DARK-BRIGHT INTEGRATED GREENHOUSE SYSTEM IN INTENSIVE RECIRCULATING ECO-AQUACULTURE AND AQUACULTURE METHOD

Abstract

A dark-bright integrated greenhouse system in intensive recirculating eco-aquaculture and aquaculture method thereof. The greenhouse system comprises a bright area and a dark area: the bright area is mainly a water-quality biological purification area, and the dark area is mainly an aquaculture area. The aquaculture method of the present invention is an intensive recirculating eco-aquaculture method, which can improve and regulate the eco-aquaculture environments like illumination and temperature suitable for growth and development according to the requirement of aquaculture species on illumination.

Claims

1. A dark-bright integrated greenhouse system in intensive recirculating eco-aquaculture, comprising a greenhouse, wherein the greenhouse comprises a pond and a sunlight board covering above the pond, the pond is separated into a bright area and a dark area by a first partition, a sun shield or a sun cloth is covered on the sunlight board right above the dark area, the first partition is provided with a fixed block-net and a pump outlet, the pump outlet is connected with a pump, the pump is located in a pump cage; the bright area is separated into a first water treatment area and a second water treatment area by a second partition, the first water treatment area is provided with a primary sedimentation purification area and a water-quality biological purification area, the second water treatment area is also provided with a water-quality biological purification area, and the water-quality biological purification area is provided with a submerged flora planting area and a photosynthetic bacterium application area; and the dark area is provided with a probiotics application area and a plurality of aerators.

2. The dark-bright integrated greenhouse system in intensive recirculating eco-aquaculture according to claim 1, wherein the pump is a low-heading pump or a water-pushing aeration pump to pump purified water of the bright area into the dark area, and a daily water-body exchange frequency between the dark area and the bright area is 0.1 to 5 times per hour.

3. The dark-bright integrated greenhouse system in intensive recirculating eco-aquaculture according to claim 1, wherein submerged plants are planted in the primary sedimentation purification area, comprising one or more of Vallisneria natans, Ceratophyllum demersum, Hydrilla varticillata and Myriophyllum verticillatum.

4. The dark-bright integrated greenhouse system in intensive recirculating eco-aquaculture according to claim 1, wherein photosynthetic bacteria applied in the photosynthetic bacterium application area comprise a photoheterotrophic bacterium and a photoautotrophic bacterium.

5. The dark-bright integrated greenhouse system in intensive recirculating eco-aquaculture according to claim 1, wherein the dark area comprises an aquaculture area for culturing fishes, shrimps or crabs.

6. An application of the dark-bright integrated greenhouse system in intensive recirculating eco-aquaculture according to claims 1 in aquaculture.

7. An aquaculture method of a dark-bright integrated greenhouse system in intensive recirculating eco-aquaculture based on the system according to claim 1, wherein the aquaculture method regulates different illumination intensities of the dark area using different shading methods and shading areas to meet different requirements and adaptabilities of different aquaculture species and different growth stages to dark light.

8. The aquaculture method according to claim 7, wherein when the aquaculture specie is Alosa sapidissima, the illumination intensity is 100 to 400 1, when the aquaculture specie is Perca flavescens, the illumination intensity is 50 to 150 1, when the aquaculture specie is Siniperca chuatsi, the illumination intensity is 150 to 400 1, when the aquaculture specie is Eriocheir sinensis, the illumination intensity is 50 to 100 1, and when the aquaculture specie is Penaeus vannamei, the illumination intensity is 50 to 300 1.

9. The aquaculture method according to claim 7, wherein when culturing shad, ammonia nitrogen is 0.2 to 0.8 ppm, dissolved oxygen is no lower than 5 ppm, and a temperature is 16 to 28 C.

10. The aquaculture method according to claim 7, wherein when feeding Penaeus vannamei, a water temperature is 22 to 32 C., a pH value is 7.2 to 8.5, dissolved oxygen is more than 4 mg/L, ammonia nitrogen is less than 0.2 mg/L, and nitrite is less than 0.1 mg/L.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a schematic diagram illustrating an external structure of a dark-bright integrated greenhouse aquaculture system;

[0028] FIG. 2 is a structural schematic diagram of a dark-bright integrated greenhouse aquaculture system of the present invention; and

[0029] FIG. 3 is a structural schematic diagram of a pond portion of the present invention.

DETAILED DESCRIPTION

First Embodiment: Shad Culturing in Dark-Bright Integrated Greenhouse

[0030] Shad is a migratory fish, and is a stenothermal organism, which is suitable to grow in a temperature ranging from 18 to 28 C. Therefore, it is necessary to keep warm in winter and prevent sunstroke in summer. To ensure the survival rate, the shad must be cultured in the greenhouse, and also provided with good water-quality, water flow and adequate dissolved oxygen throughout the culturing.

[0031] The dark-bright integrated greenhouse system in intensive recirculating eco-aquaculture is as shown in FIG. 1, wherein the greenhouse is a plastic film greenhouse or color steel tile structure greenhouse (as shown in FIG. 1 or FIG. 2). A culture pond or pond is built in the greenhouse, which may be a cement pond or a soil pond. The greenhouse comprises a pond 1 and a sunlight board 22 covering above the pond 1, the pond 1 is separated into a bright area 2 and a dark area 12 by a first partition 6, a sun shield or a sun cloth is covered on the sunlight board 22 right above the dark area 12, the first partition 6 is provided with a fixed block-net 19 and a pump outlet 8, the pump outlet 8 is connected with a pump 5, and the pump 5 is mounted in a pump cage 4. Purified water of the bright area is pumped into an aquaculture area 20 of the dark area 12 by the pump to provide purified water with excellent water-quality for the shad. Due to a pressure deficit, the aquaculture sewage automatically flows into a primary sedimentation purification area 18 and a water-quality biological purification area 16 through the fixed block-net 19 of a wall body in the center for purification, thus forming consistent water-quality exchange and recirculating. The bright area 2 is separated into a first water treatment area and a second water treatment area through a second partition 13. The first water treatment area is provided with the primary sedimentation purification area 18 and the water-quality biological purification area 16, submerged plants 17 are planted in the primary sedimentation purification area 18 to reduce a water flow speed and promote pollutional granules to settle by bushy plants.

[0032] The second water treatment area is also provided with the water-quality biological purification area 16. The water-quality biological purification area 16 is provided with a submerged flora planting area 3 and a photosynthetic bacterium application area 15.

[0033] The bright area 2 of the present invention is a water-quality biological purification area designed by an imitative-ecological principle. The bright area 2 is an aquatic-photosynthetic bacterium symbiosis system composed of aquatic plants mainly based on photosynthesis and photosynthetic bacteria living on light energy, forming a three-dimensional imitative-ecological water-quality biological purification system, which can effectively reduce cultivation pollution such as ammonia nitrogen and phosphide. The sewage flowing in from the dark area 12 (i.e., the aquaculture area) through the fixed block-net 19 is purified. A sunlight board or plastic film with better light transmission is adopted in the bright area 2, providing sufficient illumination for the bright area 2, so that the illumination intensity of a water surface layer of the bright area 2 is greater than 5000 1. A partition wall of the bright area can be formed in the center of the bright area by brick walls or sandbags, to separate the bright area 2 into several areas to extend a water flow path for sewage purification and provide different water-purification ecological environments. The pump 5 is a low-heading pump or a water-pushing aeration pump. A power of the pump 5 depends on a size of a water body, and a daily water body exchange rate between the dark area 12 and the bright area 2 is 0.5 to 5 times. Purified water of the bright area 2 is pumped into the aquaculture area 20 of the dark area by the pump 5 through a pump outlet 8 to provide purified water with excellent water-quality for aquaculture species. Due to a negative pressure, the aquaculture sewage automatically flows into the primary sedimentation purification area 18 of the bright area through the fixed block-net of the wall body in the center for purification. The primary sedimentation area 18 of the bright area 2 has a water depth of 1.2 to 3.5 meters, planted with high-stem submerged plants 17 such as reeds and Vallisneria natans. The flourishing plants can slow down the flow rate and promote the sedimentation of the culturing sewage particles and the water quality purification of the photosynthetic bacteria. The water-quality biological purification area is an aquatic-alga-bacterium symbiotic system with a shallow water of 1.0 to 2.5 meters, planted with submerged floras 3 such as Vallisneria natans, and regularly applied with photosynthetic bacteria and beneficial algae fluids that are sprayed 1 to 6 times in every month to promote the diversified balanced development of aquatic-bacterium and three-dimensional water-quality purification. In the aquatic-bacterium symbiotic system, the aquatic plants 3 are submerged plants comprising reeds, Vallisneria natans, Myriophyllum verticillatum, Ceratophyllum demersum, Crispus and Hydrilla. The photosynthetic bacteria applied in the photosynthetic bacterium application area comprise a photoheterotrophic bacterium and a photoautotrophic bacterium.

[0034] The dark area 12 is an intensive culture pond, the top layer of which is covered by the sun cloth or sun shield to shield the sunshine and form the dimly-lit area, i.e., the dark area 12. Generally speaking, the illumination intensity of the water surface layer is 100 to 400 1, which is suitable for culturing shads. The illumination requirements of the shads vary with the developmental stages, and the larvae love illumination more than the luce. Our growth tests show that the larvae of the shads with a weight of 20 to 80 g glow faster under the illumination of 800 1 than that under the illumination of 200 1. However, under the illumination condition of 800 1, the mortality (42.5%) of the shad (200 to 500 g) is significantly higher than the mortality under the illumination condition of 200 1 (8.6%), which is due to the premature maturation of a strong light-induced gonadal development, and a three-month intensive rear-end collision in spring that result in the death of the shad by injury. Therefore, the illumination intensity for culturing shads shall be regulated according to the individual development stages of the shads, and the illumination shall be especially for the shads (200 to 500 g) in the spring to avoid direct sunlight. The key to improve the survival rate for culturing the shad is to regulate different illumination intensities in the dark area by different shading methods and shading area, and to meet the different needs and adaptabilities of the different development stages of the shads to the dark light. Generally speaking, it is suitable for culturing shads when the illumination intensity of the water surface layer is 100 to 400 1.

[0035] Due to the physiological characteristics of migration to the ocean of the shad, it mainly obtains oxygen through punching caused by fast swimming to promote the exchange of dissolved oxygen. Therefore, the dissolved oxygen is the most critical ecological factor in shad culturing, and swimming is a necessary behavior for the shads to obtain the dissolved oxygen. A large-area aquaculture water body meets the behavior of shad swimming in a large area and is of great significance for obtaining oxygen. A suitable aquaculture area is 50 to 400 m.sup.2, and a suitable stocking density is 5 to 20 fishes/m.sup.2.

[0036] In the intensive aquaculture area 20 of the dark area 12, the water depth is 1.0 to 3.0 meters, and a peddle-wheel aerator or a nano-tube aerator is used for oxygen aeration, so as to meet the dissolved oxygen supply for the shads. Taking the peddle-wheel aerator 10 as an example, several peddle-wheel aerators are installed in the intensive aquaculture area according to the aquaculture density or organic load to increase oxygen stir the water body and form a directional water flow 21 in the aquaculture area. The water body is agitated to flow in an opposite direction to the shad school at the same time of oxygenation, which conforms to the habit of the shads to obtain oxygen by moving and promotes water exchange in the water body. The shads are fed 3 to 6 times a day and for 10 to 20 min in each time. The dissolved oxygen and the temperature are measured regularly to ensure that the dissolved oxygen is maintained above 5 ppm. The water temperature is regulated through the deep well water flowing into the culture pond from a deep well water pipe, and the temperature is controlled within 18 to 30 C., so as to avoid the injury of a stress reaction to the shads caused by too low or too high temperature.

[0037] In the probiotic application area 9 of the intensive aquaculture area, probiotic preparations are regularly applied to enhance the water-quality purification capacity of the water body. For example, probiotics including Bacillus, nitrifying bacteria and lactic acid bacteria are mainly sprayed 1 to 6 times in every month to establish a healthy and active microbial community with purified water-quality.

[0038] Our production scale researches have shown that the dark-bright integrated greenhouse system in intensive recirculating eco-aquaculture according to the present invention is very suitable for the shads. The water-quality purification system in the bright area is relatively stable (the ammonia nitrogen is 0.2 to 0.8 ppm, the dissolved oxygen is no less than 5 ppm, and the temperature is 16 to 28 C.). In the dark area (the illumination is 300 to 600 1), 78% of shad larvae (6 g) grow to 600 g (standard for sale) in 10 months, and the survival rate is as high as 92.4%. As a comparison, a standard factory-based recirculating aquaculture system is adopted; although the water-quality conditions are more stable, only 36% of shad larvae (6 g) grow to 600 g (standard for sale) in 10 months, and the survival rate is as 83.7%. The production efficiency is remarkably lower than that of the dark-bright integrated greenhouse system in intensive recirculating eco-aquaculture according to the present invention. We believe that the ammonia nitrogen is less than 0.8 ppm under the factory-based culturing condition, but the nitrate is higher than 2.6 ppm sometimes due to excessive nitrate enrichment caused by denitrification function deficiency; therefore, the toxicity of NH.sub.3 is improved with the increase of pH value. Anyway, the artificial operation and the unstable culturing environment under the factory-based culturing condition induce a stress reaction which inhibits the growth of the shads. Obviously, the eco-aquaculture environment of the dark-bright integrated greenhouse is excellent, the eco-aquaculture water-quality purification effect is remarkable, the dark-bright integrated greenhouse system in intensive recirculating eco-aquaculture is highly successful in culturing shads, and will become the key to the sustainable development of the precious culture industry such as shads.

Second Embodiment: Culturing of Penaeus vannamei in Dark-Bright Integrated Greenhouse

[0039] The dark-bright integrated greenhouse system of the embodiment is the same as that of the first embodiment.

[0040] Penaeus vannamei is euryhaline, and is a nocturnal animal, which loves a warm environment and is afraid of light, and is suitable to grown in a temperature ranging from 18 to 36 C. Therefore, it is necessary to keep warm in winter and prevent sunstroke in summer. To ensure the survival rate, the Penaeus vannamei must be cultivated in a dark greenhouse, and provided with water with good quality and adequate dissolved oxygen throughout the culturing.

[0041] 1) Larvae stocking: before the shrimp seed stocking, and after clearing the pond for a week, the water depth is regulated to a range from 1.2 to 1.8 m. The recirculating pump in the bright area 2 of the greenhouse is opened to start the recirculating water in the bright area 2 and the dark area 12, wherein the water body exchange capacity is less, which is 0.1 to 0.5 times/hour. The fixed block-net 19 of the first partition 6 has 10 to 30 meshes.

[0042] In the dark area 12, the illumination intensity is controlled within a range from 50 to 300 1. Floating artificial fiber aquatics are placed to expand the habitats of the shrimps. The stocking density of the larvae is 40 to 100/m3 and the specification of the larvae is about 0.8 to 1.2 cm.

[0043] 2) Water-quality management: the Penaeus vannamei is extremely demanding on the water-quality. A suitable water temperature for growth is 22 to 32 C., a pH value is 7.2 to 8.5, dissolved oxygen is more than 4 mg/L, ammoniacal nitrogen is less than 0.2 mg/L, nitrite is less than 0.1 mg/L, and a transparency ranges from 30 to 40 cm. In the early stage of aquaculture, the water body exchange capacity was small. With the growth of the shrimp seeds, the water body exchange capacity is gradually increased by 20 to 40% every month. Water-quality monitoring is carried out regularly in the culturing process every week, temperature and dissolved oxygen are measured in the morning and evening of each day, ecological indexes of water-quality such as ammonia nitrogen and nitrite are measured every week, and management measures are regulated in time according to relevant measurements to ensure the culturing environment is within an appropriate range.

[0044] 3) Water-quality purification management in the bright area: because the Penaeus vannamei has higher requirements on water-quality indexes and is extremely sensitive to environmental changes, the water-quality stability is extremely important. Although the water purification stability of the aquatic-photosynthetic bacterium symbiosis system is strong, it is easy to be affected by weather. Therefore, probiotics preparations should be added in time to avoid the change of water-quality in continuous rainy days.

[0045] 4) Daily feeding and management: the Penaeus vannamei are fed for 4 to 8 times every day, the feeding amount is mainly based on the growth status of the larvae, the temperature and the water-quality, and an eight full principle is adopted to avoid overfeeding and destroying the water-quality. Attention shall be paid to the ingestion situation and larva activities to timely adjust the feeding amount and water-quality management measures.

[0046] 5) Disease and insect control: the Penaeus vannamei have strong disease resistance and is not easy to get ill generally, but it is very difficult to treat once it is ill. Therefore, prevention should be prevailing. The most critical preventive measure is to strictly control the quality of the larvae and the water-quality management. Due to the relatively small water body exchange capacity, the application of microecological preparations in the dark area every week becomes the key to the water-quality management for Penaeus vannamei culturing, and the main microecological preparation is Bacillus.

[0047] 6) Growth and survival rate: The system of the present invention shows great advantages in the culturing of the Penaeus vannamei, and is suitable for the growth environment of the Penaeus vannamei in dark environment and micro-water flow. The most important is that the ecological environment for culturing is excellent and stable, and is not affected by the external environment. In addition, in the dark environment of the present invention, the Penaeus vannamei no longer eats at night or in the morning and evening, but eats all day long. The daily ingestion time is prolonged, so that the growth advantage is manifested. After a four-month growing period, a specification of 20 to 40 Penaeus vannamei per 500 g is achieved, and the survival rate is 82 to 94%. Compared with the traditional culturing method, the harvesting date is advanced by about 20 days and the survival rate is higher by 20 to 30%; in addition, the Penaeus vannamei have no earthy smell, the taste and meat quality thereof are closer to those of wild Penaeus vannamei, and have better market evaluation and promotion values.

[0048] The above-mentioned embodiments should be understood as merely illustrative of the present invention and are not intended to limit the scope of protection of the present invention. After reading the contents recorded in the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent changes and modifications also fall within the scope of the present invention as defined in the claims.