By RDBA Executive Director Annette Maggi, MS, RDN, LD, FAND
With limited land available for agriculture as well as heightened interest in conserving nature resources like water, new types of agriculture – both plant and animal – are emerging. As consumers become more savvy in their knowledge of these options, retailers are increasing product offerings from new agriculture methodologies. Today’s article explores one of these methodologies – aquaponics.
In aquaponics, fish are raised in concert with soil-less growing of plants. The fish waste provides an organic source of food for the plants, and the plants filter the water for the fish. This creates a dynamic system where both are able to thrive, without assault by pests or the addition of natural resources or pesticides.
Digging deeper, there are more complexities to the process. As a part of their waste, fish excrete ammonia. Bacteria are introduced into the system as a filter, converting the ammonia to nitrites and then to nitrates, the form of nitrogen that plants can use to grow. Mechanical filters use air bubbles to break up the size of fish waste particles, which is also used as a type of compost to promote plant growth. Oxygen must be added to the water for the fish, and fish feed is introduced into the system.
A key benefit of aquaponics is the continuous recycling of water, with estimates indicating 90% less water usage than traditional plant growing agriculture methods. Because the growing environment is completely contained and controlled, pests (think viruses, insects, weeds) cannot easily impact the plants or fish. Because they do not rely on weather patterns, hydroponic systems can be built anywhere, creating local food options.
Commercial production is what matters to retailers, as they are feeding millions of shoppers each week, and while there are some aquaponic farmers doing larger scale production, it is still limited in comparison to the total industry. Edenworks in Brooklyn, NY grows papaya, tomatoes, and root vegetables and sells caviar. Superior Fresh in Wisconsin offers salmon, trout and a variety of leafy greens. Oko Farms, also in Brooklyn, raises catfish, tilapia, crawfish, freshwater prawns, gold fish, koi, and bluegill as well as rice, lemongrass, mint, okra, peppers, spinach, beans, garlic, chamomile, tomatoes, and eggplant. Their products are sold on the farm as well as to restaurants. Chatterson Farms in Florida sells a variety of leafy greens, root vegetables, tomatoes, fresh herbs and Tilapia fish through farmers’ markets, home delivery in a consumer club and to local restaurants.
If you’re interested in learning more about aquaponics, USDA has information and resources available here.