Floating rope deepwater cage fish technology
2018-06-04 23:00:13
In the past 20 years, the large-scale deep-water cage culture technology represented by Norway has been rapidly developed around the world and has achieved remarkable results. It is considered to be the most successful model for marine fish farming. In 2001, Dongtou County, Zhejiang Province produced a total of 25 deep-water cages of three types (of which 18 floating-water deep-water cages), with a total capacity of nearly 30,000 square meters; in 2002, under the guidance of preferential policies, the people The enthusiasm is very high, and 205 floating-water type deep-water cages have been added. The specifications are mostly 13mx13mx8m. Breeding has been successful. The breeding techniques in the test process are summarized as follows:
First, the sea area choice
l. Deep water cages have a deeper water level than traditional cages, which are generally more than 8 meters. Therefore, the minimum tide level of large tides in the sea area should be greater than 10 m.
2. The bottom is suitable for mud or silt. If there is a high sediment content, it is necessary to pay attention to whether the anchor or pile can have enough “grasping†power. There should be no reefs (stones) and large hard sediments within the anchorage range.
3. Although the floating rope type deep-water cages are more resistant to wind and waves than the traditional frame type cages, the destructive power of strong typhoons is unpredictable. Therefore, it is advisable to consider sheltering objects for site selection. In addition, try to avoid the trenches.
4. The water quality requirements are relatively clear, the transparency is above 30cm, the pH value can be maintained at about 8, and there is no factory sewage impact.
5. The maximum flow velocity of the general tide should not exceed 1.1m/s.
Second, culture species Currently, deep-water cage culture species mainly include American redfish, squid, large yellow croaker, scallop, squid, red snapper, bell pepper, sea bream, black sea bream, sea bream, etc. In short, the deep-water cage aquaculture species, one must consider its resistance to waves, anti-flow capacity; the second is the growth rate and survival rate; Third, the market demand conditions and prices and other comprehensive factors.
Third, cage materials and production of deep-water cage mesh materials must have high strength, corrosion resistance and other properties, such as polyethylene, cotton and other filaments, can not use inexpensive renewable products; mesh generally 3cm - 5cm, No knots; economic conditions permit, the best anti-fouling paint mesh treatment. Deep-water cages are relatively large and it is difficult to make home-style containers. They should be equipped with equipment, experienced and qualified network manufacturers. In addition to the nets around the cage, there must be certain reinforcements in the middle of the cage. Mesh Gang, reinforced ribs and mesh seams and joints must first be threaded through the mesh to fix the mesh, and then be fixed with the mesh or ribs, and should not slip. Vertical meshes, ribs and upper and lower mesh joints, and upper and lower corners of cages should have reinforced (or double-layered) mesh.
Fourth, the anchoring system is based on the local fishermen's production habits and anchored anchorage. Each group of cages can be connected in series of 5 - 7 ports, the main anchor weight 400kg or more, with an anchor cable diameter greater than 38mm, the secondary anchor (also known as edge anchor) weighing more than 250kg, equipped with a diameter greater than 30mm anchor cable. The length of anchor cable is about 100m for the main anchor, 60m for the sub anchor, or the depth of water for the sea area. The length of the main anchor cable is equal to or greater than 4 to 5 times the depth of the tidal orgasm, and the length of the auxiliary anchor cable is equal to or greater than The tide is 3 to 4 times deeper.
5. After the orientation of the cage loading and unloading operations is completed, the steps for loading and unloading the cage are as follows:
1. Install the cage 1 cage under the sea, tie the cage to the frame rope; 2 tie the buoys; 3 turn the mouth net over the buoy and attach it to the frame rope; 4 lower the sinker to open the cage.
2. Lifting cage 1 from the sink, remove the nets; 2 Gradually pull the net around the cage to the bottom, enter the net to catch the fish to the corner, or to open the net and The outline of the frame rope, remove 1 - 2 buoys into the frame so that the cage will be separated from the cage net mesh gradually pulled up to the fish or completely from the net.
Six, aquaculture daily management
1. Feeding Due to the wider waters in deep-water cages and smooth water flow, the natural biological feeds are much more abundant. Therefore, the amount fed can be less than that of traditional cages. If it is fed artificial compound feed, fresh feed and artificial feed ratio can be fed 4--5:1. When feeding, pay attention to the fish feeding conditions in the cage. If fish is found to be significantly reduced, check the cage for damage.
2. Networking and cleaning of fouling attachments in the sea area not only affects the exchange of water inside and outside the cage, but also increases the pressure of the water on the cage. If oysters and other hard shellfish are attached, the cage will be worn out. Therefore, check the net frequently. The contamination of tanks is one of the most important aspects of the management of deep-water cage culture. When necessary, it is necessary to clean or change the net. Because deep-water cages are more difficult to change screens, it is best to use them together with fish size grading.
3. The daily management of deepwater cage culture is basically similar to that of traditional cages.
4. In order to accumulate experience, relevant records should be made in the breeding process.
VII. Breeding density and biomass Because deep-water cage fish farming is still in the initial stage of development, the current breeding density and unit yield are still very low. Under normal circumstances, the float rope type deep-water cage with the specifications of 13mx13mx8m can be stocked to specifications of about 150g. The species of fish is 40,000-50,000, and the yield is about 25,000 kg.
Li Shengkai Chen Guowei Dongtou Fisheries Research Institute, Zhejiang Province 325700
First, the sea area choice
l. Deep water cages have a deeper water level than traditional cages, which are generally more than 8 meters. Therefore, the minimum tide level of large tides in the sea area should be greater than 10 m.
2. The bottom is suitable for mud or silt. If there is a high sediment content, it is necessary to pay attention to whether the anchor or pile can have enough “grasping†power. There should be no reefs (stones) and large hard sediments within the anchorage range.
3. Although the floating rope type deep-water cages are more resistant to wind and waves than the traditional frame type cages, the destructive power of strong typhoons is unpredictable. Therefore, it is advisable to consider sheltering objects for site selection. In addition, try to avoid the trenches.
4. The water quality requirements are relatively clear, the transparency is above 30cm, the pH value can be maintained at about 8, and there is no factory sewage impact.
5. The maximum flow velocity of the general tide should not exceed 1.1m/s.
Second, culture species Currently, deep-water cage culture species mainly include American redfish, squid, large yellow croaker, scallop, squid, red snapper, bell pepper, sea bream, black sea bream, sea bream, etc. In short, the deep-water cage aquaculture species, one must consider its resistance to waves, anti-flow capacity; the second is the growth rate and survival rate; Third, the market demand conditions and prices and other comprehensive factors.
Third, cage materials and production of deep-water cage mesh materials must have high strength, corrosion resistance and other properties, such as polyethylene, cotton and other filaments, can not use inexpensive renewable products; mesh generally 3cm - 5cm, No knots; economic conditions permit, the best anti-fouling paint mesh treatment. Deep-water cages are relatively large and it is difficult to make home-style containers. They should be equipped with equipment, experienced and qualified network manufacturers. In addition to the nets around the cage, there must be certain reinforcements in the middle of the cage. Mesh Gang, reinforced ribs and mesh seams and joints must first be threaded through the mesh to fix the mesh, and then be fixed with the mesh or ribs, and should not slip. Vertical meshes, ribs and upper and lower mesh joints, and upper and lower corners of cages should have reinforced (or double-layered) mesh.
Fourth, the anchoring system is based on the local fishermen's production habits and anchored anchorage. Each group of cages can be connected in series of 5 - 7 ports, the main anchor weight 400kg or more, with an anchor cable diameter greater than 38mm, the secondary anchor (also known as edge anchor) weighing more than 250kg, equipped with a diameter greater than 30mm anchor cable. The length of anchor cable is about 100m for the main anchor, 60m for the sub anchor, or the depth of water for the sea area. The length of the main anchor cable is equal to or greater than 4 to 5 times the depth of the tidal orgasm, and the length of the auxiliary anchor cable is equal to or greater than The tide is 3 to 4 times deeper.
5. After the orientation of the cage loading and unloading operations is completed, the steps for loading and unloading the cage are as follows:
1. Install the cage 1 cage under the sea, tie the cage to the frame rope; 2 tie the buoys; 3 turn the mouth net over the buoy and attach it to the frame rope; 4 lower the sinker to open the cage.
2. Lifting cage 1 from the sink, remove the nets; 2 Gradually pull the net around the cage to the bottom, enter the net to catch the fish to the corner, or to open the net and The outline of the frame rope, remove 1 - 2 buoys into the frame so that the cage will be separated from the cage net mesh gradually pulled up to the fish or completely from the net.
Six, aquaculture daily management
1. Feeding Due to the wider waters in deep-water cages and smooth water flow, the natural biological feeds are much more abundant. Therefore, the amount fed can be less than that of traditional cages. If it is fed artificial compound feed, fresh feed and artificial feed ratio can be fed 4--5:1. When feeding, pay attention to the fish feeding conditions in the cage. If fish is found to be significantly reduced, check the cage for damage.
2. Networking and cleaning of fouling attachments in the sea area not only affects the exchange of water inside and outside the cage, but also increases the pressure of the water on the cage. If oysters and other hard shellfish are attached, the cage will be worn out. Therefore, check the net frequently. The contamination of tanks is one of the most important aspects of the management of deep-water cage culture. When necessary, it is necessary to clean or change the net. Because deep-water cages are more difficult to change screens, it is best to use them together with fish size grading.
3. The daily management of deepwater cage culture is basically similar to that of traditional cages.
4. In order to accumulate experience, relevant records should be made in the breeding process.
VII. Breeding density and biomass Because deep-water cage fish farming is still in the initial stage of development, the current breeding density and unit yield are still very low. Under normal circumstances, the float rope type deep-water cage with the specifications of 13mx13mx8m can be stocked to specifications of about 150g. The species of fish is 40,000-50,000, and the yield is about 25,000 kg.
Li Shengkai Chen Guowei Dongtou Fisheries Research Institute, Zhejiang Province 325700