Systems and Methods for Culturing Algae With Bivalves

Abstract

Provided herein are systems and methods for extracting lipids and/or producing biofuel from algae in marine and freshwater environments, wherein algae and bivalves are co-cultured in a system of enclosures comprising water that comprises recycled nutrients that are essential for algal growth. The system also include enclosures for culturing fishes which are used to harvest the algae.

1 - 29 . (canceled) 
     
     
         30 . A method for extracting lipids from planktivorous fishes comprising:
 a. deploying planktivorous fishes into a body of water comprising algae and bivalves;   b. harvesting the algae by feeding the algae to the planktivorous fishes;   c. harvesting the planktivorous fishes; and   d. extracting lipids from the planktivorous fishes.   
     
     
         31 . The method of  claim 30 , wherein the extracting comprises heating the planktivorous fishes to a temperature of between 70° C. and 100° C., pressing the fishes to release the lipids, and collecting the lipids. 
     
     
         32 . The method of  claim 30 , further comprising processing the lipids by a technique selected from the group consisting of chromatography, fractional distillation, molecular distillation, enzymatic splitting, low-temperature crystallization, supercritical fluid extraction, and urea complexation. 
     
     
         33 . The method of  claim 30 , further comprising polishing the lipids to form a biofuel. 
     
     
         34 . The method of  claim 33 , wherein the biofuel is biodiesel. 
     
     
         35 . The method of  claim 30 , further comprising processing the lipids to form a product comprising at least one of EPA and DHA. 
     
     
         36 . The method of  claim 35 , wherein the processing comprises transesterifying the lipids. 
     
     
         37 . The method of  claim 35 , wherein the processing comprises removing C 14  to C 18  fatty acid ethyl esters from the lipids. 
     
     
         38 . The method of  claim 35 , wherein the processing comprises at least two distillation steps. 
     
     
         39 . The method of  claim 35 , wherein the product is for human consumption or animal feed. 
     
     
         40 . The method of  claim 30 , wherein the planktivorous fishes or the bivalves are used as food. 
     
     
         41 . The method of  claim 30 , wherein the body of water is a eutrophic zone. 
     
     
         42 . The method of  claim 30 , wherein the body of water is an open farming system. 
     
     
         43 . The method of  claim 30 , wherein the planktivorous fishes are from a local aquatic trophic system. 
     
     
         44 . The method of  claim 30 , wherein the planktivorous fishes and the algae are parts of a naturally occurring trophic system. 
     
     
         45 . The method of  claim 30 , wherein the planktivorous fishes are selected from the group consisting of  Brevoortia patronus, Clupea harengus , and combinations thereof. 
     
     
         46 . The method of  claim 30 , wherein the planktivorous fishes are transgenic 
     
     
         47 . The method of  claim 30 , wherein the algae composition in the body of water changes seasonally. 
     
     
         48 . The method of  claim 30 , wherein the algae are of a size selected from the group consisting of greater than about 20 μm and about 20 to 200 μm. 
     
     
         49 . The method of  claim 30 , wherein the algae are fed to the bivalves at a rate such that the algae produced in the system is greater than when the algae is cultured in the system without the bivalves. 
     
     
         50 . The method of  claim 30 , wherein the bivalves filter algae of a size smaller than the algae filtered by the planktivorous fishes. 
     
     
         51 . The method of  claim 30 , wherein the bivalves are selected from the group consisting of pseudofeces-producing bivalves, filter-feeding bivalves, deposit-feeding bivalves, and combinations thereof. 
     
     
         52 . The method of  claim 30 , wherein the bivalves are selected from the group consisting of  Mytilus edulis, Crassostrea virginica , and combinations thereof. 
     
     
         53 . The method of  claim 30 , wherein the salinity of the body of water is selected from the group consisting of about 12 to about 40 g/L and about 20 to about 24 g/L. 
     
     
         54 . The method of  claim 30 , wherein the temperature of the body of water is selected from the group consisting of about 16° C. to about 27° C. and about 18° C. to about 24° C. 
     
     
         55 . The method of  claim 30 , wherein the planktivorous fishes are selected based on a factor selected from the group consisting of the lipid composition and content of the fishes, the feed conversion ratio, the growth rate of the fishes, and combinations thereof.