Aquaponic Gardening

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In light of the recent conversation surrounding worms in an aquaponic system and the potential of the introduction of contaminants, I had a discussion with Jim Rakocy about it.  After having visited my farm a couple weeks ago and meeting my dogs, horses and cats, Jim commented that in order to be absolutely Biosecure, that before entering the greenhouse we should wash hands and maybe even consider putting on coveralls in the greenhouse and when working around the plants and  system.  

 

The thinking behind this is that we all know that dogs for instance like to roll in certain things and what if theoretically, the dog rolled in some nasty e.coli laden poo, you pet the dog and presto, you just now transferred e.coli to your system.  Probably altogether possible and not too outlandish, but how diligent should we be with our systems to insure nothing can get in?  Really only enclosed systems can be that secure. One could never secure an open exposed  system with squirrels, possum and other rodents possibly and most likely visiting at night.  Ultimately it seems that enclosed AP systems can absolutely boast being the safest way to grow food as it can control sources of outside contaminants.  How does this compare to outside systems or conventionally grown produce.  Is our concern about e.coli in our systems perhaps a little too drastic?  Food has been grown for centuries in the dirt with all kinds of visitors and potential carriers exposing it to risks, yet when we hear of an outbreak, the point of contamination is almost always a human related failure at the processing level.  

 

Thoughts?  

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Replies to This Discussion

I feel it's a bit extreme.  It sort of goes into the the same category as people that use the anti-bacterial soap all the time.  Some studies have found that the body may not have as good of an immune system when it isn't exposed to "contagions" on a normal basis.

 

Unless you have a perfectly sealed greenhouse, you're going to have a risk of contamination...birds and bats love finding little holes in our buildings....even when you think they are sealed.  We also get mice, squirrels, and the occasional woodchuck finding their way into the greenhouse.

 

Even the USDA has an "acceptable" amount of mouse droppings that can be found in grain silos...which makes it way directly into the food supply.....

 

Nothing is pure.

"E. coli and related bacteria constitute about 0.1% of gut flora,[7] and fecal-oral transmission is the major route through which pathogenic strains of the bacterium cause disease. Cells are able to survive outside the body for a limited amount of time, which makes them ideal indicator organisms to test environmental samples for fecal contamination." Wikipedia.

It would seem that the likelyhood of ecoli spreading though aquaponics system would be limited to the instances you mentioned above. I would imagine that it is good enough to wash your hands and try to keep warm blooded creatures at bay. Short of a racoon pulling down its pants and doing its business in your grow bed, I don't think it likely that you will contaminate your system. 

I think an interesting question would be how long does it last outside the body and can it incubate inside the aquaponics  system. I hypothesize that it wouldn't based upon water purification methods using constructed wetlands that have shown to eliminate  e.coli and other baddies. 

 

I think the bad guys we should stress more about are water borne ilnesess. 

Salmonella can last for weeks outside a body, but thrive in anaerobic conditions and are less likely to survive aerobic conditions.
Sources of salmonella according to wikipedia article.
  • Infected food, often gaining an unusual color, odor, or chewiness, that is then introduced into the stream of commerce;
  • Poor kitchen hygiene, especially problematic in institutional kitchens and restaurants because this can lead to a significant outbreak;
  • Excretions from either sick or infected but apparently clinically healthy people and animals (especially endangered are caregivers and animals);
  • Polluted surface water and standing water (such as in shower hoses or unused water dispensers);
  • Unhygienically thawed fowl (the meltwater contains many bacteria);
  • An association with reptiles (pet tortoises, snakes, iguanas[20][21] and frogs, but primarily aquatic turtles) is well described.[22]
I would be more concerned about people filling their systems with river (or swamp) water instead of well water or at least rain water.  I'd hate to pick up some of the nasty stuff like giardia. (AKA beaver fever, and we're not talking about Justin, which may make you even sicker!)

LOL Rob, you are too funny!  I have to agree with you, it is like the hype surrounding antibacterial.  It reduces immunity and resistance.  If just healthy in general, I assume a system much like a body will boast better resistance.  

 

Miguel, great point about E.Coli verses Salmonella. I too think water borne illnesses probably pose a greater threat.   I don't know about those raccoons though.  I've seen them do some pretty nifty tricks!  

 

 

Aloha Gina

I got wore out with the conversation on how we would test for all the possible things.  I still think that is impossible and improbable.  The things that Rob and Miguel have said here make a lot of sense.  I work in a clinical laboratory doing microbiology and other laboratory work.  We deal with the E coli  and the other food borne bugs all the time.  Number one the optimum temp for these organisms to grow is 35 to 38 c so which is body temp.  They are not flourishing in our water.  As the guys mentioned the main source of these organisms is the fecal oral route.  Good hygiene is the only method that will keep these out of the systems.  I taught a course in Microbiology at the Univwersity of NE at Omaha to potential nurses.  When all the antimicrobial stuff came out I went out and bought 20 or so different bottels of antibacterial soaps and cleaners. I asked the class what they thought this would do to the bugs out there.  All they do is not kill the really bad guys and then we can not kill them when they invade our body.  But good food saftey practices is the answer to keeping our food safe.  Look at all the farmers in America and across the world.  How many outbreaks do you find.  Not that many compared to the number of farmers out there.  If you look at the cause of the Listeria in the cantalopes it was do to dirty machines.  Bad food safety practices.  We have to be vigilant but not insane.  . 

It doesn't seem like Dr Rakocy was too concerned about it.  He just suggested good food safety practices.  Wash your hands before you touch anything on your system,  I vote for him

 

My take on this is I agree with Dr.Racocy  in a greenhouse wash hands, clean outside clothing, I would also consider a boot wash inside the greenhouse, mainly for plant health . Keep animals out of the growing area (except the fish).  The water should be from safe source meeting EPA drinking water standards.

I tend to agree with Earl on this one.

It might seem a little over the top, but you'll find such practices are common place in commercial hydroponic operations, and many aquaculture operations.

If we're going to aim to promote aquaponics on the basis of "purity" by it's organic nature and growth methods, then we should aim to adopt best practices from the start, particularly in a "commercial" context.

Other often forgotten practices that are rarely considered are

  •  a complete ban on smoking
  • washing of hands for anyone that does smoke before handling of any plants
  • washing of hands after handling any diseased plants
  • washing of hands after handling any "potting" mixes
  • immediate removal and disposal of any diseased plant stocks
  • immediate removal and disposal of any harvest remnants/prunings etc

Most of the above relate to potential transmissions of mosaic viruses in particular, and/or other possible pathogens/contaminants, particularly those that might be contained in potting mixes.

I'd also advocate having a totally seperate area for

  • Seeding/potting
  • Produce washing/processing
  • Feed storage
Agree :-)

RupertofOZ said:

I tend to agree with Earl on this one.

It might seem a little over the top, but you'll find such practices are common place in commercial hydroponic operations, and many aquaculture operations.

If we're going to aim to promote aquaponics on the basis of "purity" by it's organic nature and growth methods, then we should aim to adopt best practices from the start, particularly in a "commercial" context.

Other often forgotten practices that are rarely considered are

  •  a complete ban on smoking
  • washing of hands for anyone that does smoke before handling of any plants
  • washing of hands after handling any diseased plants
  • washing of hands after handling any "potting" mixes
  • immediate removal and disposal of any diseased plant stocks
  • immediate removal and disposal of any harvest remnants/prunings etc

Most of the above relate to potential transmissions of mosaic viruses in particular, and/or other possible pathogens/contaminants, particularly those that might be contained in potting mixes.

I'd also advocate having a totally seperate area for

  • Seeding/potting
  • Produce washing/processing
  • Feed storage
Hey Rupert!  Seems like I haven't seen you in a while!     I agree on the greenhouse procedure.  Those that have them can absolutely practice safe handling practices that involve all of the above, hand washing, boot wash, etc.  However if we consider this from an industry wide perspective, we must consider outside exposed systems.  Look at UVI and other commercial systems that are completely exposed to the great outdoors.  I've seen systems with cats crawling all over the rafts and poised above fish tanks staring at fish, dogs running around, even goats!    Then surely there are little creatures that visit at night looking for a drink of water and that could be anything from squirrels, to possum, raccoon, and more.  What say about these commercial installations?  How can they ever offer the same level of bio security?  Can we then conclude that these outdoor installations only have at best the same level of food safety as traditional soil grown crops in a field and exposed to the same potential mammalian visitors?  Hmmmm?

All you say is true Gina... and as such I don't believe they offer any level of bio-security.... nor any real control over entry of contaminants... from animals, pests or pesticides etc...

 

Plus, by their nature... they're almost impossible to control environmentally....

 

Factors that work against the bottom line of profitability... and commercialisation... in the long run...

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