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Oyster culture technology Author: coreone Submission Date: March 29, 2006 1 9: 34: 00 | Classification: | Visits: 345 I. Oyster culture method (1) Riprap culture method This method is suitable for intertidal zone and subtidal zone with hard substrate, and boxing stone or larger stone is selected as attachment base. At present, this law has been phased out. (II) Cement belt cultivation method This method is the most widely used oyster cultivation method in China at present, and its main cultivation techniques are: after cement belt seedlings are attached, the date of transplanting and cultivation should be correctly grasped. In order to shorten the incubation period, the transplanting work should start after 10+00, because barnacle seedlings are basically not attached in this sea area after 10+00. Try to finish it before the end of 1 1. Breeding area should be selected in low tide area, which can increase feeding time. In the muddy sea area, avoid the place where the tide is too fast. This is because the shells of oysters are opened at high tide and low tide, and sediment is poured into the body, leading to suffocation and death. In the choice of cultivation form, the hard substrate can be single-inserted, and the soft coating substrate should be tufted, because this can enhance the wind resistance, avoid soft feet from falling to the ground, and save labor. Cultivation method: the arrangement should be in the tidal direction, and the drainage between rows can reduce sedimentation and subsidence. (3) The hanging culture method is an advanced technology of oyster culture at home and abroad, which has the advantages of short culture cycle and high yield, and is the development direction of oyster culture in China. The following are introduced respectively: 1, raft culture method: This method is suitable for the inner bay with water depth of more than 4 meters and calm wind and waves during dry tide. The structure and size of rafts vary from place to place, and there is no uniform specification. Rafts are usually made of logs and bamboo, ranging from 5× 10/0m to10m. Each raft uses 6-9 floating buckets or other floating objects as buoyancy and is fixed to the seabed with anchors or piles. Hang oyster shell strings and rubber strips with seedlings on the raft for culture, or hang a single oyster cage on the raft for cage culture of oysters. 2. Long rope culture method (used in Ningbo): The long rope is twisted with 1500 strands of polyethylene monofilament, with a total length of 96 meters. Piling shall be carried out at both ends of the seabed, with 30-meter-long pile cables at both ends (specifically, the length of pile cables shall be determined to be at least twice the water depth at full tide), and the middle 36-meter floating raft shall be tied every 1.5 meter. The distance between extension lines is 1- 1.5 times that of local tidal culture. The floating raft should form an angle of 50-60 degrees with the mainstream to form a pull-out phenomenon. The advantage of this method is that it has great ability to resist wind and waves. 3. Scaffolding culture: This method requires a steady tidal current with a flow rate of 20-25 cm/s and an appropriate amount of fresh water. Physical and chemical factors such as food organisms, water temperature and salinity in this sea area are suitable for oyster culture. The culture area should be selected in the low tide area or the area with a water depth of 2-3 meters in the small flood season. The transparency of seawater should be above 0.5 meters, and the coating should be flat and not too soft, and the coating should be sandy or muddy. Scaffolding consists of two or more rows of corresponding parallel stumps (bamboo and stone) and horizontally laid polyethylene ropes (or bamboo). The stakes are arranged downstream. The distance between two piles in a pile row is 3-4m, and the relative distance between rows is about 1 m.. The length of pile row depends on the farm site, generally 3 meters, and the pile head is larger. At the top of the pile head, the piles are connected in series with more than 240 strands of polyethylene rope or bamboo, and the polyethylene rope is fixed at both ends of the pile row with inclined piles to form a fixed low shed. 40-45 days after picking seedlings, after the seedlings meet the production requirements, the seedling pickers with oyster seedlings are dispersed and moved to the scaffolding in the low tide area for cultivation. Hang the two ends of the oyster shell seedling picker on the polyethylene rope or bamboo in the cultivation shed, and the seedling strings are slightly parabolic, with the string spacing of 20-25 cm, and hang in parallel, and the lowest point of the seedling strings is more than 20 cm away from the beach surface. (4) Other ways of culture: At present, there are other ways of oyster culture in China, such as bottom sowing and beach planting. Second, the routine management of oyster culture includes: regular inspection and observation, especially after the typhoon, the seedling attachment device should be arranged in the sea in time to reduce the sedimentation and subsidence in the process of raising oysters with cement. Under normal circumstances, mud should be scraped along the furrow of the cluster feet once a month. In hanging culture, impurities and excessive attachments attached to rafts and seedlings should be removed in time. When a broken rope falls into the mud, it should be hung up in time, especially to prevent the raft and rope from being washed away and the scaffold from collapsing, and it should be reinforced in time before the typhoon season comes. (1) Red tide: Red tide is very harmful not only to fishery, but also to shellfish culture. The organisms that produce red tide mainly include Cyclobalanopsis, Chlamydomonas, Cercospora, spinosad, nocturnal insects and so on. A large number of oysters died due to the invasion of red tide. (2) Carnivorous Gastropods and other natural enemies: Carnivorous Gastropods such as red snails and litchi snails are extremely harmful to oysters, while barnacles, sea squirts and bryozoa compete with oysters for attachment and food, which affects the attachment and growth of oysters; Others, such as Scylla serrata, shrimp and some sole fish, are also very harmful to oysters. (3) Fungi and parasites: There are few reports about oyster diseases and parasites in China, and there are reports abroad that microsporidia parasitism in oysters leads to a large number of oyster deaths, and Vibrio disease in Japanese oysters. Bovine paragonimiasis and trichinosis involve oysters. (4) Industrial wastewater pollution and pesticide pollution: At present, with the development of township enterprises, many industrial wastewater is discharged into the sea without treatment, which has caused great harm to oyster culture. In addition, due to the excessive use of many highly toxic pesticides, the water discharged from farmland will also become one of the pollutants. For these hazards, as farmers, we should avoid red tide-prone sea areas and agricultural wastewater pollution areas in site selection, strengthen the management of enemy organisms, especially at seedling stage, and remove enemy organisms attached to seedlings in time.