Natural fish seedlings from near-seaside fisheries have grown in ponds over a period of seven months. The specification is 0. 17 kg per tail and is a high-quality, high-quality, disease-free species。
Ii. Main technologies
Fish breeding
At the beginning of january, the fish species were fed in the first half of the month by dry ponds with raw lime water, amounting to 60 kg/acre, in order to kill the harmful fungus and other fish shrimps, and then into 1 m deep water, with a concentration of 1,200 tails/acres, with a specification of 0. 25 kg/tails, and a total of 2090 kg。
2. The bait feed
At the end of march, when the temperature of the good water rose, a small number of food cakes were fed at a rate of 0. 45 kg/acre between two and three days. By 25 april, the daily feeding rate had increased to 0. 9 kg/acre, at 10 a. M., and at the beginning of may there had been a gradual introduction of better-quality silver luminous granule feed (fast growth material), which had also increased, to 8 kg/acre by 25 may and an increase or decrease in the feeding rate based on daily inspections. The daily feeding rate increased to 14 kg/acre by 25 june. When the water quality deteriorates or when the fish head is severe in the morning, no bait is delivered at once and measures are taken accordingly。
3. Water quality management
One of the keys to fish farming is to regulate the quality of water and guard against floating ponds. The water is usually added once a week and the water is increased by more than 20 cm each. If the water is thicker, the water is pumped into the pool and added to the new water, so that the water is more than 30 cm transparent, so that the water is yellow or brown, so green as oil, and so on, so long as it is old as ink, blue and so forth, it must be replaced by heavy water. It starts at 12 p. M. Every day and closes after 8 a. M. If the weather is bad and the water quality deteriorates, the water level will be kept to the highest level after the end of may。
4. Prevention of fish disease
The pikes are impetuous and vulnerable to injuries during water pumping, on-boarding, etc., so as to keep the fish in the pond as low as possible when they move by the pond, when they open, and every half month they are sprayed with lime, amounting to 15 kg/acre, in order to prevent bacterial diseases such as aqueous disease and skin disease. In the event of detection of an abnormal activity or death, the diagnosis is timely and the symptoms are drugged。
Capture techniques
In recent years, the price of pikes has been highest in june-august, so good returns are dominated by hot water catch, which is best at 0. 35 to 0. 6 kg/end. But there was a high mortality rate in the summer, so there was an increase in the good and bad methods of fishingEconomic benefitsKey。
Non-fast-growing feeds, such as casseroles or powder no. 4, must be replaced about 10 days before the arrest, with a slight reduction in feeding. Eating one or two days before the arrest is stopped and the net is drawn more than three times, but in order to control the timing and speed of the pull, it is generally done at a slow pace when the first pull is not floated in the morning, without allowing the shuttle to jump or to move too intensely, otherwise it will be hit or bruised. The formal pull will also be slow, with around half an hour to reach the remaining one-third of the pond area, while the aerobic booster will be operated, and in case of a shortage of oxygen, the pump will have to be pumped for oxygen, which will reduce the death of the pike, usually with a survival rate of over 90 per cent。
6. Stock recharge
Once the fish that meets the specifications has been caught, the tablets taken from the sea are replaced with 3 to 6 cm, preferably immersed with disinfectants to prevent bacteria. Depending on the size of the pre-existing large-specified pike, only a small fraction of the original amount could be replenished by approximately 2000 tailings/acre。
Iii. Results
The pond, which covers an area of 11. 5 acres, was seized five times during the period from july to august, with a total of 3511 kg and a total of 8165 tails, with an average specification of 0. 43kg/tail and a gain of $13. 41 million. By the end of the year, another 1888. 5 kg of barp, with an average specification of 0. 51 kg/tail, yielded $497 million. A total of 1785 kg, with a total of 1115 tails, with a total output of 0. 16 kg/tails of 7184. 5 kg, with an average acre production of 624. 7 kg, acre production of 427. 6 kg (of which 182 kg/acre weight of species and 15. 1 kg/acre of tablet fish) and a survival rate of 86. 1 per cent for commercial fish and 48. 5 per cent for species。
The total revenue of the pond (of which the species were not retained for sale at $20/kg) amounted to $80,000 at a total cost of $13,950,000 for a net profit and $121,000 for acre profits。
Summary discussion
1. Pork farming, the most efficient farming species in the region in recent years, has generated such acreage gains, mainly because the price of permeable fish is more than several times higher than that of other farmed fish, while the cost of farming is similar to that of conventional fish farming, and because of its low level of disease, high growth, variety of food and environmental resilience。
2. In the view of the authors, the main reason for the high price is the insufficiency of supply and demand in the market, while there are currently some areas of limitation and scope for the sale of piston farming. Cultivated areas are mainly salty freshwater ponds along the coast of ningbo, sausing and sea ponds, where seedlings are easily sourced and obtained from natural fishing. For other farming areas, the rate of long-distance transport of seedlings to life is lower, and no unit of mass artificial reproduction is available, so that the total production of puss is not too high. And there are good consumption habits for pikes in areas like hangzhou。
3. Possiculture is an advanced and new farming model in the eastern part of tsinghu city in recent years, and is mostly combined. The advantage of this farming method is that it does not have to be used exclusively for baiting the puss, but simply to improve water quality management requirements, which generally have a concentration of 300 tails/acres. The disadvantage is that it is not possible to fish exclusively for the herring, but only once at the end of the year。
4. In the course of farming, fish have repeatedly surfaced in open ponds, mainly because of the fact that water quality is too high and transparency is only 25 cm, and because it is difficult to satisfy the dissolved oxygen requirements of fish when an oxygen-added machine starts at 10 p. M., it is essential that the water quality of the ponds be strictly controlled and not overweight, that once it is overweight and that two 3 kilowatts of oxygen be installed in fish ponds from 10 to 15 acres, in case of uncertainty. There is also a need not to be over-heavy with regard to nutrient density, and it is recommended that 900 - 1,200 tails/acres be appropriate。
It is important that the specifications of the pikes be kept under control, that the market is now the most popular of which is 0. 35 to 0. 6 kg/tails, and that there will be a marked decline in prices if they are too large or too small, and that, as a result, in the farming process, it is necessary to check regularly the farm specifications of the fish in the pool, which should be fed to fast-growing feed at a smaller scale, and that overspect feed should be delivered less or with high levels of crude fibre to slow their growth。
