Aquatic structure and method

Abstract

A structure is provided for promoting growth of aquatic species for aquaculture operations and other purposes. The aquatic structure may have a buoyant member, a flexible sheet, and flexible strips (such as fronds, ribbons or filaments). The flexible materials are suspended from the buoyant member. The flexible materials may have high surface area structures for promoting growth of autotrophic (including algae) and heterotrophic organisms (such as bacteria) in photic and heterotrophic sections, respectively. The autotrophs and the bacteria are food, and the dispersed flexible strips provide an attractive habitat for the larger feeding organisms such as fish, crustaceans and mollusks. Ballast devices may be used, if desired, to secure the aquatic structure to the benthos. The ballast devices may be formed of flexible material. The flexible ballast devices may be filled with granular material after the apparatus is transported to the job site. The aquatic structure is easy to handle and deploy in aquatic environments. In alternative embodiments of the invention, additional float devices and/or tethered anchors may be provided for maintaining the apparatus in the desired location.

What is claimed is:  
     
         1 . An aquatic structure for promoting biological growth, said structure comprising: 
 a buoyant member;    a flexible sheet connected to said buoyant member, said sheet having a high surface area structure for promoting growth of autotrophic organisms in a photic zone; and    flexible strips connected to said flexible sheet, said flexible strips being arranged to promote growth of heterotrophic organisms.    
     
     
         2 . The structure of  claim 1 , wherein said buoyant member includes a hollow tube.  
     
     
         3 . The structure of  claim 2 , further comprising a flexible sleeve for connecting said flexible sheet to said hollow tube.  
     
     
         4 . The structure of  claim 3 , further comprising stitches for connecting said flexible strips to said flexible sheet.  
     
     
         5 . The structure of  claim 4 , wherein said strips and said sheet are formed of different materials.  
     
     
         6 . The structure of  claim 3 , wherein said strips and said flexible sheet are integrally formed of a single sheet of fabric.  
     
     
         7 . The structure of  claim 3 , wherein said strips extend downwardly into the water in use, and said hollow tube extends horizontally across the surface of the water.  
     
     
         8 . The structure of  claim 7 , wherein said strips have free ends that are not connected to each other.  
     
     
         9 . The structure of  claim 8 , wherein said strips have a specific gravity that is greater than or equal to 1.02.  
     
     
         10 . The structure of  claim 9 , further comprising ballast devices for anchoring one or more of said strips to the benthos.  
     
     
         11 . The structure of  claim 10 , wherein said ballast devices include metal weights attached to one or more of said free ends of a first group of said strips.  
     
     
         12 . The structure of  claim 9 , wherein said structure has no ballast device, and wherein said strips are not anchored to the benthos.  
     
     
         13 . The structure of  claim 9 , wherein said strips are movable with respect to each other to form an underwater branched habitat for aquatic species.  
     
     
         14 . An aquaculture apparatus, comprising: 
 an elongated buoyant device arranged to float on the water surface;    flexible material having a high surface area structure for promoting aquatic growth, said flexible material having a specific gravity greater than or equal to 1.02, said flexible material being connected to said elongated buoyant device; and    at least one ballast device for anchoring said aquaculture apparatus, said ballast device being connected to said flexible material.    
     
     
         15 . The apparatus of  claim 14 , wherein said flexible material includes a flexible sheet and flexible strips, said sheet being located between said buoyant device and said strips.  
     
     
         16 . The apparatus of  claim 15 , wherein said strips extend downwardly toward the benthos in use, and said buoyant device floats in a horizontal position on the surface of the water.  
     
     
         17 . The apparatus of  claim 16 , wherein said strips have free ends that are not connected to each other.  
     
     
         18 . The apparatus of  claim 17 , wherein said ballast device is connected to at least one of said free ends.  
     
     
         19 . The apparatus of  claim 18 , wherein said ballast device is formed of flexible material and contains granular material.  
     
     
         20 . The apparatus of  claim 14 , further comprising float devices located at the ends of said elongated buoyant device.  
     
     
         21 . The apparatus of  claim 14 , further comprising anchors tethered to the ends of said elongated buoyant device.  
     
     
         22 . An aquaculture method, comprising the steps of: 
 floating a buoyant device on the surface of a body of water;    suspending a flexible sheet from said buoyant device in said body of water;    suspending flexible strips from said flexible sheet; and    subsequently, promoting growth of autotrophic and heterotrophic aquatic organisms on said flexible sheet and said flexible strips.    
     
     
         23 . The method of  claim 22 , further comprising the step of resting free ends of said flexible strips on the bottom of said body of water.  
     
     
         24 . The method of  claim 23 , further comprising the step of anchoring a first group of said free ends to said bottom.  
     
     
         25 . The method of  claim 24 , further comprising the step of forming ballast devices by adding ballast material to flexible ballast containers.  
     
     
         26 . The method of  claim 23 , further comprising the step of moving said free ends relative to each other to form a branched underwater habitat.  
     
     
         27 . The method of  claim 26 , further comprising the step of growing heterotrophic organisms within said habitat.  
     
     
         28 . The method of  claim 26 , further comprising the step of providing float devices at opposite ends of said buoyant device.  
     
     
         29 . The method of  claim 22 , further comprising the step of tethering anchors to said buoyant device.  
     
     
         30 . An aquaculture apparatus, comprising: 
 an elongated buoyant device arranged to float on the water surface; and    flexible sheet material hanging from said elongated buoyant device, said flexible sheet material having a high surface area structure for promoting aquatic growth, said flexible sheet material having a specific gravity greater than or equal to 1.02, and said flexible sheet material being connected to said elongated buoyant device.    
     
     
         31 . The apparatus of claim  30 , wherein said flexible sheet material includes a flexible sheet and flexible strips, said sheet being located between said buoyant device and said strips.  
     
     
         32 . The apparatus of claim  31 , wherein said strips have first ends that are not connected to each other, and second ends that are contiguous with said sheet.