Method for temporarily rearing undaria pinnatifida offspring seed curtain in sea area

Abstract

The invention discloses a method for temporarily culturing undaria pinnatifida offspring seeds in a sea area, and belongs to the technical field of large seaweed culture. According to the method, an undaria pinnatifida seedling curtain is transformed, the seedling curtain is sleeved with a plastic bag of a specific specification, and then sea surface temporary rearing at a specific depth is carried out. According to the method, the current situation that the temporary rearing link in the early stage of algae production can only depend on manual seedling rubbing for a long time, the labor intensity of offshore operation is high, the production quality is unstable, and the labor cost is high is changed, a brand-new undaria pinnatifida seedling temporary rearing method is explored according to the production requirements of enterprises, and the method is convenient to operate and high in practicability. The method saves two seedling rubbing steps, maintains the seedling density and quality stability, reduces the labor intensity, improves the working efficiency of sea temporary rearing of undaria pinnatifida seedlings, reduces the production cost, and has important practical significance.

Description

Technical Field

[0001] The present invention relates to the technical field of large seaweed cultivation, and particularly relates to a method for temporary cultivation of Undaria pinnatifida seedling curtains in the sea area. Background Art

[0002] Undaria pinnatifida is one of the three major economic seaweeds in China. It is edible and is mainly distributed in Dalian, Liaoning, Weihai, Shandong and other places in China, and is also widely distributed in other parts of the world. Undaria pinnatifida is a nutritious marine vegetable, rich in various amino acids and vitamins. The polysaccharides it contains are one of the important active ingredients, and its main forms are fucoidan and alginate, which have the effects of lowering blood sugar, antioxidant, anti-cancer, immune regulation, etc.

[0003] The cultivation of Undaria pinnatifida seedlings needs to go through two stages: indoor cultivation and temporary cultivation in the sea area. In the middle and late September of each year, according to the water temperature, the Undaria pinnatifida seedling curtains cultivated indoors are taken out of the warehouse and hung on the floating rafts in the sea area for temporary cultivation. During the temporary cultivation in the sea area, a large number of fouling organisms such as floating mud, Caprella equilibra, Obelia geniculata, and Gammarus sp. will attach to the seedling curtain ropes, and it is necessary to appropriately rub and rinse the seedling curtains. Specifically, the first rubbing is carried out on the fifth day after the seedling curtains are put into the sea, rubbing off the floating mud and part of the fouling organisms, and rubbing the seedling curtain ropes until the original rope color; two days later, the second rubbing is carried out, and according to the emergence situation and the attachment situation of the seedling curtain attachments, the strength is reduced, and the floating mud and miscellaneous algae on the surface are rubbed off.

[0004] In this temporary cultivation method, the rubbing operation rubs off the Undaria pinnatifida seedlings growing on the outer surface of the seedling ropes together with the fouling organisms and floating mud on the seedling ropes. Basically, the bottom seedlings located between the strands of the seedling ropes are utilized, and the number of seedlings cannot be guaranteed; at the same time, the main fouling organisms with strong attachment ability such as Obelia geniculata are difficult to rub off by rubbing, which harms the growth of the seedlings; moreover, when carrying out the second rubbing, it is difficult to grasp the rubbing strength. If the strength is large, the bottom seedlings will be lost greatly; if the strength is small, the fouling organisms cannot be removed thoroughly, and this work is more difficult for newly recruited workers. Rubbing has a large labor intensity, is time-consuming and laborious. The existing method of preventing fouling by rubbing has problems such as unstable seedling density, unstable quality, and even serious pollution of the seedlings by fouling organisms, resulting in the failure of the temporary cultivation of Undaria pinnatifida seedlings in the sea area. Whether it is the current production practice or relevant literature reports, there is no introduction to solve this aspect of the problem. Therefore, for this necessary link in algae production, for a long time, it has only been possible to rely on the proficiency of the workers to carry out manual operations, resulting in high labor intensity in offshore operations, unstable production quality, and high labor costs. Therefore, in enterprise production, it is necessary to explore a method for temporary cultivation of Undaria pinnatifida seedlings with stable seedling density and quality and reduced labor intensity. Summary of the Invention

[0005] In view of the above-mentioned prior art, the purpose of the present invention is to provide a method for temporarily culturing Undaria pinnatifida seedling curtains in the sea area. Traditionally, during the temporary culturing of Undaria pinnatifida seedling curtains in the sea area, a two-time seedling rubbing process is required. The present invention saves the two-time seedling rubbing process and ensures the stability of seedling density and quality. The present invention improves the working efficiency of temporarily culturing Undaria pinnatifida seedlings at sea, saves costs, is convenient to operate, and has practical application value for Undaria pinnatifida farming work.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] In the first aspect of the present invention, there is provided a method for temporarily culturing Undaria pinnatifida seedling curtains in the sea area, including the following steps:

[0008] (1) Take the Undaria pinnatifida seedling curtain that has emerged from indoor cultivation, put it into a plastic bag with openings at both the upper and lower ends, and place it in the sea for temporary cultivation;

[0009] (2) When the length of the Undaria pinnatifida seedlings reaches 0.3 - 0.7 mm, remove the plastic bag; according to the growth state of the Undaria pinnatifida seedlings, lift the Undaria pinnatifida seedling curtain in a timely manner, and harvest when the Undaria pinnatifida seedlings reach the seeding size.

[0010] Furthermore, in step (1), the width of the plastic bag is 5 - 10 cm longer than the crossbar of the Undaria pinnatifida seedling curtain; the length of the plastic bag is 1 m - 1.2 m, and the lower opening edge of the plastic bag is 5 - 10 cm longer than the lower end of the seedling rope.

[0011] Furthermore, in step (1), the initial length of the hanging rope of the seedling curtain is 0.3 - 0.7 m shorter than the seawater transparency.

[0012] Furthermore, in step (2), at the knot of the hanging rope for tying the Undaria pinnatifida seedling curtain, tie the upper port of the plastic bag and put the seedling curtain into the plastic bag.

[0013] Furthermore, in step (2), in the part between the mouth of the bag and the crossbar of the seedling curtain, 5 - 10 holes with a diameter of 1 - 2 cm are horizontally arranged at equal intervals on each surface of the plastic bag at a distance of 3 cm from the crossbar of the seedling curtain.

[0014] Furthermore, in step (2), starting from the day after removing the outer plastic bag, rinse the seedlings every day until harvest.

[0015] Furthermore, in step (2), when the seedlings reach 0.7 - 1.5 mm, lift the length of the hanging rope of the seedling curtain to half of the transparency; when the seedlings reach 1.6 - 2.5 mm, shorten the length of the seedling rope to 1 - 2 m.

[0016] The beneficial effects of the present invention:

[0017] (1) The present invention modifies the kelp seedling curtain. The seedling curtain is put into a plastic bag of a specific specification and then temporarily cultured in seawater at a specific depth. In seawater, the plastic cloth is washed by the tidal current and wave current, and floating mud, fouling organisms such as gammarids and caprellids cannot adhere to the surface of the plastic cloth on the surface of the kelp seedlings, so the plastic bag is relatively clean. The plastic bag adheres to the seedling rope. Due to the small space inside the bag, the nutrients and dissolved oxygen are reduced, and the growth of fouling organisms on the seedling rope is inhibited. A small amount of seawater enters the plastic bag through the holes, and there is less fouling substance entering the plastic bag, and the pollution intensity is small. Therefore, there is less fouling substance on the seedling rope. The appearance of the plastic bag is relatively clean, and the light-blocking effect is not obvious. In the early stage, the kelp seedlings are small and have little demand for light and nutrients. The initial hanging rope length is 0.3 - 0.7 m shorter than the seawater transparency, which can ensure the light demand of the internal kelp seedlings with the outer plastic bag, and the normal growth of the kelp seedlings is not affected.

[0018] (2) The method for temporarily culturing the kelp seedling curtain designed by the present invention can replace the two rubbing seedling operations in actual production. This temporary culturing method does not affect the growth of kelp seedlings. The density and seedling specifications are similar to those in actual production, and the same growth time is consumed to reach the seeding specification, reducing the labor intensity and improving the seedling quality. In terms of reducing the labor intensity, during the temporary culturing of kelp seedlings at sea, a breeding team of about 40 workers needs to manage 1,000 seedling curtains. In addition to handling the daily affairs of their respective management areas, when performing the rubbing seedling operation, in order to meet the production requirement of rubbing seedlings once a day, all the workers in the breeding team need to go to work. Rubbing seedlings once requires a total of 40 man-hours. The bagging operation can save this process. In terms of improving the seedling quality, since the bottom seedlings on the seedling rope (the bottom seedlings generally refer to the gametophytes in the strands of the seedling rope or the sporophyte seedlings developed from the gametophytes) are relatively fragile, when rubbing seedlings for the second time, excessive rubbing force can rub off the bottom seedlings. In the present invention, no rubbing seedlings is carried out, which can preserve the bottom seedlings and improve the seedling quality. Therefore, the method of the present invention improves the working efficiency of temporarily culturing kelp seedlings at sea, saves costs, is convenient to operate, and has practical application value for kelp breeding work. Description of the Drawings

[0019] Figure 1 It shows the condition of the kelp seedling curtain with an open plastic bag (before going to sea). Figure 1 In the photo, the left side of the plastic bag (without a green structure in the background) is the lower end, and the right side (with a green structure in the background) is the upper end (near the sea surface). From the figure, it can be seen that the seedling rope in the plastic bag will not exceed the lower left port of the plastic bag even when straightened.

[0020] Figure 2 It shows the mud adhesion and fouling organism attachment situation of the seedling curtain with an open plastic bag after being in the sea for a period of time. Figure 2In the photo, the lower end is on the left side of the plastic bag (with no green structure in the background), and the upper end (near the sea surface) is on the right side (with a green structure in the background). From the figure, it can be seen that even when the seedling rope in the plastic bag is straightened, it will not exceed the lower port on the left side of the plastic bag.

[0021] Figure 3 It is a seedling curtain for covering window screening.

[0022] Figure 4 It is a seedling curtain for covering perforated plastic bags.

[0023] Figure 5 It is a seedling curtain with an inner layer of window screening and an outer layer of open plastic bags.

[0024] Figure 6 It is a seedling curtain with an outer layer of perforated plastic bags and an inner layer of window screening.

[0025] Figure 7 It is a seedling curtain of Undaria pinnatifida after the second seedling rubbing operation.

[0026] Figure 8 It is the microscopic examination situation of the seedlings of Undaria pinnatifida on the seedling curtain covered with open plastic bags.

[0027] Figure 9 It is the microscopic examination situation of the seedlings of Undaria pinnatifida after two seedling rubbing operations.

[0028] Figure 10 It is a section of the seedling rope of Undaria pinnatifida on the seedling curtain covered with open plastic bags before seedling clamping production.

[0029] Figure 11 It is a section of the seedling rope of Undaria pinnatifida after two seedling rubbing operations before seedling clamping production. Specific implementation mode

[0030] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0031] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the technical solution of the present application will be described in detail below in combination with specific embodiments.

[0032] During the testing and production process of the present invention, the transparency is measured with a transparency disk. The size of the transparency depends on the turbidity of the water (referring to the degree of turbidity caused by various plankton and suspended substances in the water) and the chromaticity (the color caused by suspended organisms and dissolved organic matter). Therefore, the transparency varies in different seasons. When in use, the transparency disk is lowered to the depth where it can just not be seen clearly, and the length of the rope below the water surface is marked as the transparency of the water body.

[0033] The test materials not specifically described in the embodiments of the present invention are all conventional test materials in the art and can be obtained through commercial channels. The material of the seedling rope (seedling line) on the seedling curtain for Undaria pinnatifida is vinylon rope with a diameter of 2 mm containing a small amount of polyethylene filaments; the window screen is made of 18-mesh polyethylene material.

[0034] The seedlings of Undaria pinnatifida start to be cultivated in June every year. Around the end of September, the indoor seedlings are transferred to the sea area for temporary cultivation. In October, the seedlings that reach the seeding specification are seeded onto the cultivation seedling ropes and are cultivated by floating rafts in the sea area. The main harvest period is from February to April of the following year. The experiment of the present invention was carried out in the sea area of Bailanzi, Lvshunkou District, Dalian.

[0035] Example 1: Temporary cultivation of Undaria pinnatifida seedling curtains with bags and nets

[0036] On September 23, bagging and netting operations were carried out on 15 Undaria pinnatifida seedling curtains with consistent appearance and seedlings cultivated in the seedling nursery. The specific bagging and netting methods are as follows:

[0037] (1) Cover with window screen

[0038] After removing the redundant frame of the Undaria pinnatifida seedling curtain, a window screen with open upper and lower ends is put on the seedling curtain. At the knotting points of the two hanging ropes for tying the seedling curtain, the upper port of the window screen (the end close to the cross bar of the seedling curtain is the upper end) is tied with a cable tie, and the seedling curtain is set inside the window screen. The width of the window screen is 5 cm longer than the cross bar of the Undaria pinnatifida seedling curtain tied with iron rods. The mesh of the window screen is 18 meshes, the material is polyethylene, and the length is 1 m, ensuring that the lower opening edge of the window screen is 5 cm longer than the lower end of the seedling rope.

[0039] (2) Cover with an open plastic bag

[0040] After removing the redundant frame of the Undaria pinnatifida seedling curtain, a white polyethylene plastic bag with open upper and lower ends is put on the seedling curtain. At the knotting points of the two hanging ropes for tying the seedling curtain, the upper port of the plastic bag (the end close to the cross bar of the seedling curtain is the upper end) is tied with a cable tie, and the seedling curtain is set inside the plastic bag. The width of the plastic bag is 5 cm longer than the cross bar of the Undaria pinnatifida seedling curtain tied with iron rods. The length of the plastic bag is 1 m, ensuring that the lower opening edge of the plastic bag is 5 cm longer than the lower end of the seedling rope. At the part between the upper end tie of the bag and the cross bar of the seedling curtain, 7 holes with a diameter of 1.5 cm are horizontally arranged at equal intervals 3 cm away from the cross bar of the seedling curtain on each side of the plastic bag. See specifically Figure 1 .

[0041] (3) Cover with a plastic bag with holes tied

[0042] After removing the redundant Undaria pinnatifida seedling curtain frames, put a white polyethylene plastic bag with an open upper end and a sealed lower end on the seedling curtain. At the knotting points of the two suspension ropes binding the seedling curtain, use cable ties to bind the upper port of the plastic bag (the end closer to the crossbar of the seedling curtain after placement is the upper end), and the seedling curtain is sleeved inside the plastic bag. The width of the plastic bag is 5 cm longer than the crossbar of the Undaria pinnatifida seedling curtain binding the iron rod, and the length of the plastic bag is 1 m, ensuring that the lower end of the seedling rope at the lower opening edge of the plastic bag is 5 cm long.

[0043] In the part between the upper end tie of the bag and the crossbar of the seedling curtain, 7 holes with a diameter of 1.5 cm are horizontally arranged at equal intervals on each side of the plastic bag, 3 cm away from the crossbar of the seedling curtain. At the bottom of the plastic bag, 7 holes with a diameter of 1.5 cm are tied at equal intervals. Thus, a plastic bag with holes is formed.

[0044] (4) Inner sleeve of window screen net and outer sleeve of open plastic bag

[0045] After removing the redundant Undaria pinnatifida seedling curtain frames, successively put a window screen net and an upper and lower open plastic bag on the seedling curtain, and the specific steps are the same as the aforementioned methods (1) and (2).

[0046] (5) Inner sleeve of window screen net and outer sleeve of plastic bag with holes

[0047] After removing the redundant Undaria pinnatifida seedling curtain frames, successively put a window screen net and a plastic bag with holes on the seedling curtain, and the specific steps are the same as the aforementioned methods (1) and (3).

[0048] For the above 5 bagging methods, each method bags 3 curtains. Put the bagged Undaria pinnatifida seedling curtains in adjacent positions in the same sea area for temporary cultivation. During the season when the Undaria pinnatifida seedling curtains are temporarily cultivated in the sea, the transparency of the Dalian sea area is generally 4 m, and the length of the suspension ropes of the seedling curtains is also set to 4 m according to this transparency. After putting on the plastic bags, the plastic sheets will have a certain light-shielding property, reducing the light intensity on the seedling curtains, which may affect the growth of Undaria pinnatifida seedlings. However, in the early stage of the temporary cultivation of the seedling curtains in the sea, the Undaria pinnatifida seedlings are relatively small and have weak requirements for light and nutrients. After comprehensive consideration of various factors, the initial length of the suspension ropes being 0.3 - 0.7 m shorter than the sea water transparency can ensure the light requirements of the Undaria pinnatifida seedlings inside the plastic bags. Therefore, the initial length of the suspension ropes of the seedling curtains is set to be 0.5 m shorter than the sea water transparency, that is, 3.5 m (in traditional operations, the length of the suspension ropes of the seedling curtains is the same as the transparency, which can be seen in the subsequent comparative examples).

[0049] On September 27th, temporarily lift all the Undaria pinnatifida seedling curtains out of the water surface, observe the mud and fouling organisms attached to the outer nets and bags of the Undaria pinnatifida seedling curtains, and then put them back into the sea at the same position for continued cultivation.

[0050] On October 8th, temporarily lift all the Undaria pinnatifida seedling curtains out of the water surface, observe the mud and fouling organisms attached to the outer nets and bags of the Undaria pinnatifida seedling curtains (see Table 1), and measure the seedling length.

[0051] Observation of each bagging method in Table 1

[0052]

[0053] Compared with the seedling curtains covered with window screens ([[]] Figure 3 ), the seedling curtains covered only with plastic bags ([[]] Figure 2 Seedling curtains covered with open plastic bags, Figure 4 Seedling curtains covered with perforated plastic bags) have less mud and fouling organisms attached, and are convenient to observe; but for the seedling curtains covered with perforated plastic bags ([[]] Figure 4 ), when pulled out of the seawater, the seawater that fails to be discharged in time sprays out from the bag, is heavy, takes a long time, and is inconvenient to operate; according to Figure 5 and Figure 6 , after covering the inside of the plastic bag with a screen (seedling curtains with a window screen inside and an open plastic bag outside, seedling curtains with a window screen inside and a perforated plastic bag outside), the plastic bag is propped up, the water inflow and the amount of dirt are large, and more floating mud adheres to the window screen and the seedling rope. The floating mud on the seedling curtain is even more; the attachment of mud and fouling organisms on the upper and lower ends of the open plastic bag before removing the outer bag (see Figure 2 ), compared with Figure 1 the condition of the seedling curtain of Undaria pinnatifida covered with an open plastic bag (before going to sea), whether attached to the outside of the plastic bag or on the seedling rope, there is less mud and fouling organisms attached, it is relatively clean as a whole, and the seedlings on the seedling rope show a healthy dark brown color. (This Figure 2 effect is also similar to that of the Figure 7 seedling rope in the subsequent photo) Generally speaking, the seedling curtain covered with an open plastic bag has the best effect.

[0054] After measurement, for the seedling curtains covered with open plastic bags and perforated plastic bags, the larger seedlings reach 0.5 mm, and for the seedlings on the seedling curtains covered with window screens, seedling curtains with a window screen inside and an open plastic bag outside, and seedling curtains with a window screen inside and a perforated plastic bag outside, the larger seedlings are 0.4 mm. Remove the outer bags of each bagging on the outside of the Undaria pinnatifida seedling curtain, and after removal, put it back in the same position in the sea for continued cultivation. Then, rinse the seedlings every day, that is, vigorously rinse the seedling curtain in the seawater to wash off the floating mud, fouling organisms, and weakly attached seedlings.

[0055] On October 11th, all the kelp seedling curtains were temporarily lifted out of the water for seedling rinsing. The length of the seedlings was measured. For the seedling curtains with open plastic bags and perforated plastic bags, the seedlings reached 1 mm. For the seedling curtains with window screens, the combination of inner window screen and outer open plastic bag, and the combination of inner window screen and outer perforated plastic bag, the seedlings reached 0.8 mm. For the kelp seedling curtains bagged in five ways, three ropes were randomly cut from each seedling curtain, and 10-cm seedling segments were taken from the upper, middle, and lower positions of the seedling ropes (i.e., at the crossbar of the seedling curtain, in the middle of the seedling rope, and at the tip of the seedling rope) for dissection microscope observation and photo recording for subsequent comparison. Subsequently, all the kelp seedling curtains were lifted to a water layer with half the transparency and then put back into the sea for continued cultivation.

[0056] On October 21st, all the kelp seedling curtains were temporarily lifted out of the water, and the length of the seedlings was measured. For the seedling curtains with open plastic bags and perforated plastic bags, the seedlings reached 2 mm. For the kelp seedling curtains bagged in five ways, three ropes were randomly cut from each seedling curtain, and 10-cm seedling segments were taken from the upper, middle, and lower positions of the seedling ropes for kelp seedling density statistics. Subsequently, the length of the seedling ropes was shortened to 1.5 m, and the kelp seedling curtains were put back into the sea for continued cultivation.

[0057] On October 31st, all the kelp seedling curtains were lifted out of the water, and the kelp seedlings were measured. For the seedling curtains with open plastic bags and perforated plastic bags, the seedlings had reached 0.5 cm, and this length met the standard for seeding clamping for subsequent production. The density of the kelp seedlings on each test seedling curtain was statistically counted again. Three ropes were randomly cut from each seedling curtain, and 10-cm seedling rope segments were taken from the upper, middle, and lower positions of the seedling ropes for counting.

[0058] Comparative Example 1: The kelp seedling curtains were temporarily cultured without bagging (rubbing the seedlings).

[0059] The method of this Comparative Example 1 is a commonly used method in current production, that is, the kelp seedling curtains are not bagged, and the rubbing method is used to remove the attached mud and fouling organisms.

[0060] On September 23rd, 9 curtains of kelp seedling curtains with the same appearance as in Example 1 and germinated in the nursery were taken for temporary cultivation in the sea, and were placed adjacent to the kelp seedling curtains treated with bagging in the same sea area. The length of the hanging ropes was the same as the transparency, that is, compared with the example, the length of the hanging ropes was 0.5 m longer than that in the example.

[0061] On September 27th, all the kelp seedling curtains were temporarily lifted out of the water for the first rubbing to remove the floating mud and some fouling organisms, and the ropes of the seedling curtains were rubbed until they returned to the original rope color.

[0062] On September 30th, skilled workers temporarily lifted all the kelp seedling curtains out of the water for the second rubbing. According to the emergence situation and the attachment of the seedling curtains, the intensity was reduced, and the floating mud and miscellaneous algae on the surface were rubbed off (seeFigure 7 )。Subsequently, the seedlings are rinsed every day.

[0063] On October 11th, when the seedlings reached 1 mm, the seedling curtain was lifted, the length of the hanging rope was shortened to half of the transparency, and then it was put back into the sea for continuous cultivation.

[0064] On October 21st, when the seedlings reached 2 mm, the length of the seedling rope was shortened to 1.5 m, and then it was put back into the sea for continuous cultivation.

[0065] On October 31st, it was observed that the seedling curtain of Undaria pinnatifida had reached the level for seeding and could be used for subsequent production activities. The density of the Undaria pinnatifida seedlings that reached the seeding specification was statistically counted again.

[0066] Test Example

[0067] The samples and data of Example 1 and Comparative Example 1 were observed and statistically analyzed.

[0068] (1) The seedling ropes with and without plastic bags (normal rubbing of seedlings) sampled on October 11th were observed under a dissecting microscope. It was found that the length, density, and seedling state (whether the color was normal, whether there were deformities) of the Undaria pinnatifida seedlings on the seedling curtain with an open plastic bag were similar to those of the seedling curtain with rubbing operation (see Figure 8 、 Figure 9 ).

[0069] (2) The density of Undaria pinnatifida seedlings on the seedling curtains with and without plastic bags (normal rubbing of seedlings) sampled on October 21st was statistically counted. The specific density is shown in Table 2:

[0070] Table 2 Determination of the density of Undaria pinnatifida seedlings for each treatment method on October 21st

[0071] Group Bagging method Density range (plants / 1 cm) 1 Cover with screen window net 59～71 2 Cover with open plastic bag 43～55 3 Cover with perforated plastic bag 18～47 4 Inner cover with screen window net and outer cover with open plastic bag 49～71 5 Inner cover with screen window net and outer cover with perforated plastic bag 55～77 6 No bagging (normal seedling rubbing) 43～56

[0072] According to the density statistical results, the size and density of the Undaria pinnatifida seedlings in the open plastic bag group were the most similar to those of the seedlings with normal rubbing; for the seedling curtain group with a window screen, the group with a window screen inside and an open plastic bag outside, and the group with a window screen inside and a perforated plastic bag outside, the density of the Undaria pinnatifida seedlings was high, the specifications were small, and the specification differences of the Undaria pinnatifida seedlings were large. In the group with a perforated plastic bag, the number of Undaria pinnatifida seedlings was small, the size and density of the seedlings were uneven, and the effect was the worst.

[0073] (3) The morphological observation and density statistics of the Undaria pinnatifida seedlings on the seedling curtains with and without plastic bags (normal rubbing of seedlings) sampled on October 31st were carried out.

[0074] The density and specifications of the Undaria pinnatifida seedlings with an open plastic bag were the most similar to those with normal rubbing (see Figure 10 、 Figure 11 ), and the statistical data of the Undaria pinnatifida seedlings for each treatment method were obtained. The specific density is shown in Table 3:

[0075] Table 2 Measurement of the density of Undaria pinnatifida seedlings for each treatment method on October 31

[0076] Group Bagging method Density range (plants / 1 cm) 1 Cover with screen window net 45～55 2 Cover with open plastic bag 21～34.5 3 Cover with perforated plastic bag 9.5～31 4 Inner cover with screen window net and outer cover with open plastic bag 50.5～53 5 Inner cover with screen window net and outer cover with perforated plastic bag 53～59 6 No bagging (normal seedling rubbing) 22.5～31.5

[0077] Among the 5 bagging methods, the density of Undaria pinnatifida seedlings in the groups with window screen bags, inner window screen bags and outer perforated plastic bags, and inner window screen bags and outer open plastic bags is too large, the seedling specifications are small, and they are uneven, so they cannot be applied to actual production; in the group with perforated plastic bags, the number of Undaria pinnatifida seedlings on the seedling ropes is small, and the distribution of Undaria pinnatifida seedlings on the seedling ropes is uneven, which is not suitable for production use; the seedling curtain of Undaria pinnatifida seedlings temporarily cultured in the group with open plastic bags is the most similar to the seedling curtain of Undaria pinnatifida seedlings using the secondary rubbing seedling technology in the current actual production situation in terms of both the density and specifications of Undaria pinnatifida seedlings, meeting the production requirements.

[0078] By applying the method of the present invention, the growth of fouling organisms on the seedling ropes is inhibited, while the normal growth of Undaria pinnatifida seedlings is not affected: 5 - 10 holes with a diameter of 1 - 2 cm are made on each surface of the plastic bag between the bagging opening and the cross bar of the seedling curtain. A small amount of seawater enters the plastic bag under the action of wave current, and after passing through the surface of the seedling rope, it flows out from the lower opening of the plastic bag. The water flow is small, the medium flow is weak, and the main fouling animals such as Obelia geniculata, Gammarus sp., and Caprella equilibra in the plastic bag are lack of nutrition, and their growth and reproduction are restricted. At the same time, the two sides of the plastic bag are attached to the seedling rope, the nest - making of Gammarus sp. is restricted, the tentacles of Obelia geniculata and the appendages of Caprella equilibra are restricted in stretching, and the ingestion of food is blocked, and the growth and activities of the main fouling organisms are restricted in space. In the early stage of the temporary culture of the seedling curtain in the sea, the Undaria pinnatifida seedlings in the plastic bag are very small, with little biomass, requiring less nutrition and less space. The nutrition of the small amount of seawater entering the plastic bag can meet the growth and development needs of the Undaria pinnatifida seedlings. Therefore, after bagging, the Undaria pinnatifida seedlings grow normally, while the growth and reproduction of the main fouling animals are inhibited. When the Undaria pinnatifida seedlings reach 0.5 mm, the outer bag is removed, and the water flow is not restricted. At this time, the false roots grown from the Undaria pinnatifida seedlings are firmly attached to the seedling rope. The curtain - rinsing operation can rinse off the seedlings and dirt that are not firmly attached, meeting the requirements of removing fouling and protecting seedlings.

[0079] The method for temporary cultivation of Undaria pinnatifida seedling curtains designed by the present invention can replace the two seedling rubbing operations in actual production. This temporary cultivation method does not affect the growth of Undaria pinnatifida seedlings. The density and seedling specifications are similar to those in actual production, and the same growth time is consumed to reach the seedling clamping specifications, reducing the labor intensity and improving the seedling quality. In terms of reducing the labor intensity, during the temporary cultivation of Undaria pinnatifida seedlings at sea, a breeding team of about 40 workers needs to manage 1,000 seedling curtains. In addition to handling the daily affairs of their respective management areas, when performing the seedling rubbing operation, in order to meet the production requirement of rubbing the seedlings once a day, all the workers in the breeding team need to go to work. Rubbing the seedlings once requires a total of 40 man-hours. The bagging operation can save this process. In terms of improving the seedling quality, since the bottom seedlings on the seedling ropes (the bottom seedlings generally refer to the gametophytes in the strands of the seedling ropes or the sporophyte seedlings developed from the gametophytes) are relatively fragile, when rubbing the seedlings for the second time, excessive rubbing force can rub off the bottom seedlings. In the present invention, without rubbing the seedlings, the bottom seedlings can be preserved, improving the seedling quality. Therefore, the method of the present invention improves the working efficiency of the temporary cultivation of Undaria pinnatifida seedlings at sea, saves costs, is convenient to operate, and has practical application value for the Undaria pinnatifida breeding work.

[0080] The foregoing is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A method for temporarily culturing Undaria pinnatifida seedling curtains in the sea area, characterized in that, It includes the following steps: (1) Take the wakame seedling curtain grown indoors, put it into a plastic bag with openings at both the upper and lower ends, and place it in the sea for temporary cultivation; (2) When the length of the wakame seedlings reaches 0.3 - 0.7 mm, remove the plastic bag; according to the growth state of the wakame seedlings, lift the wakame seedling curtain in a timely manner, and harvest when the wakame seedlings reach the seeding specification.

2. The method for temporary cultivation of Undaria pinnatifida seedling curtains in sea areas according to claim 1, wherein, In step (1), the width of the plastic bag is 5 - 10 cm longer than the crossbar of the wakame seedling curtain; the length of the plastic bag is 1 m - 1.2 m, and the lower opening edge of the plastic bag is 5 - 10 cm longer than the lower end of the seedling rope.

3. The method for temporary cultivation in the sea area of Undaria pinnatifida seedling curtains according to claim 1, characterized in that, In step (1), the initial hanging rope length of the seedling curtain is 0.3 - 0.7 m shorter than the seawater transparency.

4. The method for temporary cultivation in the sea area of the wakame seedling curtain according to claim 1, characterized in that, In step (2), at the knot of the hanging rope for tying the wakame seedling curtain, tie the upper port of the plastic bag and put the seedling curtain into the plastic bag.

5. The method for temporary cultivation in the sea area of Undaria pinnatifida seedling curtains according to claim 1, characterized in that, In step (2), in the part between the tied mouth of the bag and the crossbar of the seedling curtain, 5 - 10 holes with a diameter of 1 - 2 cm are horizontally arranged at equal intervals 3 cm away from the crossbar of the seedling curtain on each side of the plastic bag.

6. The method for temporary cultivation in the sea area of wakame seedling curtains according to claim 1, characterized in that, In step (2), starting from the day after removing the outer plastic bag, rinse the seedlings every day until harvest.

7. The method for temporary cultivation in the sea area of Undaria pinnatifida sporeling curtain according to claim 1, wherein In step (2), when the seedlings reach 0.7 - 1.5 mm, lift the hanging rope length of the seedling curtain to half of the transparency; when the seedlings reach 1.6 - 2.5 mm, shorten the seedling rope length to 1 - 2 m.

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