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[WARNING] Shrimp and Pesticides

George Farmer

Founder
Joined
21 Jun 2007
Messages
6,741
It has become apparent that some aquatic plants may be treated with pesticides that may cause shrimp fatalities.

For more background information please read through this thread thoroughly –

viewtopic.php?f=10&t=19481

In summary it is suspected that plants imported from Asia are most at risk. This is due to the majority being grown outdoors in an environment that may be highly populated with pests.

Although by UK law, imported plants are not allowed to be treated with pesticides, the overwhelming anecdotal evidence suggests these plants are being treated.

Here is an extract from a message I received -

My suspicion is that the toxic compound is an insecticide, which has low vertebrate /plant toxicity, but is toxic to invertebrates at very low concentrations. It could be applied as a fog to the whole growing facility or it could be a systemic insecticide that is being sprayed onto the aerial portions of the plants (to eradicate aphids, thrips etc.).

I think this is a more likely option than an insecticide drench applied to water, but if environmental controls were very lax that might be a possibility. If the production facility was in a country where mosquito borne diseases (Malaria, Dengue, West Nile Disease) were endemic, you may be able to obtain water borne insecticides fairly easily, and residues would be universal in water supplies etc. allowing you to just drain the waste water into the nearest water course, sewer etc.

If it is a persistent systemic insecticide it might take a long time in quarantine to make the plant "shrimp safe", if it is a contact insecticide it would be a lot quicker and easier to clean the plant up.

If I was a grower and purely interested in producing a large volume of plants as cheaply as possible, and didn't have to worry to much about health and safety, treatment of waste water etc., I would use the cheapest persistent systemic insecticide I could find.

At the moment there seems to be no easy way to treat said plants, except for a long-term quarantine (up to 6 weeks) in combination with plenty of chemical adsorption media filtration such as activated charcoal/carbon. Even if this is done, if the insecticide has been up-taken by the plant; there is still a potential hazard.

If you keep shrimp and are receiving plants then our advice is to ask where they are sourced. If they are imported from Asia then speak with the vendor and try to ascertain what/if any quarantine measures have been undertaken. A thorough rinse under freshwater is apparently not enough to ensure any pesticides have been removed.

Bear in mind that many Asian-sourced plant suppliers are providing these plants at relatively low cost, and they have a valuable role in the marketplace. The trade-off is the potential for these plants to be contaminated. Whether or not it is the retailer's/supplier’s responsibility to ensure the plants are 100% shrimp safe goes beyond the scope of this topic. For any retailers out there that supply Asian plants; I would recommend providing some form of care sheet indicating the potential dangers and how to minimise them. Please also feel free to point them in the direction of this topic.

If you want to be more certain that your plants are not contaminated then consider purchasing plants from a known European nursery such as Aquafluer and Tropica. The trade-off here is that they are relatively expensive.

To minimise risk to zero then consider purchasing tissue-cultured plants grown in sterile conditions with no chance of contamination from suppliers/retailers such as Tropica 1-2-Grow and Anubias In-Vitro. Again, the trade-off is that these plants are relatively expensive.

With the rise in popularity of shrimp in the UK and elsewhere I believe this issue needs to be highlighted and I encourage you all to share the contents of this thread with shrimp keepers.

As the situation develops and we find out more information, this thread will be updated accordingly.
 
Thanks George.

A couple of comments, having been through this myself...

Firstly, whilst Tropica and Aquafleur produce good quality plants without the use of pesticides, I would say that it is always worth being cautious with all plants added to shrimp tanks, as there is always a possibility they may have picked up some sort of contamination during their passage through the shippers and retailers.

Secondly, I think if adding plants to an established shrimp tank then it's probably worth testing for toxicity using a 'sacrificial' shrimp or two, even after a good clean/quarantine. Move a couple of shrimp into a clean container with water from their tank, with some floating plants/moss/leaves to make them feel secure. Wait until they've adjusted to their new surroundings and are happily grazing, then add the new plants to the container. If there are pesticides on the plants then you should see the shrimp react quickly, swimming around in distress and possibly 'backflipping' within a few minutes. If there is no adverse response within a few hours then you are probably safe to add the plants to the main tank.

There used to be a video of the shrimp behaviour when exposed to these pesticide son Youtube, but it seems to have been removed.
 
Very informative and well written George. Nice work! Just out of interest, who was that supplied the pesticide info?
Also great input Tom, maybe we could try and hunt that video down as it'd be a great example of what to look out for. I think I can say this has been somewhat of an eye opener for a lot of us!
 
I haven't got any issue with asia imported plants and I always prefer them over other producers that sell emersed grown plants. George has anyone lab tested those plants to see if they are treated with pesticides? I don't have the patience to go and read all the thread.

Cheers,
 
clonitza said:
George has anyone lab tested those plants to see if they are treated with pesticides? I don't have the patience to go and read all the thread.
No, which is why I have been careful with my wording. It is also why there has been no 'naming and shaming' on our behalf.

However, if you do find the patience at any point to read the thread, you will see that the anecdotal evidence is very strong.

Since this matter has been highlighted I have been contacted by various reputable hobbyists, and one author, who also suspect the issue may lie with pesticides.

Even if it is not pesticides, there is obviously something amiss when adding some new plants to aquariums containing shrimp, and the cautionary advice remains very relevant.

I would also like to re-iterate my point that plants imported from Asia have a very important role to play in the hobby and this thread is by no means meant to discredit any suppliers of these plants. I regard it as my duty to the UKAPS membership for communicating these potential risks, which is why this thread was created.
 
There might be also a contamination in the vendor's tanks or an unfortunate coincidence. A lab test I think it's more appropriate to dismiss or confirm it otherwise we are just spreading unfounded rumors. As time passes I tend to be more skeptical what people say. As I said there were no issues here with imports from Asia here in Romania, maybe some snails or algae but that's what you get from trading with hobbyists also.

Cheers,
 
Fair points, Mike.

However, with the sheer quantity of anecdotal evidence I feel obliged to point out the potential risks.
 
True mate, better buy from trusted sources. I do that just because I don't like to quarantine anything. When something new arrives I let other experiment with it first then if nothing happened I buy from them, it's like outsourcing a quarantine tank. :lol:
 
Hi all,
I'll need to do a little more digging, and then I'll run it by George first, but I think I may have found a/the potential pesticide. It is a compound that is widely used as larvicide for mosquito control (including in Singapore), and would combine being both persistent and highly toxic to crustaceans.

The other thought following Tony's earlier post would be "what are FERA/DEFRA treating the plants with when they arrive in the UK?" It may be the fumigant they use that it is the problem, rather than a contaminant that arrives with the plants.

If it is something that happens at UK customs, that would explain why Mike hasn't had any problem in Romania, and if not every imported plant is treated it could account for a "patchy" kill.

cheers Darrel
 
Can someone PM me the name please?

I was going to add some shrimp to my riparium and my plants are from various sources. Mostly aquafluer but a few others mixed in.
 
dw1305 said:
Hi all,
I'll need to do a little more digging, and then I'll run it by George first, but I think I may have found a/the potential pesticide. It is a compound that is widely used as larvicide for mosquito control (including in Singapore), and would combine being both persistent and highly toxic to crustaceans.

The other thought following Tony's earlier post would be "what are FERA/DEFRA treating the plants with when they arrive in the UK?" It may be the fumigant they use that it is the problem, rather than a contaminant that arrives with the plants.

If it is something that happens at UK customs, that would explain why Mike hasn't had any problem in Romania, and if not every imported plant is treated it could account for a "patchy" kill.

cheers Darrel
Fascinating. Thanks, Darrel.
 
George Farmer said:
However, with the sheer quantity of anecdotal evidence I feel obliged to point out the potential risks.


and so you should...a very good post George. :thumbup:
 
ianho said:
George Farmer said:
However, with the sheer quantity of anecdotal evidence I feel obliged to point out the potential risks.


and so you should...a very good post George. :thumbup:
Thanks mate. Feel free to share on TFF... 😉
 
Interesting Darrel thanks for sharing. Yes you are right, the plants arriving here are not treated what so ever, in fact I don't really think the packages are even scanned. When you take them from customs you have to open them though in front of them, don't think ahead that they are checking them for drugs :lol: they just wanna know the items on the invoice are the same with the ones in the package, for taxing reasons. 🙂

Cheers,
 
Hi all,

I arranged the initial post of this thread to be posted on the PFK Forum by their admin, as I believe this issue needs to be made aware to as many shrimp keepers as possible.

Here is an interesting post from their pinned thread, from "Somerset Sam". This use of bi-carb of soda is news to me, and if it works is a very low cost option.

Daphnia make for a useful indicator species for arthropod targeted pesticides if you don't want to sacrifice any shrimp.
Artemia would not make such a useful indicator species as they are much less sensitive.

It would make sense to test batches of purchased plants in a small tank (or bucket) with Daphnia with a high plant to water concentration, if any significant number die over a period of several days then you have a contamination issue.

As far as decontamination goes, providing you are not dealing with a systemic pesticide (which i believe would not be commonly used in semi/aquatic argiculture) the following actions would be sensible and not overly time consuming:

-Rinsing the plants very well under running water, obviously.

-Removal of any algal growth (if any) algae has a higher fatty acid content than many plant tissues, many insecticides are fat soluble, the algae is also the first thing that will be eaten in a shrimp tank.

-Removal of rock wool or any sponge-like material shipped with the plant.

-A quick rinse in a sodium bicarbonate solution will deactivate organophosphate insecticides, a quick dip and swill and make sure to rinse the solution off.

-A bath of micronized activated carbon suspension, to adsorb insecticides.

Activated carbon is not massively expensive and sodium bicarbonate is pennies, if treating a batch of plants the cost and little time involved mean a safe saving if you choose to buy the cheaper asian imports.

Link here - http://forum.practicalfishkeeping.co.uk ... ostcount=3
 
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