Seawater fertilization method for increasing yield of oyster culture

Abstract

The invention relates to a seawater fertilization method for increasing the yield of oyster culture, which comprises the following steps: S1, putting oysters in a culture area for culture until the transparency of the water body in the culture area reaches more than 3m, and applying a first nutrient solution to the culture area until the average shell length of the oysters is more than 6cm; s2, a first nutrient solution or a second nutrient solution is applied to the culture area until the average shell length of the oysters is larger than 9 cm; s3, a first nutrient solution or a second nutrient solution or a third nutrient solution is applied to the culture area, and fertilization is stopped 3-5 days before oyster harvesting; the first nutrient solution is prepared from 3.7 to 5.9 g / L of basic nutrient substances and 0.52 to 1.55 mg / L of plant growth hormone; the second nutrient solution contains 6.0 to 8.0 g / L of basic nutrient substances and 0.53 to 1.55 mg / L of plant growth hormone; the third nutrient solution contains 2.4 to 2.9 g / L of basic nutrient substances and 0.22 to 0.42 mg / L of plant growth hormone. According to the seawater fertilization method for increasing the yield of oyster culture, the oysters can grow rapidly, the fertility degree is improved, the culture period is shortened, and growth and weight increment of the oysters are promoted.

Description

Technical Field

[0001] The invention relates to the field of aquaculture, and in particular to a seawater fertilization method for increasing the production of oyster culture. Background Art

[0002] Oysters are a high-protein, low-fat food rich in vitamins, minerals and high-quality protein. They have high nutritional value and play an important role in maintaining the health of the male reproductive system, children's development, preventing osteoporosis in the middle-aged and elderly, maternal and child health, preventing arteriosclerosis, anti-thrombosis, anti-aging, enhancing immune function and preventing cancer. Oysters are the main cultured shellfish, and their output ranks first in the world's shellfish aquaculture production. They have great economic value. Oyster farming is an important part of my country's fishery economy. For many years, my country's oyster production has ranked first in the world. In 2023, my country's oyster production hit a new high of more than 6 million tons, accounting for 87% of the global production. The oyster industry not only plays a key role in national food security and economic stability in coastal areas, but also provides a large number of employment opportunities for fishermen and farmers, increasing their sources of income.

[0003] Currently, there is no artificial bait for oysters on the market, so the growth of oysters still depends on natural bait (single-cell algae) in seawater. The existing oyster farming methods generally adopt the longline farming method. However, the existing oyster farming methods have a large farming density. In addition, as the oysters grow, their filtering feeding ability and filtering feeding intensity are also increasing, which easily leads to a large amount of unicellular algae in the seawater being eaten, and the reproduction and growth rate of the unicellular algae cannot supply the feeding speed and feeding amount of the oysters; at the same time, high-density farming and high-intensity filtering feeding also make the local seawater barren (the main basis for judgment is that the chlorophyll concentration in the farming area is too low), the concentration of microalgae drops sharply, and the primary productivity decreases; although some oyster farming methods also add nutrients to the oyster farming area, which can promote the rapid growth of unicellular algae, but the promotion of the reproduction ability of unicellular algae is limited, and it still cannot meet the large amount of oyster filtering. Therefore, the oysters cultivated by the existing oyster farming methods are prone to malnutrition, resulting in slow growth, low fatness (meat yield), and long farming cycle, and the long farming cycle will bring more risks, such as the increase of oyster detachment rate, reduced production, and low economic benefits caused by typhoons. Summary of the invention

[0004] Based on this, the purpose of the present invention is to provide a seawater fertilization method for increasing the production of oyster culture, which can promote the growth of oysters, shorten the oyster culture cycle, and at the same time improve the meat yield of oysters to produce more high-quality oysters.

[0005] A method for fertilizing oysters with seawater for increasing production, comprising the following steps:

[0006] Step S1: culturing oysters in a culture area until the water transparency of the culture area reaches more than 3 meters, applying a first nutrient solution to the culture area until the oysters grow to an average shell length of more than 6 cm;

[0007] Step S2: applying the first nutrient solution or the second nutrient solution to the culture area until the oysters grow to an average shell length of more than 9 cm;

[0008] Step S3: applying the first nutrient solution, the second nutrient solution, or the third nutrient solution to the culture area until fertilization is stopped 3 to 5 days before the oysters are harvested;

[0009] The first nutrient solution contains 3.7-5.9 g / L basic nutrients and 0.52-1.55 mg / L plant growth hormone; the second nutrient solution contains 6.0-8.0 g / L basic nutrients and 0.53-1.55 mg / L plant growth hormone; the third nutrient solution contains 2.4-2.9 g / L basic nutrients and 0.22-0.42 mg / L plant growth hormone.

[0010] Since oysters can filter seawater efficiently and increase the transparency of water quality, the seawater fertilization method for increasing the production of oyster farming of the present invention adjusts the nutrient solution formula according to the transparency of the water body in the breeding area and the growth status of oysters. The first nutrient solution, the second nutrient solution and the third nutrient solution of the present invention not only contain basic nutrients, but also contain plant growth hormones, which can not only better promote the growth rate of unicellular algae in the breeding area, but also increase the reproduction rate of unicellular algae, meet the food intake of oysters, make oysters grow rapidly, improve fatness, shorten the breeding cycle, and promote the growth and weight gain of oysters. In addition, the inventors have found that too low a basic nutrient concentration has limited promoting effect on unicellular algae, while too high a basic nutrient concentration easily leads to the growth of Enteromorpha, Ulva and other miscellaneous algae in the breeding area, thereby competing with unicellular algae for nutrients and growth space, affecting the growth of unicellular algae in the breeding area. Similarly, too low a plant growth hormone has limited effect on promoting the reproduction of unicellular algae, and too high a plant growth hormone will inhibit the reproduction and growth of unicellular algae. The limitation of the concentration range of the above basic nutrients and plant growth hormones is most conducive to the cultivation of oysters. The concentration ranges of the basic nutrients and plant growth hormones of the first nutrient solution, the second nutrient solution, and the third nutrient solution defined by the inventor based on a large amount of practical experience and experimental data have a good effect on promoting the growth and development of oysters.

[0011] Furthermore, the oyster is a diploid fry; the initial culture shell of the oyster in step S1 has a shell length of 1 to 3 cm and a shell width of 1 to 1.5 cm.

[0012] Furthermore, the basic nutrients include macroelements, trace elements, vitamins and urine; the macroelements include NaNO3, NaH2PO4, Na2SiO3·9H2O; the trace elements include ZnSO4·7H2O, Cl2Mn·4H2O, CuSO4·5H2O, Na2MoO4·2H2O and FeC6H5O7·5H2O; the vitamins include VB 12 , VB1 and VH; the plant growth hormones include GA3 gibberellin, 6-BA cytokinin and brassinolide.

[0013] Further, the application frequency of the first nutrient solution is:

[0014] (1) When the average shell length of the oyster is less than 4 cm: apply once every 7 to 8 days on average;

[0015] (2) When the average shell length of the oysters is ≥ 4 cm or the chlorophyll a concentration in the culture area is lower than 3.0 μg / L: apply once every 4 to 5 days on average.

[0016] When the average shell length of oysters is <4 cm, the individuals are small, and their filtering feeding ability and filtering feeding intensity are weak. The fertilization frequency of the first nutrient solution is once every 7 to 8 days, which can well meet the growth and reproduction needs of unicellular algae. However, after a period of time, the oysters grow to an average shell length of ≥4 cm, and their filtering feeding ability becomes stronger. The fertilization frequency of the first nutrient solution once every 7 to 8 days is no longer sufficient (specifically, the chlorophyll a value is continuously lower than 3.0 μg / L), and cannot meet the oysters' feeding needs for unicellular algae. Therefore, the fertilization frequency of the first nutrient solution needs to be increased to once every 4 to 5 days.

[0017] Furthermore, the second nutrient solution is applied once every 5 to 7 days on average.

[0018] Furthermore, the oyster culture method is longline culture.

[0019] Furthermore, the method for applying the first nutrient solution / the second nutrient solution is as follows: adding the basic nutrient substance and the plant growth hormone to seawater to fully dissolve them to prepare the first nutrient solution / the second nutrient solution; preparing a number of small bottles with 30 to 40 small holes, quickly dispensing the first nutrient solution / the second nutrient solution into the small bottles and sealing them; the small bottles are weighted with heavy objects and hung under the culture cable at even intervals, with a hanging density of one small bottle containing the first nutrient solution / the second nutrient solution for every 6 strings of oysters.

[0020] Furthermore, the method for applying the third nutrient solution is as follows: adding the basic nutrients and the plant growth hormone to seawater to fully dissolve them to prepare the third nutrient solution; preparing a number of small bottles with 80 to 100 small holes, quickly dispensing the third nutrient solution into the small bottles and sealing them; weighting the small bottles with weights, hanging the bottles under the breeding cables at even intervals, and the hanging density is that on average one small bottle containing the third nutrient solution is hung for every 2 strings of oysters; the frequency of applying the third nutrient solution is: once every 2 to 3 days on average.

[0021] Furthermore, the step S2: applying the second nutrient solution to the culture area. When the oysters grow to an average shell length of more than 6 cm, their filtering feeding ability is further enhanced. As a further improvement of the above scheme, by using a second nutrient solution containing a higher concentration of basic nutrients, the fertility of seawater can be effectively improved, and the growth rate and reproduction rate of unicellular algae in the culture area can be further increased to meet the food intake of oysters, so that oysters grow faster, the culture cycle is shorter, and the fatness is higher. In addition, the frequency of fertilization can be reduced, thereby reducing labor costs. The concentration range of basic nutrients and auxins in the above-mentioned second nutrient solution defined by the inventor based on a large amount of practical experience and experimental data is beneficial to the cultivation of oysters. If the concentration and application amount of this second nutrient solution are too low, the oysters will be relatively thin and the growth-promoting effect will be limited. If the concentration is too high or the application amount is too large, it will cause waste of resources and even breed unfavorable factors such as weeds.

[0022] Further, the step S3: applying the third nutrient solution to the culture area. When the oyster grows to more than 9 cm, its filter feeding ability is stronger. Oysters of this specification need to be fattened before listing, that is, more abundant bait is provided to significantly improve the meat yield. Therefore, the amount of basic nutrients is required to better stimulate the reproduction and growth of unicellular algae. However, as the oysters become larger, the agitation of the water body is greater when filtering, and the exchange of water in the culture area and the non-culture area is more obvious. Therefore, when fertilizing, low concentration (the third basic nutrient substance and the third plant growth hormone are diluted into a larger volume of 30-32L of the third nutrient solution), high density (the diluted liquid is 30-32L, which can be filled with more vials, and the vials are more densely distributed), and high frequency (the vials have more holes, and the exchange with the outside world is faster, and the fertilization frequency is 2-3 days) is adopted to ensure that the applied third nutrient solution acts more efficiently on the culture area.

[0023] In order to better understand and implement the present invention, the present invention is described in detail below in conjunction with embodiments. DETAILED DESCRIPTION

[0024] It should be clear that the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the embodiments of the present application.

[0025] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0026] In the description of this application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0027] In addition, in the description of this application, unless otherwise specified, "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0028] A method for fertilizing oysters with seawater for increasing production, comprising the following steps:

[0029] Step S1: After oysters are stocked and cultured in a culture area for 10 to 15 days, the oysters filter seawater at high intensity to make the water transparency of the culture area reach more than 3 meters, and a first nutrient solution is applied to the culture area and the application frequency is gradually increased until the oysters grow to an average shell length of more than 6 cm;

[0030] Furthermore, the oyster culture method is longline culture, with an average of 3 strings of oysters per 1m; the number of oysters attached to each string is 30 to 50 (i.e., 90 to 150 per meter). The oysters are diploid fry. The initial culture shells of the oysters in step S1 have an average shell length of 1 to 3cm and an average shell width of 1 to 1.5cm. The culture area is a sea area with unobstructed water exchange.

[0031] Furthermore, the first nutrient solution contains 3.7-5.9 g / L of a first basic nutrient and 0.52-1.55 mg / L of a first plant growth hormone; the components and the content of each component in the first nutrient solution applied to every 100-120 strings of oysters are shown in Table 1 below.

[0032] Furthermore, the method for applying the first nutrient solution is as follows: add the first basic nutrient substance and the first plant growth hormone in Table 1 to 10 to 12 L of seawater to fully dissolve and prepare the first nutrient solution; prepare several plastic bottles with a capacity of more than 500 ml, and pierce 30 to 40 small holes on the plastic bottles with a small needle, quickly dispense the first nutrient solution into the plastic bottles and seal them; the plastic bottles are weighted with heavy objects, and are evenly hung at 20 to 30 cm below the culture cable, with a hanging density of one plastic bottle containing the first nutrient solution for every 6 strings of oysters.

[0033] Furthermore, the application frequency of the first nutrient solution is:

[0034] (1) When the average shell length of the oyster is less than 4 cm: apply once every 7 to 8 days on average;

[0035] (2) When the average shell length of the oysters is ≥ 4 cm or the chlorophyll a concentration in the culture area is lower than 3.0 μg / L: apply once every 4 to 5 days on average.

[0036] Table 1. Components and contents of each component in the first nutrient solution

[0037]

[0038] Step S2: applying the first nutrient solution or the second nutrient solution to the culture area until the oysters grow to an average shell length of more than 9 cm;

[0039] Furthermore, the second nutrient solution contains 6.0-8.0 g / L of a second basic nutrient and 0.53-1.55 mg / L of a second plant growth hormone; the components and the content of each component in the second nutrient solution applied to every 100-120 strings of oysters are shown in Table 2 below.

[0040] Furthermore, the method for applying the second nutrient solution is as follows: add the second basic nutrient substance and the second plant growth hormone in Table 2 to 10 to 12 L of seawater to fully dissolve them to prepare the second nutrient solution; prepare several plastic bottles with a capacity of more than 500 ml, and pierce 30 to 40 small holes on the plastic bottles with a small needle, quickly dispense the first nutrient solution into the plastic bottles and seal them; weight the plastic bottles with heavy objects, and hang them evenly at 20 to 30 cm below the culture cable, with a hanging density of one plastic bottle containing the second nutrient solution for every 6 strings of oysters.

[0041] Furthermore, the second nutrient solution is applied once every 5 to 7 days on average.

[0042] Table 2. Components and contents of each component in the second nutrient solution

[0043]

[0044] Step S3: applying the first nutrient solution, the second nutrient solution, or the third nutrient solution to the culture area until fertilization is stopped 3 to 5 days before the oysters are harvested;

[0045] Furthermore, the third nutrient solution contains 2.4-2.9 g / L of a third basic nutrient substance and 0.22-0.42 mg / L of a third plant growth hormone; the components of the third nutrient solution applied to every 100-120 strings of oysters and the content of each component are shown in Table 3 below.

[0046] The method for applying the third nutrient solution is as follows: add the third basic nutrient substance and the third plant growth hormone in Table 3 to 30-32L seawater to fully dissolve and prepare the third nutrient solution; prepare several plastic vials with a capacity of more than 500ml, and use a small needle to pierce 80-100 small holes on the plastic vials, quickly dispense the third nutrient solution into the plastic vials and seal them; the plastic vials are weighted and evenly hung at intervals 20-30cm below the culture cable, with a hanging density of one plastic vial containing the third nutrient solution for every 6 strings of oysters. The frequency of applying the third nutrient solution is once every 2-3 days on average.

[0047] Table 3. Ingredients and contents of each ingredient in the third nutrient solution

[0048]

[0049]

[0050] Example 1

[0051] A seawater fertilization method for increasing oyster culture production in this embodiment comprises the following steps:

[0052] Step S1: After the oysters are stocked and cultured in the first oyster culture area in Jiaowei Township, Xuwen County, Zhanjiang City for 15 days, the transparency of the seawater in the culture area exceeds 3 meters, and the first nutrient solution is applied to the culture area and the application frequency is gradually increased.

[0053] In this embodiment, the application method of the first nutrient solution is as follows: add the first basic nutrient substance and the first plant growth hormone in Table 1 to 10L seawater to fully dissolve and configure the first nutrient solution; prepare 20 plastic vials with a capacity of more than 500ml, and pierce 40 small holes on the plastic vials with a small needle; quickly dispense the first nutrient solution into the plastic vials and seal them, each of which contains 500ml of the first nutrient solution; weigh the plastic vials with heavy objects such as small stones, and then hang the vials at intervals 25 to 30cm below the aquaculture cable; the hanging density is that on average, one plastic vial containing the first nutrient solution is hung for every 6 strings of oysters. The first nutrient solution in the plastic vials is replaced every 7 days.

[0054] After 30 days of cultivation, as the oysters grew, their filtering intensity increased, the chlorophyll a concentration in the cultivation area was lower than 2.0 μg / L, the first nutrient solution in the plastic bottle was replaced every 5 days, and after continuing to cultivate for 1 month, the average shell length of the oysters exceeded 6 cm.

[0055] Step S2: applying the second nutrient solution to the culture area; in this embodiment, the method for applying the second nutrient solution is as follows: adding the basic nutrients and the plant growth hormone in Table 2 to 10L seawater to fully dissolve and prepare the second nutrient solution; preparing 20 plastic bottles with a capacity of more than 500ml, and piercing 40 small holes on the plastic bottles with a small needle; quickly dispensing the second nutrient solution into the plastic bottles and sealing them, each of the plastic bottles containing 500ml of the second nutrient solution; the plastic bottles are weighted with heavy objects such as small stones, and then hung 25 to 30cm below the culture cable; the hanging density is an average of one plastic bottle containing the first nutrient solution for every 6 strings of oysters; the second nutrient solution in the plastic bottles is replaced every 6 days on average; after 2 months of culture, the average shell length of the oysters exceeds 9cm.

[0056] Step S3: Apply the third nutrient solution to the culture area; In this embodiment, the method for applying the third nutrient solution is as follows: Add the third basic nutrient substance and the third plant growth hormone in Table 3 to 30L seawater and fully dissolve them to form the third nutrient solution; Prepare 60 plastic vials with a capacity of more than 500ml, and pierce 80 small holes on the plastic vials with a small needle; Quickly dispense the third nutrient solution into the plastic vials and seal them, each of which contains 500ml of the third nutrient solution; The plastic vials are weighted with small stones and other heavy objects, and then evenly hung at intervals 25 to 30cm below the culture cable; The hanging density is that one plastic vial containing the first nutrient solution is hung for every 2 strings of oysters. The third nutrient solution in the plastic vials is replaced every 3 days on average; Fertilization is stopped after 6 months of culture, and the average fresh weight of the oysters at this time is 300g to 350g / each, which can meet market demand.

[0057] The oysters in the culture area were harvested 5 days after cessation of fertilization.

[0058] Example 2

[0059] A seawater fertilization method for increasing oyster culture production in this embodiment comprises the following steps:

[0060] Step S1: After the oysters are stocked and cultured in the oyster culture area of ​​Caotan Town, Suixi County, Zhanjiang City for 12 days, the transparency of the seawater in the culture area exceeds 3 meters, and the first nutrient solution is applied to the culture area and the application frequency is gradually increased.

[0061] In this embodiment, the method of applying the first nutrient solution and the frequency of replacing the first nutrient solution in the plastic bottle are the same as those in Embodiment 1.

[0062] After 32 days of cultivation, as the oysters grew, their filtering intensity increased, the chlorophyll a concentration in the cultivation area was lower than 2.0 μg / L, the first nutrient solution in the plastic bottle was replaced every 5 days, and after continuing to cultivate for 40 days, the average shell length of the oysters exceeded 6 cm.

[0063] Step S2: applying the second nutrient solution to the culture area; in this embodiment, the second nutrient solution and the application method thereof are the same as those in Embodiment 1. The second nutrient solution in the plastic bottle is replaced every 5 days on average; after 2 months of culture, the average shell length of the oysters exceeds 9 cm.

[0064] Step S3: applying the third nutrient solution to the breeding area; the third nutrient solution is the same as that in Example 1.

[0065] In this embodiment, the application method of the third nutrient solution is as follows: add the third basic nutrient substance and the third plant growth hormone in Table 3 to 30L seawater to fully dissolve and configure the third nutrient solution; prepare 60 plastic vials with a capacity of more than 500ml, and pierce 90 small holes on the plastic vials with a small needle; quickly dispense the third nutrient solution into the plastic vials and seal them, each of which contains 500ml of the third nutrient solution; weigh the plastic vials with small stones and other heavy objects, and then hang the vials at intervals 25 to 30cm below the aquaculture cable; the hanging density is that one plastic vial containing the first nutrient solution is hung for every 2 strings of oysters. The third nutrient solution in the plastic vials is replaced every 3 days on average; stop fertilizing after 6 and a half months of aquaculture, at which time the average fresh weight of the oysters is 300g to 350g / each, which can meet market demand.

[0066] The oysters in the culture area were harvested 5 days after cessation of fertilization.

[0067] Example 3

[0068] A seawater fertilization method for increasing oyster culture production in this embodiment comprises the following steps:

[0069] Step S1: After the oysters are cultured in the second oyster culture area of ​​Jiaowei Township, Xuwen County, Zhanjiang City (3 to 5 km away from the culture area in Example 1) for 18 days, the transparency of the seawater in the culture area exceeds 3 meters, and the first nutrient solution is applied to the culture area and the application frequency is gradually increased.

[0070] In this embodiment, the application method of the first nutrient solution is as follows: add the first basic nutrient substance and the first plant growth hormone in Table 1 to 10L seawater and fully dissolve them to prepare the first nutrient solution; prepare 20 plastic vials with a capacity of more than 500ml, and pierce 40 small holes on the plastic vials with a small needle; quickly dispense the first nutrient solution into the plastic vials and seal them, each of which contains 500ml of the first nutrient solution; weigh the plastic vials with heavy objects such as small stones, and then hang the vials at intervals 30cm below the aquaculture cable; the hanging density is that one plastic vial containing the first nutrient solution is hung for every 6 strings of oysters. The first nutrient solution in the plastic vials is replaced every 7 days.

[0071] After 30 days of cultivation, as the oysters grow, their filtering intensity increases, the chlorophyll a concentration in the cultivation area is lower than 2.0 μg / L, the first nutrient solution in the plastic bottle is replaced every 5 days, and cultivation is continued until the average shell length of the oysters exceeds 6 cm.

[0072] Step S2: applying the first nutrient solution to the culture area. The method of applying the first nutrient solution is the same as above. At this time, the first nutrient solution in the plastic bottle is replaced every 4 days. The culture is continued until the average shell length of the oysters exceeds 9 cm.

[0073] Step S3: applying the first nutrient solution to the culture area. The method of applying the first nutrient solution is the same as above. At this time, the first nutrient solution in the plastic bottle is replaced every 4 days. Fertilization is stopped when the oysters are cultured for 8 months. At this time, the average fresh weight of the oysters is 300g to 350g per oyster, which can meet market demand.

[0074] The oysters in the culture area were harvested 5 days after cessation of fertilization.

[0075] Example 4

[0076] A seawater fertilization method for increasing oyster culture production in this embodiment comprises the following steps:

[0077] Step S1: After the oysters are cultured in the third oyster culture area of ​​Jiaowei Township, Xuwen County, Zhanjiang City (6 to 7 km away from the culture area in Example 1) for 17 days, the transparency of the seawater in the culture area exceeds 3 meters, and the first nutrient solution is applied to the culture area and the application frequency is gradually increased.

[0078] In this embodiment, the application method of the first nutrient solution is as follows: add the first basic nutrient substance and the first plant growth hormone in Table 1 to 10L seawater to fully dissolve and prepare the first nutrient solution; prepare 20 plastic vials with a capacity of more than 500ml, and pierce 40 small holes on the plastic vials with a small needle; quickly dispense the first nutrient solution into the plastic vials and seal them, each of which contains 500ml of the first nutrient solution; weigh the plastic vials with heavy objects such as small stones, and then hang the vials at intervals 30cm below the aquaculture cable; the hanging density is that one plastic vial containing the first nutrient solution is hung for every 6 strings of oysters. The first nutrient solution in the plastic vials is replaced every 7 days on average.

[0079] After 30 days of cultivation, as the oysters grew, their filtering intensity increased, the chlorophyll a concentration in the cultivation area was lower than 2.0 μg / L, the first nutrient solution in the plastic bottle was replaced every 5 days, and after continuing to cultivate for 1 month, the average shell length of the oysters exceeded 6 cm.

[0080] Step S2: Apply the second nutrient solution to the culture area. In this embodiment, the method for applying the second nutrient solution is as follows: add the second basic nutrient substance and the second plant growth hormone in Table 2 to 10L seawater and fully dissolve them to prepare the second nutrient solution; prepare 20 plastic bottles with a capacity of more than 500ml, and pierce 40 small holes on the plastic bottles with a small needle; quickly dispense the second nutrient solution into the plastic bottles and seal them, each of which contains 500ml of the second nutrient solution; weigh the plastic bottles with small stones or other heavy objects, and then hang them at intervals 30cm below the culture cable; the hanging density is that one plastic bottle containing the first nutrient solution is hung for every 6 strings of oysters. The second nutrient solution in the plastic bottles is replaced every 6 days on average; continue to culture until the average shell length of the oysters exceeds 9cm.

[0081] Step S3: applying the second nutrient solution to the culture area. The method of applying the second nutrient solution is the same as above; the second nutrient solution in the plastic bottle is replaced every 6 days on average; fertilization is stopped when the oysters are cultured for 7 months, and the average fresh weight of the oysters at this time is 300g to 350g per oyster, which can meet market demand.

[0082] The oysters in the culture area were harvested 5 days after cessation of fertilization.

[0083] Comparative Example 1

[0084] An existing oyster culture method includes: stocking oysters in a culture area and naturally culturing them until the average fresh weight of the oysters is 300 g to 350 g per oyster.

[0085] Furthermore, the oyster culture method is longline culture, with an average of 3 strings of oysters per 1m; the number of oysters attached to each string is 30 to 50 (i.e., 90 to 150 per meter). The oysters are diploid fry. The initial culture shells of the oysters in step S1 have an average shell length of 1 to 3cm and an average shell width of 1 to 1.5cm. The culture area is a sea area with unobstructed water exchange.

[0086] Comparative Example 2

[0087] An existing oyster culture method is to place oysters in a culture area and culture them naturally for 8 months.

[0088] Furthermore, the oyster culture method is longline culture, with an average of 3 strings of oysters per 1m; the number of oysters attached to each string is 30 to 50 (i.e., 90 to 150 per meter). The oysters are diploid fry. The initial culture shells of the oysters in step S1 have an average shell length of 1 to 3cm and an average shell width of 1 to 1.5cm. The culture area is a sea area with unobstructed water exchange.

[0089] The oyster culture effects of Examples 1 to 4 and Comparative Examples 1 to 2 are shown in Table 4 below:

[0090] Table 4

[0091]

[0092] Meat yield = fresh weight of oyster meat / total fresh weight of oysters*100%.

[0093] The average fresh weight of the oysters in Example 1 is 300-350 g / piece, which is 67% heavier than the average weight gain of the oysters without fertilizer in the same period, and the meat yield is more than 25%, reaching excellent quality and meeting market demand; the oyster culture cycle of this embodiment is 6 months, which can shorten the culture cycle by 3 months compared with the cultivation standard of the comparative example 1 with an average fresh weight of 300-350 g / piece; compared with the cultivation standard of the comparative example 2 with a cultivation period of 6 months, the average fresh weight and meat yield of the oysters are significantly improved; and the average chlorophyll a content in the entire culture week is 8.7 μg / L, and the seawater fertility in the culture area is sufficient.

[0094] The average fresh weight of the oysters in Example 2 is 300-350 g / piece, which is 66% heavier than the average weight gain of the oysters without fertilizer in the same period, and the meat yield exceeds 24%, reaching excellent quality and meeting market demand; the oyster culture cycle of this embodiment is 6.5 months, which can shorten the culture cycle by 2.5 months compared with the comparative example 1 which also uses the average fresh weight of 300-350 g / piece as the culture standard; and the average chlorophyll a content in the entire culture week is 8.8 μg / L, and the seawater fertility in the culture area is sufficient.

[0095] The average fresh weight of the oysters in Example 3 is 300-350 g / piece, which is 23% heavier than the oysters without fertilizer in the same period, and the meat yield is more than 23%, reaching excellent quality and meeting market demand; the oyster culture cycle of this embodiment is 8 months, which can shorten the culture cycle by 1 month compared with the comparative example 1 which also takes the average fresh weight of 300-350 g / piece as the cultivation standard; however, the average chlorophyll a content during the culture week is less than 1 μg / L, and the fertility in the later period is obviously insufficient. The weight gain effect and shortening of the culture cycle of the oysters cultured in this embodiment 3 are not as good as those in Examples 1 and 2.

[0096] The average fresh weight of the oysters in Example 4 is 300-350g / piece, which is 33% heavier than the average weight gain of the oysters without fertilizer in the same period, and the meat yield exceeds 23%, reaching excellent quality and meeting market demand; the oyster culture cycle of this embodiment is 7 months, which can shorten the culture cycle by 2 months and achieve significant weight gain compared with the comparative example 1 which also takes the average fresh weight of 300-350g / piece as the cultivation standard. In this embodiment 4, during the culture period of step S2, the average chlorophyll a level in the culture area can reach 3.6μg / L, and during the culture period of step S3, the average chlorophyll a level in the culture area does not exceed 1.2μg / L, which is significantly improved compared with Example 3, but compared with Example 1 and Example 2, the oyster culture fertility in this embodiment 4 is obviously insufficient. Therefore, the weight gain effect and shortening of the culture cycle in this embodiment are better than those in Example 3, but not as good as those in Example 1 and Example 2.

[0097] Compared with the existing oyster culture method, the seawater fertilization method of the present invention for increasing the production of oyster culture is based on long-term practice. The nutrient solution formula is adjusted according to the water transparency of the culture area and the growth status of the oysters. By applying the nutrient solution containing basic nutrients and plant growth hormones to the seawater, the reproduction and growth of phytoplankton are effectively improved, thereby improving the primary productivity, satisfying the oysters' food intake, promoting the growth of cultured oysters, increasing the growth rate of oysters, shortening the culture cycle, and thus improving the economic benefits of farmers. In addition, the oysters' filtration produces a large amount of feces, which can be used as feces, improve the storage rate and efficiency of organic carbon in the anaerobic environment of the seabed, form a virtuous cycle, promote the absorption of carbon dioxide in the atmosphere by seawater, and form a significant negative carbon flux.

[0098] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims

1. A method for increasing the production of oysters by applying seawater fertilizer, characterized in that: The following steps are involved: Step S1: culturing oysters in a culture area until the water transparency of the culture area reaches more than 3 meters, applying a first nutrient solution to the culture area until the oysters grow to an average shell length of more than 6 cm; Step S2: applying the first nutrient solution or the second nutrient solution to the culture area until the oysters grow to an average shell length of more than 9 cm; Step S3: applying the first nutrient solution, the second nutrient solution, or the third nutrient solution to the culture area until fertilization is stopped 3 to 5 days before the oysters are harvested; The first nutrient solution contains 3.7-5.9 g / L basic nutrients and 0.52-1.55 mg / L plant growth hormone; the second nutrient solution contains 6.0-8.0 g / L basic nutrients and 0.53-1.55 mg / L plant growth hormone; the third nutrient solution contains 2.4-2.9 g / L basic nutrients and 0.22-0.42 mg / L plant growth hormone.

2. The method for increasing the production of oyster aquaculture by applying seawater fertilizer according to claim 1, characterized in that: The oysters are diploid fry; the initial culture shells of the oysters in step S1 have a shell length of 1 to 3 cm and a shell width of 1 to 1.5 cm.

3. The method for increasing the production of oyster aquaculture by applying seawater fertilizer according to claim 1, characterized in that: The basic nutrients include macroelements, trace elements, vitamins and urine; the macroelements include NaNO3, NaH2PO4, Na2SiO3·9H2O; the trace elements include ZnSO4·7H2O, Cl2Mn·4H2O, CuSO4·5H2O, Na2MoO4·2H2O and FeC6H5O7·5H2O; the vitamins include VB 12 , VB1 and VH; the plant growth hormones include GA3 gibberellin, 6-BA cytokinin and brassinolide.

4. The method for increasing the production of oyster culture by applying seawater fertilizer according to claim 1, characterized in that: The application frequency of the first nutrient solution is: (1) When the average shell length of the oyster is less than 4 cm: apply once every 7 to 8 days on average; (2) When the average shell length of the oysters is ≥ 4 cm or the chlorophyll a concentration in the culture area is lower than 3.0 μg / L: apply once every 4 to 5 days on average.

5. The method for increasing the production of oyster culture by applying seawater fertilizer according to claim 1, characterized in that: The second nutrient solution is applied once every 5 to 7 days on average.

6. The method for increasing the production of oyster culture by applying seawater fertilizer according to claim 1, characterized in that: The oyster culture method is longline culture.

7. The method for increasing the production of oyster culture by applying seawater fertilizer according to claim 1, characterized in that: The method for applying the first nutrient solution / the second nutrient solution is as follows: adding the basic nutrient substance and the plant growth hormone to seawater to fully dissolve them to prepare the first nutrient solution / the second nutrient solution; preparing a number of small bottles with 30 to 40 small holes, quickly dispensing the first nutrient solution / the second nutrient solution into the small bottles and sealing them; weighting the small bottles with heavy objects, hanging the bottles under the culture cable at even intervals, and the hanging density is that on average one small bottle containing the first nutrient solution / the second nutrient solution is hung for every 6 strings of oysters.

8. The method for increasing the production of oyster culture by applying seawater fertilizer according to claim 1, characterized in that: The method for applying the third nutrient solution is as follows: adding the basic nutrients and the plant growth hormone to seawater to fully dissolve them to prepare the third nutrient solution; preparing a number of small bottles with 80 to 100 small holes, quickly dispensing the third nutrient solution into the small bottles and sealing them; weighting the small bottles with weights, hanging the bottles under the breeding cables at even intervals, with a hanging density of one small bottle containing the third nutrient solution for every 2 strings of oysters on average; the frequency of applying the third nutrient solution is: once every 2 to 3 days on average.

9. The method for increasing the production of oyster culture by applying seawater fertilizer according to claim 1, characterized in that: The step S2: applying the second nutrient solution to the breeding area.

10. The method for increasing the production of oyster culture by applying seawater fertilizer according to claim 8, characterized in that: The step S3: applying the third nutrient solution to the breeding area.

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