Pond Full Of Leeches

[Richb2004v2]

This is a strange request for advice. We have had a small pond for over three years and keep giant gourami, cat fish and three terrapins. A few months ago I did the regular clean of the pond and noticed quite a few leeches in there. I killed all the ones that I saw and thought nothing much more of it. That was about two months ago. Since then my wife has emptied and cleaned the pond and she mentioned the leeches too. I returned home from four weeks away yesterday to see one of the (rice field) terrapins looking almost dead in the pond. Today he was dead. When I checked him I found him to be covered in small leeches. The other two red eared terrapins still look healthy but on inspection I found them to have an infestation but to a lesser extent. We de-leeched them and put them in a separate pond. However I would now like to rid the pond of the leeches before I put the terrapins back. I have no idea how to do this other then emptying the pond and cleaning with boiling water. Even then the leeches may return from where ever they came from in the first place.

Any ideas or suggestions?

[Goshawk]

When I checked him I found him to be covered in small leeches

maybe they laid eggs somewhere in/around your pond that you failed to notice when cleaning before ? while you were away they hatched and attacked your terrapin ? Just a guess..

was surprised to learn that leeches are hermaphrodites, they have both female and male reproductive organs (although they don't have 'sex with themselves' )

[Richb2004v2]

When I checked him I found him to be covered in small leeches

maybe they laid eggs somewhere in/around your pond that you failed to notice when cleaning before ? while you were away they hatched and attacked your terrapin ? Just a guess..

was surprised to learn that leeches are hermaphrodites, they have both female and male reproductive organs (although they don't have 'sex with themselves' )

I wonder what I could use to either kill them or disinfect the pond without harming the fish? I remember that certain types of disinfectant could be used in reptile enclosures without harm i.e Savlon but not sure about fish. I wonder if a rinse with salt water would do the trick?

[Goshawk]

I wonder what I could use to either kill them or disinfect the pond without harming the fish? I remember that certain types of disinfectant could be used in reptile enclosures without harm i.e Savlon but not sure about fish. I wonder if a rinse with salt water would do the trick?

not sure about chemicals, even salt. i don't trust them.. the slightest reaction could be fatal for your animals / fish

what i would do is, assuming its a concrete or similar lined pond, first drain it.. then go round it with a blowtorch, passing lightly to and fro, over all the usually submerged areas (and a little bit above). This will kill anything either in hiding, bacterial or in egg stage.. After that, clean as you normally would, re-fill it and see how it goes from there..

[TBWG]

Hi

I am not sure if this will work but it worth a try as it is inexpensive and you will not need to empty the pond. Try putting lime in the water, I have done this in a pond which had Pla nin and Gouramis in with no ill effect on the wildlife.

The Thai translation for Lime is "white powder" (technical huh) it is readily available and was only 20 odd baht a kilo. It is commonly used it to kill bacteria when growing plants and veg.

Not sure about the effect it would have on Terrapins but they are easily removed.

Originally I used it to clear the water, but I was also told to use it when I emptied the pond to get rid of some voracious predator fish. A liberal amount was spread all over the gunge at the bottom to kill all the germs and bacteria, whether it worked or not I do not know, but there were no ill effects to the fish which I wanted to keep and were promptly put back in.

A word of warning not sure of the size of your pond but stand upwind when throwing it in!! I didn't and looked like a ghost!

Good luck

TBWG

[Richb2004v2]

Thanks for the advice. I will try the lime. The problem I have is that the pond has a small 'cave' like area set back which was originally to house a pump. The fish tend to gather in this small area and is difficult to clean and probably where the leeches held out last time. Anyway I will give it a go. The terrapins seem to be ok now ans are some where in the garden now.

Any idea what kind of outlet would have Lime? I have tried to explain 'huh' to my wife but she isn't clear what I'm talking about.

Does anyone else bother keeping terrapins and if so what type?

[TBWG]

Thanks for the advice. I will try the lime. The problem I have is that the pond has a small 'cave' like area set back which was originally to house a pump. The fish tend to gather in this small area and is difficult to clean and probably where the leeches held out last time. Anyway I will give it a go. The terrapins seem to be ok now ans are some where in the garden now.

Any idea what kind of outlet would have Lime? I have tried to explain 'huh' to my wife but she isn't clear what I'm talking about.

Does anyone else bother keeping terrapins and if so what type?

Hi

I buy the lime from the same place I buy fertilizer and insecticide spray for the garden, you know the usual Thai place that sells garden tools sprayers seeds etc.

Think it is called Baeng Khao .

see also http://www.thaivisa.com/forum/Stop-Pond-Wa...ly-t121425.html

Good luck

TBWG

[Gary A]

Source

http://www.state.me.us/dep/blwq/doclake/leech.htm

A measure which can be successful in controlling leeches is bait trapping. A metal can with a reclosable lid (a one pound tobacco or coffee can is ideal) drilled with small holes (depending on the size of the nuisance species) and baited with raw meat may trap large numbers of leeches from a heavily infested area.

After feeding, the leeches will have difficulty leaving the can. Destruction of the contents of the can will help in reducing the size of the leech population.

Ducks have also been used to control leech populations, but an over abundance of ducks can create other more serious problems. In order to keep ducks near your area for leech control they will also have to be fed. Duck feed is high in phosphorus and travels rapidly through the duck's digestion system. A readily available form of phosphorus is then added to the lakes. If the lake is small and the ducks numerous, enough phosphorus can be added to the lake to cause algae to grow. Ducks are also an intermediate host for a number of parasites that may not be desirable in a swimming area.

[geriatrickid]

Leeches lay eggs that are "hardy". The eggs are in a gooey cocoon that's hard to break. (The proper term is gelatinous, but this isn't like agar or conventional jello gelatin. I'd call it super goop.) According to one paper I just looked up, the eggs can survive repeated passages through duck digestive systems, so I reckon the ducks will only be good for control of an adult phase of the infestation and not be effective in removing the problem.

I think the recommendations about going after the 1st phase of infestation will probably be more effective in the long term, so back to the eggs. Eggs are attached to rocks, debris or the inside of that cave thing you describe. (Adults can be found in the mud.) Get rid of some of the debris, or de-egg it through soaking washes.

My hunch is that you identified the infection reservoir with that cave, and I bet you that thing holds the eggs that will continue to reintroduce the leech population. Isolate the cave and you will probably be 1/2 way to victory.

The only sure way to get rid of leech eggs is through dessication. If it's hot enough and not raining (yea, right) the sun can do the job for you. Otherwise, you have to do that blow torch method, which is good for other beasties too.

I saw mention of the salt water recomendation. Although it works for the adult part of the cycle, I don't think it's effective on the egg cycle. (Just my opinion - you guys know better, if it works for you.) On the use of lime; Is it regular lime or chlorinated lime (Calcium Hypochlorite CaCl2O2) or burnt lime/quicklime (Calcium Oxide CaO)? My texts refer to chlorinated lime. I mention that in case someone gets confused and gets the wrong thing. Mind you, the intent is for the lime to "chemically" dry out the place, so maybe it doesn't matter.

One last thought: Eggs can often be introduced by planting of new aquatic foilage, i.e. they hitchhike in. If you are planting new stuff, you will have to de-egg those plants.

Leeches have to be some of the creepiest things to deal with and I don't envy you.

Edited July 26, 2008 by geriatrickid

[lannarebirth]

If you have another pond to keep your fish in for a day, I think I would call someone to give your pond a hot water pressure washing. While the pond is empty cement closed the cave opening.

[Richb2004v2]

I have been fighting these leeches for the past few days. I removed the two terrapins and cleaned them up. Within hours of their release they both jumped back in and promptly magnetized an army of leeches. It seems that the leeches do not last very long when away from water. It takes about four hours away from water for them to dry out and either drop off or become easy to remove. I have now put the terrapins in a very shallow bathing pool I keep for my other two very big terrapins. I hope they stay there.

Some time in the next few days I plan on emptying the pond completely and removing all rocks etc. I will attempt to dry the pond and allow it to bake in the sun for as long as possible. Unfortunately the one time I need the sun and it has been remarkably cool here recently, but hopefully it will be enough. The cave/recess might be harder to dry but I will try to get some lime as recommended. I will also allow the rocks a longer period of time to dry for a few days. I am hoping this will do the trick. If I see any signs of their return I will try the ‘bait trap’.

I am not looking forward to going near the water. There must be a lot of them in there and some of them are tiny. I agree that they are absolutely disgusting things, kind of like animated blood sucking bogies.

[TBWG]

I have been fighting these leeches for the past few days. I removed the two terrapins and cleaned them up. Within hours of their release they both jumped back in and promptly magnetized an army of leeches. It seems that the leeches do not last very long when away from water. It takes about four hours away from water for them to dry out and either drop off or become easy to remove. I have now put the terrapins in a very shallow bathing pool I keep for my other two very big terrapins. I hope they stay there.

Some time in the next few days I plan on emptying the pond completely and removing all rocks etc. I will attempt to dry the pond and allow it to bake in the sun for as long as possible. Unfortunately the one time I need the sun and it has been remarkably cool here recently, but hopefully it will be enough. The cave/recess might be harder to dry but I will try to get some lime as recommended. I will also allow the rocks a longer period of time to dry for a few days. I am hoping this will do the trick. If I see any signs of their return I will try the ‘bait trap’.

I am not looking forward to going near the water. There must be a lot of them in there and some of them are tiny. I agree that they are absolutely disgusting things, kind of like animated blood sucking bogies.

I have the answer ....just put your foot in the water for half an hour...remove and pick off the critters!! alternatively rent someones leg for a few hours and go through same process.

Myself I'd favour the latter solution.

TBWG

[TBWG]

I have the answer ....just put your foot in the water for half an hour...remove and pick off the critters!! alternatively rent someones leg for a few hours and go through same process.

Myself I'd favour the latter solution.

TBWG

Well you have got me thinking now! What would happen if you dangled an uncooked chicken leg or any piece of meat in the pond, if it acts like a leech magnet then thats the way to go! save the leg.

TBWG