technology of raising fingerlings in the pen nursery should be tested. Attempts should also be taken to develop a low cost supplemental feed using locally available feed materials.
- Study should be carried out to observe and demonstrate the advantages of using stunted fingerlings of Indian major carp for increased production in pen culture.
- Plankton communities in irrigation canals and other waterbodies suitable for pen culture should be investigated with a view to establishing what levels of fish production these communities could sustain.
- Culture experiments with locally available pen materials such as bamboo and nylon netting should be carried out to evaluate their relative suitability and durability.
- Sharputi (Puntius gonionotus) and shrimp should be included as stocking species in pen culture since these species are found to perform well in polyculture.
Bangladesh Centre for Advance Studies (BCAS) (1989). Experimental Project for New Improved Management of Open Water Fisheries in Bangladesh. Final Report submitted to Govt. of the Peoples Republic of Bangladesh. August, 1989.
Brylinsky, M. 1980. Estimating the productivity of lakes and reservoirs. In: The functioning of freshwater ecosystems, Edited by E.D. Le Cren and R.H. Lowe- Mc Connel. Cambridge, England. Cambridge University Press, International Biological Programme. 22: 411-454.
Karim, M. (1988). Status and prospects for pen and cage culture in Bangladesh. FAO/UNDP TA -Project BGD/83/010. IDA/WB Agricultural Research II project. Report No. 18. March, 1988.
Redding, T. A. and Midlen, A.B. (1991). Fish production in irrigation canals. A review. FAO Tech. Paper, 314. Rome, FAO, 111p.
Appendix - I: Design of net pen walls
Appendix - II: Women's training programme on fish culture in pen
Appendix - III: Preparation of extension pamphlet
Appendix - IV: Pilot scale pen culture demonstration project in DND canal
Appendix - V: Abbreviations used
Fig. Schematic diagramme of bamboo fencing pen in canal/dead river
Fig. Schematic diagramme of net pen in ox-bow lake
Women's Training Programme on "Fish Culture in Pen" organised by FRI, Riverine Station, Chandpur, from 19-28 June, 1994.
|
SL. |
No. Subject/Topics |
Theoretical/Practical |
Duration (day) |
|
|
1. |
Prospect and Future of Fish Culture in Pen |
Theory |
|
|
|
2. |
Role of pen culture on the improvement of socio-economic condition of Rural Women in Bangladesh |
Theory |
1 |
|
|
3. |
Self employment and Bank Credit system for fish culture operation |
Theory |
|
|
|
4. |
Types of fish culture in pen and selection of pen site |
Theory |
|
|
|
5. |
Selection of pen material and construction of pen |
Theory |
|
|
|
6. |
Construction and preservation net wall for pen |
Pract. |
1 |
|
|
7. |
Construction of bamboo fences and split bamboo fence (bana) |
Pract. |
1 |
|
|
8. |
Construction and installation of pen |
Pract. |
1 |
|
|
9.
|
Preparation pen for stocking: |
|
|
|
|
|
-removal of predatory weed fishes |
Theory Pract. |
1 |
|
|
-application of lime fertilizer |
Theory Pract. |
|
||
|
10. |
Selection of species, stocking density, species combination, fry transportation and stocking |
Theory Pract. |
|
|
|
11. |
Natural artificial food of fish preparation of artificial feed feeding regime |
Theory Pract. |
1 |
|
|
12. |
Fish disease and preventive measures observation of fish growth |
Theory Pract. |
1 |
|
|
13. |
Harvesting, Preservation and Marketing of fish |
Theory Pract. |
1 |
|
|
1|4. |
Economic analysis of fish culture in pen and distribution of pen material among trainees |
Pract. |
1 |
|
FISH CULTURE IN PEN
Introduction:
Both pen and cage culture could be generally termed as "enclosure culture" which holds the cultured species within an enclosed space while maintaining a free exchange of water. However, both the methods are different from one another. In cage culture, the side as well as the bottom structures are closed with wooden mesh or net screen. On the other hand, in pen culture the sides being constructed from wooden poles, mesh or netting and the bottom of the structure is the natural bed (soil bed). A pen may be enclosed on all the sides, or it may require enclosure on some sides, the other sides being already formed by any natural barrier such as the bank of the waterbody itself.
Site selection
Selection of waterbody for pen culture must be judged against the requirement of species to be cultured and period and duration of culture. Waterways constitute the most important mode of transportation in rural Bangladesh. Therefore, care should be taken in selecting areas to avoid or to reduce conflict with navigation in the waterways. Again the pen sites should be protected from frequent cyclonic storm, strong current and wave action. The site of the penned area should be out of danger from flooding. The following points, should be considered in selecting pen sites:
a) Water depth
Depth of water is a important factor for growth of fish. The depth of water should be at least 60 cm during summer otherwise water may get heated up beyond the tolerance limit of fish. Water depth of 1.5 to 2.5 m is ideal for fish growth.
b) Soil type
Soil type is important for both the installation of pen wall and productivity of pen site as well. Soft muddy bottom is preferable to hard sandy bottom. Fixing the bottom line of the pen or driving the poles into sandy or very hard bottom would be a problem. At the same time the bottom should not be too slushy which will make the pen wall or poles vulnerable to water current and wind action.
c) Pollution
The selected side should be away from any pollution source. Untreated industrial wastes are highly toxic to fish and other aquatic organisms. Sugar mills, tanneries, jute mills, paper and pulp mills, shrimp and frog legs processing plants are the major source of pollution. Other sources of pollution may be from sewage, domestic wastes, decomposed aquatic vegetation etc.
d) Aquatic vegetation
Presence of excessive aquatic vegetation pose difficulty in the installation of pen and fish harvesting also become very difficult. Drifting patches of water hyacinth may clog the pen in some places. Therefore it is essential that weeds are eradicated before the pen is installed.
Construction of Pen
Various materials such as bamboo splits, nylon, and HDPE (high density polyethylene) are generally used as fencing material for pen. However, nylon netting does not appear to be suitable for two reasons- high cost and vulnerability to crab cuts. Bamboo splits from mature bamboo form excellent fencing material particularly in relatively shallow water. Pressurized treatment with chemicals and tar can prolonged the life of bamboo. HDPE webbing material is superior to nylon, being cheaper, lighter and resistant to cuts by crabs. HDPE webbing is also quite resistant to sunlight.
Bamboo screen fencing- Bamboo screen is made with bamboo splits (5-10 m.m width) interwoven with coconut coir rope (3 m.m) or HDPE rope. Pen wall can be constructed in several pieces having a frame work consisting of a few rows of horizontal struts and two vertical struts along the two sides. Bamboo screens can also be kept in rolls and installed as is necessary. Bamboo screen fencing is suitable in irrigation canals, narrow and shallow rivers, road side canals, flooded fields and similar waterbodies. The fence can best be installed when there is little or no water. The bottom part should be inserted about 30 cm into the mud. If the bottom is dry, firm or sandy, a furrow with a metallic furrower has to be made to fix the bottom part. Vertical bamboo bracers at intervals of 4 m or more should be provided depending on the bottom condition, water current, wind velocity etc. In waterbodies with strong current, the fence should be deep enough (0.5 m) so that fence do not washed away due to the pressure of the current.
Synthetic net fencing- The mesh size of the netting should not be more than 10 m.m. Bamboo posts should be chiselled to a sharp point and a shallow groove on the bamboo about 50 cm above the lower end should be cut. Loop of the bottom rope should be tied at the groove and driven into the bottom mud. This arrangement is to ensure tucking of about 30 cm of the net into the mud. Steps for installation of net pen are more or less similar to the bamboo screen fencing, however, care should be taken for inserting the bamboo line into appropriate depth of mud. The head line of the net should be tied to horizontal struts 2 m intervals above the highest water level.
Removal of predators and weed fishes
After constructing of pen all the predator fishes like shol (Channa straitus), Boal (Wallogo attu), Gajar (C. marulius), Aor (Mystus aor), Taki (C. puntatus), Pholi (Notopterus notopterus) etc. should be removed by repeated netting or by other means. Weed fishes like Bele (Glossogobius giuris), Punti (Puntius sp.). Mola (Amblypharyngodon mola), Chapila (Gadusia chapra), Chanda (Chanda sp.) etc. should also be removed.
Selection of species
Fish species which feed on different layers of water should be stocked for better utilization of fish food. In a pen, continuous intrusion of small fish is inevitable and some of them may become large size predators. It is therefore important to stock large size fingerlings which will have a better chance of survival and grow to a marketable size within 4 to 6 months. Carps such as silver carp (Hypophthalmicthys molitrix), big headcarp (Aristichthys nobilis), rohu (Labeo rohita), mrigal (Cirrhinus mrigala), catla (Catla catla), common carp (Cyprinus carpio) etc. in combinations are suitable for waterbodies with water depth 120 cm or more, rich in plankton, benthic organisms and organic detritus. Catfish like Pangasius and sharpunti (Puntius gonionotus) may also be selected.
Stocking rate
Pen should be stocked with healthy fingerlings. The size of the fingerlings should not be less than 10 cm. Smaller fry will be easily vulnerable to predator since it not always possible to eradicate all the predatory fish species from the pens.
Promising result has been achieved by FRI with polyculture of carp at a stocking density of 20,000/ha in pens in the Chandpur Irrigation Project (CIP) canal. The most suitable species combination and ratio should be 30:20:10:10:30 for Rohu, Mrigal, Catla, Silver carp and Common carp.
Feeding
Regular feeding is an important step in pen culture. A feed mixture of rice bran, wheat bran, oilcake and fish meal (if available) may be used. FRI has obtained good results with a feed mixture of fish meal, mustard oilcake, rice bran, wheat bran, wheat flour and molasses in the ratio of 15:40:20:20:3:2. The feed mixture should be administered in dough form to minimize the loss due to dispersion if applied in powder form. Fish should fed at the rate of 2-3% of the standing crop. If grass carp is one of the species being cultured, aquatic weeds may be supplied in the pen.
Pests control
Different types of plants and animals can interfere with pen structure and the culture operation. They may damage pen walls, wooden structures, or block the pen mesh. Some may pollute the water. Many undesirable animals and plants get trapped inside the pens when installed. Repeated netting with small- mesh nets, trapping and manual removal will be required for prestoking pest removal. Cutting of pen walls by crabs is a menacing problem. Although bamboo splits and thick HDPE (0.75 m.m or thicker twine) netting are resistant to crab cuts, frequent checking may be necessary. Periodic cleaning of-the pen wall particularly along the upper water line with a soft brush will keep the mesh free from clogging. Drifting water hyacinth and other debris can be kept away from pen by placing upstream few thick bamboos in at a distance from the pens.
Harvesting
Harvesting of fish should best be adjusted according to the waiter depth, water temperature and culture system employed. In seasonal waterbodies, harvesting needs to be completed before water level gets excessively low. Normally fish grow to marketable size within 5-7 months if larger fingerlings are used.
Cast net, drag net, seine net or gill net may be used for harvesting. Complete harvesting of fish is very difficult from a pen even if water depth is only 50 cm. However, some canals may get dry up where complete harvesting is possible.
Production
FRI, Riverine station, Chandpur in an experimental pen culture operation in the CIP canal has achieved a production of 2.7 t/ha for a period of 6 month culture period. The average size reached by catla, common carp and silver carp were 1.01, 0.90 and 0.55 kg respectively, while rohu and mrigal attained an average size of 0 31 and 0.35 kg respectively.
Table 1. Economics of pen culture in the CIP canal undertaken by FRI for 6 months culture period is as follows:
|
Operating cost: |
|
|
a) Bamboo fencing construction |
Tk. 1,500/- |
|
b) Fish fingerlings (Tk. 400/- per thousand) |
4,000/- |
|
c) Feed |
7,179/- |
|
d) Knotless HDPE netting |
449/- |
|
e) Bamboo |
995/- |
|
f) Ropes and twines |
500/- |
|
g) Labour cost for pen installation |
500/- |
|
h) Fish harvesting |
200/- |
|
Total cost |
= 15,323/- |
|
i) Interest on capital (6 months) |
= 1,225/84 |
|
Total expenditure |
= 16,548/84 |
|
Income: |
|
|
Fish sale proceeds Tk. 60/- per Kg |
73,211/- |
|
Weed fish sale Tk. 40/- per Kg |
4,800/- |
|
Total income |
Tk. 78.021/- |
Net profit (income - expenditure) = 61,472/16 Net profit per ha per 6 months culture period = Tk. 122,944/32* Cost for bamboo fence, net material, rope etc. are calculated for 6 months considering the life span of 2 and 4 years for bamboo and net materials respectively.
RESEARCH PROPOSAL
|
1. |
Institute code No.: |
|
||
|
2. |
Name and Address: |
Fisheries Research Institute Riverine Station, Chandpur. |
||
|
3. |
Title of the Project: |
Pilot Scale Demonstration Fish Culture in pen in DND Canal |
||
|
4. |
Title of the Individual study and Experiment: |
|||
|
|
|
To study the feasibility of large scale pen culture of carp and catfish. |
||
|
5. |
Name and Designation of the Project Leader: |
|||
|
|
|
Dr. G. C. Halder, CSO, Riverine Station, Chandpur. |
||
|
6. |
Name and Designation of the Project Leader and Associates together with the time propose and works to be done. |
|||
|
|
|
|||
|
SL. |
No. Name |
Designation |
Time to be spent (m/m) |
Work to be done |
|
1. |
Dr. G.C. Halder |
C.S.O. |
3 |
Overall supervision |
|
2. |
Mrs. J.N. Akhter |
S.O. |
6 |
Supervise and conduct the experiments |
|
3. |
To be appointed. (One) |
(Field Asstt.) |
36 |
To assist in field works |
|
4. |
To be appointed |
Master Role (Three) labour (ML) |
36 |
Three will work as full time guard and will assist the Field Assistant. |
|
|
|
|||
|
7. Location of the Research Project with Complete Address: |
DND canal |
|||
|
|
Near Mukti Sarani, |
|||
|
|
Demra, Dhaka. |
|||
8 (1). Objective of the study:
a) To fine tune the technology of seed raising and polyculture of carp and catfish in pen in large scale.b) To recommend appropriate species and their suitable stocking rate under different environmental and dietary conditions along with suitable pen materials in varying conditions for pen culture operation.
8 (2). Output:
This project will popularize the pen culture technology among fish farmers. Development of pen culture technology using various species of fish will help to increase total fish production of the country.
8 (3). Practical utility:
Pen culture technology will be perfected to be used by farmers through out the country for increasing fish production by utilizing various waterbodies like irrigation canals, dead rivers, and other shallow waterbodies.
9. Review of the work done in the past:
In Bangladesh, various types of waterbodies (e.g. ponds, borrow pits, drainage/natural canals, irrigation canals, reservoirs, low lying depression etc.) within FCDI project area have vast potential for pen culture development. Besides these, the country is endowed with huge number of other waterbodies outside FCDI project, which can also be suitably utilized through pen culture of carp and catfishes etc.
Pen culture is quite prevalent in China for rearing carps in fresh water lakes. Many irrigation systems in China now produce 300-500 kg/ha/yr of fish from extensive aquaculture using pens in canals. This system is particularly refined in the Zhujiang deltaregion, where fish production can be as high as 1350 kg/ha/yr (Redding and Midlen, 1991). The principal species being cultured in pen are carps (e.g. grass carp, Ctenopharyngodon idella, big head carp, Aristichthys nobilis, silver carp, Hypophthalmicthys molitrix). Some experimental pen culture of carps has been carried out in pens in ox-bow lakes in Hungary (Muller, 1979; Muller Varadi, 1980). In India, experiments on Penaeus monodon and P. indicus made at Killai backwaters have given an yield of 250 kg/ha and 300 kg/ha respectively and the low yield has been attributed to low tidal amplitude and sandy nature of the area (Annon, 1982).
In Bangladesh during 1981-84, experimental pen culture activities under the ADB assisted aquaculture development project were undertaken by DOF in few places viz. Bahadur pur baor, Nabaganga river and Saganna baor - all three in Jhenidah and Dhanmondi lake and Gulshan lake in Dhaka city (Karim, 1988). All the experimental/demonstration pen culture installations used high density polyethelene (HDPE) or nylon netting and bamboo patta split bamboo woven together) as fencing material for the pen. Carp polyculture of 5 species viz. silver carp (Hypophthalmicthys molitrix), catla (Catla catla), rohu (Labeo rohita), mrigal (Cirrhina mrigala) and grass carp (Ctenopharyngodon idella) at the rate of 30,000/ha and 38,600/ha were stocked in Bahadurpur baor and Dhanmondi lake respectively. Mustard oilcake and rice bran were used as supplemental feed. A total of 1890 kg fish was produced after 8 months from 0.5 ha pen in Bahadurpur baor and 1195 kg from 0.25 ha pen in Dhanmondi lake after 6 months of culture period.
Since 1990 Fisheries Research Institute, Riverine Station, Chandpur has initiated a research project on pen culture of fish in Chandpur Irrigation Project (CIP) canal with promising results. However, the technology developed by FRI Chandpur need to be tried in pilot scale so as to fine tune the technology for wide adoption. FRI will undertake a pilot scale adaptive research project on pen culture in DND canal for better management and efficient utilization of the waterbody.
10. Technical programme with activity chart:
A) Technical programme:
The project will be based at DND canal. The project site will be near Sirulia north to Mukti Sarani between Kanchpur - Demra portion of the canal. Three pens each 220 m long and 45.5 m wide covering an area of 1.0 ha will be constructed side by side in a row. Fencing will be made of two types of materials viz, bamboo splits and knotless poly-ethylene webbing. Each of the bamboo splits will be 12 - 13 feet long and 0.5 inch wide and will be interwoven with HDPE rope to form a fence. The highest water depth in the canal is 11 feet. The bottom part of the bamboo fence will be inserted about 30 cm deep into the mud to make the pen wall secure in position and to ensure that stocked fish do not escape through the bottom. The top of the bamboo fencing can be joined to a horizontal length of netting to prevent fish from jumping out. Sufficient bamboo posts and horizontal bars will be used to support and hold pen walls in position against water current, wind and wave actions. Two pen walls will be constructed using only split bamboo fencing and two walls will be constructed using both hollow bamboo fencing and HDPE netting material together to compare their relative cost and durability as pen wall.
Since availability of large size fingerlings is a problem, one of the pen will be used for raising the fish fry to fingerling stage. The fry of Indian major carps viz. catla, rohu, and mrigal will be grown in polyculture. Fry will be obtained from FRI hatchery. Supplemental feed composed of fish meal, mustard oilcake and rice bran will be applied. Attempts will also be made to raise the Indian major carp fry in a high density of 50,000/ha for 8-10 months so that they do not grow much and become stunted due to high stocking density. These fingerlings will be used in a trial for polyculture of stunted Indian major carps in pen using a stocking density of 10,00/ha.
One pen will be used for polyculture trial using Indian and Chinese carps. The fishes will be stocked at the rate of 20,000/ha. Since DND canal contains aquatic vegetations like Najas sp., duck weed (Lemna minor) and water cabbage (Pistia stratiotes) grass carp will also be introduced. The species combination will be rohu 20%, mrigal 20%, catla 10%, silver carp 10%, common carp 20% grass carp 10% and Thai sharpunti 10%. Fish will be fed supplemental feed at the rate of 2-3% of body weight. The feed will composed of fish meal (15%) mustard oilcake (25%), wheat bran (30%) and rice bran (30%). Depending on the growth performance of individual species after one year culture period, the species combination will be changed to have a best species combination for optimum growth.
A trial on polyculture of catla and Pangasius sutchi will be undertaken. The stocking density will be 10,000 P. sutchi/ha and 5,000 catla/ha. Fingerlings for all the experiments will be obtained from FRI hatchery. The feeding regime will be same as described earlier. Depending on the result obtained, the stocking density and species combination will be modified. At the end of 2nd year the performance of the bamboo and HDPE netting as pen material will be evaluated.
Data on water quality parameters including plankton and benthos population will be collected from the pens to determine their effects on fish production. Details records of initial capital investment, operating costs, fish, feed and sale proceeds will be carefully maintained to allow an economic analysis.
10 (B). Work Plan and Activity chart:
|
Major Activities |
Duration in year |
|
|
1) |
Construction of Pens |
01 |
|
2) |
Raising of fingerlings |
02 |
|
3) |
Polyculture of Indian and Chinese carps |
03 |
|
4) |
Polyculture of Indian major carps using stunted fish |
03 |
|
5) |
Polyculture of catla and pangas |
02 |
|
6) |
Collection of data on water quality parameters |
03 |
|
7) |
Testing of pen materials |
02 |
|
8) |
Writing terminal reports on research findings and recommendations |
01 |
Activity Chart (3 years)
|
Major activity No. |
FY-1 |
FY-2 |
FY-3 |
|
1 |
___________ |
||
|
2 |
____________________ |
||
|
3 |
________________________________________ |
||
|
4 |
_______________________ |
||
|
5 |
________________________________________ |
||
|
6 |
_________________________ |
||
|
7 |
_____________ |
||
|
8 |
|
||
|
11. |
Date of start: |
July, 1995 |
|
|
12. |
Likely date of completion: |
June, 1998 |
|
|
13. |
Estimated man month: |
153 m/m |
|
|
|
|
Scientific staff: |
9 m/m |
|
|
|
Supporting service: |
144 m/m |
|
14. |
Facilities required: |
Hach kit, chemicals, fish, feed, boat, guard shed etc. |
|
|
15. |
If financed by an organisation other than the institute, then give the detailed information in terms of fund, time and personnel: |
||
|
|
Detailed information in terms of fund, time, personnel are enclosed. |
||
|
16. |
Approximate cost: |
Tk. 1153,000/- |
|
|
|
|
Salary of the scientific staff will be borne by FRI |
|
|
|
|
Salary of supporting staff: |
Tk. 240,000/- |
|
|
|
Equipment and Facilities: |
Tk. 843,000/- |
|
|
|
Contingencies: |
Tk. 70,000/- |
|
17. |
Signature of Project Leader: |
|
|
|
18. |
Signature of' CSO |
: |
|
|
19. |
Signature of Director |
: |
|
|
|
|
(Dr. M. A. Mazid) |
|
References
Anon (1982). Brackish water aquaculture in Tamil Nadu. Fishing Chimes, 2:38-39.
Karim, M. (1988). Status and prospect for pen and cage culture in Bangladesh. FAO/UNDP TA project BGD/83/010: Report No. 18, 58p.
Muller, F. (1979) the European and Hungarian results of cage culture of fish. In: Proceedings of IDRC/Aquaculture Department SEAFDEC International workshop on pen and cage culture of fish. 11-22 February 1979. Tigbuan, Iloilo, Philippines, Iloilo, Philippines, SEAFDEC, pp 33-40.
Muller, F and L. Varadi, (1980). The results of cage fish culture in Hungary. Aquacult. Hungary, 2:.154-67.
Total Budget at a glance (in Lakh Taka)
|
Components |
FY-1 |
FY-2 |
FY-3 |
Total |
|
1. Personnel |
0.80 |
0.80 |
0.80 |
2.40 |
|
2. Capital cost |
0.96 |
0.10 |
0.10 |
1.16 |
|
3. Research operation |
2.92 |
2.10 |
2.25 |
7.27 |
|
4. Contingency |
0.30 |
0.20 |
0.20 |
0.70 |
|
Total |
4.98 |
3.20 |
3.35 |
11.53 |
Detailed budget for personnel (in Taka)
|
Position |
No. of posts |
Basic |
Allowances* |
Yearly** total |
Total for the period |
|
|
1. |
Project leader |
01 |
Salary and allowances will be borne by FRI |
|||
|
2. |
Project Associates (SO) |
01 |
-do- |
|||
|
3. |
Field Assistant |
01 |
1745/- |
935/- |
35,662/- |
106,986/- |
|
4. |
M. R. Labour |
03 |
|
|
43,800/- |
131,400/- |
|
|
Total |
|
|
|
79,462/- |
238,386/- |
* Includes house rent and medical allowances
**Festival allowances included
Detail budget for research operation (in Lakh Taka)
|
|
Line item |
FY-1 |
FY-2 |
FY-3 |
Total |
|
1. |
Field research expenses |
2.47 |
0.65 |
1.65 |
5.77 |
|
2. |
Travelling Transportation |
0.25 |
0.25 |
0.25 |
0.75 |
|
3. |
Fuel, Oil maintenance |
0.10 |
0.10 |
0.10 |
0.30 |
|
4. |
Office supply services |
0.05 |
0.05 |
0.05 |
0.15 |
|
5. |
Printing Publication |
0.05 |
0.05 |
0.20 |
0.30 |
|
|
Total |
2.92 |
2.10 |
2.25 |
7.27 |
Detailed budget for. capital and field research expenses
|
|
FY-1 |
FY-2 |
FY-3 |
|
A. Capital Expenses: |
|||
|
1. Balance (2) 5 30 kg capacity |
6,000/- |
|
|
|
2. Hach Kit |
55,000/- |
|
|
|
3. Seine net hapa Scoop net |
15,000/- |
|
|
|
4. Chemicals and reagents |
20.000/- |
10.000/- |
10,000/- |
|
Total |
96,000/- |
10,000/- |
10,000/- |
|
B. Field research expenses: |
|||
|
Bamboo fencing |
20.000/- |
|
|
|
Bamboo for post support |
10,000/- |
|
|
|
Netting (HDPE) |
20.000/- |
|
|
|
Rope, Twine etc. |
5,000/- |
|
|
|
Construction Installation |
8.000/- |
|
|
|
Boat |
7,000/- |
|
|
|
Guard shed-cum-store room |
12.000/- |
|
|
|
Fish fry fingerling |
40,000/- |
40,000/- |
40,000/- |
|
Feed materials |
125,000/- |
125,000/- |
125,000/- |
|
Total |
247,000/- |
165,000/- |
165,000/- |
MAP: LOCATION OF PROPOSED PEN CULTURE PROJECT SITE
|
ADB |
= |
Asian Development Bank |
|
BCAS |
= |
Bangladesh Centre for Advance studies |
|
BFDC |
= |
Bangladesh Fisheries Development Corporation |
|
BRAC |
= |
Bangladesh Rural Advancement Committee |
|
BWDB |
= |
Bangladesh Water Development Board |
|
CIP |
= |
Chandpur Irrigation Project |
|
CSO |
= |
Chief Scientific Officer |
|
DND |
= |
Dhaka Narayangonj Demra |
|
DOF |
= |
Directorate of Fisheries |
|
FRI |
= |
Fisheries Research Institute |
|
FAO |
= |
Food and Agricultural Organisation |
|
FCD |
= |
Flood Control Drainage |
|
FCDI |
= |
Flood Control Drainage Irrigation |
|
HDPE |
= |
High Density Polyethylene |
|
IFDP |
= |
Integrated Fisheries Development Project |
|
IFAD |
= |
International Fund for Agricultural Development |
|
MPO |
= |
Master Plan Organisation |
|
NGO |
= |
Non Government Organisation |
|
RS |
= |
Riverine Station |
|
UNDP |
= |
United Nations Development Programme |
