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Angling for a Better Way to Farm Fish--And Vegetables, Too

Aquaponics fertilizes plant crops with bacteria-treated fish waste products. The plants return the favor by filtering the fish's water—and humans can eat both of them

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WASTE NOT:

Ferry scoops up a mound of compost containing beneficial earthworms. The relatively small amount of waste generated by the aquaponic greenhouse, be it filtered solids from the tanks, dead fish or wilted plants, is composted and applied to terrestrial crops elsewhere on the farm.....[ More ]

GERM OF THE IDEA:

The heart of the aquaponic system is a bacterial bioreactor that converts fish-generated ammonia to plant-friendly nitrate in a two-step process. The plastic "wagon wheels" inside the bioreactor [ inset ] house colonies of Nitrosomonas and Nitrobacter, the two types of bacteria that process the ammonia.....[ More ]

SALAD SOMEDAY:

Rafts of Bibb lettuce, one of many varieties of salad greens grown in Cabbage Hill's aquaponic system, float in a tub of fish-fertilized water.....[ More ]

RAFT OF ROOTS:

Ferry hoists a polystyrene "raft" of lettuce greens that floats in one of the tubs. The plants are grown hydroponically (without soil) so the roots dangle below the raft and draw nutrients directly from the nitrate-rich water.....[ More ]

IN THE LOOP:

In these tubs, flooded with water fertilized by fish waste, Cabbage Hill grows high-value food crops such as basil, lettuce and other leafy greens. The roots of the vegetables act as filters, drawing nitrates from the water so that it can be returned to the fish tanks, completing a closed loop.....[ More ]

FOOD FIGHT:

A net full of nearly market-size bass is much more volatile than one of fingerlings. Each of these fish weighs about 1.5 pounds (0.68 kilogram) and fights vigorously when caught. Whereas tilapia is the staple fish of aquaponics, more glamorous species like bass are often considered more desirable and can fetch higher prices from restaurant chefs and other customers.....[ More ]

FINNED FARMER:

Cabbage Hill's Kevin Ferry lifts young bass from one of the aquaponic tanks. The fish take about 11 months to reach market size from one-inch (2.5-centimeter) fingerlings, during which time they will have fertilized several rounds of vegetable crops.....[ More ]

RISING TO THE OCCASION:

Tilapia rise to the surface in one of Cabbage Hill's tanks. A consumer favorite, the hardy species, amenable to high-density living environments, lends itself well to aquaponics. As of 2006, tilapia was the fifth most consumed seafood in the U.S.....[ More ]

MULTITASKERS:

In the aquaponic greenhouse at Cabbage Hill Farm in Mount Kisco, N.Y., tankfuls of edible fish serve a dual purpose: They produce thousands of pounds of salable food fish each year which, as they grow to market size, excrete metabolic by-products that are harnessed to fertilize high-value vegetable crops.....[ More ]

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