System and Method for Oyster Aquaculture

Abstract

A system and method for oyster aquaculture employs a hemispherical, dome shaped, hollow structure that is disposed in tidal or intertidal waters. This structure includes a plurality of small through-holes that allow fluid communication between the interior and exterior of the structure. An oyster seed source is suspended within the interior of the dome structure. The interior and exterior surfaces of the dome structure provide the hard surface required for the attachment of oyster spat and the resulting growth of adult oysters.

Claims

1. A structure for facilitating oyster reproduction comprising: a. a generally hemispherical shell having an outer surface and an inner surface; b. a plurality of through-holes provided in said shell, said through-holes providing fluid communication between an interior of said shell and an exterior of said shell; and c. means for suspending an oyster seed source suitable for the production of oyster sperm and oyster eggs in an interior of each of said shell structures.

2. The structure of claim 1 wherein said shell is constructed from a cementitious material.

3. The structure of claim 1, wherein said means for suspending an effective number of live oysters within said interior of said shell is comprised of a PVC tube.

4. The structure of claim 1, wherein said means for suspending an effective number of live oysters within said interior of said shell is comprised of a mesh bag suspended from said inner surface of said shell.

5. A method for establishing an oyster reef comprising the steps of: a. disposing in tidal or intertidal waters a plurality of generally hemispherical shaped shell structures; b. providing a plurality of through-holes in each of said shell structures; c. suspending an oyster seed source suitable for the production of oyster sperm and oyster eggs in an interior of each of said shell structures; d. providing a confined space for fertilization of said oyster eggs; e. providing a hard surface for attachment of said fertilized oyster eggs; f. allowing said fertilized oyster eggs to develop into adult oysters; g. allowing said adult oysters to continue creating additional oyster sperm and oyster eggs; whereby, an effective number of adult oysters are created and attached to said plurality of shell structures to create said oyster reef.

6. A method for treating red tide comprising the steps of: a. disposing in tidal or intertidal waters a plurality of generally hemispherical shaped shell structures; b. providing a plurality of through-holes in each of said shell structures; c. suspending an oyster seed source suitable for the production of oyster sperm and oyster eggs in an interior of each of said shell structures; d. providing a confined space for fertilization of said oyster eggs; e. providing a hard surface for attachment of said fertilized oyster eggs; f. allowing said fertilized oyster eggs to develop into adult oysters; g. allowing said adult oysters to continue creating additional oyster sperm and oyster eggs; whereby, an effective number of adult oysters are created to filter sufficient water to treat red tide.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numbers indicate like features and wherein:

[0023] FIG. 1 is a side perspective view of the oyster dome of the present invention, prior to deployment;

[0024] FIG. 2 is a side perspective view of the oyster dome of the present invention, including a cut away to show the interior surface of the oyster dome, after the oyster dome has been deployed;

[0025] FIG. 3 is a side perspective view of the oyster dome of the present invention with an oyster seed source holder;

[0026] FIG. 4 is a side perspective view of a seed source holder;

[0027] FIG. 5 is a side perspective view of a lifting mechanism used for deployment of oyster domes;

[0028] FIG. 6A is a side sectional view of the seed source and the released sperm and eggs;

[0029] FIG. 6B is a side perspective view of a mesh bag oyster seed source holder;

[0030] FIG. 6C is a side perspective view of a deployed oyster dome with movement of oyster sperm and eggs;

[0031] FIG. 7 is a side perspective view, including a cut away, to show fully developed oyster growth on the interior and exterior of the oyster dome; and

[0032] FIG. 8 is a plan view of grid of deployed oyster domes.

REFERENCE NUMBERS INCLUDED IN THE DRAWINGS

[0033] The below table provides a ready reference for the reference numbers used in the appended drawings and in this specification:

TABLE-US-00001 Ref. No. Description Ref. No. Description 100 Oyster Dome 101 Through Holes 102 Rough Surface 201 Interior Oyster 202 Exterior Oysters 203 Ocean Floor 300 Seed Holder 301 Removable Cap 302 Holes 401 Screen 501 Hook 601 Seed Oysters 602 Sperm & Eggs 603 Mesh Bag 604 Wood Plug 605 Hanger Hook 303 Downpipe

DETAILED DESCRIPTION OF THE INVENTION THROUGH THE DRAWINGS

[0034] Referring to FIG. 1, oyster dome 100 is shown. Oyster dome 100 is a hemispherical, hollow, dome shaped, shell-type structure preferably constructed of high strength concrete or like cementitious material. Alternatively, oyster dome 100 may be constructed of any material suitable for long-term disposition in tidal or intertidal waters, and that provides a hard surface suitable for the attachment and growth of oyster spat. Each oyster dome 100 has a diameter of approximately 4 feet, and weighs between 400 to 450 pounds. The interior and exterior concrete surfaces of oyster dome 100 are provided with a rough surface finish 102 that promotes the attachment of interior oysters 201 (not shown) and exterior oysters 202 (not shown) to oyster dome 100. Each oyster dome 100 also includes a plurality of through holes 101 that allow fluid communication between the interior space of oyster dome 100 and the surrounding water. Preferably, each oyster dome 100 includes between 5-10 through holes 101, and each through hole 101 has a diameter of approximately 4 inches.

[0035] Referring to FIG. 2, oyster dome 100 is shown disposed and in contact with ocean floor 203. The beginning growth of interior oysters 201 and exterior oysters 202 is further shown. Referring to FIG. 3, seed holder 300 is shown prior to insertion into oyster dome 100. In this embodiment, seed holder 300 is constructed of a downpipe 303 that includes multiple holes 302 and a removable cap 301. In this embodiment, seed holder 300 may be constructed of PVC, similar plastic material, or other material suitable for long-term immersion in tidal or intertidal waters. Holes 302 allow fluid communication between the interior of downpipe 303 and the surrounding environment. Referring to FIG. 4, seed holder 300 further includes a screen 401 at the bottom of downpipe 303. Referring to FIG. 5, hook 501 is shown for purposes of lifting, lowering, or otherwise positioning oyster dome 100.

[0036] Referring to FIG. 6A, a sectional view of seed holder 300 is shown. Seed oysters 601 are shown disposed within the interior of downpipe 303. Typically, between 3 and 10 seed oysters 601 are used. When seed oysters 601 spawn, sperm and egg 602 are released. Sperm and egg 602 may then move from the interior of downpipe 303 into the interior of oyster dome 100 through holes 302 and screen 401. Referring to FIG. 6B, an alternate embodiment is shown. In this embodiment, a wood plug 605 is embedded in the top portion of oyster dome 100 (the portion where, as shown in FIG. 3, seed holder 300 is inserted into oyster dome 100), and seals an opening through the top of oyster dome 100. Hook 605 is used to secure a mesh bag 603 which contains seed oysters 601. Preferably, mesh bag 603 is formed from hemp, or some other biodegradable material.

[0037] The embodiments shown in FIGS. 6A and 6B are illustrative only. These embodiments provide a mechanism for suspending seed oysters 601 in a manner that allows fluid communication with the surrounding environment and maintains the seed oysters above any silt layer on the ocean floor. This functionality can be provided in a number of ways. For example, seed oysters could be glued or attached with hook and loop fasteners to the interior wall of the oyster dome 100; a cage containing seed oysters can be suspended from the upper portion of the interior of oyster dome 100; seed oysters can be suspended on strings hanging from the top of oyster dome 100.

[0038] Referring to FIG. 6C, oyster dome 100 is shown disposed in tidal or intertidal waters and resting on ocean floor 203. Sperm and eggs 602 are shown migrating from the interior of oyster dome 100 into the surrounding environment. As shown in FIG. 7, over time, interior oysters 201 and exterior oysters 202 cover the interior and exterior surfaces of oyster dome 100. As seen in FIG. 8, a grid pattern of oyster domes 100 provides an efficient mechanism for creating a large area of oyster reef.

[0039] In operation, an oyster dome 100 is formed through standard concrete construction methods. Typically, through holes 101 are created as part of initial concrete construction process and are sized to be large enough to allow sufficient communication of tidal or intertidal waters but small enough to exclude large predators. Concrete is an excellent construction material as it provides the weight necessary to secure the oyster dome 100 in place (and resist wave and tidal action), it provides the hard surface oyster spat require for development into adult oysters, and it is extremely durable in aquatic environments. Because of the inherent strength in the hemispherical shape, no reinforcing steel is required.

[0040] Once placed in tidal or intertidal waters, oyster dome 100 is loaded with seed oysters 601. Seed oysters 601 are suspended within the interior of oyster dome 100. Once seed oysters spawn, the resulting sperm and eggs 602 are initially enclosed in a semi-restricted area, significantly increasing the probability of fertilization. Once fertilization occurs, oyster dome 100 provides an ideal hard surface for the resulting oyster spat to attach and grow. This oyster growth occurs on both the interior and exterior surfaces of oyster dome 100.

[0041] Because oysters are filter feeders, oysters also have the ability to significantly increase water clarity. Increasing water clarity provides additional environmental benefits such as removing harmful algae (e.g., the algae producing red tide) and allowing sufficient sunlight to reach the sea floor so that seagrasses may grow.

[0042] In one preferred implementation, as shown in FIG. 8, a grid of multiple oyster domes 100 is disposed over a tract of sea floor. Positioning multiple oyster domes 100 in close proximity to each other creates a positive feedback loop by providing both a large number of spawning oysters and a large amount of surface area suitable for oyster spat attachment and growth. A large number of oysters filters a large amount of water, thereby increasing water clarity and encouraging and enabling the growth of seagrasses. The structure provided by the oyster domes 100 and the seagrass habitat created provides a foundational environment for many aquatic species. Finally, the grid structure also provides wave attenuation and decreases the destructive force of significant weather events such as hurricanes.