Fish n' e coli

[Aaron]

I have been disecting Tanya sawyers amazing discussion on AP on a survival podcast (featured on this site). She mentioned that e coli aren't an issue in fish b/c fish don't harbor them in their digestive tract. Did I misunderstsnd her? True or false?

[TCLynx]

Fish don't carry the e. coli that are dangerous to people.  That doesn't mean that e. coli can't get into an aquaponics system (if you were to let chickens roost over the fish tank that would defeat the safety net that fish don't carry it.)

 

 

[Kobus Jooste]

It is a cold blooded VS warm blooded gut organism thing.  On a different note though, I got to thinking about AP systems and the bacteria they harbour the other day when I was clearing my gravel bed inlets of plant roots.  The PVC had plenty sharp edges and by the end of fighting with four inlets, I was pretty scratched and sliced.  That did not phase me until a few hours later when I noticed that everywhere that skin was broken, mild infection was setting in as the cuts were red and swollen.  Still not an issue - just grab the anti-bacterial ointment and the cuts are fine.  It got me thinking about the whole food safety issue and people living the "bacteria is bad" lifestyle.  Surely if a sample of AP water is used to start an agar culture it will go wild with all the beneficial guys we rely on.  I wonder how this will go down with trying to attain HACCP or ISO status.

[Aaron]

People can put "bad" e coli it in AP system with unwashed hands after bathroom (or letting chickens deficate in it) but can bad be seporated from good once introduced?

[TCLynx]

I'm not sure if they can be separated but perhaps out-competed  to the point of minimal danger.  Remember that most e.coli that people carry isn't highly dangerous and is all over most of our skin in small amounts.  However there are some strains of e.coli that do tend to make people very sick (these tend to come from feed lot beef in high concentrations.)  People with compromised immune systems are of course in more danger from anything.

 

Careful handling of produce (especially produce that is normally eaten raw) is important.

[David Waite]

Ammonia or fish poo will kill ecoli on contact period. My uncle raised catfish commercially for years and stated on numerous occasions that not one case of ecoli ever transmitted from the employees to the fish systems and back to the consumer in any aquaculture system in the US ever. Ecoli has transmitted to fish processing for obvious reasons, The lazy ass didnt wash after he took a crap. Farmed fish in the US has some of the lowest rates of samonilla as well. We should as a community really keep our systems clean and tout the benefits of these systems. On another note in the phillipines they put the chickens over their tanks to feed the tilapia and the fish love it. Not saying I would do it but they are doing it all over the third world. Had a hard time getting my wife to eat the lettuce after I peed in the tank to get things going hehe.

[TCLynx]

Well, I've never been terribly worried about the e.coli or salmonella being transmitted from the fish to people eating the fish since I don't know of anyone who eats sushi made of fresh water fish, no worries there.  Cooking kills both those pathogens.

 

Asian cultures have used manure heavily in aquaculture of millenia.

 

This is Aquaponics though and remember that most people don't cook their lettuce.

However, If you are loading your system with these pathogens and then eating lots of raw greens from the system, that is another matter.  Lettuce can suck up huge amounts of water into the plant and if it is heavily loaded with such pathogens, it could be dangerous.  I still don't recommend using untreated or un-composted warm blooded animal manure in aquaponics.  Sealing up the urine of a healthy person in a bottle for several weeks (or until the pH reaches 9) to let the urea convert into ammonia will kill off the e.coli that is generally present in any urine leaving the body through a natural opening.  Urine might be relatively sterile but not perfectly so.  Let the urea convert to ammonia and it becomes that smelly cleaning agent that people used before ammonia could be synthesized chemically.

[Aaron]

Wow! Great insight on this one guys! Thanks!!! Now I can start cycling in my toilet (kidding)

[Chi Ma]

And you wonder why it tastes like crap

[TCLynx]

Come on Chi, eat your fish poo....I mean veggies

[Gina Cavaliero]

Eeewww y'all!

[Theresa Baker]

I had something terrible happen. My ducks, normally never near my AP system, got loose last week, and I came home to find they had defeated the tight cover on my fish tank and swam in it... 

Of course, I immediately halted all harvesting in the greenhouse until I figure out what to do. Naturally, the plants are THRIVING from the duck poo, and there is no visible detriment, other than those scary INVISIBLE ones: Ecoli/and others.  I am just now starting my search to figure out what to do. I'm heartbroken. :(

Any suggestions? How in the world do you rid an AP system (which is, by DESIGN a bacteria Disneyland) of UNdesired bacteria? I feel overwhelmed right now.  Thanks everyone. 

Too bad ducks are toxic, the growth in the plants is amazing :(

TCLynx said:

Fish don't carry the e. coli that are dangerous to people.  That doesn't mean that e. coli can't get into an aquaponics system (if you were to let chickens roost over the fish tank that would defeat the safety net that fish don't carry it.)

 

 

[TCLynx]

Before you panic too terribly, any veggies that you will cook well, can still be cooked and eaten.

Keep in mind that e. coli is everywhere.  It is on all of our skin and in all of our guts (it's part of our natural digestion), there are probably countless varieties of e. coli and they only make us sick when we accidentally get them in the wrong place.  (if you have ever experienced a bladder or urinary tract infection, that is a likely example of digestive bacteria getting into the wrong place.)

Now I'm not sure what to tell you about the salad crops in your system but I believe you can have your system water tested for e. coli.  Though with birds, I'd probably also want to test for salmonella as well.  Is anyone in your family immune impaired?  Any really small children or elderly?  Those would be the groups most at risk of getting sick from a small dose of salmonella or e. coli.