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Sanitation and cleanliness of an operation is critical to ensure Good Agricultural Practices (GAP) regarding food safety (Hollyer et al. 2012). This is important because as of 2018, the CDC estimated that each year, 48 million people get sick from a foodborne illness, 128,000 are hospitalized, and about 3,000 people die. If the aquaponics industry wants to become a larger part of global food production and the fresh-cut sector, it is critical to maintain a good reputation and positive public perception of food safety for both fish and plants cultured within the same system.
The largest food safety concern within aquaponics is the spread of zoonotic pathogens (E. coli, salmonella, etc.), which can be present in harmful quantities within the water. The contamination can happen from people contacting the water or from consuming plant leaves that have been in contact with the aquaponic water (Hollyer et al. 2012). Analyzing water and plant samples annually will help producers build a strong understanding of potential sources of contamination.
Prevention is the best tactic for biosecurity and food safety, which is why every aquaponics operation should have SSOPs (Sanitation Standard Operating Procedures) and follow the seven principles of HACCP (Hazard Analysis and Critical Control Point). SSOPs are written rules for food processing that an operation develops and implements to prevent any contamination of their tools or production space. HACCP dictates the maximum/minimum values to which biological, chemical, or physical parameters must be maintained at a critical control point to prevent food safety hazards. Examples of sanitation procedures to eliminate the spread of disease, pests, and food safety issues for both fish and plants include:
Annual pathogen and bacterial tests
Continuous improvements to SSOPs and HACCPs
Overall production space cleanliness and biosecurity
Proper food storage
Sanitation is especially important when considering that most aquaponics systems are recirculating, and what is normally done in recirculating aquaculture to treat sick fish cannot be done easily in recirculating aquaponics due to the integrated plant production. Therefore, a net dip should be present on-site to prevent the spread of fish pathogens through fish contact with a contaminated net. Virkon is one example of a fish-safe net sanitation product that can be applied to a net according to the manufacturer\'s instruction. Keeping tank rims clean of uneaten fish food is a simple way to reduce potential fungus and pest growth. Monitoring and maintaining feed quality will reduce risks associated with fish getting sick from ingesting moldy food.
Creating and following a detailed plan of how fish and plants are processed will drastically reduce food safety concerns. Fish processing requires producers to follow strict HACCP regulations and inspections, which is prohibitive to most aquaponic producers due to the amount of fish per harvest and overhead costs associated with fish processing. Therefore, many aquaponics farms will sell whole fish either live or on ice.
Fish processing regulations may vary from state to state. Plant processing will be regulated by SSOPs, which will include washing hands before harvesting or after touching water; washing tools in soap or diluted bleach solution; maintaining a clean harvest area; and cleaning rafts/grow media with disinfectants (soap, hydrogen peroxide, etc.) (Figure 23).
Potential hazardous foods (PHF) are foods that will spoil, causing food safety issues, if kept at room temperature for certain amounts of time (Busta et al. 2003).This would include both fish and plants (vegetables, microgreens, fruits) produced within aquaponic systems. Improper cooling of foods is the number one cause (>30%) of foodborne illness. Time and temperature are the two factors influencing food spoilage the most. Humidity of the storage environment and equipment will also impact food shelf life. Microgreens and sprouts are especially of concern when considering food safety, as they require no processing or heat- treatment prior to consumption and have a shorter shelf life, making them more susceptible to bacterial spoilage.
Utilizing education, training, and readily available information for employees about food safety practices is the best strategy for prevention. Signs reminding employees to maintain cleanliness can also help.
Additionally, educating employees on where the highest risks of food safety contamination can occur within any operation is key. Cost implications food safety procedure and compliance should be included within a budget.
Source: Janelle Hager, Leigh Ann Bright, Josh Dusci, James Tidwell. 2021. Kentucky State University. Aquaponics Production Manual: A Practical Handbook for Growers.