Detailed Explanation of the Code of Practice for Pollution-Free Breeding of Domestic Fish

I. Pollution-Free Management and Cultivation of Broodstock

1. The breeding base is required to be free of pollution from the three types of waste; the atmospheric environment must comply with the requirements of "GB3095-1996 Ambient Air Quality Standard"; the soil environment must comply with the requirements of "GB15618-1995 Soil Environmental Quality Standard"; and the aquaculture water must comply with the requirements of "NY5051-2001 Pollution-Free Food Freshwater Aquaculture Water Quality Standard".

2. Broodstock ponds should have an area of 5-15 mu and a water depth of 1.5-2.5 m. The ponds should be exposed to the sun and then strictly disinfected with quicklime and other substances before use.

3. Broodstock should come from nationally qualified improved breed farms, and reserve broodstock should be appropriately selected and bred. Strict transport and epidemic prevention protocols should be adopted for broodstock transport to ensure that the broodstock are disease-free and injury-free.

4. Broodstock should be stocked according to a scientific mixed culture ratio, with emphasis on the main stocked species and appropriate control of the proportion of secondary species, so as to ensure good @#@233@#@ cultivation and normal development of the main species.

5. Broodstock feed and fertilizer must be harmless. Feed quality must comply with the testing requirements of the national quality department and the provisions of "NY5072-2002 Pollution-Free Food Safety Limits for Fishery Compound Feed". Green feed is required to be fresh, tender, and palatable. Organic fertilizer must be fully fermented before application.

6. During broodstock cultivation, attention should be paid to water quality regulation, keeping the water quality lively, tender, and refreshing. Water quality should be improved through regular water injection and exchange, application of quicklime, frequent aeration during high-temperature seasons, and application of microbial preparations.

7. Adhere to prevention as the main approach and strengthen disease and pest prevention and control. When using drugs for prevention, the selection of fishery drugs should comply with the provisions of "NY5071-2002 Pollution-Free Food Guidelines for the Use of Fishery Drugs".

8. Set up posts on duty year-round, with dedicated personnel managing and protecting the broodstock, and carry out the "five preventions" work of anti-theft, anti-harm, flood prevention, anti-escape, and anti-injury.

9. Keep a pollution-free broodstock cultivation management log, and timely record the various operational contents and effects in broodstock cultivation production.

II. Production Management Operations During Induced Spawning and Hatching

1. Before hatching production begins, fully complete preparations in all aspects, including production technical training, personnel post assignment, preparation of various materials, and trial operation of mechanical equipment and hatching facilities.

2. Half a month before hatching, seine the ponds to observe the condition of the broodstock and sort the broodstock. During induced spawning, operations such as seining, selecting, and transferring broodstock must be carried out carefully, and the broodstock must not be frightened or injured.

3. The selection of induced spawning time should be determined in combination with the gonadal development status of the broodstock, pond water temperature, effective accumulated temperature, season, and weather factors, so as to ensure the success rate of induced spawning and hatching and improve fry quality and survival rate.

4. The preparation of induced spawning agents must be carried out strictly according to technical requirements. Suitable types and doses of induced spawning agents should be selected separately according to the species, sex, body weight, and development status of the broodstock, and preparation must be strictly carried out on a one-fish-one-injection basis.

5. Strengthen the management and care of post-spawning broodstock to reduce injury. For broodstock that have completed spawning, place them into post-spawning cultivation ponds promptly after disinfection treatment. For broodstock that partially spawned or did not spawn, after appropriate egg stripping, apply ointment to the wound sites and place them into post-spawning cultivation ponds after strict disinfection. Broodstock with more severe injuries must be cultivated separately and returned to pond cultivation after the wounds heal.

6. Reservoirs, induced spawning ponds, and circular hatching channels should be disinfected and prepared for use at appropriate times. Water used must be strictly disinfected. Production operations such as egg collection must be careful to prevent damage to fish eggs. Egg distribution density should be appropriate, and counting should be as accurate as possible.

7. Hatching management must be careful: frequently lift the boards and stir the water; adjust the nozzle positions appropriately; the water flow speed should be suitable; water temperature and water quality should be tested once every 4 hours; filter screens should be washed and brushed frequently; keep fish eggs and fry living in a suitable flowing water environment; pay attention to sanitation management during hatching; all tools used must be disinfected promptly; and timely prevent viruses and predators of fish eggs and seedlings.

8. Timely observe the development process of fry and promptly handle emergencies. When the fry develop the waist spot, collect and release the fry promptly. Do not overcrowd the fry excessively. Before the fry are released into ponds, feed them an appropriate amount of egg yolk slurry once to improve the survival rate of fry after pond release.

9. Timely keep production records during induced spawning and hatching.

III. Pollution-Free Operations During Fry Cultivation

1. The cultivation pond environment, water quality, and other conditions must all comply with the relevant provisions for pollution-free food production (the same as the broodstock cultivation requirements), and require sufficient electricity, convenient transportation, and complete auxiliary facilities such as irrigation and drainage systems.

2. Pond clearing, cleaning, and disinfection must be thorough; water injection should be appropriate; and water quality fertilization should be moderate.

3. The stocking quantity of fry should be suitable: no more than 200,000 fry per mu at the water-fry stage, no more than 20,000 per mu at the black-fry stage, and within 10,000 per mu at the summer-fry stage. Water fry and black fry cultivation should be carried out in monoculture. At the summer-fry stage, fish species may be appropriately polycultured, but the main cultured fish must be emphasized and the combination must be reasonable.

4. Feed feeding should be scientific, determined according to water quality conditions, fish feeding conditions, weather, and other factors. During water fry cultivation, soybean milk should be splashed evenly and carefully. In the later stage of black fry cultivation, begin training feeding of pellet feed to omnivorous fish. Feed quality must comply with the provisions of "Pollution-Free Food Safety Limits for Fishery Compound Feed" (NY5072-2002). Feeding operations should follow the requirements of "three observations and four fixings".

5. During the cultivation process, water quality regulation should be strengthened. Water quality should be improved through water injection and exchange, application of quicklime, adjustment of water level, and application of microbial preparations, maintaining water quality that is "fertile, lively, tender, and refreshing".

6. Adhere to prevention as the main approach and strengthen the concept of disease prevention. Drug use must follow the provisions of the "Pollution-Free Food Guidelines for the Use of Fishery Drugs". Under the guidance of technical personnel, use drugs scientifically to prevent and treat diseases, and do not abuse fishery drugs.

7. Timely keep production records, and record the various production operation procedures and effects during the aquatic seedling cultivation process in accordance with the traceability requirements for aquatic product quality.