Disclosure of Invention
The invention provides a method for breeding big snapdragon by utilizing a nutrient source in prawn breeding wastewater to proliferate natural baits on coastal reclamation beaches, which has remarkable breeding benefit, and meanwhile, the mangrove purifies the water quality, so that the method is a breeding method with sustainable development, and provides a solution for utilizing the reclamation beaches in the southeast coastal areas and relieving the sharp contradiction between the mangrove and the beaches.
The invention adopts the following technical scheme:
(1) enclosing a reclamation beach area by silt or silt, removing impurities in the beach area, leveling a depression and a ditch pit, then making ridges around, digging ditches at the inner sides of the ridges, dredging at regular time, digging main drainage ditches in the south-north direction at the middle positions of the beach area, arranging opening and closing water gates at the south-north ends of the main drainage ditches, communicating the peripheral ditches with the main drainage ditches, communicating the main drainage ditches with the water outlets of the high-position shrimp culture pond, preparing soil and making ridges, wherein the ridges are in the south-north direction, the width of each ridge is 1.1-1.2 meters, the ridge surface is compacted, the height of each ridge is 0.1-0.15 meters, and the depth of each ridge is 0.15-0.2 meters, and the ridges are communicated with the ditches; a bracket is arranged around the pool and covered with a nylon net;
(2) draining the water in the shrimp pond in the water collecting channel after the culture of the prawns in the high-position shrimp culture pond is finished, splashing activated bacillus subtilis, airing, rolling and grinding to obtain an organic fertilizer for later use;
(3) cleaning a pool with bleaching powder in 1 month, draining accumulated water in a tidal flat area, turning over the tidal flat area, and airing the tidal flat area for 1 month;
(4) in the month of 2, ploughing fine soft mud, shaping ridge surfaces, airing, and splashing zeolite powder;
(5) in 3 months, setting the row spacing of the mangrove seedling plants to be 0.9-1 meter and the plant spacing to be 0.5-0.6 meter, transplanting the mangrove seedling plants of 2 years old to the ridge surface with earth balls, planting, spreading the shrimp pond sludge treated in the step (2) on the ridge surface, irrigating fresh seawater, splashing activated bacillus subtilis, keeping the water level to be 0.03-0.07 meter higher than the ridge surface for at least 20 days, replacing the fresh seawater once every 4-6 days, exposing the ridge surface during drainage, and splashing benthic algae growth compound and microbial preparation after water replacement;
(6) in the month of 4, feeding the fingerlings of the mackerel according to the feeding density of 4000-6000 fish/mu, irrigating the upper-layer culture wastewater of a high-position shrimp pond every day, keeping the water level about 0.1 meter higher than the ridge surface, and applying benthic algae growth compound nutrient salt after two weeks;
(7) watering the upper layer cultivation wastewater of the high-level shrimp pond at noon every 5-6 months, wherein the irrigation amount of each time submerges the ridge surface by 0.04-0.07 m; airing the ridge surface every morning, applying benthic algae growth composite nutrient salt every 4-6 days,
(8) in 7-8 months, irrigating natural seawater until the water level is slightly lower than the ridge surface, then irrigating the upper layer culture wastewater of the high-position shrimp pond until the water level is 0.03-0.05 m higher than the ridge surface, reducing the water level after at least 6 hours, then irrigating the upper layer culture wastewater of the high-position shrimp pond with the same amount, airing the ridge surface every 2 weeks, and splashing benthic algae growth compound and microbial agents after supplementing fresh seawater;
(9) in 9-10 months, continuously mixing and irrigating natural seawater and upper layer cultivation wastewater of a high-position shrimp pond, simultaneously sprinkling a substrate modifying agent, feeding water to the water level 0.1-0.3 m higher than the ridge surface every morning, airing the ridge surface at night, and applying fertilizer once a week, wherein the fertilizer is benthic algae growth compound nutrient salt;
(10) fertilizing once in two weeks in 11 months, wherein the fertilizer is benthic algae growth compound nutrient salt, the culture wastewater in the high-level culture pond keeps the water level 0.01-0.03 m higher than the ridge surface at night, the ridge surface is aired in the daytime, and the big barracuda are caught for the first time;
(11) and in 12 months, fishing the big elastic paintfish for the second time, airing the ridge surface for one week, and irrigating seawater with the water level 0.1-0.3 m higher than the ridge surface.
The technical effects of the invention are as follows: 1. constructing a mangrove forest culture habitat, transplanting the mangrove forest to a high latitude area, constructing a inhabitation environment suitable for the growth and the propagation of the big snapdragon, realizing reclamation beach ecological culture, and producing green aquatic products without using products such as fisheries, chemical fertilizers and the like in the whole culture process; 2. coupling a prawn culture wastewater utilization technology, controlling conditions such as hydraulic retention time, water level, daily treated water amount and the like through adsorption, precipitation and purification, improving water quality purification efficiency and realizing standard discharge of culture wastewater; meanwhile, natural bait is cultivated by using a nutrient source in the wastewater, the fullness of the mackerel is obviously higher than that of a commercially available product, and the commercially available price of the product is improved. 3. The systematic culture process, airing ridge surfaces and topdressing are key technical means for cultivating benthic diatoms, seedlings with proper density and specification are put in, and stable input and output are kept by culture management technologies such as scientific water level adjustment and the like.
The purification principle of the prawn pond culture wastewater in the technical scheme is as follows: the method is characterized in that soft mud is used as a filling matrix, a ridge making pool is enclosed, the mangroves are prepared and ridged, a channel is opened, and mangroves are planted on the surface of the ridge to form a surface flow artificial wetland, and a horizontal plug flow is used as an operation mode, so that the content of dissolved oxygen in the wetland is increased, the hydraulic retention time is long, the hydraulic load is small, and the pollutant removal effect is improved. The main functions of the soft mud matrix are as follows: can attach a large number of microorganisms to form a biological bacterial film, adsorb precipitates and exchange ions; mangrove plants: the root system secretes oxygen and provides a larger root surface area for aerobic microorganisms to attach, an aerobic zone and an anaerobic zone are formed in the substrate, the substrate nitrification and denitrification capacity is enhanced, and meanwhile, the plant grows to absorb nutrient salts.
The mangrove forest culture habitat is created, the original ecological environment of the big mackerel is restored, the function of maintaining the big mackerel resources is achieved, the nitrogen pollutant emission is reduced, the ecological benefit is remarkable, and the method is a sustainable development culture mode.
The invention is described below with reference to the accompanying drawings and specific embodiments.
DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION
And (3) experimental design: the Dapaoyu fish culture test is carried out in the Yongxing reclamation south China area in the Wenzhou city, the area belongs to the subtropical monsoon climate, the annual sunshine number is 1442-. The area of each of the two culture ponds is 2 mu, the bottom of the pond is flat, the mud is soft mud, and the salinity is about 10-20 per mill. Ridges are formed around the 2 breeding ponds, the ridge surface is 0.6m higher than the beach surface, the width is 0.5m, and the ridges are solid and do not leak water. A ditch with the width of 1.0 meter and the depth of 0.4 meter is dug at the inner side of the ridge, and after the ditch is used, the ditch is dredged at regular time to prevent sludge from being blocked.
A test cell: preparing soil, making ridges in the south-north direction, and planting 2-year-old Kandelia candel on the ridge surface. The culture method takes shrimp pond mud as a base fertilizer, introduces shrimp pond upper surface water containing abundant diatoms and blue-green algae to cultivate benthic algae to grow. During the test period, according to the seasonal change and the growth of mangrove, the watering mode is finely adjusted, and shrimp pond mud fermentation liquor is applied to proliferate sufficient natural bait for feeding and growing the mudskipper.
And (4) comparison pool: the flat beach surface is used for culturing benthic diatoms, the pond is periodically dried in the sun according to the traditional paradigm, shrimp pond sludge fermentation liquor is topdressed, natural sea water algae is irrigated, and the traditional paradigm is used for culturing the mudskipper.
The specific process for culturing the mackerel in the mangrove forest region comprises the following steps:
(1) the method comprises the following steps of enclosing a reclamation beach area by silt or silt, removing impurities in the beach area, leveling a depression and a ditch pit, then making ridges around the periphery, digging ditches at the inner sides of the ridges, dredging at regular time, digging a trunk drainage ditch in the south-north direction at the middle position of the beach area, arranging opening and closing water gates at the south-north ends of the trunk drainage ditch, communicating the peripheral ditches with the trunk drainage ditch, communicating the trunk drainage ditch with a water outlet of a high-position shrimp culture pond, and adding a fence facility at the inner sides of the ridges and the water inlet and outlet to prevent escape and invasion of harmful organisms; preparing soil and making ridges, wherein the ridges are in the north-south direction, the width of the ridge surface is 1.1-1.2 meters, the ridge surface needs to be compacted, the height of the ridge is 0.1-0.15 meters, the depth of each furrow is 0.15-0.2 meters, and the furrows are communicated with the ditches; a bracket is arranged around the pool and covered with a nylon net;
(2) draining the water in the shrimp pond in the water collecting channel after the culture of the prawns in the high-position shrimp culture pond is finished, splashing activated bacillus subtilis, airing, rolling and grinding to obtain an organic fertilizer for later use;
(3) cleaning a pool with bleaching powder in 1 month, draining accumulated water in a tidal flat area, turning over the tidal flat area, and airing the tidal flat area for 1 month;
(4) in the month of 2 and 2, ploughing fine soft mud, shaping ridge surfaces, airing, splashing zeolite powder, checking escape-proof facilities such as purse nets on the inner sides of the ridges and the like;
(5) pulling a measuring rope, digging 0.2 x 0.2 meter tree pits on the ridge surface, setting the row spacing of the mangrove seedling plants to be 0.9-1 meter, the inter-plant spacing to be 0.5-0.6 meter, transplanting the mangrove seedling plants of 2 years old to the ridge surface with soil balls, planting, spreading the shrimp pond sludge treated in the step (2) on the ridge surface, irrigating fresh seawater, splashing activated bacillus subtilis, keeping the water level to be 0.03-0.07 meter higher than the ridge surface for at least 20 days, replacing the fresh seawater once every 4-6 days, exposing the ridge surface during drainage, and splashing benthic algae growth compound and microbial preparations after water replacement;
(6) in the month of 4, feeding the pelagic mackerel fries according to the feeding density of 5000 fries/mu, irrigating the upper-layer culture wastewater of the high-position shrimp pond every day, keeping the water level 0.1 meter higher than the ridge surface, and applying benthic algae growth composite nutrient salt after two weeks;
(7) watering the upper layer cultivation wastewater of the high-level shrimp pond at noon every 5-6 months, wherein the irrigation amount of each time submerges the ridge surface by 0.04-0.07 m; airing the ridge surface every morning, applying benthic algae growth composite nutrient salt every 4-6 days,
(8) in 7-8 months, irrigating natural seawater until the water level is slightly lower than the ridge surface, then irrigating the upper layer culture wastewater of the high-position shrimp pond until the water level is 0.03-0.05 m higher than the ridge surface, reducing the water level after at least 6 hours, then irrigating the upper layer culture wastewater of the high-position shrimp pond with the same amount, airing the ridge surface every 2 weeks, and splashing benthic algae growth compound and microbial agents after supplementing fresh seawater;
(9) in 9-10 months, continuously mixing and irrigating natural seawater and upper layer cultivation wastewater of a high-position shrimp pond, simultaneously sprinkling a substrate modifying agent, feeding water to the water level 0.1-0.3 m higher than the ridge surface every morning, airing the ridge surface at night, and applying fertilizer once a week, wherein the fertilizer is benthic algae growth compound nutrient salt;
(10) fertilizing once in two weeks in 11 months, wherein the fertilizer is benthic algae growth compound nutrient salt, the culture wastewater in the high-level culture pond keeps the water level 0.01-0.03 m higher than the ridge surface at night, the ridge surface is aired in the daytime, and the big barracuda are caught for the first time;
(11) and in 12 months, fishing the big elastic paintfish for the second time, airing the ridge surface for one week, and irrigating seawater with the water level 0.1-0.3 m higher than the ridge surface.
The mixing ratio of the natural seawater in the step (9) to the upper layer aquaculture wastewater in the high-position shrimp pond is 1: 1. And the substrate modifier is sprayed while mixing, takes zeolite powder as a main raw material and is compounded with Chinese herbal medicine components such as scutellaria baicalensis, coptis chinensis, sodium humate, golden cypress and the like, so that the substrate modifier has double effects of adsorbing toxic substances, detoxifying and the like. When the content of nutritive salt in the upper layer cultivation wastewater exceeds the degradation and transformation capacity of benthic algae and probiotics, 1; adding fresh seawater in a proportion of 1, diluting the inlet water concentration, and simultaneously splashing the substrate modifier to adsorb ammonia nitrogen and remove part of bacteria.
The benthic algae growth compound in the steps (5) and (8) comprises sodium silicate, ferric trichloride, enzyme preparation (protease), vitamin B1, lactobacillus activation solution and vitamin B12; the lactobacillus splashes into the mangrove forest to absorb nitrite, ammonia nitrogen and other nutritional ingredients in the aquaculture wastewater, control the growth of floating algae, improve the transparency of water, facilitate the photosynthesis of benthic algae, and the enzyme preparation decomposes protein in the shrimp pond sludge to generate amino acid for the nutrition required by the growth of benthic algae.
The benthic algae growth compound in the steps (5) and (8) comprises 120g of sodium silicate, 2g of enzyme preparation (protease), 10g of triacontanol and vitamin B110g of vitamin B121g, the ratio is 120:2:10:10:1, the substances are dissolved in 100L of lactobacillus fermentation liquor and are sprinkled for preparation for use; the fermentation method of the lactobacillus comprises the following steps: adding 2kg of shrimp pond sludge, 1kg of corn steep liquor, 1kg of brown sugar and trace elements into a 50L fermentation vat, uniformly mixing, adjusting the pH value to 6.5, and performing anaerobic fermentation at 28 ℃ for 48 hours to obtain the shrimp pond sludge.
The microbial preparation in the steps (5) and (8) comprises photosynthetic bacteria and bacillus which are used in a compound way, and the bacterial application amount of each cubic water body is 1 multiplied by 109CFU, Bacillus and photosynthetic bacteria ratio of 4: 1.
The benthic algae growth composite nutritive salt in the steps (6), (7), (9) and (10) comprises shrimp pond sludge, bacillus subtilis, brown sugar, seawater auxin, sodium silicate, vitamins B1 and B12. Shrimp pond sludge is a nitrogen and phosphorus nutrition source, brown sugar is a carbon source, bacillus subtilis is a decomposer, and growth promoting factors such as seawater auxin, sodium silicate, vitamins and the like are added to prepare the compound nutrient salt.
The shrimp pond sludge is obtained through the step (2). The shrimp pond sludge is decomposed by bacillus and then completely aired, and the nutrient components are dissociated.
Before fertilizing with composite nutritive salt for the growth of benthic algae, 200L food-grade plastic barrels are used, 1/2 natural seawater is added into each barrel, 30kg shrimp pond mud is added, and 30g Bacillus subtilis is addedThe viable bacteria amount is more than or equal to 2.0 multiplied by 1010CFU/g, heating and dissolving 4.5kg brown sugar, pouring into seawater, mixing, fermenting for 48 hr, adding 500g seawater auxin, 120g sodium silicate (analytically pure), and vitamin B16g、B1250mg, dissolved, the dosage is 1 barrel/mu. In the fermentation process of the bacillus, nutrient components of the shrimp pond sludge are further released into the fermentation liquor, growth promoting factors are added and sprinkled to the ridge surface, and nutrient salt is adsorbed on the soil surface layer and can be used as nutrients required by the growth of benthic algae.
The activation method of the bacillus subtilis in the step (2) comprises the following steps: adding 1/3-2/3 of natural seawater into a 50L plastic barrel, adding a bacillus culture medium, pouring the mixture into seawater after thermal dissolution, and adding bacillus subtilis (the viable bacteria amount is more than or equal to 2.0 multiplied by 10)10CFU/g), the water temperature is kept at 25 ℃, and the oxygenation is activated for 4 hours. The bacillus activating solution is prepared temporarily, can grow to logarithmic phase within 4 hours under the conditions of proper water temperature and sufficient nutrition, and is sprayed into mangrove forest, so that the activity of bacteria is the best, and further growth and reproduction are facilitated.
The specific process of traditional paradigm culture of Pacific mackerel as a contrast pond is as follows:
(1) selecting 1 test pool in the same area as a reference pool, wherein the east-west trend is 45 meters long by 30 meters wide, the mud condition of the mud flat is completely the same, the mud flat is leveled without making ridges on the mud flat, a well-shaped annular ditch is excavated in the pool, the ditch width is 1.2 meters, and the depth is 0.3 meter; the water inlet and outlet gates are connected in the north-south direction and used for daily water inlet and outlet.
(2) Draining the pond water in 3-4 months, airing the mudflat until the mudflat surface is completely cracked, irrigating natural seawater, keeping the water level at 0.1 m, after one month, putting the mudflat fingerlings in the early 4 months, wherein the putting density is consistent with that of the test pond, the putting density is 5000 tails/mu, the putting specification is 5.76 +/-0.18 cm in body length, and the weight is 2.63 +/-0.28 g. In the initial stage of fry setting, the water level is kept at 0.15 m at night, the water level is reduced to 0.05 m in the daytime, and after one week, the big barracuda already establishes a cave and the water level is adjusted to 0.05-0.1 m. Draining water after one month of cultivation, sunning the lawn, only keeping water in the circular ditches, irrigating natural seawater after completely cracking, and re-culturing benthic diatoms.
(3) And in 5-6 months, replacing the water body every 4-5 days, and keeping the water level at 0.05-0.1 m. After draining water, insolating the beach surface for 2-3 days, after cracking the surface layer, re-feeding fresh seawater, and meanwhile, according to the mangrove forest culture step (3), putting benthic algae to grow compound nutrient salt, wherein the fertilizing amount is 1 barrel/mu, and fertilizing once per week.
(4) In 7-8 months, because of the high temperature of the terrace, the water level of the culture pond needs to be increased to 0.15 meter, the beach surface is sunned once every week, and the awning is erected around the culture pond to shade the big elastic paintings.
(5) In 9-11 months, the cultivation mode refers to the step (3).
(6) During months 11-12, the mackerels were harvested throughout the netpen in sunny and mild weather.
1 measurement items and methods
1.1 Kandelia candel growth monitoring
The growth and development conditions of the Kandelia candel are monitored for 3 times in the test process, namely 4 months, 8 months and 12 months respectively, the plant height (the distance from the root neck to the top) and the base diameter (the base diameter of the trunk) are measured as indexes, and the leaf number and the branch number are recorded.
1.2 weight of Pacific saury
The biological indexes such as the weight (W) and the body length (L) of the mackerel are measured once every two months, the number of samples is 20, the length is measured by a vernier caliper, the precision is 0.01mm, and the weight is weighed by an electronic balance, the precision is 0.01 g.
1.3 monitoring of Water quality
In the test process, the change of the water quality index is monitored in 5-month-1 day (spring), 7-month-15 day (summer) and 10-month-1 day (autumn), and the determination indexes comprise: ammonia nitrogen, nitrite nitrogen, total suspended particulate matter and chemical oxygen demand CODMnThe monitoring method refers to section 4 of ocean monitoring Specification: sea water analysis.
1.4 data processing
The data obtained were analyzed using EXCEL and SPSS software. Wherein the calculation formula is as follows: specific Growth Rate (SGR) ═ ln (ln), (w) -ln (w)0) -/(t). times.100%, and a fullness K of 100 × (W/L)3)。
2 results and analysis
Growth and development conditions of 2.12-year-old Kandelia candel
Table 1 shows the growth of 2-year-old Kandelia candel, which can grow to 1m in height after one year, with a base diameter of 6.7 + -0.8 cm, a crown width of 87 × 69cm, a leaf number of 184.3 + -17.3, a branch number of 17.21 + -2.06, and good growth. In 4-8 months, the temperature gradually rises, the growth amount of the Kandelia candel is the most remarkable and is the most main growth season, and the growth is not obvious with the reduction of the temperature after 8 months.
2.2 growth of Pacific saury
As can be seen from FIGS. 1 and 2, the difference between the different culture methods is significant at the level of 0.05, as indicated by the lower case letters in the figures. The basic growth indexes of the fish body mainly include weight and body length, and compared with the basic growth indexes of the mackerel under the two culture methods, the basic growth indexes of the mackerel are discovered, the culture period is 8 months, compared with the traditional paradigm, the body length of the mackerel from 4 months to 12 months is respectively increased by 24.9%, 20.0%, 18.5% and 11.5%, and the body weight is respectively increased by 97.8%, 99.2%, 78.6% and 61.2%, and both reach significance levels (P < 0.05).
Fig. 3 shows the change of body type indexes of the mackerel under two culture methods, the difference between the fullness levels of the mackerel from 4 months to 6 months is not significant (P >0.05), the difference between the fullness levels of the mackerel from 8 months to 12 months is significant (P <0.05), which shows that the body type of the mackerel cultured in the mangrove forest area is more beautiful, the total change trend is increased along with the extension of the culture period, and compared with the traditional paradigm, the fullness levels of the mackerel from 4 months to 12 months are respectively increased by 1.6%, 15.1%, 7.4% and 16.2%.
As can be seen from figure 4, the growth speed of the mudskipper is high from 4-6 months to 6-8 months, the water temperature gradually rises in the stage, the temperature is in a proper range of growth at 15-30 ℃, the proliferation of natural baits such as benthic algae is facilitated, the natural baits are rich due to the fact that the crayfish pond sludge is used as a base fertilizer in the mangrove forest region, and auxiliary growth factors such as vitamins, trace elements and microbial agents are added, and the specific growth rate of the mudskipper is remarkably different from 4-6 months (P < 0.05). Along with the prolonging of the culture time, benthic algae growth compound nutrient salt is applied in the traditional paradigm, so the difference of specific growth rate is not obvious in 6-12 months, and the specific growth rate of individual small mudskipper is obviously greater than that of individual large mudskipper.
Table 2 lists the benefit conditions of the mangrove forest and the traditional paradigm, and compares the harvest specification, weight gain, specific growth rate and yield of the mudskipper under the two breeding methods, and the result shows that the mudskipper size harvested in the mangrove forest area is 44 tails/kg, the yield is 77.9 kg/mu, and the economic benefit yield is 1.56 times of that of the traditional paradigm.
TABLE 1 growth and development of Kandelia candel
TABLE 2 comparison of the breeding benefits of Pacific saury under two breeding methods
2.3 purification Effect of the wastewater from the wetland of mangrove forest shrimp pond cultivation
As can be seen from Table 3, with the growth of Kandelia candel, the removal rates of the nutrients in the low-concentration shrimp pond culture wastewater are respectively: 21.10 percent of total nitrogen, 53.11 percent of nitrite nitrogen, 32.80 percent of ammonia nitrogen, 27.77 percent of active phosphate, 44.74 percent of total suspended particulate matters and CODMn15.63 percent. In the process of culturing the mackerel, the water irrigation quantity of the shrimp pond is adjusted along with the growth condition, seasonal change and bait abundance of the mangrove, the hydraulic retention time is optimized, the water concentration of the shrimp pond is diluted, and the purification effect of the mangrove forest is obvious.
TABLE 3 purification of waste water from shrimp ponds from mangrove forest
3 conclusion
From the data, the land is prepared and the ridges are made, 2-year-old kandelia candel is planted on the ridge surfaces, the shrimp pond sludge is used as a base fertilizer, the shrimp pond water is submerged regularly, and the water can grow to 1 meter high in the current year and grows well. The method for breeding the mudskipper in the mangrove forest area simulates the natural mangrove forest habitat, adjusts the water irrigation mode of a shrimp pond according to seasonal changes, periodically dries out the water, applies benthic algae to grow composite nutrient salt, can proliferate sufficient natural baits, and has the advantages that the body length, the body weight, the fertility, the growth speed and the yield of the mudskipper are obviously larger than those of the traditional paradigm, and the economic benefit is obvious. In the process of culturing the mackerel, the water irrigation quantity of the shrimp pond is adjusted along with the growth condition of the mangrove, the seasonal change and the abundance of the bait, the hydraulic retention time is optimized, the water concentration of the shrimp pond is diluted, the discharge of the seawater culture wastewater is effectively reduced, and the ecological benefit is obvious.