1.0 INTRODUCTION
Molluscan shellfish such as oysters, clams and mussels are important protein sources for humans. Yet their maximum utilization as food is hindered by the public health problems associated with their consumption. Outbreaks of typhoid fever, infectious hepatitis, cholera and paralytic shellfish poisoning (PSP) are among the most commonly reported cases linked to the ingestion of contaminated bivalve meat. These maladies more often results from eating shellfish meat raw or half-cooked. Hence, existing post-harvest technology for molluscan shellfish deals largely on transport, handling, storage and purification procedures of live/fresh shellfish to ensure a safe and edible supply of shellfishes to the public.
2.0 MICROBIAL SAFETY OF SHELLFISH
Bivalves are commonly grown and harvested in estuarine areas. This is where industry and population growth usually occurs and where stream runoff ultimately flows. Consequently, accumulation of microbial pathogens from sewage pollution, heavy metals, pesticides and other toxic substances very likely exists. As bivalves are filter feeders, feeding on planktons and other microflora of the estuary, they are able to concentrate pathogenic bacteria, virus, parasites and other dissolved toxic substances present in the rearing waters.
To safeguard public health, sanitary control of the shellfish industry is highly recommenced through the following steps:
Depuration.
| Coliform Bacteria | Fecal Coliform Bacteria | Fecal Streptococci | Clostridia |
| Characteristics | |||
| Gram-negative rods, facultative, ferment lactose at 35°C | Gram-negative rods, facultative, ferment lactose at 44.5°C | Gram-positive cococci, facultative, grow in the presence of sodium azide | Gram-positive endosporeforming rods, anaerobic, yield stormy fermentation of milk |
| Component Species | |||
| Escherichia coli, E. freundii Enterobacter aerogenes (Acrobacter aerogenes) Klebsiella pneumoniae | Primarily Escherichia coli | Streptococcus faecalis, S. bovis, S. equinus, (S. faccium?) | Primarily Clostridium perfringens |
| Abundance in Human Fecesa | |||
| Escherichia coli: 108.4 (104.3–9.3) Enterobacter aerogenes + Klebsiella pneumoniae: 107.6 (104.0–9.0) | Escherichia coli: 108.4 (104.3–9.3) | S. faccalis + enterococci: 107.4 (103.3–9.3) | 107.4(103.7–9.0) |
(From Finstein, 1973)
Table 1.
Either total coliforms or fecal coliform levels are tested (Table 1) as index of sewage contamination. This becomes the basis for the classification and control of harvest areas thereby prohibiting the culture or harvest of shellfish from areas not meeting approved standards (Table 2). Unfortunately in the Philippines as well as in many Asian countries, most shellfish growing areas do not meet the approved criteria for the culture of shellfish (Table 3).
The bacteriological quality of the shellfish meat is likewise tested using the levels of coliform bacteria as an index of sewage contamination based on the standard procedures set by the American Public Health Association. Generally, the Most Probable Number (MPN) of fecal coliform of not more than 230 per 100 gram meat and a plate count of not more than 500,000 per gram of meat sample is considered to be satisfactory. The MPN values are extrapolated from Table 4. Such bacteriological quality of shellfish meat may be determined at harvest time, after purification, during storage, at the wholesale market and at the retail market level.
3.0 POST-HARVEST HANDLING OF LIVE/FRESH SHELLFISH
As consumers prefer raw or half-cooked shellfish, efficient post-harvest handling techniques, in order to maintain good quality of the bivalve meat and viability of the shellfish allow the rapid proliferation of micro-organisms. Oysters maybe stored by a wet or a dry method. The former involves holding oysters in natural waters either intertidally or subtidally. The dry storage method holds the oysters out of water maintaining a low ambient temperature and high humidity (Table 5). During transport, the shellfish are packed in moist gunny sacks which are constantly moistened with seawater. In addition, rough handling and transport may stress them, resulting in mortalities.
3.1 Purification of bivalves
If shellfish are harvested in culture areas with an unacceptable level of coliforms, they should either be moved to areas of approved waters for a specified period of time, usually 7–15 days. Such a procedure is called “relaying”. This is a natural process of purification by which the shellfish are placed in clean waters to allow elimination of the accumulated pollutants. Another efficient method of bivalve purification is called depuration. The shellfish are stocked in trays inside tanks with almost sterile flowing water. The pumping mechanism of the shellfish while filter feeding eventually reduces the microbial load of the shellfish. Infectious organisms such as virus and bacteria are generally reduced to acceptable levels in 48 hours. Heavy metals, however, are significantly reduced only after 20 days.
| COUNTRY | Recommended Criteria (Limits per 100 ml Water) |
| U.S.A. | Approved area: median MPN should not exceed 70, and not more than 10% of the samples should ordinarily exceed 230 |
| Conditionally approved area: refers to an area potentially subject to pollution; conditional approval is based on meeting requirements as for an approved area and on assurances that contributory-waste treatment facilities are performing satisfactorily | |
| Restricted area: refers to an area from which shellfish may be marketed only after purification by effective procedures (relaying or controlled purification); median MPN should not exceed 700, and not more than 10% of the samples should exceed 2,300 | |
| Prohibited area: refers to an area from which shellfish may be marketed by special permit only, after purification by effective procedures (relaying is preferred over controlled purification); water is of poorer quality than indicated for restricted areas | |
| New Zealand (1966) | Coliforms not to consistently exceed 50 per 100 ml |
| Chile (1951) | Approved areas: coliform monthly average 70 per 100 ml |
| Provitionally approved areas: coliform monthly average 70–700 per 100 ml | |
| Portugal (1968) | Average of two monthly samples 50 coliforms per 100 ml, or 100 coliforms per 100 ml in either sample |
| Italy | Approved area: E. coli MPN of 2/100 ml in 90% of samples taken in one year; not more than 10% of samples taken in one year must contain 6 E. Coli/100 ml. |
| France | Class I (Satisfactory, no E. coli) |
| Class II (Acceptable, 1–60 E. coli/100 ml) | |
| Class III (Suspicious, 60–120 E. coli/100 ml) | |
| Class IV (Unfavorable, over 120 E. coli/100 ml) |
(Complied from Finstein, 1973 and Palpal-Latoc et al. 1986)
Table 2.
Sanitary Quality of Four Oyster - Growing Areas in Pangasinan, Philippines.
| Place | Oyster Production in Tons per annum | Total Coliform (MPN/100 ml) | E. Coli (MPN/100 ml) |
| Dawel (Dagupan City) | 87 | 170 to 24,000 | 2 to 16,000 |
| Salapingao (Binmaley) | 267 | 350 to 24,000 | 20 to 16,000 |
| Gayaman (Binmaley) | 85 | 8 to 9,200 | 2 to 5,400 |
| Nibaliw Central (San Fabian) | 28 | 110 to 24,000 | 2 to 24,000 |
(From Palpal-Latoc et al: 1986)
Table 3.
| Positivea | Positivea | Positivea | Positivea | Positivea | Positivea | ||||||||||||||||||
| 10 | 1 | 0.1 | MPNb | 10 | 1 | 0.1 | MPNb | 10 | 1 | 0.1 | MPNb | 10 | 1 | 0.1 | MPNb | 10 | 1 | 0.1 | MPNb | 10 | 1 | 0.1 | MPNb |
| 0 | 0 | 0 | 0 | 1 | 0 | 0 | 2 | 2 | 0 | 0 | 4.5 | 3 | 0 | 0 | 7.8 | 4 | 0 | 0 | 13 | 5 | 0 | 0 | 23 |
| 0 | 0 | 1 | 1.8 | 1 | 0 | 1 | 4 | 2 | 0 | 1 | 6.8 | 3 | 0 | 1 | 11 | 4 | 0 | 1 | 17 | 5 | 0 | 1 | 31 |
| 0 | 0 | 2 | 3.6 | 1 | 0 | 2 | 6 | 2 | 0 | 2 | 9.1 | 3 | 0 | 2 | 13 | 4 | 0 | 2 | 21 | 5 | 0 | 2 | 43 |
| 0 | 0 | 3 | 5.4 | 1 | 0 | 3 | 8 | 2 | 0 | 3 | 12 | 3 | 0 | 3 | 16 | 4 | 0 | 3 | 25 | 5 | 0 | 3 | 58 |
| 0 | 0 | 4 | 7.2 | 1 | 0 | 4 | 10 | 2 | 0 | 4 | 14 | 3 | 0 | 4 | 20 | 4 | 0 | 4 | 30 | 5 | 0 | 4 | 76 |
| 0 | 0 | 5 | 9 | 1 | 0 | 5 | 12 | 2 | 0 | 5 | 16 | 3 | 0 | 5 | 23 | 4 | 0 | 5 | 36 | 5 | 0 | 5 | 95 |
| 0 | 1 | 0 | 1.8 | 1 | 1 | 0 | 4 | 2 | 1 | 0 | 6.8 | 3 | 1 | 0 | 11 | 4 | 1 | 0 | 17 | 5 | 1 | 0 | 33 |
| 0 | 1 | 1 | 3.6 | 1 | 1 | 1 | 6.1 | 2 | 1 | 1 | 9.2 | 3 | 1 | 1 | 14 | 4 | 1 | 1 | 21 | 5 | 1 | 1 | 46 |
| 0 | 1 | 2 | 5.5 | 1 | 1 | 2 | 8.1 | 2 | 1 | 2 | 12 | 3 | 1 | 2 | 17 | 4 | 1 | 2 | 26 | 5 | 1 | 2 | 64 |
| 0 | 1 | 3 | 7.3 | 1 | 1 | 3 | 10 | 2 | 1 | 3 | 14 | 3 | 1 | 3 | 20 | 4 | 1 | 3 | 31 | 5 | 1 | 3 | 84 |
| 0 | 1 | 4 | 9.1 | 1 | 1 | 4 | 12 | 2 | 1 | 4 | 17 | 3 | 1 | 4 | 23 | 4 | 1 | 4 | 36 | 5 | 1 | 4 | 110 |
| 0 | 1 | 5 | 11 | 1 | 1 | 5 | 14 | 2 | 1 | 5 | 19 | 3 | 1 | 5 | 27 | 4 | 1 | 5 | 42 | 5 | 1 | 5 | 130 |
| 0 | 2 | 0 | 3.7 | 1 | 2 | 0 | 6.1 | 2 | 2 | 0 | 9.3 | 3 | 2 | 0 | 14 | 4 | 2 | 0 | 22 | 5 | 2 | 0 | 40 |
| 0 | 2 | 1 | 5.5 | 1 | 2 | 1 | 8.2 | 2 | 2 | 1 | 12 | 3 | 2 | 1 | 17 | 4 | 2 | 1 | 26 | 5 | 2 | 1 | 70 |
| 0 | 2 | 2 | 7.4 | 1 | 2 | 2 | 10 | 2 | 2 | 2 | 14 | 3 | 2 | 2 | 20 | 4 | 2 | 2 | 32 | 5 | 2 | 2 | 95 |
| 0 | 2 | 3 | 9.2 | 1 | 2 | 3 | 12 | 2 | 2 | 3 | 17 | 3 | 2 | 3 | 24 | 4 | 2 | 3 | 38 | 5 | 2 | 3 | 120 |
| 0 | 2 | 4 | 11 | 1 | 2 | 4 | 15 | 2 | 2 | 4 | 19 | 3 | 2 | 4 | 27 | 4 | 2 | 4 | 41 | 5 | 2 | 4 | 150 |
| 0 | 2 | 5 | 13 | 1 | 2 | 5 | 17 | 2 | 2 | 5 | 22 | 3 | 2 | 5 | 31 | 4 | 2 | 5 | 50 | 5 | 2 | 5 | 180 |
| 0 | 3 | 0 | 5.6 | 1 | 3 | 0 | 8.3 | 2 | 3 | 0 | 12 | 3 | 3 | 0 | 17 | 4 | 3 | 0 | 27 | 5 | 3 | 0 | 79 |
| 0 | 3 | 1 | 7.4 | 1 | 3 | 1 | 10 | 2 | 3 | 1 | 14 | 3 | 3 | 1 | 21 | 4 | 3 | 1 | 33 | 5 | 3 | 1 | 110 |
| 0 | 3 | 2 | 9.3 | 1 | 3 | 2 | 13 | 2 | 3 | 2 | 17 | 3 | 3 | 2 | 24 | 4 | 3 | 2 | 39 | 5 | 3 | 2 | 140 |
| 0 | 3 | 3 | 11 | 1 | 3 | 3 | 15 | 2 | 3 | 3 | 20 | 3 | 3 | 3 | 28 | 4 | 3 | 3 | 45 | 5 | 3 | 3 | 180 |
| 0 | 3 | 4 | 13 | 1 | 3 | 4 | 17 | 2 | 3 | 4 | 22 | 3 | 3 | 4 | 31 | 4 | 3 | 4 | 52 | 5 | 3 | 4 | 210 |
| 0 | 3 | 5 | 15 | 1 | 3 | 5 | 19 | 2 | 3 | 5 | 25 | 3 | 3 | 5 | 35 | 4 | 3 | 5 | 59 | 5 | 3 | 5 | 250 |
| 0 | 4 | 0 | 7.5 | 1 | 4 | 0 | 11 | 2 | 4 | 0 | 15 | 3 | 4 | 0 | 21 | 4 | 4 | 0 | 31 | 5 | 4 | 0 | 130 |
| 0 | 4 | 1 | 9.4 | 1 | 4 | 1 | 13 | 2 | 4 | 1 | 17 | 3 | 4 | 1 | 24 | 4 | 4 | 1 | 40 | 5 | 4 | 1 | 170 |
| 0 | 4 | 2 | 11 | 1 | 4 | 2 | 15 | 2 | 4 | 2 | 20 | 3 | 4 | 2 | 28 | 4 | 4 | 2 | 47 | 5 | 4 | 2 | 220 |
| 0 | 4 | 3 | 13 | 1 | 4 | 3 | 17 | 2 | 4 | 3 | 23 | 3 | 4 | 3 | 32 | 4 | 4 | 3 | 51 | 5 | 4 | 3 | 280 |
| 0 | 4 | 4 | 15 | 1 | 4 | 4 | 19 | 2 | 4 | 4 | 25 | 3 | 4 | 4 | 36 | 4 | 4 | 4 | 62 | 5 | 4 | 4 | 350 |
| 0 | 4 | 5 | 17 | 1 | 4 | 5 | 22 | 2 | 4 | 5 | 28 | 3 | 4 | 5 | 40 | 4 | 4 | 5 | 69 | 5 | 4 | 5 | 430 |
| 0 | 4 | 6 | 9.4 | 1 | 5 | 0 | 13 | 2 | 5 | 0 | 17 | 3 | 5 | 0 | 25 | 4 | 5 | 0 | 41 | 5 | 5 | 0 | 240 |
| 0 | 5 | 1 | 11 | 1 | 5 | 1 | 15 | 2 | 5 | 1 | 20 | 3 | 5 | 1 | 29 | 4 | 5 | 1 | 48 | 5 | 5 | 1 | 350 |
| 0 | 5 | 2 | 13 | 1 | 5 | 2 | 17 | 2 | 5 | 2 | 23 | 3 | 5 | 2 | 32 | 4 | 5 | 2 | 56 | 5 | 5 | 2 | 540 |
| 0 | 5 | 3 | 15 | 1 | 5 | 3 | 19 | 2 | 5 | 3 | 26 | 3 | 5 | 3 | 37 | 4 | 5 | 3 | 64 | 5 | 5 | 3 | 920 |
| 0 | 5 | 4 | 17 | 1 | 5 | 4 | 22 | 2 | 5 | 4 | 29 | 3 | 5 | 4 | 41 | 4 | 5 | 4 | 72 | 5 | 5 | 4 | 1600 |
| 0 | 5 | 5 | 19 | 1 | 5 | 5 | 24 | 2 | 5 | 5 | 32 | 3 | 5 | 5 | 45 | 4 | 5 | 5 | 81 | 5 | 5 | 5 | 2400+ |
a Number of positive tubes with each of three volumes used.
b All figures under MPN may be divided by 100 for reporting MPN per milliliter (or per gram).
Table 4.
| Storage temperature (°C) | Shell-life (days) |
| Room temperature 24 | 2 |
| Under blanket of ice 3.4 | 14 |
| Chilled 4 | 22 |
| Frozen -25 | 64 |
| (From Llobrera et al., 1986) | |
Table 5.
In the depuration process the seawater may be treated with ultraviolet (UV) rays or other disinfecting methods (Table 6) to achieve optimum reduction of microbial load. An open water system is recommended rather than a closed system.
3.1.1 Environmental factors that affect the depuration process are:
Water temperature
Dissolved oxygen
Salinity
Phytoplankton
Turbidity
Bio-deposits on tank bottom
Mortalities
3.1.2 Other considerations
Washing and culling
Baskets
| Sampling Period | Control | Clorine | Iodine | Filtered | Ozone | UV |
| 12 hr. | 2400+ | 2400+ | 130 | 2400+ | 2400+ | 350 |
| 24 | 2400+ | 79 | 540 | 2400+ | 350 | 540 |
| 36 | 2400+ | 2400+ | 2400+ | 2400+ | 350 | 540 |
| 48 | 2400+ | 46 | 110 | 130 | 60 | 79 |
| 60 | 240 | 79 | 33 | 40 | 110 | 43 |
| 72 | 79 | 79 | 110 | 46 | 170 | 13 |
(From Gallego, 1986)
Table 6.
Depuration tanks
Water circulation
Time of depuration
4.0 TOXIC RED TIDES AND SHELLFISH TOXICITY
Some Asian countries experience blooms of the dinoflagellate, Pyrodinium bahamense var. compressa which causes a reddish coloration of the affected waters. These organisms releases a powerful toxin, known as saxitoxin, which can be accumulated into the viscera of shellfishes and fish found in the affected area. When the contaminated shellfishes are consumed by man, the powerful toxins cause Paralytic Shellfish Poisoning symptoms within 30 minutes of investigation. The symptoms are:
| MILD | Tingling sensation or numbness around lips, gradually spreading to face and neck. Prickly sensation in fingertips and toes. Headache, dizziness, nausea. |
| SEVERE | Incoherent speech. Progression of prickly sensation to arms and legs. Stiffness and uncoordination of limbs. General weakness and feeling of lightness. Slight respiratory difficulty. Rapid pulse. |
| EXTREME | Muscular paralysis. Pronounced respiratory difficulty. Choking sensation. |
Death can occur 12 hours after consumption of the toxic shellfish. Even after several months, the toxin is retained by the shellfish. In Sabah, for instance, a 3-month retention period in oysters was reported. Unfortunately, there is no efficient detoxification process so far. Hence, surveillance to monitor the plankton population and mouse bioassay tests need to be conducted the whole year round to warn the public in the imposition of shellfish harvesting bans.
5.0 PROCESSING TECHNOLOGY
Other processing techniques for shellfish are: pickling, salting, smoking, drying, freezing of cooked meat and canning. A popular by-product is the oyster sauce. Moreover, shells of bivalves are important raw materials for lime production, buttons, jewelry, wall decor, lamp shades, window panes, wind chimes and other ornamental items. Another well known by-products are pearls.
6.0 PROBLEMS AND CONSTRAINTS
The level of sewage pollution continues to be a deterring factor in promoting consumers acceptability of shellfish. Although depuration offers a solution for the microbial contamination problem, the resulting blanding effect on the depurated bivalve and its inability to remove heavy metals and biological toxins causing Paralytic Shellfish Poisoning are important limiting constraints. In addition depuration operations entails additional cost to the final product.
7.0 GLOSSARY
| Cholera: | an acute, infectious, epidemic disease characterized principally by serious intestinal disorders caused by a bacterium, Vibrio cholerae and Vibrio parahaemolyticus. |
| Coliforms: | group of bacteria such as Escherichia coli, Enterobacter aerogenes and Klebsiella pneumoniae mostly comprising the microbial flora of the human intestine |
| Hepatitis: | Infectious hepatitis: a viral infection resulting in enlargement of the liver, jaundice, and fever. |
| MPN: | Most Probable Number: a statistical estimate of the number of bacteria per unit volume or weight of medium. |
| PSP: | Paralytic Shellfish Poisoning: a food poisoning condition caused by dinoflagellate toxins which are absorbed by shellfishes to levels toxic to man. |
| Pathogens: | organisms with the ability to cause infection/disease. |
| Run-off: | part of rainfall that is not absorbed directly by the soil but is drained off into streams/rivers. |
| Sewage: | usually refers to human waste matter. |
| Shucking: | removing the shellfish shell. |
| Typhoid fever: | an acute infectious fever caused by the bacteria Salmonella typhosa characterized by severe intestinal disturbances. |
REFERENCES
Cheong, L. 1982. Country Report: Singapore In: Bivalve Culture in Asia and the Pacific. A Proceeding of a Workshop held in Singapore 16–19 February 1982. F. B. Davy and M. Graham (eds.) Ottawa, ont., IDRC 200e pp. 69–71.
Clem, J. D. 1973. Microbiological Considerations in the handling and processing of Molluskan Shellfish In: Microbial Safety of Fishery Products. CO. O. Chichester and H.D. Graham (eds.) Academic Press pp. 55–58.
Davy, F. B. and M. Graham. 1982. Bivalve Culture in Asia and the Pacific. Proceedings of a Workshop held in Singapore 16–19 February 1982. Ottawa, Ont., IDRC - 200e. 90p.
Hunt, D. A., Miescier, J., Redman, J. and A. Salinger. 1985. Molluscan Shellfish, fresh or fresh frozen oysters, mussels or clams. In: Foods and their Safety and Quality. pp. 523–539.
Gacutan, R. Q., Bulalacao, M. L. and H. L. Jr. Baranda. 1986. Bacterial depuration of grossly-contaminated oysters, Crassostrea iredalei p. 429–432. In J. L. Maclean, L. B. Dizon and L. V. Hosillos (eds.) The First Asian Fisheries Forum. Asian Fisheries Society, Manila, Philippines.
Lakshmanan, P. R. and P. N. Krishnan Nambisan. 1985. Uptake and loss of mercury in three bivalve molluscs, Perna viridis (Linnaeus), Villorita cyprinoides var. cochinensis and Meretrix casta (Chemnitz). In: Harvest and Post-Harvest Technology of Fish R. Raumdran, N. Unni Krishnan Nair, P. A. Perigreen, P. Madhauan, A. G. Gopalakrishna Pillai, P.A. Panickor and Ms. Thomas (eds.) Society of Fisheries Technology. Cochin, India pp. 411– 423.
Llobrera, A. T., Bulalacao, M. L. and N. Sunaz. 1986. Effects of storageon the microbial quality of slipper oysters, Crassostrea iredalei p. 437–442. In J.L. Maclean, L. B. Dizon and L. V. Hosillos (eds.). The First Asian Fisheries Forum. Asian Fisheries Society, Manila, Philippines.
Metcalf, T. G., L. W. Slanetz, and C. H. Bartley. 1973. Enteric pathogens in estuary waters and shellfish. In: Microbial Safety of Fishery Products C.O. Chichester and H. D. Graham (eds.) Academic Press pp. 215–237
Neilson, B. J., Haven, D.S. Perkins, F. O., Morales-Alamo, R. and M. W. Rhodes. 1978. Bacterial depuration by the American Oyster (Crassostrea virginica) under controlled conditions. Vol. II. Special Scientific Report No. 88. Virginia Institute of Marine Science, U.S.A. 48 p.
Quayle, D.B. 1980. Tropical Oysters: Culture and Methods. Ottawa, Ont., IDRB-TSITE 80 p.
Palpal-Latoc, E. O., Garcia, R. P., Caoile, S.J.S., Luna, C. Z., Carianga, A. M. and S. A. Fernandez. 1986. The sanitary quality of four Philippine Oyster - Growing areas, p. 447–450. In J. L. Maclean, L. B. Dizon and L. V. Hosillors (eds.). The First Asian Fisheries Forum. Asian Fisheries Society, Manila, Philippines
Rowell, T. W., Robert, G., Swansburg, K. B. and R. Favis. 1976. Soft-shell clam Depuration (Digby, Nova Scotia). Technical Report No. 687 Fisheries Research Board of Canada, Halifax, Nova Scotia. 121 p.
Finstein, M.S. 1973. Sanitary Bacteriology In: Handbook of Microbiology Vol. I Organismic Microbiology A. I. Laskin and H. A. Lechevalier (eds.). CRC Press pp. 789–800.
White, A. W., Anraku, M. and K.K. Hooi. 1984. Toxic Red Tides and Shellfish Toxicity in Southeast Asia. Proceedings of a consultative meeting held in Singapore 11–14 September 1984. SEAFDEC and IDRC ISBN 9971-88-061-X 133 pp.
PUBLICATIONS AND DOCUMENTS OF THE REGIONAL SEAFARMING DEVELOPMENT AND DEMONSTRATION PROJECT RAS/90/002 (RAS/86/024)
Working Papers
RAS/86/024
NACA-SF/WP/87/1. Lovatelli, A. Status of scallop farming: A review of techniques. 22 pp.
NACA-SF/WP/88/2. Lovatelli, A. Status of oyster culture in elected Asian countries. 96 pp.
NACA-SF/WP/88/3. Lovatelli, A. and P. B. Bueno, (eds.). Seminar report on the status of oyster culture in China, Indonesia, Malaysia, Philippines and Thailand. 55 pp.
NACA-SF/WP/88/4. Lovatelli, A. Status of mollusc culture in selected Asian countries. 75 pp.
NACA-SF/WP/88/5. Lovatelli, A. and P. B. Bueno, (eds.). Seminar report on the status of seaweed culture in China, India, Indonesia, ROKorea, Malaysia, Philippines and Thailand. 79 pp.
NACA-SF/WP/88/6. Lovatelli, A. and P. B. Bueno, (eds.) . Seminar report on the status of finish culture in China, DPRKorea, Indonesia, ROKorea, Malaysia and Singapore. 53 pp.
NACA-SF/WP/88/7. Lovatelli, A. Seafarming production statistics from China, Indonesia, ROKorea, Philippines, Singapore and Thailand. 37 pp.
NACA-SF/WP/88/8. Lovatelli, A. Site selection for mollusc culture. 25 pp.
NACA-SF/WP/88/9. Lovatelli, A. and P. B. Bueno, (eds.). Seminar report on the status of finfish netcage culture in China, DPRKorea, Indonesia, ROKorea, Malaysia, Philippines, Singapore and Thailand. 56 pp.
NACA-SF/WP/88/10. Chong, K. C. Economic and social considerations for aquaculture site selection: an Asian perspective. 17 pp.
NACA-SF/WP/89/11. Chen J. X. and A. Lovatelli. Laminaria culture - Site selection criteria and guidelines. 30 pp.
NACA-SF/WP/89/12. Chen J. X. Gracilaria culture in China. 18 pp.
NACA-SF/WP/89/13. Seafarming Project, RAS/86/024. Site selection criteria for marine finfish netcage culture in Asia. 21 pp.
NACA-SF/WP/89/14. Lovatelli A. Seafarming production statistics from China, India, Indonesia, ROKorea, Philippines, Singapore and Thailand. 47 pp.
NACA-SF/WP/89/15. Chong K. C. and D. B. S. Sehara. Women in aquaculture research and training. 20 pp.
Working Papers
RAS/90/002
SF/WP/90/1. Chen J. X. Brief introduction to mariculture of five selected species in China. 32 pp.
Bibliography
NACA-SF/BIB/88/1. Selected bibliography on seafarming species and production systems. 20 pp.
NACA-SF/BIB/88/2. Selected bibliography on seafarming species and production systems. 52 pp.
NACA-SF/BIB/89/1. Selected bibliography on seafarming species and production systems. 49 pp.
Training Manuals
Manual on seaweed farming: Eucheuma spp. (Training manual No. 1). 25 pp.
Culture of the Pacific oyster (Crassostrea gigas) in the Republic of Korea. (Training manual No. 2). 64 pp.
Culture of the seabass (Lates calcarifer) in Thailand. Training manual No. 3. 90 pp.
Training manual on marine finfish netcage culture in Singapore. (Training manual No. 4). 275 pp.
Culture of kelp (Laminaria japonica) in China. (Training manual No. 5). 204 pp.
Training manual on Gracilaria culture and seaweed processing in China. Training manual No. 6. 155 pp.
Training manual on artificial breeding of abalone (Haliotis discus hannai) in Korea DPR. Training manual No. 7. 124 pp.
Meeting Reports
Report of the First National Coordinators' Meeting of the Regional Seafarming Development and Demonstration Project, 27–30 October 1987, Bangkok, Thailand. 71 pp.
Report of the Second National Coordinators' Meeting of the Regional Seafarming Development and Demonstration Project, 20–23 September 1988, Singapore. 102 pp.
Report of the Third National Coordinators' Meeting of the Regional Seafarming Development and Demonstration Project, 24–27 August 1989, Qingdao, China. 103 pp.
Workshop Reports
Report of the FAO Asian Regional Workshop on Geographical Information Systems: Applications in Aquaculture, 5–23 December 1988, Bangkok, Thailand. FAO Fisheries Report No. 414, FIRI/R414. 13 pp.
Report of the Workshop and Study Tour On Mollusc Sanitation and Marketing, 15–28 September 1989, France. FAO/UNDP Regional Seafarming Development and Demonstration Project RAS/86/024. 212 pp.
General Reports
Progress report on the 1988 Regional Training/Demonstration Courses organized under the Regional Seafarming Development and Demonstration Project (RAS/86/024). 26 pp.
Report of the Seafarming Resources Atlas Mission. Regional Seafarming Project RAS/86/024, July 1989. 74 pp.
Audio-visual Materials
Culture of the Pacific Oyster (Crassostrea gigas) in the Republic of Korea. 71 slides.
Culture of the seabass (Lates calcarifer) in Thailand. 40 slides.
Marine finfish netcage culture in Singapore. 37 slides.
Culture of Kelp (Laminaria japonica) in China. 30 minutes video.
Seafarming Atlas Series
Regional Seafarming Resources Atlas. FAO/UNDP Regional Seafarming Development and Demonstration Project (RAS/86/024), January 1990. (Atlas series No. 1). 83 pp.
