Fish farming
is increasing to meet seafood demands.
Fish farming, or aquaculture, resulted in 40 percent of the seafood we ate in 2007, according to Time magazine. If the world's current demand for seafood remains the same, The U.N. Food and Agriculture Organization estimates that "an additional 40 million tons of aquatic food will be required by 2030." The United Nations also believes that wild fish are 75 percent overfished. In response to the continually rising demand for seafood, a variety of fish farming techniques and methods have emerged.
Recirculating Marine Aquaculture
The UMBI Center of Marine Biotechnology developed a system that filters and recycles simulated seawater and captures the methane emitted from fish waste as energy. This is a commercial method of fish farming that ships harvested fish to restaurants for use in sushi.
Cage Culture
A floating net enclosed by floating plastic pipe is inserted into a section of a pond. Young fish are placed in the pond and farmers feed the fish until they reach harvesting age. According to Steven Van Gorder, author of "Alternative Aquaculture Association Sells Small-Scale Aquaculture," this method works best for catfish and will produce enough edible fish for a family.
Greenhouse Aquaponics
This method of fish farming is beneficial to both plants and fish. The fish are placed in a swimming pool-size tank where waste water is drained off into gravel beds where plants, typically vegetables, are growing. The plants use the waste water as fertilizer and filter the water where it is circulated back into the tank where fish are growing. SoCal Fish Farms say that this method uses only 10 percent of water typically needed for growing plants and decreases the amount of water in fish farming as well.
