Annex X
STATUS OF SANITATION AND MARKETING OF MOLLUSCA IN THE REPUBLIC OF KOREA

Yoon Ho Dong

National Fisheries Research and Development Agency

I. INTRODUCTION

Marine products in the Republic of Korea play an important role in providing protein food for the people as well as generating income for fishermen and foreign exchange for the country. On the other hand, as population increases and the economy becomes highly industrialised, the coastal areas will likely become more polluted with effluent from industries and homes, especially if measures are not taken to lessen or avoid their impact.

Shellfish growing in coastal areas are particularly susceptible to contamination from inland. The shellfish accumulate chemicals harmful to man which makes it very necessary to consider the problem of food sanitation. Persistent pesticides especially the organochlorine insecticides, heavy metals, PCB (polychlorinated biphenyls) and radioactive substances, aside from pathogenic microorganisms, remain in the water. However, the impact of these chemicals on the environment has not been fully assessed. The spread of these persistent chemicals into most parts of the environment would be a cause for anxiety until we know much more about persistence, distribution and long term ecological effects.

In order to solve these problems of safety, and to produce shellfish for export, the ROKorea has been conducting sanitary examination on oyster farming since 1961. In 1972, the government concluded a sanitation agreement on shellfish in connection with a contract made with the United States of America. The government designated four areas called “Blue Belts” in which molluscs for export are produced. The Blue Belts are controlled for sanitation and anti-pollution. They have a total area of 20,614 ha. In addition, the government has designated 29 “Preservation Areas” to control reclamation, dredging and establishment of factories in coastal zones.

Mollusc production from capture totalled 829,307 MT in 1988. This included squid and other species. The catch is sold through cooperatives located in coastal regions and in public markets which are located inland.

Shellfish species of commercial importance include oyster, baby clam, are shell, cockle, top shell and abalone. Most of these are sold fresh, some as processed products i.e. canned, frozen and dried which are also exported. With oyster, the total quantity of frozen oyster exported added up to 1,212 MT. Oysters in airtight containers was 8,980 MT, dried oysters 782 MT. The average price of mollusca sold in Korea was 565 Won per kg in 1988. However, fishery products are subject to fluctuations in prices because of its high perishability, irregularity of production, seasonal variation, and other uncertainties caused by environmental and natural reasons.

II. SANITARY QUALITY OF SHELLFISH GROWING AREAS

1. Present conditions

The sanitation principles of the bacteriological quality in Blue Belts in Korea agree with that of the Approved Areas in America. Bacteriological quality of sea water for harvesting shellfish is as follows: The total coliform median or geometric mean MPN of the sea water does not exceed 70 per 100 ml and less than 10% of the sample exceeds MPN of 230 per ml for a five-tube decimal dilution test.

Table 1 shows that the bacteriological quality of both Blue Belt and non-Blue Belt areas in the southern coast of Korea are in accordance with standards. The figures indicate that at present the shellfish growing areas are in good condition.

Table 1. Density of coliform group in oyster growing areas (1987).

2. Yearly variation of water quality, Southern Coast

The sanitary quality might be based on the total quality of habitat, the amount of effluent from sewage treatment plants, vessel traffic and rainfall in the area. Quality of fishery products is therefore related to the water quality. Table 2 shows that the water quality in Chungmu in the vicinity of the urban community is deteriorating. In recent years, the density of sanitary indicative bacteria (E. coli) in the area has been increasing.

Table 2. Yearly variation of water quality in Chungmu harbour.

III. SANITARY QUALITY OF SHELLFISH

1. Bacteriological quality of oyster during harvest. The bacteriological quality of shellfish and fishery products for export must meet the following standards: The fecal coliform median or geometric mean MPN does not exceed 230 per 100 gm of sample. The total bacteria plate count does not exceed 100,000 per gm.

   The National Fisheries Research and Development Agency has examined the bacteriological quality of oyster in Blue Belts and non-Blue Belts, in accordance with the above-mentioned standards, over several decades. The fecal coliform median of oysters in both areas were less than 18 per 100 gm of oyster and not more than 6.1% of the samples exceeded an MPN of 230 per 100 g. The bacterial plate count did not exceed more than 50,000 (Table 3).

Table 3. Sanitary quality of oysters during the harvesting period in 1987.

2. Heavy metals and radioactive substances. In the process of industrialization, the environment has been polluted by hazardous materials. Some heavy metals such as As, Cd, Hg, Cu, Pb which are poisonous and deleterious substances penetrated the organisms during processing, treatment and handling. As has been reported, there have been some incidents of food poisoning due to heavy metals. One example is the Minamata disease from Hg poisoning, another is the Itai-Itai disease caused by Cd.

   Fishery products are closely related with water quality. The permissible limits for hazardous substances in fish and fishery products are shown in Table 4.

   The contents of heavy metals in oyster are slightly higher than that of mussels but all the contents are below the legal limits enforced in several countries (Table 5).

Table 4. Legal limits for hazardous substances in fish and fishery products in various countries (ppm).

In 1985, we investigated the distribution of radioactive matter such as gross beta activity, strontium-90 and cesium-137 in shellfish and seaweeds from the shellfish growing area and in the vicinity of Kori nuclear power plant. The concentration of gross beta activity in shellfish ranged from 12.6 to 132.9 PCI/g-ash The concentration of strontium-90 and cesium-137 in shellfish ranged from 0.01 to 3.83 and 0.01 to 7.56 PCi/g-ash, respectively. Comparing the highest values of radioactivity of the marine species to the maximum permissible concentration for drinking water recommended by the International Commission for Radiological Protection (ICRP), the ratio of shellfish to the recommended level were 1/13 to 1/4 for strontium-90, 1/834 to 1/101 for cesium-137. This means that the radioactive content of shellfish in Korea was far below the recommended level of radioactivity for drinking water.

Table 5. Content of heavy metals in oyster and mussels (ppm).

3. Persistent pesticides. The persistent pesticides, especially the organochlorides BHC, Aldrin, Endrin, Heptachlor, DDT, etc. have a long-term persistent activity. These chemicals are very harmful to human beings. Our agency has been surveying the content of residual pesticides for several years now. The data on oysters show that the levels are below the limits set by the FDA (Table 6).

Table 6. Permitted limits in shellfish by FDA.

IV. MARKETING OF MOLLUSC

The 1988 catch of mollusc by the fishery section is shown in Table 7. The total volume was 829,307 MT including squid and other cephalopods.

Table 7. Mollusc landings from different fishery section in 1988 (MT)

The market prices of the various molluscan species in 1988 are listed in Table 8.

Table 8. Retail price of several mollusc species in 1988.

The average price of mollusc was 565 Won/kg. The price of fresh fish, shellfish and other fishery products are subject to fluctuations because of various factors that include the high perishability of the commodity, uncertainties in production, seasonality, environment and other reasons.

In small-scale fish landing and facilities, the marketing of fishery products becomes a problem when large quantities are brought in.

V. PROBLEMS

In order to make good use of space, each coastal country should consider a plan for protecting the fishery resources from pollution. Measures would include formulation of a land use and management law and an evaluation of the factors that relate to sanitary quality of a shellfish growing area such as sources of pollution, effects of wind, tides and currents in the distribution an dilution of pollutants, and the bacteriological quality of the water.

It is strongly recommended that a government permit be required for the growing of shellfish and that such permit may be revoked or suspended for just cause. It is also recommended that the government have authority to regulate the discharge of sewage, radioactive and other toxic wastes from boats in the vicinity of approved shellfish growing areas.