Hard to Get Rich from Aquaculture? Disease Prevention and Control Is the Key
In recent years, with the increase in stocking density and the amount of commercial feed fed, and the pollution of the water environment, a number one enemy has emerged in aquaculture, and that is aquaculture diseases. Once a disease worsens, it brings huge economic losses to farmers. Many farmers have truly gone to great lengths to solve this problem, but the results are often less than satisfactory. In response to this situation, the first thing to do is to understand the types and causes of current aquaculture diseases, and to propose timely and effective prevention and control measures, so as to be prepared before diseases occur and to remedy them after they occur.
1. Epidemic Trends of Aquaculture Diseases
At present, the epidemic trends of aquaculture diseases are mainly as follows. First, there are many types of diseases, and new diseases keep emerging. Because some diseases occur for the first time, they are difficult to detect in advance, and moreover some farmers are not yet sufficiently aware of disease prevention and control, so new diseases persist for a period of time. Second, diseases spread over a wide range and occur very frequently. There are now more and more aquaculture areas, which naturally broadens the range of aquaculture diseases and makes the harm greater. Finally, current prevention and control of aquaculture diseases involve the use of large amounts of drugs, which gives many pathogens a certain drug resistance; drug-resistant diseases are severe, and the difficulty of prevention and control increases accordingly.
2. Causes of Aquaculture Diseases
Aquaculture diseases occur from time to time in fishery production and always cause certain losses. Only by knowing yourself and your enemy can you win every battle, so if you want to carry out disease prevention and control, understanding the causes of diseases is essential:
2.1 Water Quality Cannot Be Guaranteed
In much aquaculture, farmers place relatively great importance on the selection of fish species and feed, and most pay great attention to quality, but they neglect the most fundamental thing, namely the water on which fish depend for survival. Some farmers do not understand water quality and environmental quality well enough, believing that fish quality is more important than water quality; they focus only on the fish and not on the water, fail to cultivate a good pond of water, and do not clean and replace the pond water regularly, making the water quality environment in the pond very poor.
2.2 Insufficient Preventive Measures
Many other farmers have weak awareness of disease prevention, do not pay attention to quarantine, and do not pay attention to disinfection work in daily operations. Fish ponds are cleaned less and less, or even not cleaned at all, causing diseases to occur continuously and to be unusually severe. When diseases are discovered, they become frantic and turn to any remedy in desperation, indiscriminately applying various drugs to the fish pond, which throws the pond's ecosystem into chaos. As a result, the disease is not alleviated but instead worsens, and more importantly, the drug resistance of the disease increases, harm is also brought to the cultured aquatic products, and new diseases form.
3. Prevention and Control Measures for Aquaculture Diseases
Diseases occur every year and tend to intensify, so under such circumstances it is essential to carry out prevention and control measures, and farmers must attach importance to disease prevention and control:
3.1 Prevention and Control of Bacterial Diseases
The bacterial diseases occurring in our region mainly include bacterial gill rot, red skin disease, and bacterial enteritis. The prevention and control of bacterial diseases mainly requires thorough disinfection work, and the items requiring disinfection include fish ponds and fry, neither of which can be omitted. Fish pond disinfection should be carried out after the autumn and winter harvest, exposing the fish pond to the sun and leaving it for about one and a half months, then disinfecting with a highly effective disinfectant. The main disinfectants used are quicklime and bleaching powder. Among them, quicklime has the best pond-clearing and disinfection effect; it can not only increase the calcium content in the pond but also has a direct fertilizing effect, and quicklime can also eliminate harmful organisms and prevent some bacterial fish diseases.
3.2 Prevention and Control of Fungal Diseases
The common main fungal diseases in this region include saprolegniasis and gill mold disease, and the main drugs used are bromochlorohydantoin and strong chlorin. How to use bromochlorohydantoin: when using, dilute with more than 1000 times water and splash evenly over the whole pond. Treatment: one dose is 0.03~0.04g per 1 cubic meter of water (calculated as bromochlorohydantoin), once a day, and for severe cases use for 2 consecutive days. Prevention: one dose is 0.03~0.04g per 1 cubic meter of water (calculated as bromochlorohydantoin), once every 15 days. Precautions: 1. Do not use metal containers to hold it; 2. Do not use it in oxygen-deficient water; 3. When the water is relatively clear and the transparency is higher than 30cm, reduce the dose as appropriate; 4. Halve the dose for fry. How to apply strong chlorin: when using, dilute with 1000~3000 times water and splash evenly over the whole pond. Treatment: 0.090~0.135g per 1 cubic meter of water (calculated as available chlorine), once daily. Use for 1~2 consecutive times.
3.3 Prevention and Control of Viral Diseases
Secondary infection with bacterial diseases is the main cause of death after cultured aquatic products are infected with viral diseases. Such aquatic diseases mainly include viral septicemia. When carrying out prevention and control, corresponding viral disease preventive measures should be taken. First, clean the fish pond and disinfect it with refined iodine. Then, before the disease season, carry out a second disinfection with refined iodine. Finally, put oral drugs into ponds where the disease has already occurred for prevention and control.
3.4 Prevention and Control of Parasitic Diseases
First, also clean the fish pond, and pay attention to disinfection and sterilization treatment. Second is disinfection of fry. Then, during the disease period, use disinfectants for disinfection and feed the aquatic products with oral drugs. Finally, carry out sterilization treatment when the disease occurs.
Although aquaculture diseases are a major scourge for fisheries and the prevention and control process is also quite arduous, this does not mean that prevention and control of aquaculture diseases is impossible. In fact, as long as prevention and control methods are mastered and prevention and control are carried out in the right direction, the effect of disease prevention and control is very obvious. This article introduces the current epidemic trends and causes of aquaculture diseases, and on the basis of these analyses proposes prevention and control measures. It is hoped that these measures can truly help aquaculture farmers achieve disease prevention and control, increase the survival rate of aquatic products, and ensure the quality of aquatic products, thereby achieving relatively large economic benefits.
Author: Feng Chengrong. Friends of Peasant Wealth
