Artificial reef

Abstract

An artificial reef for providing a habitat for aquatic species in water, comprising: a base arranged to be anchored to a seabed surface, at least a portion of the base being a concrete material; the plurality of organic casings are coupled to the base; and a plurality of rods having a first end coupled to the base and a second end extending away from the base, the rods being made of a natural material.

Description

Technical Field

[0001] The present invention relates to an artificial reef, and in particular, but not exclusively, to an artificial reef for providing a habitat for aquatic species in water. Background Art

[0002] In Hong Kong, bamboo poles are widely used for scaffolding and, when they reach the end of their useful life, are dumped into landfills. Although bamboo poles are biodegradable and can usually be disposed of naturally, discarding them in landfills is still a poor choice because the remaining value of the bamboo is not fully utilized.

[0003] Food waste, such as oyster shells and other marine shells, is also dumped after being harvested or served in restaurants. Oyster shells are either discarded in landfills or left as litter on shorelines. However, this disposal method does not benefit marine life and aquatic ecosystems, but instead increases the use of valuable land for storing waste.

[0004] Improved waste management is urgently needed to reduce the depletion of landfill space occupied by solid waste. It is also feasible to explore ways to utilize biodegradable waste to promote sustainable development and alleviate the environmental problems associated with landfills. Summary of the Invention

[0005] According to a first aspect of the present invention, there is provided an artificial reef for providing a habitat for aquatic species in water, comprising:

[0006] - a foundation arranged to be anchored to a seabed surface, at least a portion of said foundation being of concrete material;

[0007] - a plurality of organic shells coupled to the base; and

[0008] - A plurality of rods having a first end coupled to the base and a second end extending away from the base, the rods being of a natural material.

[0009] In an embodiment of the first aspect, the first end of the rod further extends through the base to form an anchoring portion below the base.

[0010] In an embodiment of the first aspect, the anchoring portion formed by the rod comprises a flat and rigid base surface for resting on a flat surface of the seabed.

[0011] In an embodiment of the first aspect, at least one fifth of the length of the organic housing and the rod is inserted into the base.

[0012] In an embodiment of the first aspect, the organic housing and the rod are inserted into the base in one or more different orientations relative to a vertical axis of the base.

[0013] In an embodiment of the first aspect, the poles are arranged to split longitudinally to define the surface area of the habitat complexity.

[0014] In an embodiment of the first aspect, the plurality of rods form a semicircle, although other forms or shapes are possible.

[0015] In an embodiment of the first aspect, the plurality of rods and the shell are spaced apart from each other to allow intrusion of concrete material.

[0016] In an embodiment of the first aspect, the concrete material is formed from a concrete mixture of cement, aggregate, and water.

[0017] In an embodiment of the first aspect, the natural material comprises bamboo and the organic shell comprises a bivalve shell.

[0018] In an embodiment of the first aspect, the concrete composition further comprises a shell having a size no greater than 0.5 centimeters.

[0019] In an embodiment of the first aspect, the cement content is 10% to 25% of the total concrete mixture.

[0020] In an embodiment of the first aspect, the size of the aggregate is no greater than 0.5 centimeters.

[0021] In an embodiment of the first aspect, the bamboo has a size between 0.2 meters and 1.5 meters.

[0022] In an embodiment of the first aspect, the bivalve shell comprises an oyster shell.

[0023] In an embodiment of the first aspect, the longest dimension of the oyster shell is not less than 5 centimeters.

[0024] In an embodiment of the first aspect, the base is made by sand casting.

[0025] According to a second aspect of the present invention, there is provided a method for manufacturing an artificial reef, comprising the following steps:

[0026] -a) inserting a plurality of organic shells and a plurality of rods into a sand mold;

[0027] -b) pouring a flowable concrete mix into the sand mould; and

[0028] - c) drying the flowable concrete mix to form a foundation arranged to be anchored to the seabed surface.

[0029] In an embodiment of the second aspect, the method further comprises, before step a):

[0030] -a) Sand casting molds are formed by placing the pattern in a sand box or pile of sand.

[0031] In an embodiment of the second aspect, the method further comprises, after step c), the following steps:

[0032] -d) Cut the rods below the base to create a flat surface below the base. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

[0034] Figure 1 is a schematic diagram illustrating the overall structure of an exemplary bamboo reef according to an exemplary embodiment of the present invention;

[0035] Figure 2 It shows that Figure 1 A schematic diagram showing examples of orientations of bamboo poles of a bamboo reef; and

[0036] Figure 3 is a schematic block diagram illustrating a method for preparing a bamboo reef according to an example embodiment of the present invention. DETAILED DESCRIPTION

[0037] Through their own trials and experiments, the inventors discovered several shortcomings of existing artificial reefs. For example, while bamboo has been used to cultivate oysters in some parts of Asia and China, for example by inserting bamboo poles into the sediment, the poles may only provide substrate for oysters and are not designed to provide microhabitats for other species. Bamboo poles are also used to construct bamboo frames, which are tied with ropes and sunk into the seabed with rocks or concrete blocks. However, the manufacture and installation of these frames are labor-intensive, and they do not provide sufficient habitat complexity to support diverse species communities.

[0038] The inventors also found that most artificial reefs using concrete require complex and expensive molds or frames (e.g., metal, wood, or plastic) to construct the concrete artificial reef units (e.g., reef balls). Other artificial reef units are made by packaging shells in metal or plastic cages or bags, which have their own limitations: metal rusts and cracks, weakening the reef's structural integrity; and plastic decomposes and pollutes the environment.

[0039] In the present invention, a reef unit is provided that provides suitable surface area and microhabitats for aquatic species to reproduce, inhabit, and feed, thereby increasing marine and freshwater biodiversity and, consequently, ecosystem functions and services. Furthermore, the reef unit can reuse materials that might otherwise be considered waste in a landfill, thereby increasing waste recycling while reducing the demand on landfill resources.

[0040] refer to Figure 1, shows an artificial reef 100 for providing a habitat for aquatic species in water, which includes: a base 120 arranged to be anchored to the surface of the seabed, at least a portion of the base 120 is a concrete material; a plurality of organic shells 140 coupled to the base 120; and a plurality of rods 160, whose first ends 162 are connected to the base 120 and second ends 164 extend away from the base 120, and the rods 160 are natural materials.

[0041] In this embodiment, artificial reef 100 is a reef primarily made of bamboo. The main structure of bamboo reef 100 includes a base portion 120, an organic shell layer 130, and an upper pole layer 150. Base portion 120 forms the basic structure for supporting the upwardly extending organic shell layer 130 and upper pole layer 150. Together, organic shell layer 130 and upper pole layer 150 can form a habitat for aquatic species.

[0042] Since the artificial reef 100 must be submerged in water and fixed to a surface underwater, each component should be made of a material that will not corrode or deteriorate in fresh or salt water after a predetermined period of time.

[0043] Base 120 can have any geometric shape, preferably symmetrical about horizontal and vertical axes A. Base 120 includes a lower surface 122 that contacts the ground and an upper surface 124 that is exposed to and surrounded by seawater. Lower surface 122 and upper surface 124 are relatively flat, allowing lower surface 122 to have sufficient area to contact and anchor to the ground, while upper surface 124 provides a flat surface for arranging multiple organic shells 140 and rods 160. Upper surface 124 is extruded from lower surface 122 with a small thickness 126 to form a three-dimensional shape with a relatively low profile.

[0044] The material selected for the base portion 120 is preferably one that provides sufficient strength and stability to maintain the position of the reef 100 while being non-corrosive. The base portion 120 is made of a heavy material having a specific gravity greater than that of the fluid, so that the reef 100 can sink under its own weight and prevent the reef 100 from flipping over or being dislodged from the surface by the current.

[0045] For example, the base portion 120 can be made of a non-corrosive material (e.g., concrete or prestressed concrete). More preferably, the base portion 120 is a concrete slab formed from a phase-change material that can initially be in a fluid state and then solidify into a solid state. The fluid phase-change material can first be poured into the plurality of oyster shells 140 and bamboo poles 160, filling the gaps formed between the organic shells 140 and the bamboo poles 160. Once the phase-change material solidifies, it can bond at least a portion of the organic shells 140 and bamboo poles 160 to the concrete slab 120.

[0046] The shape of the concrete slab 120 can be predefined, such as by sand casting or other methods. Although the concrete slab 120 is a thin disk in this exemplary embodiment, it can also be formed into other geometric shapes, such as spheres, pyramids, squares, tubes, truncated cones, etc.

[0047] The phase change material can be a concrete mix, which is formed from cement, fine aggregate, and water. Cement, fine aggregate (<0.5 cm), and water are mixed in any known flowable concrete ratio. The physical properties of the concrete are determined by the cement ratio. For example, the cement content of the concrete can be varied from a low cement content (10%) to a high cement content (25%).

[0048] In an alternative embodiment, concrete slab 120 can also be made from eco-friendly concrete. For example, concrete slab 120 can also be formed from other substitutes that can partially replace fine aggregate (<0.5 cm). While larger organic shells (approximately 5 cm) can be used to form organic shell layer 130, crushed organic shells (<5 cm) are also useful and can be hammered (crushed) into smaller sizes. For example, small pieces of crushed organic shells (<0.5 cm) can partially replace up to 50% of the fine aggregate.

[0049] Preferably, the upper pole layer 150 can be formed by a plurality of poles 160 made of a natural material having multiple fibers. For example, the poles 160 can be bamboo, which generally has a high tensile strength and tensile modulus. Alternatively, the bamboo poles 160 are cut from original bamboo poles, with a longitudinal length ranging from 0.2m to 1.5m. Alternatively, the upper pole layer 150 can be made of new bamboo poles or discarded bamboo poles from the construction industry.

[0050] Bamboo poles 160 are elongated, tubular members that are inherently rigid. Their lower ends 162 are securely coupled to the concrete slab 120 to withstand currents on the seabed. Upper ends 164 extend from the base 120, spaced apart to allow water to flow around the gaps and reduce excess fluid pressure on the surface area of the upper pole layer 150. This reduces the bending moment exerted on the joints between the lower ends 162 of the poles 160 and the concrete slab 120. While a certain amount of water flow must be allowed through the reef 100, the presence of this spacing reduces the motion caused by the currents and deflects them into multiple, smaller streams.

[0051] Preferably, the organic shell layer 130 can be formed from a plurality of bivalve shells 140, such as shellfish shells, such as oyster and mussel shells that have been harvested or served in restaurants, or shells discarded from oyster farms. For example, clean oyster shells 140 larger than about 5 centimeters can be used to form the organic shell layer 130 of the reef 100.

[0052] Each oyster shell 140 can provide grooves that serve as shelter for aquatic species, allowing them to attach and colonize the inner surface of the oyster shell 140. Oyster shells 140 can also serve as a habitat for larvae and other aquatic or marine organisms. Furthermore, oyster shells are a significant source of calcium carbonate, potentially containing up to 95% calcium carbonate. This is advantageous because subsequent decomposition of the shells can return this material to the ocean for reuse by other aquatic or marine organisms.

[0053] In this exemplary embodiment, oyster shells 140 and bamboo poles 160 are provided on the upper surface of concrete slab 120. Bamboo poles 160 further extend from concrete slab 120 to provide a blocking element for partially interrupting the water flow around organic shell layer 130. Therefore, marine species inhabiting organic shell layer 130 are not harmed by the water flow.

[0054] While the bamboo poles 160 are segmented longitudinally according to the desired dimensions of the reef unit 100, some of the bamboo poles 160 may be oriented at various diagonals and at one or more angles relative to the vertical axis A to define the dimensions of the reef unit 100. For example, the angled bamboo poles 160 may be collectively formed into any shape that is stable in an aquatic system.

[0055] exist Figure 2 In the illustrated exemplary embodiment, multiple bamboo poles 160 can be oriented in a specific arrangement to form a roughly semicircular shape for enhanced aesthetics. Some bamboo poles are shown in dashed lines and omitted for simplicity. For example, the middle bamboo pole 160a is inserted vertically into the base 120 without tilting relative to the vertical axis A. Multiple bamboo poles 160 are inserted obliquely into the base 120, so that the longitudinal axis of each bamboo pole 160b to 160g interacts with the vertical axis A to form a corresponding angle of inclination. The farther away from the middle bamboo pole 160, the greater the acute angle.

[0056] A pair of bamboo poles 160b and 160c adjacent to and sandwiching the middle bamboo pole 160a are tilted in two opposite directions relative to the vertical axis A. For example, the bamboo pole 160b is tilted at a positive acute angle a1 relative to the vertical axis A, and the bamboo pole 160c is tilted at a negative acute angle b1 relative to the vertical axis A. Another pair of bamboo poles 160d and 160e sandwiching the inner bamboo poles 160a to 160c are further tilted in two opposite directions relative to the vertical axis A. For example, the bamboo pole 160d is tilted at a larger positive acute angle a2 (greater than the angle a1) relative to the vertical axis A, and the bamboo pole 160e is tilted at a larger negative acute angle b2 (greater than the angle b1) relative to the vertical axis A.

[0057] Finally, the pair of outermost bamboo poles 160f and 160g that sandwich the inner bamboo poles 160a to 160e are further tilted in two opposite directions relative to the vertical axis A. For example, bamboo pole 160f is tilted at a maximum positive acute angle a3 (greater than angles a1 and a2) relative to the vertical axis A, while bamboo pole 160g is tilted at a maximum negative acute angle b3 (greater than angles b1 and b2) relative to the vertical axis A. Therefore, the more outermost bamboo poles 160 there are, the larger the lateral dimension of the upper pole 150.

[0058] While the bamboo poles 160 are arranged at various diagonals and together form a semicircle, one or more gaps are provided between the poles 160. The gaps are sized to allow smaller fish and other marine species to swim through while blocking the entry of larger fish or marine species. Advantageously, the gaps formed between the bamboo poles 160 allow smaller fish to escape predators and further develop.

[0059] Preferably, oyster shells 140 are stacked on top of the concrete slab 120 to form one or more upwardly-facing inclined sections for intercepting and deflecting water flowing along the edges of the inclined sections. Due to the presence of these inclined sections, the downward component of the force generated by water flowing at a certain angle relative to the inclined sections can act downward on the reef 100, pushing the reef 100 toward the seabed, thereby keeping the reef 100 substantially stationary.

[0060] The insertion pattern of bamboo poles 160 into concrete slab 120 can vary from vertical to diagonal. Preferably, at least about one-fifth of the length of bamboo poles 160 and oyster shells 140 is inserted into the sand of concrete slab 120. The number of bamboo poles 160 and oyster shells 140 inserted can vary, but sufficient space should be left between the poles 160 and oyster shells 140 to allow for concrete intrusion. Otherwise, bamboo poles 160 and oyster shells 140 may not be securely coupled to concrete slab 120, and the overall structure of reef 100 will be susceptible to turbulent water flow.

[0061] The lower surface 122 of the concrete slab 120 forms a surface indirectly connected to the seabed. For example, it can be fixed to the ground by one or more fasteners.

[0062] More preferably, the bamboo reef 100 further includes lower bamboo pole anchors 170 formed by extending the lower ends 162 of the bamboo poles 160 through the concrete slab 120 and slightly protruding from the lower surface 122 of the concrete slab 120. Each bamboo pole 160 is drilled into the sandy bottom, so the bamboo pole anchors 170 formed below the concrete slab 120 serve as anchors to the sandy bottom and eliminate the need for additional fasteners.

[0063] While artificial reef 100 is typically anchored to a sandy seabed, an alternative exemplary embodiment of the artificial reef can also be placed on a hard, flat surface. For example, bamboo pole anchor 170 can be cut into a hard, flat surface. Artificial reef 100 will be anchored to the flat surface primarily by the weight of concrete slab 120.

[0064] Advantageously, the innovative bamboo reef uses bamboo poles, oyster shells, and a small amount of concrete. The innovation offers a cost-effective and recyclable alternative to discarded bamboo and shells.

[0065] The present invention can be used to create artificial reefs and habitats for marine and freshwater ecosystems, two types of aquatic ecosystems with different salinity levels. In marine ecosystems with high salinity levels, such as the open deep ocean, brackish wetlands, coral reefs, estuaries, mangroves, sandy beaches, kelp forests, polar oceans, and rocky marine ecosystems, bamboo reefs can be anchored to sandy and rocky substrates, between oyster and coral reefs, at the base of seawalls and breakwaters, and beneath bridge piers. Conversely, in freshwater ecosystems, bamboo reefs can be anchored to the bottom of streams, lakes, canals, ponds, and reservoirs.

[0066] The present invention also describes an example method for making innovative yet environmentally friendly and cost-effective artificial reef units (such as bamboo reefs) that incorporate recycled waste natural materials to promote the growth of plants and animals in degraded aquatic ecosystems.

[0067] Final reference Figure 3 , shows an example method 300 for making an artificial reef 100, comprising the steps of: a) inserting a plurality of organic shells 140 and a plurality of rods 160 into a sand mold; b) pouring a flowable concrete mixture into the sand mold; c) drying the flowable concrete mixture to form a base 120 arranged to be anchored to a seabed surface.

[0068] The manufacturing of the bamboo reef 100 according to an exemplary embodiment of the present invention will now be described. The manufacturing of the bamboo reef 100 includes three main steps: step 310, preparing a sand mold; step 320, preparing and arranging bamboo poles 160 and organic shells 140; step 330, preparing and pouring a concrete mixture.

[0069] First, a sand mold can be prepared in step 310. For example, the sand mold can be made manually or placed in a sandbox or pile of sand. Any type of sand (from fine to coarse) can be used. The style and size of the sand mold can vary depending on the desired design. For example, a sand mold with a diameter of approximately 30 cm and a depth of approximately 5 cm is sufficient to construct a bamboo reef 100 with a base 120 having a diameter of approximately 1 meter.

[0070] Then, proceed to step 320 to prepare bamboo poles 160 and oyster shells 140. Cut the original bamboo poles 160 (to a length between 0.2 and 1.5 meters) and split them lengthwise according to the desired dimensions of the reef unit 100. Clean oyster shells 140 larger than approximately 5 centimeters are used for the reef. Oyster shells 140 are preferably screened and cleaned to avoid contaminating the seawater. Subsequently, the bamboo poles 160 and oyster shells 140 are inserted into the sand of the mold. Preferably, approximately one-fifth of the length of the bamboo poles 160 and oyster shells 140 is inserted into the sand of the mold.

[0071] Finally, concrete is prepared and poured into the sand cast in step 330. The concrete mixture for bonding can be prepared by mixing cement, fine aggregate (<0.5 cm) and water in any known flowable concrete ratio. The cement content of the concrete can vary from low cement (10%) to high cement (25%). Alternatively, small pieces of oyster shells (<0.5 cm) can replace up to 50% of the fine aggregate to make an eco-friendly concrete. The flowable concrete mixture is poured into the sand mold to form a slab 120, which allows the bamboo poles 160 and shells 140 to consolidate and bond together. After drying, the bamboo reef 100 can be removed and air-dried (step 340).

[0072] This innovative fabrication method allows for quick and easy fabrication using minimal equipment. It also allows for easy changes in reef unit design and size, as it does not rely on prefabricated molds or frames. The bamboo reef design and size can be scaled up to larger reef units. For example, the length, arrangement, and density of the bamboo stems can be modified to alter complexity, surface area, and microhabitat availability, depending on the needs of different aquatic species or communities.

[0073] It will be appreciated by those skilled in the art that many changes and / or modifications may be made to the present invention as shown in the specific embodiments without departing from the spirit or scope of the present invention as broadly described. Therefore, the present embodiments are to be considered in all respects as illustrative and not restrictive.

[0074] Unless otherwise stated, any reference to prior art contained herein should not be taken as an admission that the information is common general knowledge.

Claims

1. An artificial reef for use in water to provide a habitat for aquatic species, comprising: - a foundation arranged to be anchored to the surface of the seabed, at least a portion of said foundation being of concrete material; - a plurality of organic shells coupled to the base; as well as - a plurality of rods having a first end coupled to the base and a second end extending away from the base, the rods being of a natural material.

2. The artificial reef according to claim 1, wherein: The first end of the rod further extends through the base to form an anchoring portion below the base.

3. The artificial reef according to claim 2, wherein: The anchoring portion formed by the rod comprises a flat and rigid base surface for resting on a flat surface of the seabed.

4. The artificial reef according to claim 1, wherein: At least one fifth of the length of the organic shell and the rod is inserted into the base.

5. The artificial reef according to claim 1, wherein: The organic housing and the rod are inserted into the base in one or more different orientations relative to a vertical axis of the base.

6. The artificial reef according to claim 5, wherein: The poles are arranged to split longitudinally to define the surface area of habitat complexity.

7. The artificial reef according to claim 1, wherein: The plurality of rods form a semicircle.

8. The artificial reef according to claim 1, wherein: The plurality of rods and the shell are spaced apart from each other to allow intrusion of the concrete material.

9. The artificial reef according to claim 1, wherein: The concrete material is formed of a concrete mixture of cement, aggregate and water.

10. The artificial reef according to claim 1, wherein: The natural material comprises bamboo and the organic shell comprises a bivalve shell.

Images