IMPROVING AQUACULTURE’S VALUE THROUGH ENHANCED NUTRIENT MANAGEMENT

Terry R. Hanson*, David Blersch, Jesse Chappell, Daniel Wells, Tung-shi Huang, and Mollie Smith
 
Auburn University School of Fisheries, Aquaculture and Aquatic Sciences
203 Swingle Hall, Auburn University, Auburn, AL 36849 hansontr@auburn.edu
 

Interest in locally produced foods and sustainable production methods has increased dramatically in recent years, and for U.S.-grown fish and seafood "local" can translate to anywhere in the U.S. A national study conducted in 2003 found that an interest in healthy, safe, and fresh foods increased the likelihood of buying local foods. In addition, 40 percent of respondents to a 2011 trends survey conducted by the Food Marketing Institute cited knowing a food's source as a motivation for purchasing local foods. Consumers interested in "healthy, safe, and fresh" are likely to support aquaponics operations if their story is communicated to potential customers through effective marketing efforts.

In an international survey of aquaponics growers, Love et al (2015) found a significant relationship between sales of non-food products from aquaponics farms and the farms' profitability and suggested that aquaponics growers may want to explore revenue sources other than just vegetables and fish to enhance economic feasibility.

Farmers engaged in aquaculture make a significant investment in feed amounting to some 60 percent of overall production costs. Fish ingest the feed and then excrete some 75 percent of the total, which is often ignored or discarded. Developing an optimized system to utilize the fish waste as a way to generate additional income will improve the profitability of aquaculture and contribute to the industry's environmental sustainability.

This USDA/NIFA funded project links greenhouse production of tilapia and vegetables through the fish feed and fish excretion to explore possibilities of further use of these wastes to produce additional crops for food and energy.  Additionally, we are investigating the possibility of using solid fish waste to produce valuable bio-products, such as lactic acid via fermentation. Adding uses to produce additional saleable items can enhance the overall benefit value stream of the operation and reduce greenhouse fertilizer costs.

This project is also looking to validate food safety practices in combined fish-vegetable production.  At present, science-based, aquaponics-specific Good Agricultural Practices do not exist. There have been food safety concerns expressed by consumers about aquaponics produce, with concerns being more common among the high-end consumers who are more willing to pay premium prices. Concerns about harmful bacterial counts in the aquaponic water effluent, adequate testing and monitoring of bacteria, and whether bacteria from the fish production units would get into the vegetables is being addressed in this research. We are sampling for the presence of pathogens throughout the system. By scientifically documenting the presence or absence of pathogens and improving system bio-safety, we can contribute to the food safety goal of these systems.