RAS-1984 — Page 207

186

Y.H. CHEUNG, K.Y. TAI, S.W. TSAO AND L.B. THROWER

the kei wais during the first to fifth lunar months. This was harvested by people from China and used for feeding pigs: an average of 15,750 kg. is harvested per year.

Yield from a shrimp harvest carried out on 3 October 1978 was as follows:

Shrimps 9 kg Crabs 3 kg Freshwater fish 9 kg (striped mullet — 3 kg, tilapia 6 kg) Marine fish 3 kg

Similarly, yield from a fish harvest carried out on 6 October 1978 was:

Shrimps 12 kg Marine fish 225 kg Freshwater fish 498 kg (Japanese sea perch: 24 kg., striped mullet: 360 kg., blind sea bass: 18 kg., tilapia: 120 kg., eels: 18 kg.) Miscellaneous fish 90 kg (sea bream: 150 kg., tiger fish: 15 kg.) Crabs: 135 kg

If these figures are used to calculate the total annual yield, the result for 90 shrimp harvests and 2 fish harvests would be:

Shrimps 834 kg Crabs 540 kg Marine fish 720 kg Freshwater fish 1,806 kg Miscellaneous fish 180 kg or a total of 4,080 kg. usable produce, not including the harvested seaweed.

Unfortunately, the year of our study was the last of the current lease on kei wai No. 7 and another tenant was to take over. Consequently, the operator probably tried to extract the maximum yield during his last year of tenure. Our calculations may therefore have given an over-estimate of total yield. Indeed, the operator's own estimate of mean annual yield was just one-third of our own. However, careful comparison of every category of produce suggested very strongly that he had under-estimated. Consequently, our own estimate for annual yield has been used to calculate the