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RAUK - Archived Forum - Are leeches good for garden ponds?

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Are leeches good for garden ponds?:

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Baby Sue
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Posted: 14 Dec 2010

When it comes to de-weeding time and clearing leaves out of my pond IÆve always tried to kill as little lifeforms as I possibly can cos I donÆt like being mean and it ainÆt pondlifeÆs fault theyÆre stuck to weeds and slime and old leaves, it just doesnÆt seem right to just grab the contents of my pond and chuck it over the wall letting little lives die cos theyÆre out of the water. So I always go through it and remove water snails and other odd creatures but I have sh*t loads of tiny black leeches in my pond which are always stuck to old leaves and theyÆre a bugger to put back in the water. I shake leaves in the pond to get them to fall off but they do like to cling, also theyÆre hard to spot cos sometimes theyÆre very small. Usually I canÆt be bothered saving the lot of them because theyÆre literally stuck to everything in there, do other people try to save the lives of things in their ponds when theyÆre de-weeding? Or are leeches baddies and people donÆt like them in ponds? What do the frogs eat? Do they eat the leeches and like them being in there or do the leeches stick to froggies and pester them? I wanna know if I need to go to so much effort to not end their lives in future.

Baby Sue40526.5309953704
I wanted presents from lots of you. Snot fair that Ben Rigsby was the only one to send me Xmas & birthday presents.
ben rigsby
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Posted: 18 Dec 2010
hi sue,
firstly, all ponds (garden or otherwise) require some maintenance or they eventually clog up with weeds. so youre right to remove some aquatic vegetation from time to time. this is best done in autumn.
remove tree leaves whenever you see them though.

its great that you go to such trouble to search through the weeds and help all the invertebrates back in the water.
another approach is to simply place the vegetation on the ground right beside the pond for an hour or two and let all the little critters find their own way back into the pool. pond maintenance guides often recommend doing this.

as for the leeches, well common frogs dont feed underwater. i was surprised to read this fact which i only learned a few years ago .
leeches are too big and cumbersome for tadpoles to handle.

do you have newts in your pond too?
ive always thought leeches would be on the menu for THEM but despite often watching them "waving" openly in the water during Spring while adult newts are nearby, ive yet to see a newt ever attempt to take one. they seem to ignore them. quite unlike the reaction you get by throwing in a similar wriggly critter like small earthworm into the water. newts pounce on those immediately.
so i wonder if these small leeches have some sort of defence like toxicity so the newts leave them alone?
other members would know better than i. caleb?

in short, i think youre doing the right thing overall;
save a few where you spot them but dont worry unduly about the rest.

hope this helps,

ben

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Caleb
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Posted: 20 Dec 2010
[QUOTE=ben rigsby]i wonder if these small leeches have some sort of defence like toxicity so the newts leave them alone?[/QUOTE]

No idea on this one. Presumably they're able to bite back if they're attacked- maybe newts learn to avoid them?

I did wonder if Baby Sue's tiny black leeches might actually be planarians.
Baby Sue
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Posted: 20 Dec 2010

Hmmn, maybe. I just thought they were leeches cos they seemed a bit sucky onto things. The things in my pond look similar to this (but without wheels )

and are about 3 or 4mm long but can elongate when moving around and become right long to about 12mm.

I can start dumping lumps of weed by the side of my pond on a small tree stump I have, hopefully if I stack it high itÆll fit.

ItÆd be nice to think they could make their way to safety. Though one time I did do that and left it ages and came back when it was all dry to move it and found some dead pond snails in it. They mustnÆt have been able to save themselves. Do you think they were confused and just didnÆt know which way to go or did they suffocate on air before they reached the water?


I wanted presents from lots of you. Snot fair that Ben Rigsby was the only one to send me Xmas & birthday presents.
Caleb
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Posted: 21 Dec 2010
That's exactly what planarians look like (but without wheels).

As far as I know, they eat rotting matter in the pond, and don't do any harm to amphibians.

Your pond snails may not have been dead- they will sometimes seal themselves into their shells and revive when they get wet again.
Baby Sue
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Posted: 21 Dec 2010

Well the pond snails seemed to stay there for ages, I just presumed they were dead. I never checked on them much, much later to se if they were gone.  Next time IÆll study them better. ItÆs ace to know they donÆt suffocate when out of the water though, I didnÆt know that, I didnÆt know they could seal themselves in for long periods of time and come back to life later.

I have to remember the word planariun now. ItÆs long and fancy, bet I forget it in a few minutes. Well planariuns must real like my pond cos thereÆs plenty of rotting matter in there, IÆve loads of plant life rotting down right now. & they love the tree leaves, theyÆre always stuck to them. I still have loads of leaves in my pond even after two picking out sessions, keep thinking IÆll fall in leaning into the middle to get them. I hope I donÆt cos the neighbours on one side hate me and theyÆre always watching, bet theyÆd see and laugh.

Thanks for responding, in future IÆm gonna pile up everything I take out of my pond an leave it there for days or weeks ætil IÆm thoroughly sure everything has escaped.

Though at the golf course pond they pull out weeds and IÆve seen dead tadpoles in amongst that. I get very upset when I see theyÆve been de-weeding.


I wanted presents from lots of you. Snot fair that Ben Rigsby was the only one to send me Xmas & birthday presents.
ben rigsby
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Posted: 25 Dec 2010
definitely not leeches youve spotted then sue. calebs right - planarians.
they MIGHT have wheels underneath - personally ive never turned one over to look.

leeches, at least the ones ive got (by that i mean in the pond not on me) are around 1-2" long, light brown in colour and move with a very distinctive and wonderful undulating motion when swimming through open water. they can stretch out to more than twice their "resting" size. in spring i often watch them. at this time (breeding season?) they attach themselves to the pond floor and wave about frantically but intermittently, perhaps to attract a mate? i dont know.
your pond will probably have them so keep an eye out -
theyre very entertaining to watch.
garden pond leeches are harmless to man. only one UK species will suck your blood. that is the medicinal leech (hirudo medicinalis - i think). it is far bigger and very rare nowadays. you wont have those in your pond so dont be alarmed!

i know you dont like the idea of losing any invertebrates at all but youll never save them all. not with all the will in the world. many of them are too delicate to survive being grasped/handled too.

its much more important overall that your pond doesnt get choked with vegetation for the benefit of your main heroes (amphibians) eh?
newts especially, like a mixture of vegetated pond and open areas for their breeding rituals.
sacrifice the battle to win the war girl!

however, another method you could try is to take small clumps 1 at a time then shake the weed you remove vigorously in (pref) a WHITE bucket full of pond water. do this in good light. tiny creatures show up best against a white background. then tip the water back in the pond after.

thanks for showing the pic of your frogs.


benben rigsby40537.786712963
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ben rigsby
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Posted: 27 Dec 2010
dont worry about your pond snails suffocating in the air when you remove them along with weed.
many of the common species that inhabit the water column breathe air same as us. these are called PULMONATE snails.
they have a simple lung and come to the surface regularly to get a gulp.
you can see a hole open and shut when they do it.

here are two common species of these;



do they look familiar?

LEFT; Great Pond Snail
RIGHT; Ramshorn Snail
shown with a sprig of Hornwort

one group of pond snails DOES have gills however. the OPERCULATE snails. so-called because they have a LID which closes over the opening when the snail retracts into its shell. pulmonates dont have this.

theres less chance of you fishing these out accidentally though because they usually live on the pond floor or partially buried in the mud.

ben
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Baby Sue
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Posted: 10 Jan 2011

Do all ponds have leeches cos IÆm pretty sure there ainÆt nothinÆ bigger than planarians in my pond?

IÆve tried sticking pulled out weeds into a washing up bowl and shaking a bit and stuff does come out and then I can pour the water back in but it is true, you canÆt get them all. I wonder if my pond is too choked by plants? ItÆs pretty full but I leave a space of nothing (at the bottom of the pic), but frogs donÆt tend to go there, they seem to stick their heads out from where thereÆs plants in the middle (in summer). They have sex there too and bang into the plants a bit. I had grass growing over the water a year back and I gave that a good pulling out cos it was taking over but left some cos the smaller frogs liked sitting on it. IÆll take up-to-date photos sometime. This is from last May after I'd pulled out loads of grass, the yellow flowers ainÆt flowered yet but thereÆs about the same amount of plantlife in it.

Too much plantlife?

ThereÆs lots of hornwort under the water which I thin out but I can get rid of more of that if you think I should.

IÆve got a few Great Pond Snails but thereÆs tonnes more Ramshorn Snails. (YouÆre teaching me words ). ItÆs the Ramshorn Snails that end up entangled with the weeds when IÆm de-weeding. There shouldnÆt be mud on my pond floor BTW, never put my hand in the middle at the bottom but on the bottom around the sides itÆs just the plastic pond lining.


I wanted presents from lots of you. Snot fair that Ben Rigsby was the only one to send me Xmas & birthday presents.
Baby Sue
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Posted: 11 Jan 2011

This is what the frogs were sh*gging in last spring. The plantlife is a little more thinned out now but is it not good for frogs having it that overgrown?


I wanted presents from lots of you. Snot fair that Ben Rigsby was the only one to send me Xmas & birthday presents.
ben rigsby
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Posted: 16 Jan 2011
hi sue.

i dont know that ALL garden ponds have leeches. only that they are very common and i that i often see them.
they would be harder to spot in your pond perhaps.
it IS quite well-vegetated. but not excessively id say.


i should point out im far from an expert compared to many members.
i just know a lot more than the average joe in the street thats all!

but it sounds like your doing a good job maintenence-wise. if the frogs didnt like it they wouldnt be there.
how many years have you had them?

common frogs arent very fussy where they breed and will "shag" (as you put it! ) in puddles sometimes.
last year on my post round i even saw 2 frogs/spawn in a washing up bowl sunk into the ground in an urban backyard.
they panicked like crazy at my approach but had nowhere to much to hide apart from under a few leaves.
that was funny!

the latin name Rana TEMPORARIA reflects their here-today-gone-tomorrow breeding routine.
unlike other frog species that are far more aquatic and spend more time in water.

i cant see any cause for you to be concerned from what youve shown.
maybe you could thin it out a little more perhaps but thats just my opinion. its hard to know how much submerged vegetation there is from your pix.
im guessing that most of your plants are potted.
its good that youve got Hornwort too.

with ref to your Duckweed/ice query in the Help for duckweed sufferers post, few animals can survive been frozen solid. some can tho as i read on another thread about tree frogs here recently.
if they havent avoided the surface freeze then theyre probably dead anyway.
though im only speculating here. maybe its more common than i know.
as i said, no expert.

hope this helps,
ben


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Baby Sue
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Posted: 17 Jan 2011

IÆve lived in my house coming up to 3 years now and the woman before me put in the pond and she was there 3 years. IÆm only metres from the lake so the frogs have just hopped over from there I presume, I doubt she kidnapped any.

IÆve seen a washing-up bowl inset into the ground too. I thought about doing the same in my back garden then decided against it cos I havenÆt the room really.

IÆve got 3 potted plants (that the last owner left) and they sit on tree stumps submerged under the water.

Is lots of hornwort good? Cos I was thinking of de-clogging my pond a bit by not thinning it out but by creating more of an open space at one side. I.e. pushing the existing vegetation to one side/chopping a bit out and having it half clogged. Good idea?

You seen my dead frog pic from yesterday? It died. ItÆs the first death in my pond IÆve ever encountered before. Do you think thereÆs a chance all my other frogs are dead in my pond too? IÆve a whole family living in there all different ages. After the death in my pond I took my garden brush and put the handle end in the water to try and disturb the plantlife to see if any other dead frogs were underneath and would come up and found that the vegetation is really thick. I couldnÆt shake it around much cos it was so thick, deep and heavy, must be loads of plantlife in there, more than I thought. Do you think it was the gases from that that killed my frog or just the ice? I knocked a hole in the pond every few days, it kept icing over but I didnÆt let it go over 3 days without having a small hole in. Was the hole not big enough or does hole size not matter? Do you think it could have died of old age and my other frogs will be ok? If they are dead they could easily be trapped under the vegetation. Do hibernating frogs always go to the deepest part of ponds to hibernate or the sides? The dead frog appeared where IÆve never seen a frog before, down the side in the deep bit, I think it was in the middle at the deepest point then floated and moved and floated up to the top. From looking at my pic in the other thread how long do you reckonÆ itÆs been dead? It looked all slimey and horrible and like had a layer of slimy gunk around itÆs head.

I took this pic yesterday. The dead frog is at the side on the left about a foot from the frog fly swatter.  Hard to see cos my camera is cr*p.

PS. IÆm traumatised. If I am going to de-weed part of it I need an adult to do it for me cos I donÆt think IÆm going to be brave enough to put my little hands back in there, not if rotting slimy dead friends are floating around, they might touch me or I might grab one and yank it out thinking itÆs plant rootage. IÆm so scared about what lies beneath now, I donÆt wanna look.


I wanted presents from lots of you. Snot fair that Ben Rigsby was the only one to send me Xmas & birthday presents.
Baby Sue
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Posted: 17 Jan 2011

Oh and in summer frogs usually hide out around the sides of the bottom right plantpot/tree stump, I sometimes disturb them when IÆm de-weeding. ItÆs not as deep at that end though so I was thinking in winter they go to the far side/middle where all the plantage is. At the very bottom of my pic the water is about 15cm deep and you can see the plastic bottom, canÆt at the other side.


I wanted presents from lots of you. Snot fair that Ben Rigsby was the only one to send me Xmas & birthday presents.
Baby Sue
Senior Member
Joined: 19 Feb 2008
No. of posts: 412


View other posts by Baby Sue
Posted: 17 Jan 2011
 
I wanted presents from lots of you. Snot fair that Ben Rigsby was the only one to send me Xmas & birthday presents.
Scale
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Joined: 05 Dec 2010
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Posted: 01 Feb 2011
I read somewhere that small black Leeches form the main
diet of aquatic phase Great Crested Newts. I can't remember
where i saw it, who published it or how old the study was
though. I would think flat worms would be easy pickings for
all amphibians.
Baby Sue
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Joined: 19 Feb 2008
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Posted: 07 Feb 2011

I gave my pond a shake up on Saturday and tried shifting the plantage over to one side more, worked for a day but now theyÆve shifted back again, all IÆve done is disturbed a live frog and broken a couple of plants in the process. Also found a large stone at the bottom of my pond, dunno what that was doing there. Scary putting my hand in to get it out.


I wanted presents from lots of you. Snot fair that Ben Rigsby was the only one to send me Xmas & birthday presents.

- Are leeches good for garden ponds?

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