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Frog deaths in small pond (1 Viewer)

jpscloud

Well-known member
Following the severe cold last year and this year, my pond water turned bad, and I found frogs and plants had died and there was/is a sort of opaque look to the water which also really smells bad. The plants are water soldier, with a miniature water lily. The lily and some of the water soldier survived.

The pond is very small, about 6' by 3' and 2' 6" deep in the middle part. It has shelves where the water is shallower and in the deepest freeze there was about 2" of ice on top of the pond. It doesn't have a filter, as there are no fish, but I overflow it with a fountain trickle from the garden hose every couple of weeks in the summer to keep it fresh.

Last year I melted ice as often as I could by using a saucepan with hot water sitting on top of the ice to melt it, but I couldn't keep up with the really severe cold while I was out at work. I heard somewhere that it's better not to try melting the ice so this year I didn't, but the result is the same.

Does anyone have any advice, or is this an unfortunate reality with a small pond and the extreme weather we've had? The pond was wonderfully healthy for ten years, with a population of ramshorn snails, different kinds of beetles and skaters, damselflies and so on. It's really heartbreaking.

The ramshorn snails survived last winter, or at least some did. I'm not sure if any have survived this one.

I'm running some water in to effect a water change now that the temperature is above freezing, but I'm not sure if this is the right thing to do.
 
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It sounds like there might be rotting vegetation in the pond. If the pond is iced over, gases from anything that's rotting can't escape, both reducing oxygen levels and potentially poisoning the pond creatures.

Did you cut back the plants and remove dead leaves in the autumn?

It might be worth completely deicing the pond, remove any leaves and rotting debris, refresh the water as best you can, and maybe buy some new submerged oxygenators like one of the native pondweeds. They obviously won't grow now, but stay in leaf and will tick over until the spring comes. As long as the light can get through they should release at least a small amount of oxygen into the water.

I would definitely try and keep an area ice free though.

It is horrible to see an unhealthy pond, so hope you can figure it out. Good luck!
 
It sounds like there might be rotting vegetation in the pond. If the pond is iced over, gases from anything that's rotting can't escape, both reducing oxygen levels and potentially poisoning the pond creatures.

Did you cut back the plants and remove dead leaves in the autumn?

It might be worth completely deicing the pond, remove any leaves and rotting debris, refresh the water as best you can, and maybe buy some new submerged oxygenators like one of the native pondweeds. They obviously won't grow now, but stay in leaf and will tick over until the spring comes. As long as the light can get through they should release at least a small amount of oxygen into the water.

I would definitely try and keep an area ice free though.

It is horrible to see an unhealthy pond, so hope you can figure it out. Good luck!

That might be it - I haven't been as diligent with removing extra plant material that falls into the pond in recent years, I suppose. I didn't think there was too much though, and every summer I do a trawl of the bottom of the pond to take out some of the sludge.

I never thought of oxygenating plants though - that might just do the trick. Do you (or does anyone else) know what kinds are best for a small pond? I'd like native ones of course, but something that won't take over too much as I love the water soldiers too.
 
clean out the pond every year before spring. then there will be clean water for the frogs to spawn in. remove dead leaves etc.

I never know what to do about ice on the pond in the winter- some people say you don't need to melt or break it, other people say you must!
 
Yes you must break any iceover, if not for fish then just to keep it oxygenated.
 
I guess as there are no fish it is ok to break the ice rather than melt it? That would be easier to do on work days when I leave before 6.30 am. I can't think of a reason breaking ice would do harm to anything in the pond if there are no fish but what about hibernating frogs?
 
thats what I was thinking jpscloud.
my tiny pond is full of frogs, but it's iced over all winter and only just melted.
I couldn't break it it was so thick in december, and I couldn't melt it as the frogs would get a nasty shock.

hope they are ok!
 
If you leave something strong in the pond, like a chunky branch or small spade, overnight, you should be able to leverage up some of the ice without causing too much shock...

Obviously don't use an old dead stick though!
 
My local radio station did a piece on this today. Due to the amount of ice build-up on ponds this year, plants can't photosynphasis due to lack of light, and so the plants die and rot. the gas produced then poisons the frogs. the answer is to break the ice to allow the gas to escape.
Jackie
 
My local radio station did a piece on this today. Due to the amount of ice build-up on ponds this year, plants can't photosynphasis due to lack of light, and so the plants die and rot. the gas produced then poisons the frogs. the answer is to break the ice to allow the gas to escape.
Jackie

I actually saw some gas bubbles popping up when I investigated the pond. I've completed the frog death survey for this year - I hope I can keep the pond healthy next winter.
 
4 dead up to now!

Went out to the pond today and found 4 dead frogs-even though the water looks quite clear & fresh. My assumption was that, as it was iced over, they were forced to stay underwater/ice (which to my limited knowledge they are not designed to do??) and suffocated.
The gas theory makes sense but could they not have suffocated?
 
It's common to find dead frogs at ponds both in nature and in man made settings.

Best thing you can do is find a very small heater that will keep a few inches of the surface ice free and put leaves in the bottom of the pond. I would go with a solar powered unit and see if that works. Usually in winter there's not many leaves to block the sun anyway.

It's pretty normal to find frogs that died during winter though and you may find more in early spring.

As far as I can tell, having breeding places is more important to their survival than just about anything else.
 
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It's common to find dead frogs at ponds both in nature and in man made settings.

Best thing you can do is find a very small heater that will keep a few inches of the surface ice free and put leaves in the bottom of the pond. I would go with a solar powered unit and see if that works. Usually in winter there's not many leaves to block the sun anyway.

It's pretty normal to find frogs that died during winter though and you may find more in early spring.

As far as I can tell, having breeding places is more important to their survival than just about anything else.

I like the sound of a heater - I'll have a scout around and see if there is something affordable. I'm not sure about putting [more] leaves on the bottom of the pond though - doesn't that just add to the rotting vegetation problem?

I didn't have a frog death problem (that I noticed, anyway) in any of the 10 years preceding the last two severe winters.
 
I like the sound of a heater - I'll have a scout around and see if there is something affordable.

Try googling "tote box heater" - a do-it-yourself heater pond owners use in the US to keep a hole open in the ice. It's made of a plastic bin and a light bulb.

Helen
 
It sounds like there might be rotting vegetation in the pond. If the pond is iced over, gases from anything that's rotting can't escape, both reducing oxygen levels and potentially poisoning the pond creatures.

Yes you must break any iceover, if not for fish then just to keep it oxygenated.

Not quite sure to the complete validity of these points - all ponds and lakes, large and small, freeze here, generally for three months or more. Fish and amphibians, the latter certainly more abundant than in the UK, survive. Would there be reason for the same species in the UK to not survive?

As for removing vegetation, that is where many of the over-wintering creatures will be, especially the invertebrate life of the pool.

PS. I never break ice cover - you would need a pneumatic drill to do so and it would freeze again in moments anyhow.
 
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the frog population won't notice the loss from your few that died, for every 1000 eggs you only need 2 to survive to breed the following year.

jos is also correct in stating that you do not need to break the ice and what's more you should not break the ice.

breaking it actually does more harm than good.

next spring give it a really good clean out get rid of all the rotting leaves and muck, stick them in a pile within a meter of the side of the pond to allow some of the insects to re colonise. then make sure you have a good 6 inches of loam based pond compost covering the bottom, this gives the invertebrates some where to over winter but doesn't contain nutrients, which is what is causing your problem here.

it's too small to expect successful over wintering anyway as you need a 1 meter square which is 1 meter deep above the mud to make this possible.

one thing you could do now is get a pond aerator and stick an aeration stone in it, this will quickly help remove the gasses that are dissolved in it and help re oxygenate the water.
 
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