NETHERLANDS FUNDS-IN-TRUST
GCP/ZAM/038/NET
August 1987
F A O/G O V E R N M E N T C O O P E R A T I V E P R O G R A M M E
Report prepared by the
Fish Culture Development Project
based on the work of
Andras Woynarovich
Consultant (carp hatchery)
This report was prepared during the course of the project identified on the title page. The conclusions and recommendations given in the report are those considered appropriate at the time of its preparation. They may be modified in the light of further knowledge gained at subsequent stages of the project.
The designations employed and the presentation of the material in this document do not imply the expression of any opinion whatsoever on the part of the United Nations or the Food and Agriculture Organization of the United Nations concerning the legal or constitutional status of any country, territory or sea area, or concerning the delimitation of frontiers.
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
Rome, 1987
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1. INTRODUCTION AND TERMS OF REFERENCE
Appendix 1: The three main units of the Chilanga Fish Farm ponds
LIST OF FIGURES
1. Sketch map of the existing carp hatchery structures of Chilanga Fish Farm
2. Building of the existing carp hatchery in Chilanga Fish Farm
3. New water supply of the Chilanga carp hatchery building and a possible arrangement of the devices
4. The suggested modifications on the devices of the Chilanga carp hatchery
The Government of Zambia, within the framework of the FAO/ Government Cooperative Programme and with funds generously contributed by the Netherlands, is engaged in project Fish Culture Development (GCP/ZAM/038/NET).
As part of project operations, FAO assigned Mr. A. Woynarovich as consultant (carp hatchery) from 17 June to 11 July 1987 with the following terms of reference:
to study the existing hatchery and nursery facilities at Chilanga Fish Farm and to recommend improvements for the production of carp eggs, hatchlings and fry.
to recommend suitable equipment for the carp production envisaged in Chilanga.
Thanks to the collaboration of the staff of Chilanga, it was possible to accomplish not only the original task, but also to obtain and install an adequate water-supply system for the hatchery devices to the most important part of the existing hatchery building (see Figure 3).
During his assignment, the consultant met the following people:
| Mr S.A.T. Wadda | FAO Representative in Zambia |
| Mr E.D. Muyanga | Director of Fisheries at Chilanga |
| Dr V. Gopalkrishnan | Project Manager, FAO |
| Mr E.D. Boma | Co-Manager, Government |
| Mrs E. Cayron-Thomas | Biologist, FAO |
The Chilanga Fish Farm consists of three separate units, namely: Office Ponds, Spurwing Ponds and C Ponds with 5,510 m2, 8,300 m2 and 31,600 m2 net water surface respectively (see Appendix 1). The areas of the Office Ponds and Spurwing Ponds are separated only by the asphalt main road, while the distance between Office Ponds and C Ponds is about 3 km. This distance can be covered on an earthen road.
The water for all three units is provided from the neighbouring dams by gravitation, and additionally a stand-by pump can provide the Office Ponds with water through the original water-feeding canal, when needed. During the rainy season (November-March) when there is enough rain, the water in the dams lasts throughout the dry season (April-October), but if there is little rain, by the end of the dry season water supply can be difficult, because the dams dry out. Water temperature is lowest in June and July even falling to below 20°C. In August and September the water starts to warm up to more than 20°C; and in November, December, January, February and March it reaches 25° – 26°C. In April and May the water temperature falls to 22° – 20°C, and again in June and July to below 20°C.
The present fish culture activities of the farm are related mostly to the local tilapia species (Oreochromis andersonii), especially fry and fingerling production, integrated rearing with duck or pig and other artificial feeding and manure-fertilizer application trials. These activities involve all but one pond, where the common carp brood-fishes are kept.
Feed, manure and fertilizer are available for these operations.
All the fish culture activities of the farm accelerate when the water temperature exceeds 20°C; i.e., the main occupation period of the workers is between September and May.
Female and male common carp breeders are kept together in pond No. 4 of the C Ponds.
After careful fishing, the consultant found nine females and three males, which implies that there are no more than 15–20 breeders, considering that not all the fish in this pond were caught at this time. The size of these breeders varies between 1.5 and 2.5 kg. The appearance of both females and males was normal, except for irregularly spread scales.
Their condition was good, the females had a roundish abdomen and the males liberated milt on pressure.
The hatchery building is situated in the Office Ponds area, approximately 35 m from the water-feeding canal (see Figure 1). Inside the building there are two concrete tanks (235 × 77 × 90 cm) which are used for the hypophysation of brood-fishes. In the main building there is a brick structure (400 × 100 × 60 cm), which serves as a platform for the metal troughs (see Figure 2).
Originally this hatchery was provided with 22 metal incubator jars (see Figure 4) and six hatchling collecting and rearing troughs (300 × 50 × 25 cm).
The water supply of the building itself (external supply) comes from the water feeding canal of the unit, through a receiving tank from where the water is fed in an underground pipe to the outside concrete tank of the hatchery (see Figure 1). The carrying capacity of this external water supply system is about 150 l/min. For the water supply of the hatchery devices a 3/4 inch pipe was fitted all around the wall with a 2 inch inlet stump. The 3/4 inch pipe had connections both with the tap water system and the outside concrete tank, while the 2 inch inlet stump was connected only with the outside water tank, through a 2 inch valve (see Figure 2). Below the window there is an electric plug which is very dangerous and should be eliminated.
Two considerations should be made before recommending tasks to be undertaken to improve the production of the common carp fry at the Chilanga Fish Farm.
How to put into operation the existing structure and devices with the least cost, to facilitate both the immediate and safe production and also future improvements.
Common carp fry production does not interfere with the existing activities of the Fish Farm, but completes them.
The demand for carp fry was taken into consideration only indirectly; because, on the one hand, the demand should be intensive and at present this cannot be expressed in definite numbers; and, on the other hand, the least modification or reform of existing facilities together with ad hoc propagation could result in many hundred thousands of fry which would be more than the immediately saleable requirement.
The various elements of carp fry production, brood-stock rearing and keeping, hatchling production and fry-rearing must be discussed one by one.
(a) Brood-stock rearing and keeping
It is not an ideal situation that the hatchery building and the C Ponds where the brood-stock must be kept are 3 km from each other, but given that peak production of the hatchery would involve not more than two transportations of breeders per week, this distance is acceptable. In order to avoid any unwanted natural spawning, the females and males must be kept separate.
The dimension of the pond, and the intensity and quality of feeding determine the quantity of the brood-fish kept in it.
Calculating a medium density of 8–10 m2/1 kg of body weight, a 2 kg/individual total weight, a regular application of manure and artificial feeding of approximately 1.5–2.0 %/weight/day, 40–50 females can be kept in the pond where they are now (C Pond No. 4).
To facilitate handling, and ensure better regeneration after artificial propagation, and also in preparation for the next one, another pond is needed, of the same size as pond No. 4 (suggest C Pond No. 5). After artificial propagation, the females should be stocked in this pond.
Two ponds, for the reason discussed previously are also needed for the males; these could be C Ponds Nos. 8 and 9. In these ponds with the same conditions, 40–50 males of approximately 2 kg each can be kept properly. This brood-stock, females and males, could be propagated twice a year (August-October and December-February approximately) yielding around 7 kg of eggs per period (14 kg/year).
Considering a normal 15–20% of mortality after propagation, 7–10 individuals of females and males respectively must be replaced in every period (15–20 individuals/year). This quantity can be easily reared in other ponds, in integrated culture with tilapia, ducks or pigs.
Net traps should be placed in the ponds to prevent the theft of brood-fish. For the proper handling and transportation of the breeders, scoop nets (open both ends) and a canvas transport tank must be made. (The latter should have the same dimensions as the already existing metal frame.)
(b) Hatchling production
The maximum quantity of water that can be supplied for the hatchery building with the existing value, pipe, etc., is approximately 150 l/min. This is enough per week for the production of 2.0–2.5 million hatchlings (see Appendix 2). The water for the hatchery must be in steady supply in the feeding canal of the unit.
As far as the water supply of the hatchery devices is concerned, the existing two facilities (see Figure 2) had to be altered to ensure the necessary quantity of water (see Figure 3). This was done using existing taps, values, etc. Thus, three separate water supply systems were made. For the first, the existing ¾ inch pipeline was modified, and now independently supplies water for the hypophysation tanks.
In the future, the tapwater connection of this system must be cut off - first, because it is no longer needed and second, it takes the water from the office. The second, newly made water-pipe system with 18 taps offers further extension possibilities and will supply water for the envisaged ten incubator jars and hatchling rearing troughs (see Figure 3).
The third already existing inlet tube with a 2-inch valve was placed below the 3-inch valve to allow for future extension as connections to new hatchling rearing jars, etc.
To ensure a better quality of water supply a gravel filter should be incorporated and kept clean, and a 300 micron sieve should be placed into the receiving concrete tank to eliminate dirt, small fishes, etc., entering the hatchery water system. To avoid the overflow of water from the concrete outside tank of the hatchery building its wall should be raised by 40 cm.
Minor modifications should be carried out on the existing hatchery devices, namely:
modify the water outlet of the hypophysation tanks (see Figure 4)
choose the ten best metal incubator jars, make water outlets, file off the water inlet tubes from the inside to make it smooth and fit with plastic tube as originally envisaged (see Figure 4)
make proper water outlets for the existing hatchling rearing troughs (two of them) using a 250–300 micron plastic sieve (see Figure 4).
Given the quantity of water available for the hatchery and the dimension of the hypophysation tanks, regular hatchling production should be about 2.0–2.5 million/week (see Appendix 2).
However, at the beginning, at least in the two propagation periods, only 0.3 million hatchling/week are envisaged; this production rate suits both the recommended area for the brood-fishes and the quantity and dimension of those ponds that would be available weekly for the fry rearing activity (see underlined numbers, Appendixes 1, 2, 3).
The arrangement of the hatchery devices can be seen in Figure 3, indicating the dual utilization of the water in the hatchery itself. Using the outflowing water of the incubator jars for hatching rearing, about 25% of the water can be saved.
Propagation can start after winter when the water temperature is permanently over 20°C and there is sufficient water available for the hatchery and for the fry rearing ponds to fill them. (When the hatchlings are sold to another farm, only the hatchery water supply should be taken into consideration.)
In the case of the hatchery building itself, a partial recirculation of water can be effected by utilizing the existing concrete tank located on the side of the building.
(c) Fry rearing
Appendix 3 shows the relationship between the quantity of hatchlings produced and the necessary pond area for different stocking densities as well as the probable duration and results according to the intensity of rearing. This appendix was compiled to demonstrate production planning. The suggested numbers are underlined; every week one or two ponds with a total area of 2 000 m2 weekly is needed. Calculating a 28-day rearing period and a 7-day drying and refilling time, five ponds are needed, with a weekly area of 2 000 m2. Considering the available ponds, two of 900 m2 and four of 2 000 m2 should be adequate.
For every cycle of refilling ponds with water, approximately 30–40 kg of feed is needed (soy, maize, fish or meat meal, duck or pig meal, mill sweepings, etc.). Although some of the chosen ponds have no monk for drainage, these could be constructed in the future.
Fry rearing is envisaged to start end-August or at the beginning of September under conditions discussed in (b).
With 10–12 stockings per period envisaged, 0.9–1.2 million fry is the minimum production that can result in the given conditions. With ad hoc propagation, this quantity can be reduced until the demand for fry reaches this envisaged production.
To intensify the demand for carp fry a survey should be carried out to determine the total area of water bodies suitable for carp stocking.
Although for the distant future a regular production should be envisaged, in the short-term, while the demand for carp fry is not very intensive, ad hoc production can be done. Both for the ad hoc and for the regular production the following recommendations are made:
(a) Brood-stock
| ponds Nos. 4–5 | for females |
| ponds Nos. 8–9 | for males |
| first year | 15–20 females |
| 20–25 males | |
| second year | 40–50 females |
| 40–50 males |
to stock 100–200 carp fry for rearing (to restitute the losses after propagation)
to make scoop nets and, for transportation, canvas tank
to calculate 7–8 kg/l kg body weight for females and 5–6 kg for males/year using the same feed as for the ducks (integrated rearing with ducks can be envisaged)
For the future, a new poor strain of common carp should be considered for introduction in Chilanga to replace the present one.
(b) Hatchling production
to clean the stone chip filter in the tank of the water feeding canal of the Office Ponds
to put a plastic sieve in the receiving tank (mesh size 300 micron)
to raise by 40 cm the wall of the external tank of the hatchery building
to complete the brick-laying work in connection with the new water supply facilities of the hatchery devices
to modify the water outlet of the hypophysation tanks (see Figure 4)
to modify the water outlet of ten metal incubator jars, as well as to file off the inside of its water inlet tube (see Figure 4)
to make the water outlet of two hatchling-rearing metal troughs (see Figure 4)
to arrange the water collecting trough of the incubator jars (see Figure 4). These collecting troughs (two) can be made from a 2-m long piece of 4-inch irrigation pipe cut in the middle.
Considering that the metal hatchery devices are not ideal, it is recommended to replace them with plastic ones, made locally or bought from abroad. (For larva rearing purposes locally available asbestos troughs can be used.)
Although the design of a plastic incubator jar can be seen in Figure 4, it is recommended to obtain the original mould not only for the egg incubator jars but also for the bigger hatchling rearing jars. This should facilitate both work in the hatchery and hatchling production of other local and exotic species which could later be introduced in Chilanga Fish Farm.
to choose the necessary quantity of females and males (sex ratio is 1:1) and calculate water consumption (see Appendix 2)
to have the dry common carp hypophyses available, the most important element for artificial propagation (calculating 6 mg for 1 kg of female body weight and 4 mg for each male). It is recommended to rear during the experimental phase at least 500–700 kg of common carp every year and, after their sexual maturation, to collect the hypophyses. (They could yield 1.5–2.0 g/year, enough for twice the propagation of the previously recommended quantity of brood-fishes.) Another possibility for collecting hypophyses is to remove them before selling carp on the market. The glands are extracted through the roof of the mouth of the fish, leaving the head in perfect condition to be able to sell the whole fish fresh and without price losses.
other material and small equipment for propagation, such as fish scales, plastic bowls, etc., are available in Lusaka.
A small scale suitable for weighing the stripped eggs, tannin, malachite-green and a sample of an incubator jar made of canvas were left at the Fish Farm.
(c) Fry production
in the case of regular fry production, it is recommended to liberate the ponds Nos. 6, 7, 13, 14, 15, 16 in the C Ponds where ad hoc production is not needed
to facilitate catching the fry, it is recommended to construct monks for the drainage of the ponds, where necessary
to intensify the sales of carp fry a survey and a careful trial should be carried out; the survey would identify potentially suitable areas for stocking fry, and the trial would evaluate the advantage of carp and tilapia polyculture as the basis of propaganda for rearing common carp in the region of the Chilanga Fish Farm.
FIGURE 1. SKETCH MAP OF THE EXISTING CARP HATCHERY STRUCTURES OF CHILANGA FISH FARM (OFFICE PONDS AREA)
| A. | WATER FEEDING CANAL OF THE STATION (0,6 m WIDE, 0,6m DEPTH) | 1. | CONCRETE TANK WITH STONE FILTER (1,6 m WIDE, 0,6m DEPTH, 4,0m LONG) |
| B. | UNDERGROUND WATER PIPE | 2. | VALVE (4,0") |
| C. | BUILDING OF THE HATCHERY (5,0 m WIDE, | 3. | CONCRETE TANK TO RECEIVE THE WATER OF THE HATCHERY BUILDING (1,2m WIDE, 2,3m LONG 1,6m DEEP) |
| D. | 9,5m LONG) METAL TANKS (r=0,5m) | 4. | CONCRETE OUTSIDE TANK FOR THE WATER SUPPLY OF THE HATCHERY DEVICES (0,8m WIDE, 2,1m LONG, 1,8m DEEP) |
FIGURE 2. BUILDING OF THE EXISTING CARP HATCHERY IN CHILANGA FISH FARM (OFFICE PONDS AREA) (VIEW FROM ABOVE)
| EXISTING STRUCTURES |  | |
| 1. | DOOR | |
| 2. | WINDOWS | |
| A. | TANKS FOR THE HYPOPHYSATION OF BROOD FISHES | |
| B. | METAL TROUGHS (B1) (2 PCD.) AND METAL BOXES (B2) (4 PCS.) FOR LARVAE-REARING | |
| C. | CONCRETE OUTSIDE TANK FOR WATER SUPPLY OF THE HATCHERY DEVICES | |
| D. | STUMP OF INLET TUBE OF THE OUTSIDE WATER TANK | |
| E. | TUBE OF THE TAP WATER FOR HATCHERY DEVICES. | |
| SPOTS OF THE NECESSARY MODIFICATIONS | ||
| I. | INLET OF THE WATER FROM THE OUTSIDE TANK | |
| II. | INLET OF THE TUBE OF THE TAP WATER | |
| III. | INSTALLATION OF THE EXISTING METAL JARS. | |
| IV. | INSTALLATION OF THE LARVAE-REARING JARS. | |
| V. | MODIFICATION OF WATER OUTLET OF THE TANKS | |
| (DIMENSIONS IN cm) | ||
FIGURE 3. NEW WATER SUPPLY OF THE CHILANGA CARP HATCHERY BUILDING AND A POSSIBLE ARRANGEMENT OF THE DEVICES
| I. VIEW FROM ABOVE | |||
 | 1. | VALVE | 3,0" |
| 2. | TAPS | ¾" | |
| 3. | VALVES | 1.5" | |
| 4. | INCUBATOR JARS  | 25 cm | |
| 5. | COLLECTING TROUGHS | ||
| LENGTH: | 200,0 cm | ||
| DEPTH: | 5,0 cm | ||
| WIDTH: | 10,0 cm | ||
| 6. | LARVAE REARING TROUGHS | ||
| 7. | VALVE | 2,0" | |
| 8. | WATER PIPE FOR BROODER TANKS | ||
| (Dimensions in cm) | GROUND LEVEL | ||
FIGURE 4. THE SUGGESTED MODIFICATION ON THE DEVICES OF THE CHILANGA CARP HATCHERY
| Unit Name | Symbol | Quantity per piece | Area m2 /piece | Area Total m2 |
| Office Ponds | ||||
| O1-O5 | 51 | 100 | 500 | |
| S1-S6 | 61 | 100 | 600 | |
| S7-S8 | 21 | 150 | 300 | |
| R1-R4 | 41 | 40 | 160 | |
| DR1-DR2 | 22 | 175 | 350 | |
| D1-D2 | 22 | 800 | 1 600 | |
| spawning pond | 1 | 2 000 | 2 000 | |
| Total | - | 22 | - | 5 510 |
| Spurwing Ponds | ||||
| SW1 | 1 | 1 400 | 1 400 | |
| SW2 | 1 | 2 200 | 2 200 | |
| SW3 | 1 | 3 200 | 3 200 | |
| SW4 | 1 | 1 500 | 1 500 | |
| Total | - | 4 | - | 8 300 |
| C Ponds | ||||
| 1 | 1 | 1 700 | 1 700 | |
| 2 | 1 | 1 600 | 1 600 | |
| 3 | 1 | 2 000 | 2 000 | |
| 4 – 5 | 2 | 800 | 1 600 | |
| 6 | 1 | 900 | 900 | |
| 7 | 1 | 900 | 900 | |
| 8 – 9 | 2 | 700 | 1 400 | |
| 10 | 12 | 800 | 800 | |
| 11 | 12 | 700 | 700 | |
| 12 | 12 | 1 000 | 1 000 | |
| 13 – 14 | 2 | 2 000 | 4 000 | |
| 15 – 16 | 2 | 2 100 | 4 200 | |
| 17 | 12 | 2 000 | 2 000 | |
| 18 –19 | 22 | 1 900 | 3 800 | |
| new pond | 1 | 5 000 | 5 000 | |
| Total | - | 20 | - | 31 600 |
1 These ponds are constructed out of concrete
2 These ponds have considerable infiltration
| Propagation frequency per week | Quantity of Females each time each week | 1 000 Pieces of Hatchlings | Quantity of water 1/min | ||||||
| ind. or kg | ind. or kg | average each time | maximum each week | ||||||
| 1 | 1 | 2 | 1 | 2 | 150 | 150 | 200 | 200 | 5–10 |
| 1 | 2 | 4 | 2 | 4 | 250 | 250 | 400 | 400 | 15–20 |
| 1 | 3 | 6 | 1 | 6 | 300 | 300 | 600 | 600 | 20–30 |
| 1 | 4 | 8 | 4 | 8 | 400 | 400 | 800 | 800 | 30–40 |
| 1 | 5 | 10 | 5 | 10 | 500 | 500 | 1 000 | 1 000 | 40–50 |
| 1 | 6 | 12 | 6 | 12 | 600 | 600 | 1200 | 1 200 | 50–60 |
| 2 | 1 | 2 | 2 | 4 | 150 | 300 | 200 | 400 | 10–15 |
| 2 | 2 | 4 | 4 | 8 | 250 | 500 | 400 | 800 | 20–30 |
| 2 | 3 | 6 | 6 | 12 | 300 | 600 | 600 | 1 200 | 30–40 |
| 2 | 4 | 8 | 8 | 16 | 400 | 800 | 800 | 1 600 | 40–50 |
| 2 | 5 | 10 | 10 | 20 | 500 | 1 000 | 1 000 | 2 000 | 50–60 |
| 2 | 6 | 12 | 12 | 24 | 600 | 1 200 | 1 200 | 2 400 | 60–70 |
| Quantity of hatchlings 1 000 pieces | Fingerling production m2 | FRY | |||
| Extensive production m2 | Semi-intensive production m2 | Intensive production m2 | Super-intensive production m2 | ||
| 150 | 6 000 | 3 000 | 1 500 | 1 000 | 750 |
| 200 | 8 000 | 4 000 | 2 000 | 1 300 | 1 000 |
| 250 | 10 000 | 5 000 | 2 500 | 1 700 | 1 300 |
| 300 | 12 000 | 6 000 | 3 000 | 2 000 | 1 500 |
| 400 | 16 000 | 8 000 | 4 000 | 2 600 | 2 000 |
| 500 | 20 000 | 10 000 | 5 000 | 3 300 | 2 500 |
| 600 | 24 000 | 12 000 | 6 000 | 4 000 | 3 000 |
| 800 | 32 000 | 16 000 | 8 000 | 5 300 | 4 000 |
| 1 000 | 40 000 | 20 000 | 10 000 | 6 600 | 5 000 |
| 1 200 | 60 000 | 30 000 | 15 000 | 8 000 | 6 000 |
| 1 600 | 64 000 | 32 000 | 16 000 | 10 600 | 8 000 |
| 2 000 | 80 000 | 40 000 | 20 000 | 13 300 | 10 000 |
| 2 400 | 96 000 | 48 000 | 24 000 | 16 000 | 24 000 |
| Intensity of production | Hatchlings stocking density 1 000 1 000 ind./m2 | Duration of production days | Average fry Quantity 1 000 1 000 ind./m2 | production Length cm |
| Fingerling | 25 | 28–35 | 7–12 | 5–6 |
| Extensive | 50 | 21–28 | 15–25 | 4–5 |
| Semi-intensive | 100 | 21–28 | 30–40 | 3–4 |
| Intensive | 150 | 21–28 | 35–60 | 2–3 |
| Super-intensive | 200 | 17–21 | 80–100 | 2 |
Observation: In this case the fingerling production is envisaged in one phase, with the stocking of hatchlings.
