Systems and methods for enhancing the effects of proliferation release and nearshore ecological connectivity

Abstract

The application provides a system and method for improving proliferation and release effect and nearshore ecological connectivity, the system comprising: a high-density seedling cultivation area for cultivating seedlings and discharging tail water; an ecological rice field area for introducing received tail water into a rice field and discharging purified tail water; an ecological conservation area for receiving purified tail water, regulating water level by setting an intelligent dam body, and temporarily storing and conserving the purified water; and an off-dike wetland area connected with the ecological conservation area, for providing an adaptation and transition place for seedlings before release. The application realizes water quality recycling, ecological purification and seedling adaptation and release in stages by constructing a proliferation and release unit system connected with each other, thereby significantly improving seedling survival rate and release effect, and realizing the synergistic gain of ecology and economy.

Description

Technical Field

[0001] This invention relates to the field of ecological restoration technology, specifically to a system and method for improving the effectiveness of stock enhancement and nearshore ecological connectivity. Background Technology

[0002] Coastal areas are a vital foundation for ecosystem diversity and fisheries production. Stock enhancement has become an important means of restoring aquatic biological resources and improving the aquatic ecological environment; however, traditional stock enhancement methods still face many limitations. In traditional stock enhancement processes, inappropriate selection of seedling size and a lack of scientific planning regarding release time and location fail to fully consider the objective needs of seedlings of different sizes at different life stages for habitat suitability, resulting in extremely low seedling survival rates and failing to generate real ecological and economic benefits. Furthermore, due to reclamation and dike construction, the ecological connectivity between nearshore waters and wetlands is poor, and seedlings lack habitat transition during release and migration, leading to limited release effects. Therefore, constructing a comprehensive stock enhancement system that integrates ecological restoration, water quality control, and ecological connectivity can significantly improve the effectiveness of stock enhancement while effectively improving water quality and reducing pollution, thereby achieving the dual goals of coastal ecosystem restoration and fisheries resource recovery.

[0003] To address the aforementioned issues, existing stock enhancement technologies generally focus on structural improvements to the release device or the construction of local ecological buffer measures, but lack overall systemic considerations and struggle to balance release effectiveness with ecological connectivity. For example, patent documents CN120077980A and CN119837062A reduce mechanical damage to seedlings during release by incorporating buffer chambers, diversion devices, or guide pipes into the release device, thereby increasing survival rates. While these technical solutions improve release safety to some extent, their improvements are limited to the release device itself and fail to consider the adaptability of seedlings and post-release ecological effects in light of the actual conditions of nearshore waters. The release effect remains susceptible to factors such as sudden environmental changes, water quality differences, and insufficient ecological connectivity, lacking a proper regulatory mechanism. Other technologies (such as patent documents CN119856695A, CN119744792A, and CN119631932A) introduce buffer pools or filtration and purification units into the release device or channel to provide a temporary buffer environment for the seedlings. While such programs can produce some stock enhancement effects, the functional units are independent of each other, still employing a single release and single-stage adaptation approach, without considering the ecological needs of seedlings at different life stages. Furthermore, they lack synergy with coastal farmland utilization, water purification, and wetland ecological restoration, resulting in limited overall ecological and economic benefits from stock enhancement. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a system and method for improving the effectiveness of stock enhancement and release programs and enhancing nearshore ecological connectivity.

[0005] A system for enhancing the effects of restocking and releasing fish and improving nearshore ecological connectivity, according to the present invention, comprises:

[0006] High-density seedling cultivation area, used for cultivating seedlings and discharging wastewater;

[0007] Ecological rice paddy area is used to introduce the received wastewater into the rice paddy and discharge the purified wastewater.

[0008] The ecological conservation area is used to receive the purified wastewater. The water level is regulated by setting up an intelligent dam to complete the temporary storage and conservation of the purified water.

[0009] The wetland area outside the dike, connected to the ecological conservation area, is used to provide an adaptation and transition site for seedlings before release.

[0010] Preferably, the high-density seedling cultivation area and the ecological paddy field area are connected by a pipeline. The individual specifications of the seedlings are checked regularly, and when they meet the preset value-added release standards, they are introduced into the ecological paddy field area through the pipeline.

[0011] Preferably, the ecological paddy field area uses diversion ridges to guide the incoming water into the paddy field in a deflection manner, and the water flow is regulated by arranging earthen ridges and field ridges to ensure that the water flow stays in the paddy field for a sufficient time.

[0012] Preferably, ecological floating islands are set up in the ecological conservation area to cultivate crops, and the tailwater of the paddy field is introduced through pipelines, purified, and then reintroduced into the high-density seedling cultivation area through water pumps to complete the water cycle.

[0013] Preferably, the water level of the ecological conservation area is controlled by setting up an intelligent dam, and it is connected to the ecological wetland outside the dam through pipelines and culverts.

[0014] Preferably, the wetland area outside the dike includes a salt gradient water body with salinity ranging from low to high and a tidal channel structure.

[0015] A method for improving the effect of restocking and releasing fish and enhancing nearshore ecological connectivity according to the present invention includes:

[0016] Step S1: Introduce seedlings into the high-density seedling cultivation area for cultivation, and discharge the seedling tailwater into the ecological paddy field area;

[0017] Step S2: The ecological paddy field area receives the seedling tailwater and irrigates the paddy field, and the paddy field tailwater is discharged into the ecological conservation area.

[0018] Step S3: The ecological conservation area receives the tailwater from the paddy fields, and the water level is regulated by the intelligent dam. The conserved clean water is pumped back to the high-density seedling cultivation area.

[0019] Preferred options also include:

[0020] Step S4: If the seedlings grow to meet the preset release standards, they are released into the ecological wetland outside the dam through a culvert or pipeline, and the seedlings that have adapted to the environment are sent into the nearshore natural waters.

[0021] Preferably, the ecological paddy field area uses diversion ridges to guide the incoming water into the paddy field in a deflection manner, and the water flow is regulated by arranging earthen ridges and field ridges to ensure that the water flow stays in the paddy field for a sufficient time.

[0022] Preferably, the seedlings are gradually adapted to different salinity and water environments in high-density seedling cultivation areas, ecological paddy fields, ecological conservation areas, and wetlands outside the dikes to complete the phased transition.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. This invention improves the survival rate and ecological adaptability of released seedlings. Suitable seedlings are introduced into a high-density seedling cultivation area for rapid cultivation. Once the seedlings reach the required size for stock enhancement and release, they are released into the tidal channels of the ecological paddy field area and then enter the ecological conservation area via the channels. Subsequently, the seedlings enter the ecological wetland area outside the dike (riverbank) through culverts or pipelines. Seedlings that have gradually adapted to the low-salinity environment can actively enter near-shore natural waters through wetland outlets, ultimately completing a tiered stock enhancement and release process. This invention fully considers the objective needs of seedlings of different sizes for habitat suitability at different life stages. Through a tiered structure of "seedling cultivation—paddy field purification—conservation and regulation—wetland transition—release into natural waters," it achieves adaptive transfer of seedlings at different habitat stages, significantly improving the survival rate of released seedlings.

[0025] 2. This invention enhances ecological connectivity and system stability. Through the rational layout of tidal channels and wetland structures, it establishes a dual hydrological and biological channel connecting artificial and natural ecosystems along the coast, promoting fish migration and ecosystem reconstruction. Utilizing structures such as tidal channels, culverts, and underground pipelines, a continuous hydrological channel is achieved, linking "inland aquaculture system – paddy field ecosystem – nearshore wetland system – natural water area." This restores and enhances hydrodynamic exchange and material cycling in the coastal area, promoting the natural reconstruction of plankton, benthic organisms, and aquatic plant communities. It provides breeding grounds for fish, crustaceans, and amphibians, thereby improving the integrity and diversity of the ecosystem. Furthermore, the system forms an internal circulation network with automatic recovery capabilities, giving the water body strong self-regulation and resistance to disturbance, enabling it to maintain a good ecological balance over the long term.

[0026] 3. This invention achieves water quality recycling and purification, as well as efficient resource utilization. The system's wastewater undergoes step-by-step purification through ecological paddy fields and conservation areas, reducing nitrogen and phosphorus accumulation and eutrophication. Simultaneously, it enables nutrient sharing between rice and fish, improving resource utilization efficiency. An internal water cycle is formed through the inflow and outflow of water from the multi-functional synergistic aquaculture area, paddy field area, and conservation area. Utilizing sedimentation, soil adsorption, plant absorption, and microbial nitrification and denitrification, nutrients in the system's wastewater are effectively removed. Residual feed and metabolites in the water decompose and become nutrients for the paddy fields, achieving a synergistic effect of "using fish to fertilize the fields and using the fields to purify the water," minimizing the pollution risk of this invention.

[0027] 4. This invention balances economic and ecological benefits, improving fishery output and ecological functions without impacting agricultural production, achieving comprehensive benefits such as increased rice paddy income, wetland restoration, and carbon emission reduction (reduced methane emissions). The system enables integrated rice-fish farming, providing both seedling stocking and ecological purification functions in the rice paddy area while ensuring rice yield. Furthermore, the tidal flow and low-velocity water flow design creates alternating aerobic and anaerobic conditions within the system, increasing dissolved oxygen levels and effectively reducing methane emissions, resulting in significant carbon emission reduction.

[0028] 5. This invention promotes regional ecological security and sustainable development. By enhancing riparian ecological connectivity and improving the quality of aquatic habitats, it helps restore the ecological buffering function of estuaries and nearshore zones, improving the region's ability to withstand extreme weather events (such as floods and storm surges). Through efficient utilization of existing spatial resources, it improves the region's flood control and drainage capabilities as well as its water storage capacity. The system requires no large amounts of fertilizers or chemical agents during operation, resulting in low overall energy consumption and enabling long-term operation with low maintenance costs. This method can be flexibly adjusted according to different regional topography and hydrological conditions, possessing good replicability and promotional value. Attached Figure Description

[0029] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0030] Figure 1 This is a schematic diagram illustrating the comprehensive efficiency enhancement of rice-aquaculture areas achieved through agroforestry-wetland integration according to the present invention.

[0031] Figure 2 This is a schematic diagram of the integrated efficiency enhancement of rice-aquaculture areas achieved by the agroforestry-wetland agro-integrated farming system according to the present invention.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Ecological paddy field area; 11. Diversion field ridges; 12. Fish ponds and tidal ditch; 2. High-density seedling cultivation area; 21. Aeration pump; 3. Ecological conservation area; 31. Ecological floating island; 32. Submerged plant area; 33. Ecological hydroponic area; 34. Intelligent lifting dam; 4. Wetland area outside the dike; 5. Dike or riverbank; 6. Culvert or pipeline; 7. Water pump; 8. Near-shore natural water area. Detailed Implementation

[0034] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0035] A system for enhancing the effectiveness of restocking and stock enhancement and improving nearshore ecological connectivity includes:

[0036] High-density seedling cultivation area 2 is used for cultivating seedlings and discharging wastewater.

[0037] Ecological rice paddy area 1 is used to introduce the received wastewater into the rice paddy and discharge the purified wastewater.

[0038] Ecological conservation area 3 is used to receive the purified tailwater. The water level is regulated by setting up an intelligent dam to complete the temporary storage and conservation of the purified water.

[0039] The wetland area 4 outside the dike is connected to the ecological conservation area 3 and is used to provide an adaptation and transition area for seedlings before release.

[0040] Specifically:

[0041] High-density seedling cultivation area 2: Used for high-density, rapid cultivation of seedlings for propagation and release. The original fishponds are modified in length, width, depth, and slope, with multiple sets of aeration pumps 21 installed at the bottom and equipped with water diversion devices. Floating high-density aquaculture facilities are introduced, and juvenile fish and shrimp are cultivated in the ponds. The wastewater generated during the cultivation process contains uneaten feed, biological debris, and nutrients, and is connected to the ecological rice paddy area 1 via a wastewater diversion pipe.

[0042] Ecological Paddy Field Area 1: This area combines rice cultivation and water purification functions. Dikes are laid out to guide the water from the ecological paddy field area 33 through the paddy field in a deflected, low-velocity flow, with overflow outlets at the end to collect the water and direct it into the ecological pond area. After entering the paddy field, the wastewater is absorbed and transformed by the paddy field ecosystem, purifying the water quality before flowing into the ecological conservation area 3. The dikes are heightened and reinforced, and tidal ditches are excavated on the inner side of the dikes to facilitate seedling movement and introduce the water into the ecological conservation area 3.

[0043] Ecological Conservation Zone 3: Water levels are regulated by intelligent dams to temporarily store and conserve purified water. This zone can be modified to accommodate small waterways or low-lying areas based on the actual terrain. The conservation zone is connected to the high-density seedling cultivation zone 2 via a circulating water pump 7. Purified water is returned to replenish the cultivation zone's water supply, maintaining stable water quality within the system. Floating islands are set up for planting ornamental aquatic plants and vegetables, while native submerged plants are grown on the water's bottom. Additionally, cash crops such as water chestnuts are planted in the open water hydroponic area. Nutrients in the rice paddy wastewater are removed through ecological sedimentation and plant absorption.

[0044] Wetland Area 4 outside the dike:

[0045] Located outside the dike or riverbank 5, the wetland features a gradient of water bodies from low to high salinity and tidal channels, providing a habitat for seedlings to adapt and transition before release. The wetland outlet connects to the nearshore natural waters 8, enabling natural migration and ecological reintegration of the seedlings.

[0046] In another embodiment, the system includes:

[0047] High-density seedling cultivation area 2: A seedling cultivation area is constructed by modifying the existing terrain. Floating high-density aquaculture facilities are installed in the cultivation area to further optimize the aquaculture space. Wastewater and organic particulate matter from the cultivation area are periodically introduced into ecological paddy field area 1 via pipelines for purification. Based on the actual needs of stock enhancement and release, juvenile grass carp, black carp, crucian carp, yellow catfish, freshwater shrimp, anchovy, and Chinese mitten crab can be introduced into the cultivation area. Individual juvenile sizes are regularly sampled and checked. Once all indicators of the juveniles meet the corresponding stock enhancement and release standards, the qualified juveniles can be introduced into ecological paddy field area 1 via pipelines.

[0048] Ecological Paddy Field Area 1: Through a well-designed water flow path and velocity control, the wastewater from the high-density seedling cultivation area 2 is effectively purified, and the purified wastewater flows by gravity into the ecological conservation area 3. The water is diverted into the paddy field via guide ridges 11, and the flow is regulated through the reasonable arrangement of earthen ridges and paddy field ridges, ensuring that the water remains in the paddy field for a preset time to complete the purification process. The preset time T can be calculated using the following formula:

[0049]

[0050] Where V is the water storage capacity of the paddy field, and Q is the tailwater discharge flow rate.

[0051] The wastewater discharged from the high-density seedling cultivation area 2 flows through the paddy field in a tidal manner. Nutrients in the wastewater are effectively removed through soil adsorption, plant absorption, and microbial nitrification and denitrification. This process not only replaces the application of chemical fertilizers but also achieves wastewater purification and reuse through the natural purification capacity of the paddy field. Fish ponds and tidal ditches 12 are set up in the paddy field to facilitate seedling activity. The seedlings can feed on weeds, algae, and pests in the paddy field and rest in the fish ponds and tidal ditches 12 when the paddy field dries up. The activity of the seedlings in the paddy field promotes the absorption of dissolved oxygen and nutrients by the rice roots, and their excrement can also supplement fertilizer for the rice and increase soil nutrients.

[0052] Ecological Conservation Zone 3: Ecological Conservation Zone 3 features floating ecological islands 31 for cultivating suitable hydroponic crops such as water spinach, water celery, and cattails, as well as ornamental flowers. An ecological hydroponic area 33 can be established within Ecological Conservation Zone 3, where aquatic economic crops such as water chestnuts, water caltrops, and lotus roots can be grown. The planting of water chestnuts and lotus roots is adjusted according to water depth, and weeds are regularly removed from the fields to maintain water quality. The vegetation community in this area not only plays a vital role in water purification but also provides habitats for aquatic organisms, promoting ecological restoration. Wastewater from the paddy fields is piped into the conservation zone. After deep purification in Ecological Conservation Zone 3, the wastewater is pumped by water pump 7 into the high-density seedling cultivation area 2 to complete the water cycle. A smart lifting dam 34 is installed at the outlet of the conservation zone to control the water level in Ecological Conservation Zone 3 and connects to the ecological wetland outside the dike via a sluice gate or pipe 6, allowing suitable seedlings to be released into the wetland.

[0053] Outside the dike wetland area 4: A culvert or pipeline 6 is installed to connect the ecological conservation area 3 and the outside wetland area 4. When the intelligent lifting dam 34 of the ecological conservation area 3 is lowered, the stocking seedlings can enter the outside wetland area 4 with the water flow through the culvert or pipeline 6. The seedlings, which gradually adapt to the low-salt environment, can actively enter the near-shore natural water area 8 through the wetland outlet, and finally complete the step-by-step stocking process.

[0054] A method for improving the effectiveness of stock enhancement and nearshore ecological connectivity includes:

[0055] Step S1: Introduce seedlings into the high-density seedling cultivation area 2 for cultivation, and discharge the seedling tailwater into the ecological paddy field area 1;

[0056] Step S2: The ecological paddy field area 1 receives the seedling tailwater and irrigates the paddy field, and the paddy field tailwater is discharged into the ecological conservation area 3.

[0057] Step S3: The ecological conservation area 3 receives the tailwater from the paddy field, and the water level is regulated by the intelligent dam. The conserved clean water is pumped back to the high-density seedling cultivation area 2 by the water pump 7.

[0058] Step S4: If the seedlings grow to meet the preset value-added release standard, they are sent through the culvert or pipeline 6 into the ecological wetland outside the dam, and the seedlings that have adapted to the environment are sent into the near-shore natural waters 8.

[0059] In one embodiment, the specific steps include:

[0060] First, construct units such as high-density seedling cultivation area 2, ecological paddy field area 1, ecological conservation area 3, and wetland area outside the dike 4. In high-density seedling cultivation area 2, introduce suitable seedlings for rapid cultivation. During the cultivation process, residual feed, biological debris, etc. are discharged into ecological paddy field area 1 with the tailwater in the form of tidal flow, thereby maintaining the aerobic-anaerobic alternation conditions in ecological paddy field area 1, promoting the purification of tailwater quality, and controlling methane emissions.

[0061] The ecological rice paddy absorbs and removes nitrogen and phosphorus nutrients, and organic particles such as residual feed can be used as a source of nutrients to replace fertilizer and promote rice growth. The wastewater after purification in the ecological rice paddy enters the ecological conservation area.

[0062] The ecological conservation area 3 uses a smart dam to regulate the water level. The conserved water is pumped back to the high-density seedling cultivation area 2 by the water pump 7 to ensure the health of the aquaculture water quality. After the seedlings grow to the size required for stock enhancement and release, they are released into the fishpond tidal ditch 12 of the ecological paddy field area 1 and enter the ecological conservation area 3 through the fishpond tidal ditch 12. Subsequently, the seedlings enter the ecological wetland area outside the dam or riverbank 5 through the sluice gate or pipeline 6. The seedlings that gradually adapt to the low-salt environment can actively enter the near-shore natural water area 8 through the wetland outlet to complete the step-by-step stock enhancement and release process.

[0063] The seedlings gradually adapt to different salinity and aquatic environments in high-density seedling cultivation area 2, ecological paddy field area 1, ecological conservation area 3, and wetland area outside the dike 4, achieving a phased transition, significantly reducing release stress response, and meeting the habitat requirements of the seedlings at different life stages from the cultivation period to the natural return period. In terms of enhancing the ecological connectivity of nearshore waters, the coordinated operation of intelligent dams, tidal channels, pipelines, and culverts enables the natural transition and connection between coastal farmland, water areas, and nearshore wetlands, providing migration channels for native species and released seedlings, improving the nearshore ecosystem structure, and promoting sustainable resource recovery.

[0064] Example 1

[0065] A system for enhancing the effects of stock enhancement and nearshore ecological connectivity includes a high-density seedling cultivation area 2, an ecological paddy field area 1, an ecological conservation area 3, and a wetland area outside the dike 4.

[0066] Different areas in this system are connected sequentially by pipelines, ditches, and waterways.

[0067] like Figure 1As shown, the high-density seedling cultivation area 2 discharges nutrient-rich tailwater into the ecological paddy field area 1 via tidal flow. The tailwater contains seedlings, and seedlings meeting the specifications are released into the ecological paddy field area 1 at the same time as the discharge. After the tailwater stays for a preset time, it completes the irrigation of the paddy field and is purified. The purified water and the seedlings in the water are temporarily stored in the ecological conservation area 3. The ecological conservation area 3 returns the ecologically purified water to the high-density seedling cultivation area 2, forming a water cycle.

[0068] The ecological conservation area 3 and the ecological wetland area are connected by dikes and riverbanks and are connected by culverts or pipelines 6. Seedlings enter the ecological wetland area through the culverts or pipelines 6 via the opening and closing of the dikes. The ecological wetland area actively releases the seedlings that have adapted to the environment into the near-shore natural waters 8.

[0069] The system comprises three zones: a high-density seedling cultivation area 2, equipped with an aeration pump 21, a sludge suction pump, and a water circulation device; an ecological paddy field area 1, equipped with a diversion embankment 11 and a fishpond tidal channel 12; and an ecological conservation area 3, equipped with ecological floating islands 31 and planted with ornamental economic crops, as well as aquatic economic crops such as water chestnuts and lotus roots in open water areas. A smart lifting dam 34 is also installed to regulate water levels, enabling the temporary storage and conservation of purified water. The smart lifting dam 34 is 8 m wide, with overflow sections on both sides, the ratio of the overflow section length to the lifting dam length being 0.4–0.8. The system is regulated by existing automated control facilities: when the water level is insufficient, the lifting dam is used for storage, keeping the water in the ecological conservation area 3; when the water level is too high, the water pump 7 periodically reintroduces the purified water from the conservation area into the high-density seedling cultivation area 2 to complete water circulation. Seedlings released for propagation can also be introduced into the ecological wetland area outside the dike via culverts or pipes 6. Four culverts or pipelines are installed in the wetland area outside the dike to connect with the conservation area.

[0070] like Figure 2 As shown, this solution provides a graded water purification agricultural ecosystem, including:

[0071] Ecological rice paddy area 1, which contains guiding paddy ridges 11 for guiding water flow and fish ponds and tidal channels 12 for water storage and biological habitat;

[0072] Downstream, it connects to the high-density seedling cultivation area 2, which is equipped with an aeration pump 21 to maintain dissolved oxygen in the water. It then connects to the ecological conservation area 3, in which ecological floating islands 31, submerged plant area 32 and ecological hydroponic area 33 are arranged in sequence. At the end, an intelligent lifting dam 34 is installed for water level regulation.

[0073] After regulation, the water overflows into the wetland area 4 outside the dike for further purification and infiltration;

[0074] The entire system is bounded by dams or riverbanks 5, connected by culverts or pipelines 6, and can be used by water pumps 7 to achieve cross-regional water transport and circulation.

[0075] High-density seedling cultivation area 2: Multiple sets of aeration pumps 21 and sludge suction pumps are installed at the bottom of the cultivation area. While ensuring sufficient oxygen supply to the water, the sludge suction pumps are used to collect organic particulate matter such as uneaten feed and biological debris generated during the aquaculture process. The tailwater and organic particulate matter from the cultivation area are introduced into the ecological rice paddy area 1 through a culvert or pipeline 6 at regular intervals. Floating high-density aquaculture facilities are installed, and juvenile grass carp, black carp, crucian carp, yellow catfish, freshwater shrimp, anchovy, and Chinese mitten crab are introduced into the cultivation area according to the actual needs of stock enhancement and release. Regularly sample and inspect the individual specifications of the fry. For each batch, randomly sample at stratified levels, taking no fewer than 60 fish and shrimp fry per fry. Record the following indicators: body length, weight, abnormal body color rate (percentage of individuals with abnormal body color out of the total sampled fry), mortality rate (percentage of dead individuals out of the total sampled fry), sludge attachment rate (percentage of individuals with attachments other than ciliates out of the total sampled fry), injury rate (percentage of individuals with developmental deformities or limb defects / damage out of the total aquatic organisms), and specification compliance rate (percentage of individuals meeting the specification requirements out of the total sampled fry). Once the specification compliance rate is ≥85%, the sum of the mortality / injury rate, abnormal body color rate, and sludge attachment rate is ≤5%, the average length of fish is ≥80mm, and the average body length of shrimp is ≥25mm, the fry meeting the specification requirements are introduced into the ecological rice paddy area 1 through a culvert or pipeline 6.

[0076] Ecological Paddy Field Area 1: A diversion embankment 11 is installed within the paddy field to allow water from the cultivation area to flow through the field at a reduced speed and in a deflected manner. Wastewater discharged from the high-density seedling cultivation area 2 flows through the paddy field in a tidal flow pattern. Suspended solids and nutrients such as nitrogen and phosphorus in the wastewater are effectively removed through soil adsorption, plant absorption, and microbial nitrification and denitrification. This process saves on paddy field fertilization costs while simultaneously purifying and reusing wastewater through the paddy field's purification capacity. 1-2 rice seedlings are planted per hill per mu (approximately 0.067 hectares), with a planting depth of 2-3 cm. Clover and other plants are planted along the slopes and embankments for slope protection and stabilization. Fishponds and tidal ditches are dug on the inner side of the embankments to facilitate seedling movement. At least one fishpond tidal ditch 12 is dug in every 3-5 mu (approximately 0.2-0.5 hectares) of paddy field, with the total area of ​​the fishponds and tidal ditches accounting for 5-10% of the paddy field area. At least one fishpond tidal ditch 12 has an outlet adjacent to the ecological conservation area 3, facilitating the entry of seedlings into the ecological conservation area 3. Seedlings can feed on weeds, algae, and pests in the paddy field, promoting the absorption of dissolved oxygen and nutrients by the rice roots. Their excrement can also supplement fertilizer for the rice and increase soil nutrients.

[0077] Ecological Conservation Zone 3: Ecological Conservation Zone 3 is equipped with ecological floating islands 31 for cultivating suitable hydroponic crops, such as aquatic water spinach, water celery, and other economic vegetables, or ornamental flowers such as iris, cattail, and water lily. An ecological hydroponic area 33 is also set up within Ecological Conservation Zone 3, with the hydroponic planting area accounting for 40-50% of the conservation zone. This area can be used to grow aquatic economic crops such as water chestnuts, water caltrops, and lotus roots. The planting of water chestnuts and lotus roots is adjusted according to the water depth, using a 1-meter square row spacing, with 65-90 kg of seeds per acre. Transplanting can be done when the water chestnut seedlings have 2-3 true leaves. During the growth period of aquatic crops, weeds in the fields are regularly removed and the water quality is kept clean. The water inlet of the conservation zone introduces tailwater from the paddy field through a culvert or pipe 6. The intelligent lifting dam 34 within the conservation zone controls the water level through automated facilities and reintroduces the purified tailwater into the high-density seedling cultivation area 2 to complete the water cycle. By setting up a culvert or pipeline at the outlet of the conservation area to connect with the ecological wetland outside the dike, suitable seedlings can be introduced into the wetland.

[0078] Outside the dike wetland area 4: A culvert or pipeline 6 is installed in the natural wetland area outside the dike to connect the ecological conservation area 3 and the outside wetland area 4. After the intelligent lifting dam 34 of the ecological conservation area 3 is lowered, the stocking seedlings can enter the outside wetland area 4 with the water flow through the culvert or pipeline 6. The seedlings, which gradually adapt to the low-salinity environment, can actively enter the nearshore natural waters 8 through the wetland outlet, ultimately completing the step-by-step stocking process and realizing the natural migration and ecological return of the seedlings.

[0079] Example 2

[0080] Taking the Chenjia Town wetland area in Chongming District, Shanghai as an example, the area covers 4,200 m², including 2,200 m² of ponds and 2,000 m² of arable land. The overall area is rectangular. The left side was originally flat arable land without field ridges, and the southern end originally had a water outlet and ditch.

[0081] The system in this embodiment includes a high-density seedling cultivation area 2, an ecological paddy field area 1, an ecological conservation area 3, and a wetland area outside the dike 4.

[0082] The construction process for each part is as follows:

[0083] High-density seedling cultivation area 2

[0084] The high-density aquaculture area covers a total area of ​​1000 m². Through the modification of the aquaculture ponds, the rearing area is designed with a length-to-width ratio of 1:2 to 1:5 and a slope ratio of 1:1.5 to 1:3. The water depth is no less than 1.5 meters, with a bottom elevation of 1.05 m and a water surface elevation of 3.05 m. The inlet is located in the northeast-southeast of the aquaculture area, and the outlet is located in the northwest corner. Water pumps 7 are installed at both the inlet and outlet to transport water. A culvert or pipeline 6 is also installed at the outlet to connect to the paddy field, allowing qualified seedlings to flow into the paddy field. A sludge suction pump is installed to collect uneaten feed, biological debris, and other organic particles, and the aquaculture wastewater is introduced into the ecological paddy field area 1. An aeration pump 21 is installed at the bottom every 5 m, for a total of 10 sets of aeration pumps 21. The aquaculture space is further optimized by installing floating high-density aquaculture facilities. Juvenile grass carp, black carp, crucian carp, yellow catfish, freshwater shrimp, anchovy, and Chinese mitten crab are introduced into the aquaculture facilities. Regularly sample and inspect the individual specifications of the fry. For each batch, randomly sample at stratified levels, taking no fewer than 60 fish and shrimp fry per fry. Record indicators such as body length, weight, abnormal body color rate, mortality rate, visceration rate, injury rate, and specification qualification rate. When the specification qualification rate is ≥85%, the sum of mortality and injury rate, abnormal body color rate, and visceration rate is ≤5%, the average length of fish is ≥80mm, and the average body length of shrimp is ≥25mm, introduce the qualified fry into the ecological rice paddy area 1 through a culvert or pipeline 6.

[0085] Ecological rice paddy area 1

[0086] The existing paddy field will be modified. The total area of ​​the paddy field is approximately 2000 m², with an effective water depth maintained at 5-20 cm. The bottom elevation is 3.00 m, the water surface elevation is 3.05 m, and the elevation of the surrounding earthwork is 3.20 m. The inlet is located in the northeast corner of the paddy field, and the outlet is located in the southeast corner. A water pump 7 will be installed about 5 cm below the bottom of the paddy field on the outer earthwork to transport water. A culvert or pipeline 6 will be installed at the outlet to connect to a pond, allowing the outflowing water to flow into the pond. A tidal flow paddy field will be implemented, with water intake from 8:00 to 11:00 and a flow rate of 3 m³ / s. 3 The flow rate is approximately 15-30 meters per hour. Water is slowly released after 11:00 AM and drained by approximately 6:00 PM, with a submersion / drainage period of 10 hours / 14 hours, which is the preset residence time. East-west oriented dikes are arranged within the rice paddy wetland to guide the water through the paddy fields in a deflected flow pattern. The height of the dikes is maintained above 20 cm, with gaps left between them and the paddy field ridges. The ratio of the gap length to the ridge length is controlled between 0.5 and 0.8. Clover and other plants are planted on the slopes and ridges for slope protection and stabilization. In every 3-5 mu (approximately 0.2-0.5 acres) of paddy field, at least one fishpond ditch 12 should be dug. The fishpond ditch 12 should be 0.5-1m deep and 0.3-0.8m wide, with its total area accounting for 5-10% of the paddy field area. A separate fishpond ditch 12 outlet should be located near the ecological conservation area 3 to facilitate the entry of seedlings into the ecological conservation area 3. Plant 1-2 rice seedlings per hill per mu (approximately 0.067 acres), with a planting depth of 2-3cm.

[0087] Ecological conservation area 3

[0088] The project involves modifying low-lying ponds and small waterways. Ecological conservation area 3 has a total area of ​​1200 m², with an average water depth not exceeding 50 cm and a water level maintained at approximately 3.5 m, including a bottom elevation of 3.1 m and a surface elevation of 3.5 m. Ecological floating islands 31 are installed in the conservation area, and economic vegetables such as aquatic water spinach and water celery, or ornamental flowers such as irises, cattails, and water lilies are cultivated. At the bottom of the conservation area is a submerged plant area 32, used to cultivate native submerged plants such as foxtail algae, hydrangea, and eelgrass. The density of submerged plants is 10-20 plants / m², covering 20-30% of the conservation area. Additionally, an ecological hydroponic area 33 is set up within ecological conservation area 3, covering 40-50% of the conservation area. This area cultivates aquatic economic crops such as water chestnuts, water caltrops, and lotus roots, using a 1-meter square row spacing and a seed rate of 65-90 kg per acre. The shallow-water water chestnut planting holes are spaced 1.5–2 meters apart, with about 2–3 seedlings planted in each hole. The inlet is located on the northeast side, and the tailwater from the paddy field is introduced through a water pump 7 and a culvert or pipe 6. The outlet is located on the southwest side, and the purified tailwater is reintroduced into the high-density seedling cultivation area 2 through the water pump 7 to complete the water cycle. An intelligent lifting dam 34 is installed on the south side of the conservation area, which controls the water level through automated facilities. A culvert or pipe 6 is set up to connect to the ecological wetland outside the dike, and suitable seedlings are introduced into the wetland for release.

[0089] Those skilled in the art will understand that, besides implementing the system and its various devices, modules, and units provided by this invention in the form of purely computer-readable program code, the same functions can be achieved entirely through logical programming of the method steps, making the system and its various devices, modules, and units of this invention function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Therefore, the system and its various devices, modules, and units provided by this invention can be considered as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; alternatively, the devices, modules, and units for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0090] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A system for improving the effectiveness of stock enhancement and nearshore ecological connectivity, characterized in that, include: High-density seedling cultivation area (2) is used to cultivate seedlings and discharge tailwater; The ecological paddy field area (1) is used to introduce the received tailwater into the paddy field and discharge the purified tailwater; it is equipped with a guide embankment (11) for guiding water flow and a fish pond tidal ditch (12) for water storage and biological habitat. The ecological conservation area (3) is used to receive the purified tailwater. The water level is regulated by setting up an intelligent lifting dam (34) to complete the temporary storage and conservation of the purified water. The wetland area outside the dike (4) is connected to the ecological conservation area (3) and is used to provide an adaptation and transition site for seedlings before release; the wetland area outside the dike (4) includes a salt gradient water body with salinity ranging from low to high and a tidal channel structure; The high-density seedling cultivation area (2) discharges nutrient-rich tailwater into the ecological paddy field area (1) in a tidal flow manner. The tailwater contains seedlings, and seedlings that meet the specifications are released into the ecological paddy field area (1) at the same time during discharge. After the tailwater stays for a preset time, it completes the irrigation of the paddy field and is purified. The purified water and the seedlings in the water are temporarily stored in the ecological conservation area (3). The ecological conservation area (3) returns the ecologically purified water to the high-density seedling cultivation area (2) to form a water cycle. There are dikes and riverbanks between the ecological conservation area (3) and the wetland area outside the dike (4), and they are connected by sluice gates or pipelines (6); seedlings enter the wetland area outside the dike (4) through the sluice gates or pipelines (6) via the opening and closing of the dikes. The wetland area outside the dike (4) actively releases the seedlings that have adapted to the environment into the near-shore natural waters (8), and finally completes the step-by-step propagation and release process.

2. The system for enhancing the effect of stock enhancement and nearshore ecological connectivity according to claim 1, characterized in that, The high-density seedling cultivation area (2) is connected to the ecological paddy field area (1) through a culvert or pipe (6). The individual specifications of the seedlings are regularly checked. When the preset value-added release standard is met, the seedlings are introduced into the ecological paddy field area (1) through the culvert or pipe (6).

3. The system for enhancing the effect of stock enhancement and nearshore ecological connectivity according to claim 1, characterized in that, The ecological paddy field area (1) uses diversion ridges (11) to allow water to enter the paddy field in a deflection manner. The diversion ridges (11) are arranged to regulate the flow and ensure that the water stays in the paddy field for a preset time.

4. The system for improving the effect of stock enhancement and nearshore ecological connectivity according to claim 1, characterized in that, In the ecological conservation area (3), ecological floating islands (31) are set up to cultivate crops. The tailwater of the paddy field is introduced through sluice gates or pipes (6), purified, and then reintroduced into the high-density seedling cultivation area (2) through water pumps (7) to complete the water cycle.

5. A method for improving the effect of stock enhancement and nearshore ecological connectivity, comprising the system for improving the effect of stock enhancement and nearshore ecological connectivity as described in any one of claims 1-4, characterized in that, include: Step S1: Introduce seedlings into the high-density seedling cultivation area (2) for cultivation, and discharge the seedling tailwater into the ecological paddy field area (1). Step S2: The ecological paddy field area (1) receives the seedling tailwater and irrigates the paddy field, and the paddy field tailwater is discharged into the ecological conservation area (3). Step S3: The ecological conservation area (3) receives the tailwater from the paddy field, and the water level is regulated by the intelligent lifting dam (34). The conserved clean water is pumped back to the high-density seedling cultivation area (2) by the water pump (7). Step S4: If the seedlings grow to meet the preset value-added release standard, they are sent through the culvert or pipeline (6) to the wetland area outside the dike (4) outside the intelligent lifting dam (34), and the seedlings that have adapted to the environment are sent into the near-shore natural waters (8). The seedlings are gradually adapted to different salinity and water environment in the high-density seedling cultivation area (2), ecological paddy field area (1), ecological conservation area (3) and wetland area outside the dike (4) to complete the phased transition; The water level in the ecological conservation area (3) is controlled by the intelligent lifting dam (34). The water is pumped back to the high-density seedling cultivation area (2) by the water pump (7) to ensure the health of the aquaculture water. After the seedlings grow to the size that meets the requirements for propagation and release, they are released into the fish pond tidal ditch (12) in the ecological paddy field area (1) and enter the ecological conservation area (3) through the fish pond tidal ditch (12). Then the seedlings enter the wetland area outside the dike or riverbank (5) through the sluice gate or pipeline (6). The seedlings gradually adapt to the low-salt environment and actively enter the near-shore natural water area (8) through the wetland outlet to complete the step-by-step propagation and release process.

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