Sahib Punjabi's recirculating farm in Winter Park, Fla.
The United States needs better food systems, and it needs more jobs. Aquaponics, a relatively new type of urban food production model, can give us both—sustainable food and green jobs.
Currently, the U.S. imports about 85 percent of our seafood, a large fraction of which is produced in overseas fish farms, by a process called aquaculture. Another 10 percent is “domestic wild catch,” which is made up of seafood caught by U.S. fishermen (NOAA). The remaining 5 percent comes from U.S. aquaculture. As global wild catch declines, aquaculture is steadily increasing as a viable replacement, although some aquaculture operations are criticized for being sited in open water or rivers, where fish escapes, exchange of fish diseases between farmed and wild fish, and environmental pollution are of concern.
But there is a different approach to aquaculture that addresses many of these concerns: aquaponics. Aquaponics is typically land-based, closed-system farming that is designed with the principles of agroecology in mind— fish species and vegetable crops are raised together in harmony— because fish waste serves as liquid plant fertilizer and plants strip the water of chemicals that are harmful to fish.
Agroecology, a method for integrating biological systems into agriculture, is widely recognized as a potential solution for increasing farm productivity and environmental sustainability of agriculture. Olivier De Schutter, UN Special Rapporteur on the Right to Food, is strongly in favor of the agroecology approach, in which farmers create “complex farming systems that replicate the complexities of nature.” Read More >
Last week I had the pleasure of attending the 12th annual International Aquaponics and Tilapia Aquaculture Course in St. Croix at the University of the Virgin Islands (UVI). I was able to meet and learn from many wonderful people who traveled from about 21 U.S. states and 18 countries including Canada, Mexico, six Caribbean islands, Peru, Argentina, the United Kingdom, Nigeria, Singapore, and Saipan, a tiny island in the middle of the Pacific Ocean. Course participants ranged from commercial and aspiring farmers to backyard hobbyists, non-profit and international development workers, aquaculture extension specialists, academics, entrepreneurs, and investors.
Charlie Schultz, course instructor, harvesting basil
Throughout the week, the course instructors emphasized that integratedfarming systems, such as aquaponics, can be more environmentally sustainable, resilient and potentially more profitable than monoculture of either fish or plant species. Course lectures included tilapia biology, broodstock spawning, fry cultivation and growout, plant propagation and hydroponics, integrated pest management, system design, and commercial considerations. Field work followed in-class lectures for hands-on learning activities.
Aquaponics is essentially a method for boosting profits from aquaculture (i.e., fish farming) by capturing excess nutrients inherent in fish waste to raise plants as a secondary revenue crop. In this regard aquaponics borrows heavily from hydroponics — a method for raising plants in a soil-less, nutrient-rich water, but it differs in one key respect. Hydroponics is performed with microbiologically clean water where all inputs come from fertilizers, while in aquaponics “we keep our system dirty” says the course’s lead instructor and UVI professor, Dr. Jim Rakocy, repeating the mantra this leader in the aquaponics movement has developed during his 30 years of research. Read More >