A kind of be algae ecological reef for estuary ecological restoration and fish resource conservation

Abstract

This invention belongs to the field of ecological restoration technology and discloses a shellfish-algae reef for estuarine ecological restoration and fish resource conservation. The reef is composed of layered composite structural units, vertically arranged as follows: a bottom shellfish attachment zone, a middle algae growth zone, and an upper fish habitat zone. The shellfish attachment zone has a porous microtexture of 50–200 μm; the algae growth zone contains an anchoring mesh and nutrient slow-release units; and the fish habitat zone has a tubular shelter structure and an spawning substrate. The units are made of biodegradable composite materials, and their surfaces are functionalized to form a bio-attachment induction interface. Multiple units are arranged alternately or intermittently to form a flow velocity gradient region. This invention can synergistically construct multi-trophic-level biological communities, improve habitat complexity and ecosystem stability, and is suitable for estuarines affected by diversion water and with low natural transparency, significantly enhancing the effects of estuarine ecological restoration and fish resource conservation.

Description

Technical Field

[0001] This invention relates to the field of ecological restoration and aquatic biological resource conservation technology, and in particular to a shellfish and algae ecological reef for estuarine ecological restoration and fish resource conservation. Background Technology

[0002] Estuarine areas are crucial transitional zones between land and sea, characterized by active material exchange and rich biodiversity, serving as vital habitats for spawning, foraging, and juvenile rearing for various fish species. However, estuarine areas are influenced by terrestrial distillate, tidal sediment transport, and hydrodynamic disturbances, resulting in naturally high suspended solids content, generally low and fluctuating water transparency. This negatively impacts organism attachment, algal photosynthesis, and visual feeding by fish, further complicating habitat restoration. Furthermore, with increased human activities, including land reclamation, channel dredging, and pollutant discharge, estuarine ecosystems have suffered varying degrees of damage, manifesting as impaired natural substrate structure, reduced habitat complexity, and decreased biodiversity.

[0003] To address these issues, existing technologies typically employ artificial reefs or ecological restoration projects to rehabilitate estuaries. These technologies, by deploying artificial structures in the water, provide habitats or attachment substrates for fish, thus promoting fish resource recovery to some extent. However, existing artificial reef structures are mostly single-function, primarily focusing on providing shelter or attachment substrates, and cannot simultaneously meet the diverse needs of fish at different growth stages, including spawning, foraging, and habitat.

[0004] Furthermore, in existing technologies, shellfish and algae are typically introduced or cultivated as independent restoration units, lacking integrated structural design. This results in insufficient synergy between different biological communities, making it difficult to form a stable multitrophic ecosystem. Simultaneously, under the complex hydrodynamic conditions of estuaries, existing ecological reef structures are poorly adaptable to environmental factors such as flow velocity and tides, easily leading to localized erosion or siltation, thus affecting the stability of ecological restoration results.

[0005] Furthermore, existing ecological restoration methods often lack a systematic design for ecological succession processes during the construction of biological communities. They frequently employ a one-off approach, making it difficult to control the gradual succession from lower-level producers to higher trophic levels, thus limiting the formation of the ecosystem's self-sustaining capacity. At the same time, the dynamic monitoring and feedback mechanisms for the restored area are still imperfect, making it difficult to adjust restoration measures in a timely manner according to ecological changes.

[0006] In summary, existing technologies for estuarine ecological restoration still suffer from problems such as a single habitat structure, separation of ecological functions, insufficient hydrodynamic adaptability, and limited capacity for ecological succession regulation, which require further improvement. Summary of the Invention

[0007] In view of this, the purpose of this invention is to provide a shellfish-algae reef and its construction method for estuarine ecological restoration and fish resource conservation, so as to solve the problems of single habitat structure, separation of ecological functions, insufficient hydrodynamic adaptability, and poor fish resource conservation effect in existing estuarine ecological restoration technologies. To achieve the above objective, this invention provides the following technical solution: A shellfish and algae reef for estuarine ecological restoration and fish resource conservation includes a layered composite structural unit. The composite structural unit is arranged vertically in sequence as a shellfish attachment area, an algae growth area, and a fish habitat area; the shellfish attachment area is located at the bottom and has a porous microtexture structure of 50-200 μm on its surface; The algae growth zone is located in the middle and includes an algae fixation grid structure and a nutrient slow-release unit; The fish habitat is located in the upper part and includes a tubular shelter structure and an spawning substrate; The composite structural unit is made of biodegradable composite material, and its surface is functionalized to form a bio-attachment-inducing interface. Multiple composite structural units are arranged in a spaced or staggered manner, forming a velocity gradient region between the units.

[0008] In one possible implementation, the biodegradable composite material comprises a polyhydroxyalkanoate matrix, reinforcing fibers, and inorganic fillers.

[0009] In one possible implementation, the functionalization process involves creating a bio-attachment inducing layer on the surface of the composite structural unit or introducing a slow-release bio-inducing agent.

[0010] In one possible implementation, the velocity gradient region can locally form a low velocity zone to improve nutrient retention and habitat stability for juvenile fish.

[0011] In one possible implementation, the shellfish attachment area, algae growth area, and fish habitat area form a continuous ecological functional zone along the vertical direction.

[0012] In one possible implementation, the diameter of the tubular protective structure is 3 to 10 cm.

[0013] In one possible implementation, the composite structural unit is an integrally molded structure.

[0014] In one possible implementation, a method for constructing a shellfish-algae reef for estuarine ecological restoration and fish resource conservation is provided, comprising the following steps: S1. Modular design and fabrication: Construct a composite structural unit, which includes a shellfish attachment area, an algae growth area, and a fish habitat area stacked vertically. S2. Functionalization treatment: Surface and / or internal modification of the composite structural unit to form a structural or material interface that promotes the attachment and growth of target organisms; S3. Adaptive deployment: The composite structural units are deployed in the estuary area, and a velocity gradient region is formed between adjacent composite structural units by spacing or staggering their arrangement. S4. Introduction of biological communities: Filter-feeding shellfish, macroalgae, and target fish are introduced in sequence according to the preset ecological succession sequence to construct a multi-trophic-level biological community. S5. Monitoring and Adaptive Regulation: Based on the results of ecological monitoring, regulate the structural configuration and / or biological community of the composite structural unit.

[0015] In one possible implementation, in the composite structural unit, the shellfish attachment area is located at the bottom, the algae growth area is located in the middle, and the fish habitat area is located at the top, so as to form an ecological functional zoning from the bottom to the top.

[0016] In one possible implementation, the composite structural unit is prepared using a biodegradable composite material, which includes a polyhydroxyalkanoate matrix, reinforcing fibers, and inorganic fillers.

[0017] In one possible implementation, the surface of the shellfish attachment area is provided with a microtextured structure, which is a porous structure with a pore size of 50–200 μm.

[0018] In one possible implementation, the algae growth zone includes a mesh structure for algae attachment and a nutrient slow-release unit for releasing nutrients.

[0019] In one possible implementation, the fish habitat includes a tubular shelter structure and a spawning substrate to provide space for fish to inhabit and reproduce.

[0020] In one possible implementation, in step S3, the composite structural units are arranged in an alternating or staggered manner to form a low-velocity zone in a local area.

[0021] In one possible implementation, step S2, the functionalization process includes setting a bio-attachment inducing layer on the surface of the composite structural unit or introducing a slow-release bio-inducing agent.

[0022] In one possible implementation, step S4, the ecological succession sequence includes: first introducing filter-feeding shellfish to improve the aquatic environment; then introducing algae to construct a primary production layer; and finally introducing fish to form a complete food chain structure.

[0023] In one possible implementation, step S5 includes water quality parameter monitoring and biological community monitoring, and the layout of the composite structural units or the biological release strategy is adjusted according to the monitoring results.

[0024] Based on the above technical solution, the present invention provides a method for constructing shellfish and algae reefs for estuarine ecological restoration and fish resource conservation. This method constructs composite structural units consisting of shellfish attachment areas, algae growth areas, and fish habitat areas arranged vertically in layers, and combines these units with spaced or staggered arrangements to form velocity gradient regions. Furthermore, it introduces shellfish, algae, and fish populations sequentially according to a preset ecological succession sequence. This method solves the problems of single habitat structure, separation of ecological functions, and poor fish resource conservation effects in existing estuarine ecological restoration technologies.

[0025] Furthermore, the layered structure enables the coordinated spatial configuration of different ecological functional zones, coupling the filter feeding of shellfish, the primary production of algae, and the habitat and reproductive needs of fish within the same structural system, thereby enhancing the comprehensive ecological function of the ecological reef. By forming a velocity gradient region, a suitable low-velocity habitat is provided for fish and their larvae, while simultaneously promoting the retention and circulation of nutrients in local areas, thus enhancing the stability of the ecosystem. By introducing biological communities according to the ecological succession sequence, the ecosystem gradually evolves from a lower production level to a higher trophic level, improving the controllability and sustainability of the ecological restoration process. By regulating the structural configuration and biological communities based on ecological monitoring results, the adaptability and regulatory capacity of the ecological restoration process are improved, thereby comprehensively enhancing the habitat complexity, biodiversity, and fish resource conservation effects of the estuarine ecosystem. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating a method for constructing a shellfish-algae reef for estuarine ecological restoration and fish resource conservation according to the present invention. Detailed Implementation

[0027] To make the technical solution and beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. In the following description, by gradually unfolding the construction method process, the composite structural unit structure, and the material implementation methods, the present invention systematically explains how it achieves the technical objectives of estuarine ecological restoration and fish resource conservation.

[0028] Specifically, the technical solution of this invention revolves around the logical main line of "structural construction - functional enhancement - spatial deployment - biological regulation": First, a composite structural unit with multifunctional partitions is constructed through modular design; second, the ability of organisms to attach and grow is enhanced through functional treatment; subsequently, a specific hydrodynamic environment is formed in the water through adaptive deployment; finally, the ecosystem is gradually constructed and optimized through the phased introduction and dynamic regulation of biological communities.

[0029] Based on this, the following embodiments will respectively focus on the method flow (corresponding to) Figure 1 The invention will be described in detail in terms of its structure, composition, and material system, so as to fully demonstrate the implementation method and synergistic mechanism of the technical solution.

[0030] I. Overall Implementation Approach The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described are only for explaining the present invention and are not intended to limit the scope of protection of the present invention. For those skilled in the art, various modifications, equivalent substitutions or improvements made to the technical solution of the present invention without departing from the spirit and substance of the present invention should be included within the scope of protection of the present invention.

[0031] like Figure 1 The diagram shows a flowchart of a method for constructing a shellfish-algae reef for estuarine ecological restoration and fish resource conservation according to the present invention. The method mainly includes steps such as modular design and preparation, functionalization, adaptive deployment, introduction of biological communities, and monitoring and adaptive regulation. Each step works together to achieve comprehensive restoration of the estuarine ecosystem and conservation of fish resources.

[0032] The overall implementation idea of ​​this invention is as follows: by constructing a composite structural unit with shellfish attachment area, algae growth area and fish habitat area, and stacking the functional areas vertically, multiple ecological functions are integrated in a single structural unit; on this basis, the composite structural unit is functionalized to improve the attachment efficiency and growth adaptability of target organisms; furthermore, through a reasonable spatial layout, multiple composite structural units form a local environment with a flow velocity gradient in the estuarine waters, thereby providing suitable habitat conditions for different biological communities.

[0033] Meanwhile, by gradually introducing biological communities of different trophic levels according to a preset ecological succession sequence, the ecosystem gradually develops from the basic production layer to the higher trophic level. Combined with continuous ecological monitoring, the layout of composite structural units and biological release strategies are dynamically regulated, thereby improving the stability and adaptability of the ecological restoration process.

[0034] Specifically designed to address the challenges of freshwater runoff and poor natural transparency in estuaries, this ecological reef utilizes the synergistic effects of bottom shellfish filtering to reduce turbidity, mid-section algae fixing carbon and increasing oxygen, and upper structure stabilizing flow and reducing disturbance to continuously improve local water transparency, providing a stable microenvironment for algal photosynthesis and fish larval rearing.

[0035] The above technical solutions can be used to construct a complex and functionally synergistic ecological reef system in estuary areas, which will help increase the complexity of aquatic habitats, promote the restoration of biodiversity, and enhance the habitat and breeding conditions for fish resources.

[0036] II. Overall Flow of the Construction Method like Figure 1 As shown in the figure, this embodiment provides a method for constructing shellfish-algae reefs for estuarine ecological restoration and fish resource conservation. The method includes steps S1 to S5, and the specific steps are as follows: (I) Step S1: Modular design and fabrication In step S1, a composite structural unit is first constructed. The composite structural unit is a structural module that integrates multiple ecological functions, including a shellfish attachment area, an algae growth area, and a fish habitat area.

[0037] Furthermore, the shellfish attachment area, algae growth area, and fish habitat area are arranged in a vertically stacked manner, creating a spatially partitioned layout for the different functional areas. Specifically, the shellfish attachment area is located in the lower region to provide a stable substrate for shellfish; the algae growth area is located in the middle region to support algae attachment and growth; and the fish habitat area is located in the upper region to provide space for fish activity, habitation, and reproduction.

[0038] Through the modular design described above, a single structural unit can simultaneously possess multiple ecological functions, thereby improving the overall functional integration of the ecological reef.

[0039] In some embodiments, the composite structural unit may include units of different functional types, including units primarily for shellfish attachment, units primarily for algae growth, and units primarily for fish habitat, so as to achieve a division of labor for different ecological functions.

[0040] (ii) Step S2: Functionalization In step S2, the composite structural unit prepared in step S1 is functionalized to improve bio-attachment and growth effects.

[0041] Specifically, by constructing microstructures on the surface of the composite structural unit, a porous microtexture structure can be formed in the shellfish attachment area, thereby increasing surface roughness and improving the shellfish attachment ability. At the same time, a bio-attachment induction layer can be set on the surface of the composite structural unit, or a slow-release bio-inducer can be introduced to promote the colonization of shellfish larvae and algal spores.

[0042] In addition, nutrient slow-release units can be set up inside the algae growth zone to slowly release nutrients over a certain period of time to support the continuous growth of algae.

[0043] In some embodiments, the functionalization process includes providing a bioattachment inducer, which is released in a sustained-release manner to promote the attachment and colonization of target organisms on the composite structural unit.

[0044] (III) Step S3: Adaptive Deployment In step S3, the functionalized composite structural units are deployed in the estuary area.

[0045] Specifically, based on the hydrodynamic conditions, topographic features, and sediment conditions of the estuary area, the composite structural units are spatially arranged. The arrangement can be either spaced out or staggered, allowing multiple composite structural units to form a spatially distributed structure within the water body.

[0046] By using the above-mentioned layout method, a velocity gradient region is formed between adjacent composite structural units, creating a low-velocity environment in local areas, thereby providing suitable habitat conditions for fish and their larvae, and also facilitating the retention and circulation of nutrients.

[0047] In some implementations, the arrangement causes the water flow to bypass or split between the composite structural units, thereby forming local slow-flow zones or stagnant zones.

[0048] (iv) Step S4: Introduction of biological community In step S4, different types of biological communities are introduced according to a preset ecological succession sequence.

[0049] In practice, filter-feeding shellfish can be introduced first to improve the aquatic environment through filter feeding; after the shellfish have settled in, algae can be introduced to form a primary production layer in the algae growth area; after the algae community has formed and improved the local ecological conditions, the target fish species can be introduced to construct a multi-trophic-level biological community.

[0050] By introducing these phased methods, the ecosystem can gradually evolve from a low trophic level to a high trophic level, thereby improving the stability and self-sustaining capacity of the ecosystem.

[0051] In some implementations, the introduction of algae is contingent upon the stable attachment of shellfish, and the introduction of fish is contingent upon the formation of algal communities, thereby forming a hierarchical ecological construction process.

[0052] In some implementations, the ecological succession process includes the phased introduction of biological communities, wherein the introduction of algae is predicated on the stable attachment of shellfish, and the introduction of fish is predicated on the formation of algal communities, thereby forming a hierarchical ecological construction process.

[0053] (v) Step S5: Monitoring and Adaptive Regulation In step S5, continuous ecological monitoring is conducted on the ecological reef area, and adaptive regulation is carried out based on the monitoring results.

[0054] Specifically, the ecological monitoring may include water quality parameter monitoring and biological community monitoring, wherein water quality parameters include water temperature, salinity, dissolved oxygen and nutrient concentration, etc., and biological community monitoring includes fish species, numbers and behavioral characteristics, etc.

[0055] Based on the monitoring data mentioned above, adjustments can be made to the layout of composite structural units or biological release strategies, such as adjusting biological release density or optimizing structural configuration, in order to maintain the stable operation of the ecosystem.

[0056] Through the coordinated implementation of steps S1 to S5 above, an ecological reef system with multifunctional integrated characteristics can be constructed in the estuary area, thereby achieving the comprehensive effect of ecological restoration and fish resource conservation.

[0057] III. Composite structural unit structure This embodiment provides a detailed description of the specific structure of the composite structural unit. The composite structural unit is a core functional carrier for estuarine ecological restoration and fish resource conservation. It is a composite structure arranged in layers along the vertical direction, including a shellfish attachment area, an algae growth area, and a fish habitat area.

[0058] (I) Overall Structure The composite structural unit adopts an integrated design, with each functional area arranged sequentially along the vertical direction to form a layered structure from bottom to top. Through this layered structure, different ecological functions can be synergistically configured within the same spatial unit, thereby improving the comprehensive utilization efficiency of the ecological reef.

[0059] In some implementations, the height ratio of the shellfish attachment area, algae growth area, and fish habitat area is adjusted according to ecological function requirements to optimize the spatial distribution of different biological communities.

[0060] The bottom section is for shellfish attachment, the middle section is for algae growth, and the upper section is for fish habitat. These functional areas are interconnected but structurally distinct to meet the habitat requirements of different biological communities.

[0061] In some embodiments, the outer surface of the composite structural unit is provided with a flow guiding structure or a through hole structure. By changing the water flow path, the water flow is decelerated or a local vortex zone is formed when passing through the composite structural unit, thereby creating a low-velocity environment around the ecological reef unit.

[0062] In some embodiments, the fish habitat includes a porous structure with a preset aperture, preferably ranging from 3 to 10 cm, to accommodate the habitat needs of fish of different sizes.

[0063] (ii) Shellfish attachment area The shellfish attachment area is located at the bottom of the composite structural unit and is mainly used to provide an attachment substrate for filter-feeding shellfish.

[0064] Specifically, the surface of the shellfish attachment area is provided with a microtextured structure, which is a porous structure with a pore size preferably of 50–200 μm. By setting the above-mentioned microtextured structure, the surface roughness and specific surface area can be significantly increased, thereby improving the attachment probability of shellfish larvae.

[0065] In addition, the shellfish attachment area can be prepared from a biodegradable composite material, which will gradually degrade during use and release a certain amount of inorganic components, which is beneficial to maintaining the stability of the local aquatic environment.

[0066] (III) Algae Growth Zone The algae growth zone is located above the shellfish attachment zone to support the attachment and growth of algae.

[0067] In terms of specific structure, the algae growth zone includes a grid structure, which provides a supporting framework for algae attachment and expansion. Simultaneously, a nutrient slow-release unit can be installed within the algae growth zone to continuously release nutrients over a certain period, thereby promoting algae growth and reproduction.

[0068] By setting up algae growth zones, a primary production layer can be formed in the ecological reef unit, providing a food source for subsequent high-trophic-level organisms.

[0069] (iv) Fish habitats The fish habitat area is located in the upper part of the composite structural unit, and is used to provide space for fish to move, live and reproduce.

[0070] Specifically, the fish habitat includes a tubular shelter structure and a spawning substrate. The tubular shelter structure forms a porous space, providing fish with a place to avoid predators and rest; the spawning substrate provides a suitable spawning environment for the fish.

[0071] Through the above structural design, fish can complete behaviors such as inhabiting, foraging and reproducing in the ecological reef unit, thereby improving the recovery capacity of fish resources.

[0072] (v) Materials and overall performance In this embodiment, the composite structural unit is preferably prepared using a biodegradable composite material, which includes a polyhydroxyalkanoate matrix, reinforcing fibers, and inorganic fillers.

[0073] By employing the aforementioned material system, not only can structural strength requirements be met, but the material also undergoes gradual degradation during use, thereby reducing long-term environmental impact. Simultaneously, the inorganic fillers in the material can, to some extent, improve the chemical environment of the local water body.

[0074] (vi) Overall Effect By layering the shellfish attachment area, algae growth area, and fish habitat area, the composite structural unit forms a multi-layered habitat structure in space, thereby achieving the synergistic effect of different ecological functions.

[0075] Specifically, shellfish improve water quality through filter feeding, algae provide primary productivity through photosynthesis, and fish use the structure for habitat and reproduction. The three form a mutually reinforcing ecological relationship within the same structural unit, thereby improving the stability and restoration effect of the ecosystem.

[0076] IV. Material Implementation Methods In this embodiment, the material system used in the composite structural unit and its implementation method are described.

[0077] (I) Overall Composition of the Material System The composite structural unit is preferably made of biodegradable composite material to balance structural strength and environmental friendliness. Specifically, the biodegradable composite material includes a matrix material, reinforcing material, and functional filler.

[0078] The matrix material is used to provide the overall structure with formability and basic mechanical properties; the reinforcing material is used to improve the strength and toughness of the material; and the functional filler is used to improve the ecological adaptability and biocompatibility of the material.

[0079] (II) Implementation of Matrix Material In this embodiment, the matrix material is preferably a polyhydroxyalkanoate (PHA) material. This type of material has good biodegradability and biocompatibility, and can gradually degrade in an aquatic environment, thereby reducing its long-term impact on the ecological environment.

[0080] In addition, the matrix material has good molding properties, which makes it easy to prepare composite structural units with complex structures to meet the structural requirements of shellfish attachment areas, algae growth areas and fish habitats.

[0081] (III) Implementation of Reinforcing Materials To improve the structural strength of the composite structural unit, a reinforcing material is added to the matrix material. The reinforcing material is preferably a fibrous material, such as natural fibers or modified fibers.

[0082] By adding reinforcing materials, the compressive strength and erosion resistance of composite materials can be improved, enabling them to adapt to the complex hydrodynamic environment of estuary areas.

[0083] (iv) Implementation methods of functional fillers In this embodiment, the composite material also includes inorganic fillers to improve the ecological function of the material.

[0084] Specifically, the inorganic filler may include calcium-containing materials to provide a calcium source in the water, thereby promoting shell formation in shellfish; in addition, it may include materials with porous structures to increase the specific surface area of ​​the material surface, thereby providing attachment sites for microorganisms and algae.

[0085] By incorporating the aforementioned functional fillers, the adaptability of the composite structural unit to the biological community can be further improved.

[0086] (v) Synergistic effect of material functions Through the synergistic effect of matrix materials, reinforcing materials and functional fillers, the composite structural unit not only possesses excellent mechanical properties, but also meets the needs of biological attachment and growth during the ecological restoration process.

[0087] In some embodiments, the shellfish attachment area, algae growth area, and fish habitat area are configured with different materials or surface structures to meet the different needs of shellfish attachment, algae growth, and fish habitat respectively. The shellfish attachment area is preferably provided with calcium-containing materials or rough surface structures, the algae growth area is preferably provided with porous structures, and the fish habitat area is preferably provided with materials with high structural strength.

[0088] Specifically, the material system can gradually degrade and participate in the ecological cycle while ensuring structural stability, thereby reducing adverse environmental impacts during long-term use.

[0089] (vi) Coordination with structure and function The material system can be adapted to different functional zones. For example, in the shellfish attachment zone, the adhesion performance can be enhanced by increasing the surface roughness and the proportion of calcium-containing fillers; in the algae growth zone, a porous structure can be set to promote algae fixation; and in the fish habitat zone, it is preferable to ensure structural strength and spatial stability.

[0090] Through the above-mentioned differentiated configuration, the composite structural units can achieve functional optimization in different areas, thereby further improving the overall ecological restoration effect.

[0091] V. Overall Ecological Effects In this embodiment, the comprehensive effects of the shellfish and algae reef constructed using the above method on estuarine ecological restoration and fish resource conservation are explained.

[0092] By using the methods described in Examples 1 to 3, after deploying composite structural units in the estuary area, the composite structural units adopt a structure in which shellfish attachment areas, algae growth areas, and fish habitat areas are stacked vertically, which can form multi-layered habitats in space, thereby increasing the structural complexity of the aquatic environment.

[0093] Furthermore, the filter-feeding shellfish in the shellfish attachment area help improve local water transparency and water quality by taking in suspended particles and organic matter in the water; the algae in the algae growth area form primary productivity through photosynthesis, providing a basic energy source for the ecosystem; and the fish habitat area provides suitable habitat, foraging and breeding space for fish, thereby contributing to the recovery of fish resources.

[0094] Meanwhile, by arranging composite structural units at intervals or in a staggered manner in the estuary area, velocity gradient regions are formed between adjacent structural units, creating a relatively stable low-velocity environment in a localized area. This environment is conducive to the residence and growth of fish larvae and helps to retain nutrients in localized areas, thereby promoting the material cycle within the ecosystem.

[0095] Furthermore, by introducing shellfish, algae, and fish populations in stages according to a pre-set ecological succession sequence, the ecosystem gradually evolves from lower to higher trophic levels, which helps to form a relatively stable multi-trophic ecological structure. Combined with continuous ecological monitoring and regulation measures, the structural configuration and biological deployment strategies can be adjusted according to actual ecological changes, thereby improving the adaptability and stability of the ecological restoration process.

[0096] In summary, the shellfish and algae reef system constructed by the method described in this invention helps to increase the habitat complexity of estuary areas, promote the restoration of biodiversity, and improve the quality of the water environment to a certain extent, thereby achieving a comprehensive effect of estuarine ecological restoration and fish resource conservation.

[0097] VI. Specific Application Examples In this embodiment, a typical estuary area is used as the application scenario to illustrate the specific implementation process of the shellfish and algae ecological reef construction method of the present invention.

[0098] A river estuary with a water depth of 2–5 m and a flow velocity of 0.2–0.6 m / s was selected as the implementation area, and ecological reef units were deployed within this area according to a pre-set layout plan. The preferred dimensions of each composite structural unit are 1.5–2.5 m in length, 1.5–2.5 m in width, and 1.0–1.8 m in height.

[0099] In one specific embodiment, the structural parameters of the composite structural unit are shown in the table below:

[0100] In step S1, a composite structural unit with a shellfish attachment area, an algae growth area, and a fish habitat area is prepared, wherein the shellfish attachment area is located at the bottom, the algae growth area is located in the middle, and the fish habitat area is located at the top.

[0101] In step S2, the surface of the composite structural unit is functionalized to form a porous microtexture structure on the surface of the shellfish attachment area, while a nutrient slow-release unit is set in the algae growth area to promote algae colonization.

[0102] In one specific embodiment, the structural parameters of each functional area in the composite structural unit are shown in the table below:

[0103] In step S3, multiple composite structural units are arranged in a spaced-out manner in the estuary area, with a preferred spacing of 3 to 5 m, so that a velocity gradient region is formed between adjacent structural units.

[0104] In step S4, biological agents are introduced according to the ecological succession sequence: Introduce filter-feeding shellfish larvae within 1 to 3 months after deployment; After the shellfish have attached and stabilized, algal spores or larvae are introduced; After the algae have formed a certain coverage, the target fish larvae are introduced.

[0105] In step S5, regular ecological monitoring is conducted on the implementation area, with a preferred monitoring period of 1 to 3 months. By monitoring water quality parameters and changes in biological communities, the layout density of composite structural units or biological release strategies are adjusted appropriately.

[0106] In one specific embodiment, the process of introducing and monitoring the biological community is shown in the table below:

[0107] Through the above implementation methods, after a certain period of operation, an ecological reef system with a multi-layered structure can be formed in the estuary area, enabling shellfish, algae and fish to develop synergistically in the same space, thereby helping to improve the aquatic environment and promote the recovery of fish resources.

[0108] VII. Comparative Examples To further illustrate the improvement of the technical solution of the present invention compared with the traditional artificial reef technology, the shellfish and algae ecological reef construction method of the present invention is compared with the traditional artificial reef technology.

[0109] Under the same estuary conditions, two experimental areas with essentially identical water depth, flow velocity, substrate type, and tidal influence were selected as Comparison Area 1 and Comparison Area 2, respectively. Comparison Area 1 employed traditional artificial reefs for ecological restoration, while Comparison Area 2 utilized the shellfish and algae reef construction method described in this invention for ecological restoration. The number of units deployed, the deployment area, and the initial monitoring cycle were kept consistent in both areas to minimize the impact of environmental differences on the comparison results.

[0110] In Comparison Area 1, traditional artificial reefs were used for restoration. These reefs are primarily constructed of concrete or stone, and their main function is to provide shelter for fish. During implementation, the artificial reefs were directly placed into the water without creating attachment zones for shellfish or areas for algae growth, and without any phased introduction of shellfish, algae, or fish. Therefore, ecological restoration in this area relied mainly on natural attachment and natural fish aggregation.

[0111] In comparison region two, the method described in this invention was used for restoration. Specifically, a composite structural unit comprising a shellfish attachment zone, an algae growth zone, and a fish habitat zone was constructed, and multiple composite structural units were arranged in an alternating or staggered manner in the estuary area to create velocity gradient zones between adjacent composite structural units. Simultaneously, filter-feeding shellfish, macroalgae, and target fish were introduced sequentially according to a preset ecological succession sequence to gradually construct a multi-trophic-level biological community.

[0112] For ease of comparison, ecological monitoring was conducted in both areas six months after deployment. Monitoring indicators included water transparency, suspended solids concentration, algae coverage, shellfish attachment density, fish occurrence frequency, number of juvenile fish, and biodiversity index. Exemplary monitoring results are shown in the table below.

[0113] Note: The implementation area is located in a typical estuary, where the natural water transparency is low due to the influence of distillate and sediment disturbance. The shellfish-algae ecological reef of this invention achieves a relative improvement and stabilization of transparency through shellfish filter feeding, structural flow stabilization, and community synergy, which is more in line with the actual conditions of the estuarine water environment.

[0114] As shown in the table above, compared with traditional artificial reefs, the method of this invention exhibits better overall effects in water quality improvement, biological attachment, biological community construction, and fish resource conservation. Although traditional artificial reefs can provide shelter for fish to a certain extent, their ecological functions are relatively simple, mainly manifested in short-term fish aggregation, making it difficult to form a stable multi-trophic-level ecosystem.

[0115] Furthermore, in Comparative Area 2, because the composite structural unit has a shellfish attachment zone, filter-feeding shellfish can attach and continuously perform filter feeding, thereby reducing the concentration of suspended solids in the water and increasing water transparency; because an algae growth zone is set up, algae can form a primary production layer with a high coverage rate under the action of the grid structure and nutrient slow-release unit; because a fish habitat zone is set up, fish can obtain habitat, avoid predators and reproduce, thereby increasing the frequency of fish appearance and the number of juvenile fish staying.

[0116] Furthermore, observations of the local hydrodynamic conditions in the two areas revealed that the water flow around traditional artificial reefs is relatively uniform, with limited areas of slow-flowing zones. In contrast, this invention, through the intermittent or staggered arrangement of composite structural units, creates velocity gradient regions between adjacent units and establishes relatively stable low-velocity zones locally. These low-velocity zones are conducive to the retention of fish larvae, as well as algal spores, shellfish larvae, and nutrients, thereby promoting the sustainable development of the ecological community.

[0117] To further illustrate the differences in functional composition between different technical solutions, the structure and ecological functions of the two are compared as shown in the table below.

[0118]

[0119] In summary, compared with traditional artificial reefs, the method described in this invention does not merely increase fish shelter to achieve fish aggregation. Instead, it achieves synergistic effects among shellfish, algae, and fish through the functional zoning design of composite structural units, the construction of flow velocity gradient regions, and the phased introduction of biological communities. This technical solution can simultaneously improve water quality, increase habitat complexity, promote the formation of primary production layers, and enhance fish habitat and reproductive conditions, thus achieving better comprehensive results in estuarine ecological restoration and fish resource conservation.

[0120] The technical solution of the present invention has been described in detail above with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the specific embodiments described above. For those skilled in the art, various modifications, equivalent substitutions or improvements can be made to the technical solution of the present invention without departing from the spirit and essence of the present invention, and all such modifications, equivalent substitutions or improvements should fall within the scope of protection of the present invention.

[0121] Furthermore, the various embodiments described in the specification can be implemented individually or combined arbitrarily as needed, and as long as there is no technical conflict, they should all be considered within the scope of protection of this invention.

[0122] It should be noted that the terminology used in this specification is only for describing specific embodiments and is not intended to limit the scope of protection of this invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention, which shall be determined by the claims.

Claims

1. A shellfish and algae reef for estuarine ecological restoration and fish resource conservation, characterized in that, Including stacked composite structural units; The composite structural unit is arranged vertically in sequence as a shellfish attachment area, an algae growth area, and a fish habitat area; the shellfish attachment area is located at the bottom and has a porous microtexture structure of 50-200 μm on its surface; The algae growth zone is located in the middle and includes an algae fixation grid structure and a nutrient slow-release unit; The fish habitat is located in the upper part and includes a tubular shelter structure and an spawning substrate; The composite structural unit is made of biodegradable composite material, and its surface is functionalized to form a bio-attachment-inducing interface. Multiple composite structural units are arranged in a spaced or staggered manner, forming a velocity gradient region between the units.

2. The shellfish and algae reef according to claim 1, characterized in that, The biodegradable composite material includes a polyhydroxyalkanoate matrix, reinforcing fibers, and inorganic fillers.

3. The shellfish and algae reef according to claim 1, characterized in that, The functionalization process involves setting a bio-attachment induction layer on the surface of the composite structural unit or introducing a slow-release bio-inducer.

4. The shellfish and algae reef according to claim 1, characterized in that, The velocity gradient region can create a low velocity zone locally, thereby improving nutrient retention and habitat stability for juvenile fish.

5. The shellfish and algae reef according to claim 1, characterized in that, The shellfish attachment area, algae growth area, and fish habitat area form a continuous ecological functional zone along the vertical direction.

6. The shellfish and algae reef according to claim 1, characterized in that, The diameter of the tubular protective structure is 3 to 10 cm.

7. The shellfish and algae reef according to claim 1, characterized in that, The composite structural unit is an integrally molded structure.

8. The shellfish and algae reef according to any one of claims 1 to 7, characterized in that, The composite structural unit can support the construction of multi-trophic-level biological communities according to the ecological succession sequence, which is: first, a filter-feeding shellfish attachment community is formed, then a large algae growth community is formed, and finally a target fish habitat and breeding community is formed.

9. The shellfish and algae reef according to claim 8, characterized in that, The process of constructing the multitrophic biological community can be adaptively regulated through water quality parameters and biological community monitoring results.

10. The shellfish and algae reef according to claim 9, characterized in that, The regulation includes optimizing the spatial configuration, structural ratio, and biological community structure of composite structural units.

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