The Centre is situated in the Integrated Fishery and Fish Culture Development Building on Lake Pheva where fish and duck are raised together. The centre occupies two rooms; the cool room, and one which contains two deep freezers, an ice machine, a table a pair of scales, and plastic fish boxes (See Figure 1). The centre was not supplied with running water and was without a drainage system. The ice machine only was connected to water mains, but the supply of water was just about sufficient.
The cool room had been assembled earlier, but it was fitted with a cooling system of twice the needed capacity, originally planned for a different (i.e. larger) type of cool room. Although assembled, the cool room had not been put into operation as the thermostat was not regulated.
The plastic boxes for fish had not been perforated in the bottom for drainage, so that the fish which was stored in them was immersed in a mixture of water and blood (as it had not been washed prior to being stored) and in this condition it was frozen in the deep freezer.
Side by side with the sale of fish produced under the project, fish is also bought from the local fishermen and then sold to the local population at the same price as the fish produced under the Project.
Fish is brought to the Centre in its natural state, the entrails being extracted in front of the Centre or by the side of the fish pond. If it is bought whole, it is first weighed and then cleaned. When sold, 15 percent is added to compensate for the loss of weight in cleaning. Fresh fish is usually stored in the deep freezer, without adding ice, when nothing else is available.
No records had been kept of the quantities received and sold, of species, of the size of fish and other data concerning the fish which was handled in the Centre.
The Consultant first put into operation the above-mentioned cool room by setting the thermostat, checking and adjusting the temperature setting until the correct temperature of ±0°C/+1°C was achieved. Next he drilled holes in the fish boxes for drainage of the liquid collected from the fish and thawing of ice. Then the personnel was given basic instructions on handling of fresh fish. Special emphasis was given to the following points:
The need for records of receiving (and sale) of fish brought to the Centre, for which purpose a register with the following colums was recommended:
| Date | Species | Where caught | Number of Species | Weight in kg whole-cleaned | Total price (Rs) | |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 |
The method of storing fish in fish boxes and adding ice;
The need to mark fish boxes to prevent confusion. The boxes should be marked with labels containing the date of reception, species, and net weight;
The need to adhere to the principle that fish which was received first should first leaves the Centres;
The methods of maintaining hygiene at the Centre, the need of through washing of accessories (boxes, scales, trays) and the floor immediately after use, to prevent impurities drying and hardening on them;
Warning was given against the harmful practice of refreezing fish that had partially thawed. Should this happen, it is advisable to consume the fish as soon as possible.
In the conditions prevailing in the Centre, however, it was not possible to achieve all the objectives as the supply of running water and sewage were not adequate.
Therefore the conditions were noted and the ground-plan of the Centre was drawn, showing the disposition of the equipment. Construction plans were then prepared for a 6 by 2 m porch over the entrance in order to protect it from direct exposure to the sun and rain and also to provide shelter for a table for cleaning and washing the fish (Figs. 2 and 3).
The erection of the porch will dispense with the need for buyers to enter the premises as they will have a measure of protection outside.
The porch will be built on a grid of steel bars anchored rigidly to the wall and covered with wavy slates or, alternatively, of wooden supports covered with a metal sheet.
The cleaning table will consist of a steel grid base anchored rigidly to the wall and a concrete slab, smoothly polished on top. It will be provided with four openings with filters, serving for drainage of dirty water into a drainpipe. The offal will be collected in a plastic box and emptied into the fish pond.
Waste water will also be drained into the pond through a covered collector.
An area of about 10 m2 will be cemented in front of the porch for the purpose of washing plastic boxes and other bulky equipment.
A wash basin will be fitted near the entrance (Fig. 3) for washing hands and small accessories.
Water from defrosted evaporators in the cool room, from thawed ice in fish boxes as well as that from washing the cool room will be drained through a pipe connected to the main collector outside. Until this is done it is advisable to put an unperforated box under each stack of boxes in the cool room to collect the liquid which will then be drained by hand.
The cool room is of the prefabricated type, made of 10 cm thick panels (polyurethane covered with plastic) and interlocking edges. The cooling equipment (compressor, evaporator, etc.) is fitted complete on one of the roof panels, ready for operation as soon as it is connected to the mains. Because of frequent large oscillations of voltage in some cities of Nepal it is desirable to fit a voltmeter with a scale of 0–250 volts to the electric starter of the cool room. In case of a voltage “drop” below 140, cooling equipment should be switched off. Fitting of a voltage stabilizer is recommended as a safety measure.
In addition, the cool room is fitted with the following:
an electric lamp operated from the outside and provided with a pilot light;
an electric thermometer for the control of temperature in the cool room;
an automatic door heater to prevent freezing of the door frame.
The cool room is not provided with an opening in the floor for drainage of defrosted water, thawed ice, washing; therefore a hole of about Æ 5 cm should be drilled in the floor and connected to the drain collector. It is also essential to protect the floor and the walls and door to the height of 10 cm with two coats of plastic to be applied with a paint brush. (This will be supplied with instructions).
The condenser is cooled by fan, i.e. by circulation of the air; so it is advisable to ventilate the premises because the ambient temperatures in Nepal are fairly high. This is best done by opening the windows (or doors) on opposite walls, if possible.
The temperature of the cool room is controlled thermostatically. The same applies to the difference in temperature which at present is of the order of 1°C. Thus, if the thermostat is set correctly to 0°C, the interior will be cooled to the temperature of ±0°C, when it will be switched off automatically. When the temperature in the cool room rises to +1°C, the system is switched on again.
Maintaining the temperature between ±0°C and +1°C is essential for fish stored in the cool room with the addition of ice. This temperature allows the ice to thaw very slowly, and it is precisely this slow thawing of ice that acts as the main cooling agent, rather than the cool room itself, which serves to prevent the sudden thawing of ice.
Overall dimensions of the cool room are L × W × H - 2.6 × 2.2 × 2.2 m, while the inside dimensions are 2.4 × 2 × 2 m. Maximum capacity of the cool room is 1 830 kg of fish with ice, stored in 61 plastic boxes (with 30 kg of fish each).
2.3.1 Fish Boxes
Plastic boxes have been found best for storage, transportation and distribution of fresh cooled fish. The boxes must be provided with holes for drainage of thawed water.
Because of the average size of fish, boxes with the capacity of 60 litres were used, having overall dimensions of 800 × 450 × 265 mm. Thirty kilos of fish with ice added can be stored in a box, which must not be full to the brim to avoid crushing of fish when boxes are stacked one upon another.
2.3.2 Ice Machines
Ice is essential to maintain the freshness of fish from the moment it is caught until it is sold. The aim should be to chill the fish as soon as possible and in the best possible way, but not to freeze it. If it is chilled in such a manner, it can be kept in excellent condition for a period of six to seven days.
Machines that produce ice in the shape of scales are best for this purpose. The scales are small but have a large surface and adhere closely to the fish without damaging the skin. Because of a rather small capacity of the ice machine in the Centre (350 to 400 kg in 24 hours) it is advisable to have sufficient quantities ready in advance if large amounts of fish are expected. In that case, ice production should start one day in advance, and the ice produced in this way should be stored in the cool room, as separate ice storage is non-existent.
2.3.3 Deep Freezer
Two deep freezers are fitted in the Centre, each with a capacity of a few boxes. According to their capacity they can be classed as auxiliary equipment.
They are used for storage of fresh fish intended for freezing. This is done either directly or chilling it in ±0°C in the cool room before freezing. It is wrong to store fish in the cool room when it starts to deteriorate in quality and then deep freeze it later. This can be tolerated only in cases of extreme need.
2.3.4 Balances
Two pairs of balances are used in the Centre. One pair is of the desk type, with the capacity of 5 kg, and the other is of suspension type and of somewhat greater capacity. However, this latter type in unsuitable for weighing larger quantities of fish, e.g. in fish boxes. It is advisable to fit a floor-type platform balance with a circular scale, having a capacity of 200 kg.
In view of the present production of fish in the Pokhara region as well as the planned yearly increase of 50 metric tons, it is advisable to build a retail fish shop in Pokhara, complete with equipment and make it operative as soon as possible. (See report of Mr H. Lisac, 1976 1).
