The time and resources for this study were not adequate for more than a very limited appraisal of the physical characteristics of the selected site at Balik Pulau. However, the text details the additional tests considered desirable, but which could not be performed in the time available.
As indicated by Fig. 2, the site is on the west side of Pinang island just south of Sungei Pinang. It lies within a diked area about 400 m in width (E-W axis) between the dikes. The remaining strip of mangrove of about 150–200 m in width is west of the outer dike and is exposed to the Malacca Straits.
The siting area between the dikes has a tidal drainage installation which has converted the area into a shallow, freshwater pond area. The ground cover varies from cutover mangrove forest, to uncut mangrove (mainly Avicennia alba) and associated vegetation.
The tides are diurnal, with a spring tide range of 1.9 m and a neap tide range of 0.5 m, as shown below and on Fig. 1.1. Data for the standard port of Pinang were found applicable to the site. Site observations showed a variation of less than 0.1 m, from the standard port.
| LLW | = | 0.2 m |
| MLWS | = | 0.6 m |
| MLWN | = | 1.3 m |
| MSL | = | 1.6 m |
| MHWN | = | 1.8 m |
| MHWS | = | 2.5 m |
(See Fig. 1.1 for abbreviations).
Compilations from the tide tables showed an average daily range of 1.5 m (1981), average monthly low tide elevations of 0.7 to 0.9 m, and a determination for November 1981 only, that 90 percent of the time the peak daily tide stage was at least El. 2.1 m. Thus, a starting basis was established for determining parameters for pumping and for control water surface elevations.
In the tropical climate of Malaysia, temperature at sea level is not a significant variable for pond culture. However, rainfall and wind conditions warrant examination. For a long time mean data were not available. The climatology data for 1979 are shown in Appendix 6. The data indicate a seasonal dry period from December through March. Pollution and water quality measurements in the dry season and during the onset of the rainy season are important. In addition, these measurements are also necessary during representative periods in the wet season.
Wind direction is important if ponds can be oriented to encourage broad wind sweeps to maximize the amount of oxygen dissolving in the surface water. Wind data for Balik Pulau are not available.
The ground level was at El. 4.0 ft, RL within 0.1 to 0.2 ft, or about 0.4 ft above MHWS. A ground level at or below MHWS is desirable to reduce pumping costs, but not essential. Lower ground elevations will increase construction costs, because the soils will have a higher water content and be more difficult to form into embarkments.
Samples were collected twice, 19 and 25 November during both rising and falling tides. The sampling locations, data collected and tidal stages of sampling are shown in Appendix 6. Station 1 was just beyond the mouth of Sg. Pinang and the Station 2 about 500 m upstream. The intake channel entrance for an aquaculture project would be between these stations. Station 1 in the bay was essentially marine at a salinity of about 30 ppt, whereas Station 2 on a neap tide, 19 November, ranged from 2.0 to 7.0 ppt. However, on the spring tide of 25 November, incoming flow, Station 2 increased to 18 ppt. Essentially, this means that if a salinity-sensitive fish is to be cultured, a detailed analysis should be made of salinity variations from the mouth upstream to ensure a satisfactory location of the entrance of the intake canal.
Otherwise, the basic data relating to dissolved oxygen, ammonia nitrogen, BOD, alkalinity, hardness and pH were satisfactory (Appendix 6).
By observation, turbidity was high. Transparency, measured with a secchi disc, near the mouth of Sg. Pinang was only 0.2 to 0.3 m. A laboratory test showed settleable solids rate of 40 percent within about five minutes and 100 percent in 25 minutes. Thus, the necessity for a settling basin, on the intake canal, should be considered.
As indicated in Appendix 6, two phytoplankton sweeps were made at the mouth of Sg. Pinang. The identification of species is given. In the context of site selection, these qualitative findings are not considered significant.
By observation and qualitative field examination of soils in the existing dikes, the soil is a heavy clay with a high moisture content. Excavation of the soil by dragline would further add to the moisture content. Dikes can be expected to take at least one year to stabilize (i.e., dry out sufficiently), before ponds can be filled.
Equipment was not available to sample soils at a depth of more than 1 m. The results of limited laboratory tests, shown below, confirm the high plasticity as indicated in the field appraisal of soil quality.
Laboratory soil analysis
| Sample #1 | Sample #2 | |
| Liquid limit | 151. | 146. |
| Plastic limit | 66. | 69. |
| Plastic index | 85. | 77. |
| Bulk density (field) lbs/ft3 | 82.6 | 87.6 |
| Bulk density (dry) lbs/ft3 | 36.5 | 43.6 |
The laboratory identification showed soil types which were clay and clay loam. Organic content was about 6 percent.
An acid sulphate test of soil samples, at the surface and at a depth of 1 m showed a pH 8.0 before oxidation and 7.5 to 8.0 after oxidation, indicating acceptability with regard to acid sulphate conditions.
A written explanation of the rating is presented to enlarge upon and qualify the findings summarized on the checklist (Table 6.1).
1 Based partly on information contributed by the Fishery Division socio-economist.
Because of the proximity of K. Sungei Pinang fishing village to the site, it can be generally concluded that all those public and private sector services available at the fishing village would also be available at the site, or could be extended to the site at minimal cost (e.g., medical care, schools, post office/communications, roads, shopping facilities). Thus, the overall rating for this kind of infrastructure is acceptable. Because of a new road connecting Georgetown with the District, government and private sector services are likely to improve in the future.
a) Ex-farm prices, and market proximity and facilities.
Prices
Of the two species, under consideration for culture at the site, Penaeus monodon fetches a higher average price at $M14/kg. This is based on empirical data obtained from the field staff. Lates calcarifer, on the other hand, fetches only $M6/kg. Seasonal and comparative prices from other areas were not available. It is thus not possible to rate the site on this aspect; however, the price data have been used in the input-output analyses in Section 3.
Market proximity and facilities
There were four fish traders in the vicinity of the site who serve the Sungei Pinang fishing village. Fish is transported to a wholesale market at Chowrasta. Transport costs are about $M0.03/kg.
The Fishery Division's economist assigned to the Team believes that the presently existing local marketing facilities would be inadequate to serve an aquaculture system in the area.
In this regard, it is noted that Pinang (Butterworth) is a centre for the processing and exporting of prawns and thus facilities and export marketing, processing and related infrastructures exist in reasonable proximity to the Balik Pulau site. Therefore, this factor could positively influence the selection of the Balik Pulau site as opposed to alternative sites more distant from these facilities, if fish farmers could obtain ready and direct access to the export market.
The rating for this aspect is thus tentatively given as acceptable.
b) Pond operating costs
No special comparative study of this factor was made for purposes of site rating at Balik Pulau as it is of relatively low importance with one exception. This is if soil tests show that acid sulphate soils may become a problem. In this case, pond operating costs could become relatively high because of the need for the purchase of large quantities of lime to counteract acid conditions.
Local operating costs information obtained for input analysis purposes is contained in Section 3.
c) Seed availability and cost
Seed of L. calcarifer and P. monodon is not readily available from wild (natural) sources at the Balik Pulau site according to the Fishery Division's economist. Also, production of P. monodon seed from local commercial hatcheries is said to be uneven in supply and relatively high in cost. This is however a general problem in Malaysia and not specific to any one area of the country. Therefore, at present seed cost and availability have little bearing on the site selection rating at balik Pulau, except for the proximity of the Fishery Institute Hatchery at Glugor, where presumably research efforts to improve the economic efficiency of P. monodon seed production will be undertaken and which could provide a limited amount of seed on a sustained basis for culture operations at Balik Pulau.
L. calcarifer seed is not presently produced in Malaysia on a commercial scale and this seed has to be imported from Thailand at $M0.40/piece. The only bearing this has for the selection of the Balik Pulau site is the proximity of the airport and the reduction of transit time which could favourably affect seed survival, as opposed to, say, a site much more distant from an airport.
d) Feed availability and cost
Chopped trash fish has been selected as the food to be provided for both P. monodon and L. calcarifer culture. The Balik Pulau site would receive a favourable rating if it could be shown that cheap and adequate supplies of trash fish could be made available to the site from local fishing villages. However, at 48 t/yr as the requirement for trash fish for one hectare of P. monodon culture, and 175 t/yr of trash fish for L. calcarifer culture per hectare, this will not be the case, based on a preliminary study of the local (Balik Pulau) trash fish supply. Briefly, this study showed that at Sugei Pinang fishing village, there are 62 inboard powered boats, mainly drift netters of 9 tons or less, and 70 small outboard powered boats. Using the 1979 Annual Fishery Statistics, it is possible to show that the trash fish catch of boats of less than 10 tons was about 1.2 t/yr for Pinang. Thus, the expected supply of trash fish from Sungei Pinang is a maximum of 162 t/yr (132 boats × 1.2 t/yr = 162 tons/yr). As the combined populations of the other two fishing villages nearby the site in the District, Pantai Acheng and Jalan Bharu, only equal that of K. Sungei Pinang, the local supply of trash fish from these villages is probably about equivalent to that of Sungei Pinang, say, an additional 160 tons, or 320 tons/yr from the vicinity of the Balik Pulau site in total. Clearly these local capture fisheries could provide trash fish sufficient only for pilot-scale P. monodon or L. calcarifer culture operations at the Sungei Pinang site.
There is little or no cost or supply advantage with regard to the Balik Pulau site, and the site rating is therefore marginal for the feed parameter. A more definitive site rating could have been obtained if it would have been possible to investigate trash fish cost and supply elsewhere in Pinang State.
Limited data available from the area indicated that the average net income of fishermen in the Balik Pulau area is well below that of the national poverty line, amounting to only $M150/month for the crews of bag and drift nets. Thus, on the basis of potential benefit of aquaculture to fishermen of the area, the balik Pulau site would receive a good rating.
Other comparative data on welfare aspects are lacking on which to base a rating.
Ideally, much of the necessary comparative information for rating the Balik Pulau site would have been obtained in a first-stage screening process. For example, because of the limited time of the study and the limited availability of the Fishery Division's economist, it was not possible to answer such a basic question as to whether Balik Pulau presents any input-output advantages for pond culture relative to other Districts in Pinang. Therefore, the ratings given here have to be viewed as tentative and conditional until more comprehensive socio-economic studies in the site vicinity are undertaken.
In summary, infrastructures are rated as adequate, and export markets and processing facilities for P. monodon are rated good if pond farmers could gain direct access to the market. Seed availability for L. calcarifer and P. monodon are rated marginal as are the cost and availability of feed. The pond operating costs are rated as adequate based on the outcome of acidsulphate soil tests. Ex-farm price investigations were inadequate and no rating can be given. Welfare parameters could not be fully investigated; however, in terms of one parameter this aspect can be rated as good.
The overall Balik Pulau site rating on socio-economic aspects therefore is acceptable, for the present.
In order to demonstrate applicability of the procedures in Section 6, the Balik Pulau site has been rated in Tables 6.1 and 6.2. To make a site selection, the site rating should be compared with ratings for other sites that are considered to be alternatives to this site.
