Sharing Practical Experience in Sea Bass Farming in Shrimp Ponds
In recent years, sea bass has become an important farmed species in northern China, especially when farmed in shrimp ponds, as it takes little time and yields quick results; this technique is worth promoting on a large scale. The farming experience is described below:
Prepare the farming pond. The pond should preferably be 1.3 to 2 hectares in size, with a water depth of about 2 m. The pond bottom may be mud or sand. It is best to dig a deep drainage ditch in the middle of the pond, and make sure there is no pollution around the farming pond. During the winter slack season, use a bulldozer to scrape off the blackened layer of silt on the surface of the shrimp pond, let the pond bottom be fully exposed to sunlight, and then apply 50 kg to 60 kg of quicklime per 1/15 hectare to clear the pond.
Fertilizing the pond and stocking sea bass fry. Introduce water in late March and apply organic fertilizer to grow the basic feed organisms in the shrimp pond. Select healthy sea bass fry of about 150 g that have no missing scales or external injuries on the body surface and respond relatively sensitively to external stimuli for stocking. In this way, after 3 to 4 months of careful feeding, by September each fish can reach more than 500 g, and the farming survival rate can exceed 95%. It is best to stock sea bass fry in May, at 800 to 1,000 fry per 1/15 hectare. Before stocking, soak them in a trichlorfon solution at a concentration of 0.2 mg to 0.3 mg per kg for 3 to 5 minutes to remove parasites on the body surface and gills of the sea bass. Use trichlorfon with extra care, because sea bass are very sensitive to it.
Feeding. Mainly feed shad, sand lance, and frozen mixed fish and shrimp, and intermittently feed young shrimp (frozen). The feeding amount should preferably be 8% to 10% of the fish body weight, fed twice a day, in the morning and in the evening. Measure the body weight of the sea bass once every 15 to 20 days, and adjust the feeding amount according to body weight. The bait must be rinsed clean to prevent contamination of the pond water, and cut into small pieces when necessary so that the sea bass can eat it.
Domestication. Sea bass need to be domesticated so that they can gather in groups at a unified facility. A facility site can be chosen at one spot in the shrimp pond, and feeding can be carried out regularly every day from 5 to 6 in the morning and from 5 to 6 in the afternoon, so that they form a conditioned reflex. When feeding, first throw in a small amount of bait to attract the sea bass to feed, and when most of the fish gather to feed, throw in more, until 70% to 80% of the fish are satiated. After about 20 days of such domestication, pond-farmed sea bass will feed at a fixed location.
Water quality control. Before the sea bass fry are put into the pond, keep the water level at about 1 m, then add 5 cm to 10 cm of water each day. Begin small water exchanges at the end of May, generally exchanging 1/3 of the water every 5 to 7 days. After late June, gradually increase the amount of water exchanged, exchanging 10 cm to 15 cm per day; after late July, exchange 1/4 to 1/3 of the water each day. At the same time, always pay attention to changes in the water color of the pond.
Disease prevention and control. Drive stakes at the sea bass facility site and hang medicine bags to disinfect and kill parasites. Irregularly mix medicine into the bait to achieve the purpose of disease prevention, and observe frequently. If diseased or dead fish are found, diagnose them promptly and apply the right medicine for the illness.