Market Overview:
This aquaculture ecosystem utilizes low RPM paddlewheels to control water flow rate and feed fish waste to algae to reduce eutrophication effects. For every ton of fish produced as much as 66 kilograms of nitrogen waste and 10.5 kilograms of phosphorus waste are produced. The waste feeds plankton and algae, and in excess can lead to blooms and then eutrophication and dead zones. Researchers have developed a method for reducing fish waste output using algal growth basins originally developed for wastewater treatment. In tests the Partitioned Aquaculture System (PAS) farmed catfish as the target fish and tilapia as secondary fish to consume algae that fed on waste, significantly reducing nitrogen levels.
Application Stage of Development
Aquaculture, waste treatment Prototype
Advantages
• PAS uses low-energy paddlewheels, reducing power costs
• Increases algal photosynthesis levels, potentially increasing the PAS carrying capacity
• Tilapia co-culture reduces potentially toxic bluegreen algae, allowing more populations of green algae
Technical Summary
PAS uses the concept of high rate algal growth originally developed for wastewater treatment to manage aquacultural byproducts that could lead to eutrophication. Tests have shown that ammonia nitrogen levels peaked at two to four ppm in PAS, a significant reduction from the over sixteen ppm when using a competing method at similar feed rates. The algae responsible for the reduced nitrogen also photosynthesize, recycling oxygen that increases the carrying capacity of the aquaculture farm. When a target fish is paired with an algavore like tilapia, it is easier for preferable green algae to flourish. PAS increases fish yields and decreases eutrophication potential, allowing for more environmentally conscious, efficient fish farms.
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Inventor: David Brune, John Collier, Arnold Eversole, Thomas Schwedler
Patent Type: Utility
Serial Number: 10/929,331
CURF Ref No: 2003-004