Fish is an important part of the diet for the people in rural areas providing protein calcium, fatty acids and vitamins.
Traditionally, a variety of local species were used in ponds, mainly carp, caught from the wild as spawn (fertilized eggs or small fish). One of the main drawbacks of this source of supply is that along with the desired fish species come many undesirable ones
Most of the species currently used in the cages are exotics. However, for decades these fish have bred naturally and distributed themselves throughout the flood plains and the delta.
A. Common Fish Types
The selection a suitable fish species will depend on various biological and economic factors, such as;
- Market price
- Growth rate
- Ability to reproduce simple culture of young fish
- Match of fish and available fish feed
- Water temperature is an important criteria in assessing which fish species is suitable.
The main types of cultivated fish are Carp, Tilapia and Catfish. Other fish suitable to cultivation are eel, tawes, mullet, snakeskin, and rohu.
Some fish are more suitable to pond conditions than others, some fish will not adapt the confined conditions while others such as the indigenous Koi (Anabas testidunous) have been found to thrive in cages.
B. Small Indigenous Species
In addition to the main cultivated species there are many indigenous breeds of fish that play an important role in the nutrition of the population. These fish are classed as small indigenous species although not all fish within this classification are particularly small.
Of the 260 species of fresh water fish found locally, over 140 species are classified as Small Indigenous Species (SIS) and account for over 80% of the total catch, consumed by the poorer section, as preferred species.
Common fish within the small indigenous species category include:
- Small catfish, Knifefishes, Snakeheads, Needlefishes, Minnows, Rasboras, and bards, Loaches,
Anchovies and sardines, Spiny eels, Climbing perch, Gobies, Mud Perches, Glassfishes, Fresh water prawns
Small, low-value fish are particularly important for the extremely poor after the rice harvest when the demand for their labor declines.
C. Feeding the Fish
With the non-intensive approach it is possible to feed fish on nothing more than scraps and waste, duck weed, oil cake, kitchen waste, rice bran and snails which will provide all the nutrition required. Some low-cost feeds are bought in by the households, typically rice bran and oilcake, but these costs are minimal. Occasionally, the diet may be supplemented with commercially available compound feeds. In most cases a mixture of diets is offered, according to their availability and needs of the fish.
FISH HARVESTING and MARKETING
Growth is rapid in the warm climate and the fish attain marketable size within 3-9 months, providing farmers with a rapid return on their investment and labor.
Fingerling production culture cycle is between 1 and 2 months. Cage nursery producers can sell fingerlings to the pond farmers and ox-bow lake operators.
Fish for food culture cycle is between 4 and 6 months. Fish food producers consume the cage fish as well as selling them in the market.
Profitability depends on many factors including the type of water body and culture, cage construction materials, the choice of fish species, fingerling size and price, stocking density, feed price, availability of
protein rich feed, culture duration, cage management, harvesting and marketing.
Another concern relates to economies of scale. Almost all enterprises are subject to economies of scale, and cage culture is no exception. The labor of looking after one small cage is far greater per kilogram of product than that for looking after a large one. The cost of the cage per kilogram of production will also be higher for a small cage versus a large cage. However, co-operative use of labor can be used to realize economies of scale in relation to labor, and this is already done in many villages.
The third concern, related to the second, is comparative advantage. A significant proportion of the fish is intended to be sold for cash rather than consumed by the farmer and his family. In the medium term, an important question is whether small-scale producers in villages are well placed to compete â€“ either with larger commercial producers, or producers from elsewhere. If they are not, and if competition increases, then prices – and returns – will steadily decline. In practice there is strong local demand for fish throughout the country, and small-scale producers are well placed to serve widely-dispersed rural markets.
Secondly, the use of surplus off-season and/or family labor is itself a comparative advantage. Thirdly, in those systems which use local food resources, such as natural foods and kitchen wastes, feed costs are relatively low compared with those for commercial producers. Small-scale fish producers should therefore be able to survive competition in much the same way as village-scale poultry producers have survived, and even to some extent benefit from the increasing number of intensive poultry operations.
For more information, contact:
Bureau of Fisheries and Aquatic Resources
Dept. of Agriculture
PCA Building, Elliptical Road
Diliman, Quezon City
Tel. Nos. (632) 929-8074 / 929-9597
Email :[email protected]
source: The original article appeared in www.practicalaction.org and was intended for Bangladesh fish farming.