Aquaponic Gardening

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I'm very concerned that e coli is being under evaluated as a potential containment.  Repeatedly I'm finding references to the idea that e coli cannot exist in aquaponics, but the references are circular and based on statements without substantive scientific backing, and I beg to differ. While there is evidence that e coli isn't a normal aquaponic component, the potential for cross contamination is still high, and according to University of HI, http://www.ctahr.hawaii.edu/oc/freepubs/pdf/FST-38.pdf (link isn't working right, help appreciated) there is still a potential for the organism to exist in an aquaponic system, although with competition for space with the positive bacterial it's ability to over-run a well maintained system seems to be limited.  If this particular concern is better addressed in a more complete study please direct me to it!  If aquaponics is to be proven safe, regular testing must occur in order to prove that this contaminant isn't in the system.  The tests are expensive, and require a UV light to guage the presence of e coli (with most the tests I've looked at). Is anyone currently testing for e coli?  Can anyone refrence a stronger scientific study for me?

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Coming from a culinary background, cross-contamination is the number one source of food borne illness, so putting HACCP standards in place would seem to be the course to take. I agree that for the hobbyist, the test costs are prohibitive, but if aquaponics is to be viewed as safe by consumers it will require a stronger footing in testing and proof with regard to potential contaminants. I'll search for Dr.Savidov's work off the school library (better journal access). As to avoidance, absolutely, but there are protocols that apply to food service and safety that must be carried into aquaponics if a reputation for safety is to be established and maintained, and I doubt many aquapons are consistently washing their hands as often as I do when I'm cooking professionally. (I'm serve-safe certified, and have deep organic produce (Whole Foods Market) segregation and handling experience).

Additionally, the tests I saw that need UV test specifically for e coli 0157





Kobus Jooste said:
I think testing for it is beyond the reach of backyard enthusiasts due to the type of technology required and the chance of confusing dangerous human strains with what I have often seen referred to "natural" fish strains of gut bacteria that is not harmful to humans. While I have not seen the issue addressed in any particular study that I have on file, I do think that some of the key issues regarding aquaponic production, safety and potential organic status was covered by Dr Savidov in two volumes produced by the Alberta crop diversification unit. I think, as with most things, you can have contamination if you do not follow good bio-control protocol. Open outside systems would never fly due to the risk of animals such as otter and mongoose and birds getting into the system. Bad human operator hygene my result in a system's contamination, but there is one of those fuzzy "in the back of my head" memories of seeing some reference being made that no case of human e.coli had ever been recorded from commercial aquaponic operations anywhere. Those guys would have to adhere to HACCP standards and should therefore test regularly for contamination. Have not heard of any of these systems failing the test as we regularly see recalls on other contaminated stuff these days.

If all is kept "correct", the only things in the system should be derived from fish, which cannot harbour salmonella or harmful human-type e-coli as far as I believe.
Daniel, Can you share some links and more information about the e. coli tests you have found?

Also, perhaps some links and more information about HACCP standards.

I expect most Backyard scale growing is treated little different than a backyard veggie garden and most of us (well at least myself) know little to nothing about the standards you mention and have experience in.
Dan, I suspect this was started by my blog post today, c'est vrai? I was basing what I said largely on what Kobus just pointed out - that E.coli can't live within the gut systems of fish, and that there have been no reported cases of E.coli from an AP system's produce. I also am not a trained chef, but it seems to me that just about anything can happen with you start introducing outside sources of harmful bacteria, i.e. cross-contamination. I know that some of the problems with the E.coli contamination was from the field workers hands, but wasn't the problem in at least one case also that there was splash-up from rain of manure that wasn't completely composted? If I'm wrong I'm happy to go into the blog post and change this. What are your thoughts?
Aloha Everyone
Testing for E. coli H7:O157 at least in the clinical microbiology lab is very involved. It would intail culturing with very special media. You would need special incubators and the like. When they say the water in a lake was tested for sewage they are testing for E. coli but the type that is normally in your gut. The pathogenic E. coli is not transmitted by fish as far as anyone knows. Salmonella (of which there are many species) is transmitted by fowl and turtles and other animals. I refuse to live in fear of these things if I use proper hygeine practices. :D :D :D I grew up on a farm in Iowa. We raised all kids of livestock.
We grew a garden every year. We canned food. We did not die of botulism because we learned the rules. In my adult life I have raised chickens, cleaned them, cooked them, and fed them to my family. I am sure I didn' t always follow the rules. We never got Salmonella. Think of the large amount of produce out there and the few cases of any of these problems. We need to use as much hygiene as we can. Wash our products and tell people to wash if you sell your products.
There is no real way to be totally safe and fear isn't going to solve that either. Inspections by the goverment are not going to solve the problem. They just said the other day on the news that the resturants are lucky if they get inspected once every 2 or 3 years. Just use say practices and enjoy. :)
This is actually a topic I'd been asked about by the restaurant owner that I took micro-greens to. I'd already asked Kobus and TC in private messages, but it had been on my mind already, when I read what you wrote I realized I wanted to initiate the conversation quickly in order to assure that specific resolutions have been determined, and that e coli was completely unviable in an aquaponic system. There have been numerous food borne illness outbreaks attributable to poor hygiene, or dirty equipment (specifically I'm thinking about sprouts that got people sick due to being sprouted in unclean drums). The problem of cross-contamination can occur at a large number of places, and it concerns me that if people believe a system is infallible against a specific thing, they tend to take more risks than are advisable with that thing. I don't think you should change what you're saying (or said), but the caveat of proper food handling at every stage in the process might be well advised. You must wash you hands after using the bathroom, or the litany of other activities that can contaminate food. I'm a food safety guy in the kitchen, and that's based on key hygenic practices and proper equipment maintence and cleaning. While aquaponics specifically limits bed cleaning, it strikes me as a potential danger zone, where the bacteria might get a foothold through someone using the bathroom and feeding their fish without taking a simple precautionary step. That's my concern. Proving e coli can survive in a system was proven by the Hawai'i testing, but the bacteria didn't rise to hazardous levels. When searching the term "e coli" on Murray's site, I found one mention of a dirty system with a dead fish in a stand pipe that led to toxicity, which leads me back around to maintaining your system well enough to identify an issue like that well before it's gotten to that level. I totally agree with Raychel, and thanks for the personal insight!!

Sylvia Bernstein said:
Dan, I suspect this was started by my blog post today, c'est vrai? I was basing what I said largely on what Kobus just pointed out - that E.coli can't live within the gut systems of fish, and that there have been no reported cases of E.coli from an AP system's produce. I also am not a trained chef, but it seems to me that just about anything can happen with you start introducing outside sources of harmful bacteria, i.e. cross-contamination. I know that some of the problems with the E.coli contamination was from the field workers hands, but wasn't the problem in at least one case also that there was splash-up from rain of manure that wasn't completely composted? If I'm wrong I'm happy to go into the blog post and change this. What are your thoughts?


Re:HACCP (Hazards Analysis and Critical Control Points) - developed by NASA, as an emulation of the level of detail which was taken on Nuclear subs for the Navy. After a lost submarine due to a pair of bolts that couldn't accommodate the stresses, the Navy put together a tracking and labeling program for all hardware on submarines. Every bolt, every washer, every nut, has an ID#. NASA did something similar with food for the astronauts to assure food safety, by looking at potential areas of contamination and focusing on those areas as critical control points. With food safety, these points include temperature as well as actual location. The time, date, and person preparing a product is clearly labeled, invoices are kept to track sources, etc. Additionally, its about working sequentially from the highest hazard food (chicken) to the lowest (fresh vegetable) in terms of physical arrangement. Understanding the hazards is one of the reasons that I never had a food-born illness incident from a kitchen I worked in, never, not one. I did accidentally give gluten to a customer who had Celiac disease (gluten intolerance), so I'm not claiming I'm the immaculate chef, but 25 years without one incident is pretty good marks, and it's because I work clean.

Food handling standards change constantly. The best way to stay up to date is to get food handling certification through the city and state, or through a private firm that offers similar courses. Serve-Safe certification is very simple, a two-day class with tests, and the certifications lasts for 5 years.


TCLynx said:
Daniel, Can you share some links and more information about the e. coli tests you have found?

Also, perhaps some links and more information about HACCP standards.

I expect most Backyard scale growing is treated little different than a backyard veggie garden and most of us (well at least myself) know little to nothing about the standards you mention and have experience in.
Great points, Dan. I have modified the blog post to reflect the need for proper hygiene. Thanks for keeping me honest :D
No problem Sylvia, just surprised (kismet) that we both hit the same topic in a matter of a couple of days. Whatever moves things forward!

OFF TOPIC - BTW - I think one of the ten tilapia is a different species. It's darker, it doesn't school, and its feeding behavior is totally different, it eats off the bottom rather than surfacing. All of them are eating well, comfortable and getting bigger every day. Thanks again!


Sylvia Bernstein said:
Great points, Dan. I have modified the blog post to reflect the need for proper hygiene. Thanks for keeping me honest
Fish are cold blooded... and can not produce e-coli.... nor can plants...

E-coli can only be trasmitted by warm blooded animals...

As such it is ALWAYS an introduced contaminant... proper hygene should always be observed....

In Australia & NZ... and I believe most other western countries,.,,, the sale of fish, in any form must be done with strict observance of the "cold chain"... and under a HACCP plan...

Similar restrictions usually apply to the sale of vegetable produce to the public... although perhaps not as stringently applied...

Anyone considering selling their fish and/or produce... even to local markets.... should seriously consider these aspects...

You are liable under most Food & Safety regulations...

As to whether or not e-coli can exist in AP system water... possibly if the water exists within certain temperature ranges, but doubtfully for any length of time... IMO...

Here's a couple of links...

http://www.backyardaquaponics.com/Travis/Aquaponics-and-Food-Safety...

http://www.backyardaquaponics.com/Travis/Safety.pdf
Nice reference material Rupert, thanks! I consider this issue resolved. E coli has to be introduced, and even when introduced (through cross-contamination) will have difficulty getting a foothold in a well maintained system.



RupertofOZ said:
Fish are cold blooded... and can not produce e-coli.... nor can plants...

E-coli can only be trasmitted by warm blooded animals...

As such it is ALWAYS an introduced contaminant... proper hygene should always be observed....

In Australia & NZ... and I believe most other western countries,.,,, the sale of fish, in any form must be done with strict observance of the "cold chain"... and under a HACCP plan...

Similar restrictions usually apply to the sale of vegetable produce to the public... although perhaps not as stringently applied...

Anyone considering selling their fish and/or produce... even to local markets.... should seriously consider these aspects...

You are liable under most Food & Safety regulations...

As to whether or not e-coli can exist in AP system water... possibly if the water exists within certain temperature ranges, but doubtfully for any length of time... IMO...

Here's a couple of links...

http://www.backyardaquaponics.com/Travis/Aquaponics-and-Food-Safety...

http://www.backyardaquaponics.com/Travis/Safety.pdf
Kobus, I think the goal of eventually creating a certifying group for aquaponics is a noble one.


Kobus Jooste said:
Sylvia, in another comment somewhere it was highlighted that there is a soil-based farming organisation or standards authority that controls the classification of "organic" status. Is it not therefore possible to bring in a similar group for AP, where standards are agreed upon for commercial production and a certification process put in place? Why bother with organic if we are never going to get it and the quality control questions are flying out there. Perhaps we can do with our own certification based on HACCP and ISO. That can even pip "organic", especially if the ISO is something like 22000 that is focused on HACCP and production amagement but also some environmental sustainability of the method.

Sylvia Bernstein said:
Great points, Dan. I have modified the blog post to reflect the need for proper hygiene. Thanks for keeping me honest
I work for a local river group here in Indiana and we have citizen volunteers sample for E. coli in the river and streams. E. coli is found in natural waterways from septic systems malfunction and livestock manure spills/runoff. I agree with the others that have posted about HAACP. The potential from contamination is really from ourselves. I won't go into detail about that program, since my experience is in testing for E.coli.

Although we use E. coli testing methods that are not as accurate or precise as a laboratory test, we use a method that has been tested statewide and compared to lab testing. It would be a good choice if you are merely interested in checking for yourself.

The method is fairly simple and only involves the supplies (growth medium and petri dish) and a basic egg incubator.

In this document, http://www.in.gov/dnr/nrec/files/nc-Riverwatch_Manual.pdf, page 66 describes the methods our volunteers use throughout the state of Indiana. My group specifically uses the Coliscan method, because we can count based on color, without any use of special lights or equipment (beyond the egg incubator). We use Micrology Labs for our supplies and have been very happy with the results.

I hope this helps :)

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