Detailed Explanation of Key Technical Points for Scientific Application of Fishery Drugs

Fishery drugs are all substances used to prevent, control and treat diseases, pests and harm of aquatic animals and plants, promote healthy growth of cultured species, enhance the body's disease resistance and improve the quality of aquaculture water. Here we specifically introduce several correct medication methods for the prevention and treatment of aquatic animal diseases:

I. Apply drugs according to the disease. There are many varieties of fishery drugs, and their physical and chemical properties differ. Therefore, before using fishery drugs, the main diseases and pathogens of the cultured prevention and treatment targets must first be accurately diagnosed, a treatment plan must be made, and then a suitable drug variety must be selected for targeted treatment; otherwise, it will not only fail to achieve the proper prevention and treatment effect, but also delay effective treatment timing, increase costs, and ultimately cause losses in aquaculture production. Accurate diagnosis is the foundation of treating the disease.

II. Apply drugs at the right time. Aquaculture targets live and move in the water throughout their entire growth cycle, and signs of disease onset are not easily observed early, so it is difficult to use drugs in time to treat and control them. For outbreaks that have already occurred, in most cases the medication period is too late; attention is often paid only when the disease has infected most of the cultured targets, especially when epidemic diseases occur. Only then does drug use begin, and most treatments for protecting production have unsatisfactory results. Therefore, in general, some preventive measures should be taken based on the occurrence information provided by the local aquatic disease forecasting department and in combination with actual aquaculture conditions, and the principle of "early detection, early isolation, early treatment" should be followed. During aquaculture management, patrol the ponds more often, observe carefully, and take timely measures as soon as problems are found. Treatment in the early stage of disease is notably effective and can quickly control the spread and contagion of diseases and pests.

III. Apply the proper amount of drugs. Before applying drugs, the water body must first be accurately measured, the pond water volume calculated, and the pond water quality characteristics as well as factors such as water temperature and pH tested, to prepare for selecting the dosage. When using various fishery drugs, it is necessary to understand whether the drug is within its efficacy period, then follow the upper and lower limits of the recommended concentration in the instructions, and select an appropriate concentration according to the severity of the prevention and treatment target's condition and the characteristics of the water quality environment. Never increase or decrease it at will or abuse it blindly. Too high a dose may cause stress in the prevention and treatment targets, while too low a dose affects efficacy, delays treatment timing, and the result is increased aquaculture costs. In addition, the number of medication applications should also be correctly controlled to achieve a good prevention and treatment effect.

IV. Apply drugs evenly. When using fishery drugs, the drug should be shaken well and diluted. In particular, disinfectant drugs should first be diluted 100 to 200 times with water, then evenly splashed from the upwind side of the pond to the downwind side. If aeration equipment is available, turn it on to let the pond water flow, so that the drug can quickly and evenly dissolve and diffuse into the water body, avoiding localized concentrated application that causes stress or poisoning in the prevention and treatment targets. The medication time should avoid the midday period of direct sunlight, and is best carried out from 8 to 10 a.m. or 4 to 6 p.m. on sunny days. Within 24 hours after application, carefully observe the population dynamics of the prevention and treatment targets and track the condition.

V. Rotate drugs. In disease prevention for cultured targets in the same pond, long-term repeated use of a certain type of drug can easily cause viruses and bacteria to develop drug resistance. This leads to reduced drug efficacy, and ultimately the drug cannot control the viruses and bacteria, causing explosive death of cultured targets. Furthermore, frequent use of the same drug can easily cause large accumulation of residual toxins in the bodies of the prevention and treatment targets, reduce their immunity, cause chronic poisoning, and also affect the quality and safety of aquatic products; after human consumption, it can also harm health. Therefore, different prevention and treatment drugs should be rotated or used alternately to prevent the development of drug resistance.

VI. Mix drugs reasonably. At present, mixed use of fishery drugs is very common. Reasonable and scientific mixing of fishery drugs can improve prevention and treatment effects, increase efficacy and reduce costs. When mixing drugs, operating procedures must be strictly followed; not all fishery drugs can be mixed. Mixing two or more drugs can produce two opposite results. One is called synergism, namely helping each other to strengthen efficacy; the other is called antagonism, namely offsetting each other to reduce efficacy. Therefore, the characteristics of the fishery drugs to be mixed must first be understood, and incompatibilities avoided, so as to prevent loss of efficacy or drug harm. For the mixing of fishery drugs, it is best to first prove the feasibility of the effect through tests by technicians, and then summarize, promote and use it.

VII. Apply drugs safely. When preparing and applying fishery drugs, attention should be paid to personal safety. Some drugs have a strong irritating odor in the air or can harm human skin upon contact at high concentrations, so masks and protective gloves should be worn during operation to avoid harming health. When applying drugs, stand on the windward side and do not apply drugs facing the wind. The use of fishery drugs should pay attention to the conditions of use, scope of use and the withdrawal period before harvest; drug residues must not exceed standards, and it must be implemented in accordance with the Guidelines for the Use of Fishery Drugs in Pollution-Free Food, carrying out "green and healthy aquaculture" and caring for consumers' health.