The economics of tilapia farming depend very much on the availability of suitable markets for the product. In extensive and simple small-scale rural farming, where the size of the product is not a major concern and no supplementary feeding is involved, the operation can be profitable when appropriate management measures are employed. In semi-intensive or intensive systems the cost of feeds, labour and, in some cases, water management become quite high and these can be compensated only by appropriate market prices for the product. In most African countries a good percentage of the consumers prefer tilapia, and they can therefore be sold at prices comparable to many other good-quality food fish. But in other parts of the world, where tilapias are exotic species, considerable market promotion is required. As mentioned in the previous section, the most important factor in developing a market for tilapia is the size of the fish, and the main thrust of recent improvements in culture technologies has been to obtain marketable-size products in as short a time as possible.
Within the limits of technological constraints, there is considerable variation in the profitability of tilapia farming, between different types and sizes of operations. This is clearly brought out by the costs and returns of sample operations in different provinces of Central Luzon (Philippines) reported by Sevilleja (1985), which are reproduced in Table 20.1. The data relate to land-based fresh-water fish ponds for the calendar year 1982, collected during 1983. The capital investment per hectare varied between the provinces, from 13 058 pesos in Bulacan (11.00 pesos for 1 US$ in 1983) to 29661 pesos in Pampanga. The data show the economic viability of both mono- and polyculture of tilapia. The average production obtained by the farms is close to the national average.
Cage farming of tilapia is preferred by producers, mainly because of the lower capital costs involved as well as the lower feeding costs in plankton-rich habitats. However, the cost of seed stock will be higher if it is to be purchased, as normally larger fingerlings are used in cage culture. Aragon et al. (1985) studied the economics of tilapia cage culture in the Laguna province of the Philippines. Table 20.2 presents cost and returns of different type of cage farm operations in San Pablo City in Laguna. It includes data on farms that undertake only
grow-out and those that have their own hatcheries. The total capital investment varies, depending on the number of cages and type of materials used in cage construction. The average capital investment in grow-out operations was 7022, 14 363 and 66 462 pesos for small, medium and large farms respectively. Large farms consisted of cages covering on average 320 m2, medium farms on average 314 m2, and small ones 280 m2. Net farm incomes from all types of cage operations are comparatively high, but the large farms with hatchery operations gave the highest gross and net returns. It should, however, be pointed out that not all cage farms in the country provide similar high incomes: for example, the gross returns from tilapia cage culture in Los Banos amounted to only 3330 pesos per season.