Aquaponics, worms and E. coli

[Kobus Jooste]

I have been made aware of a section in the latest newsletter of an aquaponics trainer making some rather interesting statements around the risk of introducing "deadly" E. coli HO157:H7 into aquaponics systems through the introduction of worms.

 

Like most promotional material, it contains enough reference to some form of correct base statement to make their argument appear compelling, but I have found the way that the section was written distressing in many ways.  On one front, we are trying our level best to ensure food safety and hygene in our units and to educate people on the safety of aquaponic production methods.  To have someone from within the community write something down the line of "if you dare put worms in your system you run a very real risk of introducing a deadly pathogen into aquaponics" is not conducive to building a fair and realistic impression of aquaponic production methods.  Worms in media beds have been in use for many years outside of the design of the group in question, with no reports of any health issues.

 

The inference made was that (without stating how many worm growers use cattle poo) red wrigglers are likely or potentially all grown in manure from corn fed cattle and this all contains the "man made" (?????!) strain of E. coli that will then most likely survive the transfer from worm to your system where you will contaminate your crops, your family or your customers.  If you are extra unlucky, a fly from a pasture containing corn fed cattle poo will also do the trick (then why bash the worms?) if they can make the trip in under 10 seconds. 

 

The article would have had more use if it simply said something down the line of "pick your worm supplier carefully - if you are cautious about E. coli, steer clear of using worm growers that cannot guarantee that their worms were not fed corn-fed cow poo from feedlots." I do not know what the ratio is of worm producers that potentially use this feed method compared to those that do not, but if it is the case that very few follow this practice, this article borders on reckless.  Then one can write follow-ups warning people on the next one in a gazilion risk such as a bird-flu contaminated duck landing in your fish tank.  As stated before, in theory, the conditions described in the text can potentially occur. Just as, in theory, a monkey can sit down in front of a typewriter, hammer away at it and write something recognisable. Not impossible, but likely? 

 

I wrote a blog a while ago about the responsibility of perceived role models in the industry related to statements made and perceptions created from a "credible" source.  This type of statement was exactly what I was talking about.  Not worth the negativety and not worth the potential bad press and poor PR for what many aquaponic producers see as a staple - media filled beds with worms in them (is there a reason for this?).  As a scientist, I would like to see some concrete evidence related to instances of the scenario described having been observed at worm farms and in aquaponic systems.  If no such data exists, is this statement fair and accurate? Why was it made? I do not want to appear to downright rubbish their concerns, but I will appreciate a percentage risk description to back up this claim.

[TCLynx]

I guess I'm kinda a compost whacko that way, just sort of assuming everyone would want to have a nice worm bin of their own.

 

If the source of the worms is reliable and you rinse the worms off, then all good.  Actually to me, I find the worm castings themselves to be great sources of good bacteria but yes that does take time.  As in you want to leave the worm bin with no new possibly pathogenic additions for like 4 months before you harvest and use the castings to be fairly certain that either the worms OR time has taken care of things like e. coli.  (4 months or 120 days being the with holding period.)

 

Come to think of it, I believe the worm bins at Growing power have that 4 month time period as well from when they stop adding anything to the bin to when they harvest the worms/castings from the bin.

 

I don't believe that e. coli multiplies in a compost bin, if it did then no amount of time would make compost safe to use. 

[Kobus Jooste]

Rebecca: I'm sorry but I am not so sure about that response.  The two scenarios do not match.  I read their newsletter (I'm on their mailing list).  There was no mention of students buying stuff off Craiglist, and the example you just put forward does not mention if there was any issues developing in the system after the Craiglist worms were added.  I'm glad they are addressing the issue though but once you hit send in the digital age, you are stuck with what pops up on the other side.  That goes for all of us.

Rebecca B said:

Susanne wrote a special newsletter:

 

"Based upon emails we've received, there seems to be some confusion in the minds of some who read our last newsletter. Here's our clarification: we are NOT saying that adding earthworms to an aquaponics system is dangerous, or even detrimental. Quite the opposite; earthworms, properly sourced, are a tremendous benefit to aquaponics Systems, and perform an essential role in systems that do not have gammarus. 

Our concern is motivated by the actions of one of our students, who recently added a media bed, and then purchased earthworms, castings, and compost combined in a gallon Ziploc bag from an ad on craigslist, and then, unthinkingly, put it directly into his aquaponics system. Earthworms can perform a useful function as mineralizers in aquaponics systems, but the compost that contained the earthworms, in this case, is of an unknown source and composition."

[Rebecca B]

The Special Edition Newsletter #5 Susanne wrote came 10/9---5 days after the #55 newsletter Tim wrote.

In a perfect world, the reason for the original newsletter would have been made clear---as in Susanne's statement "You can go either of two ways here: you can assume that a potentially dangerous thing is safe without requiring proof; OR you can assume that a potentially dangerous thing is dangerous until you can PROVE that it's safe. We want to stress that the compost and its potentially dangerous contents are what we fear, not the worms independent of questionable compost."

The upside is that the forum discussion has brought out lots of very thoughtful and informative responses. I've learned a lot, but I still wonder what should be done about worms populating the system on their own, or guarding against that fly who just came from some fresh and diseased manure.

There is no mention whether the student suffered any disastrous consequences, but maybe that's not known, yet. And is really a moot point to the warning being given.....

Which can be enlarged to include our sourcing from any unknown/wild environment. Ex: My first fish were caught in the river. The price was right and the fishing was a pleasant afternoon, but they came with fin and tail rot---and who knows what else. They died, and I gained experience in treating with salt, and the garden got some fertilizer. Which probably should have been hot composted first for 120 days!

[Sylvia Bernstein]

Not a whacko...or at least you are in lots of company!  I can't imagine why they wouldn't want to have one too! 

TCLynx said:

I guess I'm kinda a compost whacko that way, just sort of assuming everyone would want to have a nice worm bin of their own.

[TCLynx]

I'm totally the Whacko that cruises the neighborhood steeling everyone's bagged leaves that they work hard to rake off their lawn and bag up to put out by the curb and I gleefully take them and dump them on my yard in an attempt to avoid a lawn.

I think most compost whacko's wear the term whacko as a badge of honor

[Sylvia Bernstein]

LOL!  After having meet you and seen your place I can absolutely picture that, TC.  You should be proud.  It is like my 16 year old son who describes himself proudly as a computer nerd.  It is the nerds and whackos that will inherit the earth, I say!

[Earl ward]

I guess I’m a bit of a wacko myself; here everyone blows the leaves to the side walk. The city then come by and vacuums them up. Not on my block I go out with a leaf vacuum suck them up and send them through the pellet mill to make pellets to try and heat the greenhouse in the winter.

[Raychel A Watkins]

[Raychel A Watkins]

[Sahib Punjabi]

Well said Rebecca :-)

 

Unfortunately we all often jump to conclusions and forget to take into account why the statement or warning was made. It is often just to easy to shoot the messenger if we don't like their message (:

 

Just in case you are not on the e-mail list or did not get a chance to read the e-mail Rebecca mentions, I have attached a link:

Friendly Aquaponics Special Newsletter

Rebecca B said:

The Special Edition Newsletter #5 Susanne wrote came 10/9---5 days after the #55 newsletter Tim wrote.

In a perfect world, the reason for the original newsletter would have been made clear---as in Susanne's statement "You can go either of two ways here: you can assume that a potentially dangerous thing is safe without requiring proof; OR you can assume that a potentially dangerous thing is dangerous until you can PROVE that it's safe. We want to stress that the compost and its potentially dangerous contents are what we fear, not the worms independent of questionable compost."

The upside is that the forum discussion has brought out lots of very thoughtful and informative responses. I've learned a lot, but I still wonder what should be done about worms populating the system on their own, or guarding against that fly who just came from some fresh and diseased manure.

There is no mention whether the student suffered any disastrous consequences, but maybe that's not known, yet. And is really a moot point to the warning being given.....

Which can be enlarged to include our sourcing from any unknown/wild environment. Ex: My first fish were caught in the river. The price was right and the fishing was a pleasant afternoon, but they came with fin and tail rot---and who knows what else. They died, and I gained experience in treating with salt, and the garden got some fertilizer. Which probably should have been hot composted first for 120 days!

[David Waite]

I too got both letters and have read this discussion. I dont see anyone shooting the messenger, just the message. If you are going to guess on what might happen then state that. The first letter made the assumption that you should shy away from worms. The second letter did an about face and clarified due to outcry I think. If you are going to guess what might happen and put it out in this community then say so. If you have hard facts then by all means put it out as well. I am GUESSING, that you can take any worm in any compost pile and wash them off and be safe. My facts on this are well lets see about 2000 systems all over the world and no word of Ecoli contamination. That people is a fact.

Sahib Punjabi said:

Well said Rebecca :-)

 

Unfortunately we all often jump to conclusions and forget to take into account why the statement or warning was made. It is often just to easy to shoot the messenger if we don't like their message (:

 

Just in case you are not on the e-mail list or did not get a chance to read the e-mail Rebecca mentions, I have attached a link:

Friendly Aquaponics Special Newsletter

Rebecca B said:

The Special Edition Newsletter #5 Susanne wrote came 10/9---5 days after the #55 newsletter Tim wrote.

In a perfect world, the reason for the original newsletter would have been made clear---as in Susanne's statement "You can go either of two ways here: you can assume that a potentially dangerous thing is safe without requiring proof; OR you can assume that a potentially dangerous thing is dangerous until you can PROVE that it's safe. We want to stress that the compost and its potentially dangerous contents are what we fear, not the worms independent of questionable compost."

The upside is that the forum discussion has brought out lots of very thoughtful and informative responses. I've learned a lot, but I still wonder what should be done about worms populating the system on their own, or guarding against that fly who just came from some fresh and diseased manure.

There is no mention whether the student suffered any disastrous consequences, but maybe that's not known, yet. And is really a moot point to the warning being given.....

Which can be enlarged to include our sourcing from any unknown/wild environment. Ex: My first fish were caught in the river. The price was right and the fishing was a pleasant afternoon, but they came with fin and tail rot---and who knows what else. They died, and I gained experience in treating with salt, and the garden got some fertilizer. Which probably should have been hot composted first for 120 days!

[Kobus Jooste]

OK everyone - I can see where this is headed.  Statement made, follow-up published, and then the opinions of people that have read it.  If you are happy with all that were written, that is your business to be so and I'm not going to try and polarise people here.  Sahib - your desire to defuse such situations is legend and I will respect what I read between the lines here too.

 

That said, just a final question:  The scenario was sketched of a student buying worms from Craiglist, precipitating the need to warn all about the dangers of poo produced worms.  However ill-conceived a person may have tried to get the message across, why on earth not tell it like it is?  No mention of the student, no mention of Craiglist, no mention of the source of the worms, and no mention of the outcome of the whole event that precipitated the need for the warning.  I read it carefully as the person that drew my attention to it had a different interpretation to my response thus I was careful about reading it more than once.

 

Worms need to be bought somewhere.  We (almost) all put worms into media beds if we have those.  There are no records of the bacteria in question ever showing up in an AP system anywhere.  I have never seen a record of E. coli contamination in AP, traced to worms in media beds for that matter too.  What I have seen though, is a prominent member of this forum adding media beds with worms into her commercial system and terminating her training affiliation with the people that then almost instantaniously had the warning go out about worms in media beds. Funny that.  As I said before, I am not trying to polarise people, but I will be vocal when I see misinformation and I will keep an eye on how this whole episode shakes out.  I see it as a potential looming spat between two different design philosophies and if that is the case, this will not be the last of this type of event.