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close this bookEconomics of the Philippine Milkfish Resource System (UNU, 1982, 66 pages)
close this folderIII. The transformation sub-system: cultivation to market size in fishponds
View the document1. Overview
View the document2. The physical environment
View the document3. The socio-economic/cultural environment
View the document4. Tenure patterns
View the document5. Alternatives for increasing
View the document6. Size of operations
View the document7. Technique of production and average yields
View the document8. Input use
View the document9. Measures of efficiency
View the document10. Insignificant variables and measurement problems

2. The physical environment

Physically, most conditions of climate (with the exception of periodic typhoons), soils (with the exception of acid sulphate soils), water, and other natural environmental conditions in the Philippines are generally favourable for the development and growth of the local milkfish industry. But institutionally and socio-economically, conditions have not permitted the attainment of such development and growth.

The milkfish industry is characterized by the existence of well-established ponds and newly developed ponds. Newly developed ponds are reportedly less productive than well established ponds because they suffer from acid sulphate soil conditions, whereas soils in older ponds are more stabilized.

Scattered throughout the Philippine Islands are flat coastal and alluvial plains, where brackish-water ponds are found. The soils of brackish-water ponds are mostly hydrosol, either of clay, peaty clay, or silty clay. In general, these ponds are adequately supplied with seawater and freshwater. Annual rainfall ranges from a low of 89 cm to a high of 549 cm, the average being 305 cm. The average annual temperature is about 30 C. The Philippines has a year round growing season However, many of the ponds, particularly in Luzon and other islands in the Visayas, are occasionally subjected to flooding during adverse weather. Most of these ponds are excavated to a depth of 50 cm and their embankments are not substantial, making them vulnerable to flooding.

A further physical disadvantage which the Philippines suffers from is the intermittent setbacks from the occurrence of typhoons each year, beginning in June and continuing through September. Typhoons are very destructive to milkfish culture. Not only are valuable stocks of milkfish lost but algal beds and other natural fishfood are also destroyed. Milkfish farmers report that certain algae and other natural fishfood do not thrive after a heavy rain. On the average, the Philippines experiences about 19 typhoons each year, with the northern and eastern parts of the country being most affected. Typhoons in Mindanao are rare.

Although Taiwan and Indonesia are also affected by typhoons, milkfish production in the Philippines is relatively more precarious. The total loss of milkfish in 1978 from 324 farms due to typhoons and floods is estimated at P2,065,626 or an average loss of P6,375 per farm or P400 per hectare. The average loss per farm of the 97 (30 per cent) farms that reported losses is much higher, at P21,295.

Besides the loss of milkfish, costly damage is inflicted upon pond embankments, dikes, and sluice gates. Because of the weather-related damage to the ponds, repair and maintenance have to be done more often. It is, however, difficult to separate the annual repair and maintenance costs arising from normal wear and tear, which is part of the normal costs of milkfish production, from the costs of repair and maintenance incurred due to typhoons. Producers often try to reduce losses by harvesting early before the flooding begins. The cost of raising the height of embankments, according to producers, is probably more than the added benefit, given that their loss is the difference between the price they receive when harvesting early, and the price they would have received had they waited until the full rearing period was over.

The occurrence of acid sulphate soils is a further complication. Acid sulphate soils are characterized by a high content of sulphur-based compounds that produce acidity on oxidation. The chronic, sublethal effects of acidity that inhibit pond biota can result in low output of milkfish.42 Although remedial measures have been worked out, much of this information is not reaching the milkfish farmers. Apparently, many milkfish farmers do not recognize their low output as linked to an acid sulphate soil problem, because liming, to counteract acidity, is not a widely accepted practice. Some milkfish farmers interviewed realized that there is something wrong with their pond water but did not know the causes.

Not all Philippine milkfish farms are endowed with the same set of natural conditions, and certainly not all suffer from the problems itemized above. Differences in topography, soil and climate among farms give rise to differences in yields even if the same set of inputs is applied.

In the milkfish industry a balance must, therefore, be fostered among the prevailing physical and socio-economic conditions. On the one hand, the favourable environmental conditions must be capitalized upon; on the other hand, the institutional and socio-economic constraints confronting milkfish farmers must be overcome so that the available technology can be more widely adopted. Once the nature of these constraints is documented it is possible to legislate or introduce changes within the system.