Water Quality and Food Safety in Aquaponic Fish and Vegetable

Production Systems

International Aquaponics Conference: Aquaponics and Global Food Security, June 19th 2013

1Bradley ‘Kai’ Fox, 1Clyde S. Tamaru, 2James Hollyer, 3Luisa

Castro, 4Jorge M. Fonseca, 5Michele Jay-Russell, and 6Todd Low

1Department of Molecular Bioscience and Bioengineering, CTAHR 2Department of Plant and Environmental Protection Sciences, CTAHR

3Department of Natural Resources and Environmental Management, CTAHR University of Hawai‘i at Mānoa

4College of Agriculture and Life Sciences, University of Arizona 5Western Center for Food Safety, University of California, Davis

6Aquaculture Development Program, Hawai‘i Department of Agriculture

Introduction • About me

– Aquaculture training – CTAHR Assistant

Specialist • About the talk

– Background – Research – Future

Challenges and Opportunities for Aquaponics in Hawai‘i

• Tropical climate, year-round growing season – Pests

• Outdoor: slugs (rat lungworm infection), mammals, birds

• Indoor: controlled-environment

Certifying Food-Safe Aquaponic Systems

• Initiated discussions with 3rd party certifiers – Challenges: GAPs CA-

focused • Concerns

– River verses system water

– Biofilters, fish manure, fish food, etc.

• Lack of science-based information

What is Food Safety?

• Preventing foodborne illness

• Recognizing responsibility – Food safety is about

people • Chemical, physical,

microbiological • Focus:

microbiological

Foodborne Illness • Human and economic

costs – U.S.:~$77B annually – Many factors involved

• Indicator microbes in irrigation water – Fecal contamination?

• E. coli: warm-blooded origin – Birds/mammals

(humans) – Fish are cold-blooded

Symbiotic Relationships in an Aquaponic System

Ammonia

Nitrite

Nitrate

Plant

Fish

www.vedicsciences.net

(excretes)

(NH3)

(NO2)

(NO3)

(Nitrosoma spp.)

(uptake)

(water returns)

www. gopaultech.com (Nitrobacter spp.)

• Aquaponics system water: – Irrigation – Fertilizer

• Uncomposted fish poop (manure) is purposefully and persistently present

• Water remains below plants in contact with roots

Challenges and Opportunities • Food safety

certification – Large vendors

• Third party certifiers – Audits based on

industry and science – “Auto-failure”

• Currently: USDA is unwilling to support food safety for aquaponics – Lack of scientific

information

Audit Criteria

• Questions weighted differently

• Growers: >85% • Example: raw manure

Colorado River Basin

• 1,450 miles long – 7 states – 30 million people

• Irrigates – 1.8 million acres – 90% leafy vegetables – Overhead irrigation

• Fish – 56 taxa – 100 invasive species

Current Study • CTAHR: Farm Food

Safety/Aquaponics Extension Programs – Funding: HDOA

• Duration: Jan. 2011-Jan. 2012

• Methods – Samples collected,

chain of custody – Samples submitted to

accredited laboratory – Data analyzed

Results: Aquaponic System Water From Multiple Farms

Results: Produce

• Tested: lettuce, beets, cucumbers, tomatoes, watercress, green onions, pak choi, and blueberries

• Pathogens: E. coli 0157-H7 and Salmonella spp.

• Negative

Results: Inputs

• Tested: Fish food (Silver Cup Trout Chow), bone meal, kelp meal, and Sustane®

• Pathogens: E. coli 0157-H7 and Salmonella spp.

• Negative

Results: Fish Muscle • Tested:

Aquaculture/aquaponic system water and raw fillet of culture fish

• Pathogens: Generic E. coli (water), E. coli 0157-H7 and Salmonella spp. (water and muscle)

• Water: Positive (generic), Negative (pathogenic)

• Muscle: Negative

Image retrieved from: http://www.menumagazine.co.uk/archive/oct2011/fish.html

Summary

• Preliminary results • GAP: use potable

water • Need science-based

variance for “auto-failure” in aquaponic water

Future

• Continued on-farm monitoring

• Diagenetix, Inc.: Smart-DARTTM Platform – Mobile, real-time

diagnostics • Industry audits

– Commodity-specific example: mushroom industry

Acknowledgements • Nelson and Pade and the University of Wisconsin • Robin Havlovick • Hawai‘i Backyard and Commercial Farmers • Kathy McGovern-Hopkins • RuthEllen Klinger-Bowen • Vanessa Lum • Lei Yamasaki • Hawaii Food and Water Testing Laboratory