ANNEX 7

EVALUATION OF POTENTIAL AQUACULTURE SITES SURVEYED IN MALAYSIA

Some 34 sites were covered in the survey. In order to have some comparative assessment of the mangrove, a point system has been devised and each area graded the best way one can. Much of the information is gathered from people of the area besides what were observed during the survey. The results tabulated below and the method of evaluation is explained.

It should be noted that the areas covered are too vast, and time too limited, hence these observations should be considered preliminary. Further in-depth study of points to be considered after this survey will be in order and should also include pH, possible effect of pollution in the future, etc.

EXPLANATION OF THE EVALUATION BY POINT SYSTEM

A value of 10 is most ideal, while the lower the value the less ideal it becomes. The following criteria were used:

(1) Accessibility - road right into the mangrove central area would be 10; if area can be reached with short distance or within walking distance, 9; across a creek 8, and so on.

(2) Socio-economic impact - 1 000 above, families (6 persons per family) to eventually benefit takes a 10, 500-5; 20-2; etc.

(3) Water supply system - if there are ideal creeks and waterways evenly branching through the mangrove of good depth and width takes 10 points, etc.

(4) Area - 1 000 ha or above takes a 10, 500-5; 200-2, etc.

(5) Water quality - takes into consideration (a) salinity at 20–30 ppt considered ideal; (b) turbidity not of silt but moderate amount of plankton (pH was the important parameter which we had no instrument for testing hence was not included).

(6) Soil quality - sand content, organic content, diking quality, good handling (manual) quality, etc. are considered. This should be made from surface down to at least one meter.

(7) Kind of trees - nipa lowest; bakhaw or Rhizophora between the nipa, apiapi or Avicennia, higher and mixture of these and other trees also serve to arrive at a point in classification. It has been observed that nipa and high tannin containing trees have long lasting low pH effect on new ponds. Presence of certain trees, shrubs, ferns indicate in a way the elevation and prevalence of tide water overrunning the area, also certain trees indicate abundance of fresh water.

(8) Density of trees - too many big trees would take a low score as it would take a number of years to clear site of stumps and roots. No or very few trees would be high score as area would be easy to work on and no follow up cleaning and clearing roots, etc. necessary.

(9) Elevation - mean land level elevation based on zero (0) datum of the tide table (MLLW - mean lower low water). Note the land survey datum used in Malaysia is Mean Sea Level (MSL). In brackish water ponds with 3 m tidal difference or fluctuation, the ideal pond bottom level is or close to Mean higher low water (M-H-L-W). This would allow the ponds to be drained yet have maximum water when necessary. Pond bottom requirements vary with the species of organisms intended to be cultured and elevation at MSL (mean sea level) will do if Chanos is to be cultured provided the tidal range is about 3 m. In this classification MHLW land level gets a 10. Too deep or too high gets lower rating.

10 for 0.8 to 1.5 m

9 for 1.6 to 1.8 m

8 for 1.9 to 2.0 m

7 for 2.1 to 2.2 m

6 for 2.3 to 2.4 m

5 for 2.5 to 2.6 m

4 for 2.7 to 2.8 m

3 for 2.9 to 3.0 & 0.7 to 0.6 m

2 for 3.1 to 3.3 & 0.5 to 0.4 m

1 for 3.3 to 3.6 & 0.3 to 0.2 m

(10) Mechanization - how easily can the pond be constructed with the use of LGP (low ground pressure) excavation equipment, dozer traxcavator, dragline, etc. More firm soil gets higher rating -- deep soft mud that cannot hold much pressure per given area gets lower rating.

(11) Exposure - if area is shielded from strong winds by mountains - if so, it gets high rating especially if the area does not flood. Strong winds and flooding are factors influencing these ratings.

These ratings should then be multiplied by a factor which may range from 0.5 to 3. If emphasis is laid on socio-economic factor, then multiply that rating by 3 and so on then add the points for each area.

For example under Malaysian conditions, the suggested relative weights of the criteria considered are as follows:

The above relative weight multiplier will tend to minimize the importance of less important criteria while magnifying the more important ones. The total points are then added and the highly rated sites can be given a more detailed scrutiny so that a decision for the best choice of project sites can be made:

On the final decision perhaps certain other factors can and must be considered which have been omitted in the preliminary investigation due to lack of time and facilities. These are:

1. pH or acidity of soil and water

2. Proximity to international airport for flying in and out of fry

3. Availability of power supply (electricity)

4. Availability of trash fish and other feed sources

5. Availability of skilled and common manual labour

6. Abundance of suitable fry for culture in area

7. Proximity of the market

8. Pollution outlook

9. Proximity to ice plants and cold storage facilities

Considering the point system of classification, in this survey, we find that Tanjong Dawai in Kedah the highest pointer followed by Bagan Pancor, Sulgai Tinggi, Passir Hitam, Sungai Kerang and Jaron Mas in Perak as alternate in the west coast.

In the east coast, Kuala Kerteh in Trengganu seems best suited for demonstration and experiments while Sungai Chukai and Kampong Pulau Krengga and Merchang also of Trengganu may be suitable only for an experimental station but with very little area for expansion.

It should be noted however that pH or soil and water acidity is a very important factor that was not undertaken during the overall classification due to lack of facilities. It should therefore influence the final site selection to a very great degree inasmuch as the success or failure of the station might depend on it. Soil acidity can be corrected but takes a long time and with considerable expense. The suggested layout plan for these selected sites are shown in Figures 8a and 8b.

Assessment:

EVALUATION OF SUITABILITY FOR FISHPOND DEVELOPMENT OF VARIOUS SWAMPLAND SITES SURVEYED IN WEST MALAYSIA