Articles and Resources

HACCP in shrimp farming

The authors conducted a training workshop on the application of HACC in shrimp farming in Chennai, India on the request of MPEDA and NACA. This article is based on their resource paper.

The Thai shrimp aquaculture industry has had an excellent record in the production of safe products of consistent quality. However, as aquaculture production expands, the industry and regulatory agencies become more concerned with hazards that impact on people!¡¥s health an safety. Specific problems which may be encountered in shrimp aquaculture products include:

- Contamination by microbial pathogens e.g. Salmonella, Vibrio cholerae.
- Presence of veterinary drugs (and other substances) that may have hazardous effects on consumers, handlers, and the environment.
- Residues of aquaculture chemicals or other environmental contaminants.

A surveillance program for cultured shrimp can include HACCP at all operations, including the production and handling of raw materials, processing operations, the processing environment, handling and storage practices, and distribution activities. This approach reduces reliance on analytical tests and the need for comprehensive inspection of finished aquaculture products by dealing with a hazard before it impacts on processors and consumers. Hazards in shrimp aquaculture include microbiological and chemical hazards associated with the inappropriate use of drugs and chemicals in aquaculture.

Background
Production from shrimp aquaculture in Thailand has increased from 1.2 million kg in 1986 to 3.3 million kg in 2003 (Fisheries Information Center, 2004). The industry involves 80% small-scale farmers and 20% intensive scale  aquaculture. Shrimp has become a major port commodity and its production, processing and marketing a major source of income of people in the industry.

Environmental impacts of shrimp have been an increasing concern of government and the public. The impacts include mangrove removal, salinity intrusion on ground waters, impacts on coastal environment and resources, and effects of residues of chemical and drugs on health and the environment. In order to maintain trust on safety, quality and environmental concerns, preventive measures are taken to reduce the above hazard to environment and maintain the survival of aquaculture species. These measures include ICZM, farm design and management techniques, seawater irrigation systems, establishment of farmer associations, treatment of shrimp pond effluent, supportive government policies and regulation.

The Thai shrimp aquaculture industry has had an excellent record for the production of safe products of consistent quality. Techniques such as surveillance and inspection of final products do little to assure the food safety. The hazard analysis critical control point system (HACCP) enables aquaculturists and processors to exercise more control over food safety HACCP is essentially a technique based upon anticipation and prevention of food safety hazards and it may be applied throughout the food chain from producer through to final consumer, leading to enhanced food safety and better use of resources.

The Department of Fisheries together with the aquaculture industry and processing industry has jointly developed preventive approaches to assure control over raw materials, the manufacturing process, the production environment, and personnel. It is based on the identification of potential hazards, application of control measures at critical control points (CCP), and monitoring and verifying of CCPs thereby enabling the assurance of food safety during culture and processing.

Application in shrimp farming
Black tiger shrimp (Peneaus monodon) is cultured for four to five months in earthern ponds and fed with formulated pellet feed. Water can be either changed continually throughout culture period or not at all i.e zero water discharge system. Permitted antibiotics or chemicals may be used to treat shrimp at larval stages or when shrimp are found infected. Shrimp is harvested manually. Harvested shrimp is put in ice within 15 minutes after catch, it is then sorted and packed in ice and shipped to the processing factory. The process is depicted by Figure 1.

Haszard analysis
Specific hazards that may be encountered in shrimp aquaculture are shown in Table 1:

Applying HACCP
The potential hazards in aquaculture should be identified, and all activities associated with production, harvesting, processing, storage, distribution, and marketing evaluated. This includes a review of:

- The use of antibiotics, and other veterinary chemicals. - Potential sources and specific points of bacterial contamination during production and processing. - The potential for microorganisms to survive or multiply in aquaculture products. - The risks and the severity of all hazards identified. It is necessary to establish whether: - Pathogenic microorganism/toxins may be present in raw materials. - Pathogens may contaminate aquaculture products after harvest.

In Thailand it is recognized that specific hazards that may be encountered in shrimp aquaculture products include: Contamination by bacterial and viral parthogens e.g. Salmonella, Vibrio cholerae, and presence of antibiotics (and other substances) which may have potentially hazardous effects on consumers, handlers, and the environment.

It is largely accepted that the microbiological quality of the production environment impacts on the microbiological quality of the fish and ultimately the processed product. They represent a threat to human health when they are consumed raw, hence there is needed for control over production, harvesting, processing, and distribution. Claims on the potential hazards from Salmonella and Vibrio species in the context of shrimp are conflicting. Salmonella and Vibrio cholerae are known to be part of the natural microflora of brackish water cultured shrimp, and pose a major concern for processors and exporters (Reilly and Kaferstein, 1997). In contrast, Salmonella has not been recovered.

Clearly, cultured crustaceans may present a threat to public health if they are not grown and harvested under hygienic conditions. Once harvested, aquaculture species are at risk from contamination in the processing plant with a wide range of pathogenic bacteria derived from the processing environment, water used in processing, equipment, and food handlers. There is need for more research to identify and assess potential hazards and to quantify the risks. Antibiotic residues became of concern in 1992, when Japan!¡¥s healt authority rejected some shipments of shrimp products from Thailand and other Southeast Asian countries that were contaminated with oxytetracycline and oxoloinic acid. In 2002, Nitrofuran and chloramphenicol came under the spotlight of the European market. The US Food and Drug Authority expressed concerns over residues in shrimp. These prompted studies and a surveillance program to prevent these hazards initiated by the Department of Fisheries.

Preventive measures Preventive measures, using HACCP concept, can be developed specifically to prevent drug residue and chemical contamination in aquaculture products and to prevent microbiological contamination at the farm and processing plants. Those measures are outlined as follows:

Controls at farm level Measures taken:

1.Register farms
2.Control the uses of feed/antibiotics
3.Monitor residue in products from farm
4.Mobile unit control of diseases, use of antibiotic and feed
5.Monitoring the quality of water (both inlet and outlet of farms)
6.Inspect farm hygiene and post- harvest handling practices.
7.Train farmers on good aquaculture practices (GAP), safe use of chemotherapeutic agents and good handling practices

Farm registration
All shrimp farms must be registered and obtain permits to operate. General requirements include: Establishment of water treatment ponds; lay out approval by DOF; quality of water outlet does not exceed a biological oxygen demand of 20 mg/l; drainage of mud and brackish water to public water ways is not allowed; application of good farming practices; and farm hygiene and handling practices should be at a satisfactory level (based on Codex Guidelines on hygienic practices for the product of aquaculture).

Farm inspection
Farm inspection ensures that the farm observes required sanitation and operational standards. A farm sanitation checklist was developed based on Codex Guidelines and used in inspection. The criteria for inspection are: Large scale farms of more than 8 ha must institute a farm management program which is approved by DOF. Farms are inspected by DOF two to four times a year to verify farm records. Small farms (less than 8 ha.) are visited by a mobile unit inspection service. DOF operates 22 mobile units in major aquaculture areas, the units inspect approximately 8 farms a week and rotate their visits until all areas are covered, which often means not less than 5 inspections per farm over a year.

Feed quality control
In order to prevent the use ¡§ inadvertent or intentional - of feed containing antibiotics, the following control measures are enforced: Registration of feed formulas; sampling feed/analysis for antibiotic residue (from plants and farms); and inspection of feed mills.

Farm monitoring
Twenty-two mobile units operated by them Coastal Aquaculture and Fisheries Research and Development Centers conduct surveillance and provide technical advice on: Farm sanitation monitoring; disease control; water quality monitoring at inlet and outlet; soil quality inspection and determination; quality of surrounding water; antibiotic residue in shrimp from pond; and use of feed and antibiotics. A farm sanitation rating report has been developed following the Codex Code of Hygienic Practices for the product of aquaculture.

Raw materials control
The effectiveness of the surveillance program at farm level is verified by determining the level of drug residue in shrimp raw materials from farms. The 17 units equipped with HPLC were set up in major aquaculture areas to inspect the quality of shrimp prior to harvesting. The activities include: Establish record of farm; sampling shrimp from farm (> 3 months) prior to harvesting to determine level of drug and chemical residue using microbioassay. A certificate of antibiotic-free raw materials will be given for shrimp that are drug free. One unit equipped with LC-MS-MS was set up to inspect nitrofuran in shrimp before harvesting.

Processing plant monitoring
To prevent microbiological hazards such as Salmonella, monitoring of processing plants are conducted. In addition to microbiological hazards, chemical hazards such as antibiotics and chemical residues, which are of concern to a verification program are prevented through monitoring of sanitation, hygiene and processing (p48) practices of the plant and verification of end product quality.

Monitored are:
- Sanitation, hygiene, good manufacturing practice as a basic quality control program.
- Processors must demonstrate a Quality Control program based on HACCP.
- Quality system verified by DOF.
- Processing plants are inspected 2-4 times/plant/year, for sanitation, hygiene practices, quality control system, laboratories and record at Critical Control Points and sanitation record. Those that pass the grade are included in the List of Approved Fish Processing Plants and issued an Approval Number.
- Sanitary Certificate and Certificate of Analysis of the shipment are issued, on request, to processing establishment and shipment that meet standard requirements.

Product monitoring
As required still, by import authorities, shipment of fishery products must be accompanied with a certificate stating the quality or laboratory results. This requires sampling and analysis of end products for safety, quality and wholesomeness. For drug residue, shipments are examined by:

For drug residue, shipments are examined by:
- Sampling for antibiotic residues of the group of tetracycline, penicillin and others using micro-bioassay
- Sampling for oxolinic acid using HPLC
- Sampling for chloramphenicol using HPLC
- Sampling for nitrofuran and its metabolites using LC-MS-MS

For microbiological hazards, shipments are determined for pathogenic bacteria and other microorganisms based on the requirements of the market. The maximum level for antibiotics and other contaminants imposed by a number of importing countries or blocks are as per table 3.

Conclusion
Preventing hazards to people!¡¥s safet and health to human from cultured products can be made more effective by the application of HACCP at the farm, in other words, before the raw material even goes into the processing plant. Lima dos Santos (2002) said that HACCP can be applied through the food chain from primary production to final consumption but stressed that its implementation should be guided by scientific evidence of risks to human health.

A combination of measures are observed to prevent or control disease outbreaks. HACCP would be an effective complement to health management practices. HACCP application, along with observance of Good Aquaculture Practice (GAP) or Code of Conduct for sustainable aquaculture (CoC), enhance the overall effort at promoting sustainable and profitable aquaculture.

References
Tookwinas, S. and S. Suwanrangsi 1996 Hazard Control in Aquaculture. Page 338-391 in R.E. Martin, R.L. Collette and J.W. Slavin, editors. Fish Inspection, Quality Control and HACCP ; A Global Focus, Proceeding of the Conference Held in May 19-24, 1996 Arlington, Virginia, Techinnomic Pub. Co., INC. USA.
Fish Inspection and Quality Control Division. 2004. The Maximum Level for Antibiotic and Contamination Sustance in Fisheries Products, Department of Fisheries, Bangkok.
Fisheries Information Center. 2004. Fisheries Statistic of Thailand, Department of Fisheries, Bangkok (contact information).
Lima dos Santos, C.A. 2002. Hazard Analysis Critical Control Point and Aquaculture. Page103-119 in M.L. Jahneke, E.S. Garrett, A. Reilly, R.E. Martin and E. Cole, editors. Public Animal and Environmental Aquaculture Health Issues, Wiley-Interscience, Inc.
Reilly, A. and F. Kaferstein. 1997. Food Safety Hazards and the Application of the Principles of the Hazard Analysis and Critical Control in Aquaculture Production. Aquaculture Res. 1997(28): 735-752.

Tags · Shrimp Farming · HACCP · Thailand · Quality · Aquaculture · Handling · Contamination

17.02.2008. 09:45