exo
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Posts: 60 
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Post by exo on Mar 14, 2017 18:23:41 GMT
Hello, wondering if anyone can help me on any of these things ... This is mainly to do with what to do to not kill most of the tadpoles...but also dragonfly & beetle larvae. Loads of frogspawn is laid every year in my koi pond settlement/filter add-on 'bay', I'm already overfull & there's probably more on the way. Seems there's less & less 'urban' ponds, natural or otherwise around (at least around here) these days, I think possibly those that do exist may be getting an ever increasing 'amphibian catchment'.   This bay (6ftx10ft by 1.5ft deep) has a 100W pump running in it, & so far this year the pump has killed two frogs already, they get pulled into/onto the pump's 'wildlife friendly' casing & die, probably quite nastily - like guts sucked out, legs chopped off etc. A large proportion of the tadpoles seem to get 'pumped' each year, but many survive that, & another proportion of those will get eaten by the fish - although the fact that I get a lot of frogspawn every year presumably means enough survive. If I was to take extreme measures e.g. huge fine net protection filter for the pump (actually thinking of using a fishing keep-net), I reckon I could stop the carnage, but wondering if it's the right thing to do, or rather what should I do... If I'm effectively breeding (i.e. selecting-for) those tadpoles that have certain characteristics - like not swimming very far from the place they were hatched, then I might be introducing a 'false' unatural dynamic in the local frog population - is this bad ? And if I did 'save' them all, I'd have far too many to be supported by the food availability, = possibly stunted growth, or weak frog poulation ? So I'd need to offload much of the spawn/tadpoles - but where to ... maybe the local 'village pond', is this legal ?, and anyway there's fish in there as well. Torn between just letting it all happen, or getting proactive about it, any suggestions ? |
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Post by rowanberry on Mar 14, 2017 21:26:15 GMT
I don't really know what to advise, Exo... although I have seen several reports in the news that frogs and toads are becoming seriously under threat recently. Our pond has way more frogs in it this year than it has previously, (with a lot more spawn in it) and I'm presuming it is because they can't find anyplace else to go. Last year I even scooped out some of the spawn to prevent overcrowding... and even then there were SO many tadpoles! I guess all we can do is look after them the best that we can, and hope that one day a neighbour will put in a pond and give them a new place to come to. After all, there have been several outbreaks of diseases that have decimated populations, so perhaps even if we seem to be creating occasional sporadic over-populating in some areas, it might help them overall. I know a lot of mine will probably not survive, but having too many will increase the chances of some making it in the end. As to your pump situation, I think your idea of wrapping it in some kind of netting might work... and I found this charity which are devoted to looking after the welfare of amphibians in the UK... if you contact them, they might be able to give you some useful tips: www.froglife.org/It's unfortunate that two died in the pump, but I found two yesterday in our garden that looked like they'd been killed by a fox or cat... (or rather mauled- one was still alive and I had to dispatch it.  ) It isn't nice, but it does happen, and I hate to think how many are killed by cars every year. BTW, that is an amazing pond you have! |
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Post by Tringa on Mar 15, 2017 9:36:58 GMT
I'd be tempted to net the pump, Exo. At least it would stop frogs being killed.
You raise some interesting points but I think(this is very much a guess and not based on any data) the impact of possibily artificially selecting for more sedentary tadpoles will be slight. We have had a pond for over twenty years and in that time it has had a number of variations -
no aeration, no pump and no goldfish,
no aeration, no pump but with goldfish,
aeration, pump and goldfish, and
aeration, pump but no goldfish.
During all of these years and variations we have always had frog (and sometimes toad) spawn. During the goldfish years (during which the five original goldfish became close to 30) we had very few new frogs. When we had the pump and no goldfish there were plenty of frogs. The pump wasn't very powerful and could not suck in adult frogs but did capture newts, and I assume tadpoles too, but I never found any dead tadpoles in it. We found netting the pump was the only way to keep the newts out - the cage around the pump was useless at prevent newticide.
Dave
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exo
Junior Member
Posts: 60
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Post by exo on Mar 15, 2017 17:14:51 GMT
Thanks for the link to froglife rowanberry,
interesting site, possibly I'll get in touch to see if they've got any advice.
Yeah, adult frogs get maimed by cats & even jackdaws sometimes in my garden, I've had to euthanise several.
Even found several semi-starved frogs in my cellars over the years, never sure if they recuperate properly after being returned to the pond.
Had a few 'red legs' & herpes affected frogs, but overall they mostly seem robustly healthy,
not sure if the ranavirus scare ever had the feared effect of frog population.
Anyway I think I'll go with the big keep-net around to pump, might be an expensive over-the-top solution,
but it's not as if the water-space that will be occupied is being used for anything else.
Wondering what do you do with the spawn you scoop out?
I must admit I cringe even more when I see a pump-maimed newt Tringa,
they seem to be able to get into those places even a frog can't.
Sounds like an 'all you can eat tadpole sushi-bar' for goldfish wipes them out completely,
luckily there's no fish in my add-on filter bay,
but I have to cover it in fine-mesh chicken-wire every year (about now)
to stop the blackbirds taking them all, & stop the sparrows 'playing' with them - as much as possible.
Thanks for the replies, I'll post a piccy of how the netting turns out,
just in case there's others out there with the same situation / concerns...
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exo
Junior Member
Posts: 60
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Post by exo on Mar 17, 2017 17:59:50 GMT
Yes, good point, entanglement in the net was something I wasn't sure about,
was hoping the rectangular metal loops of the keep-net would keep the micromesh taut enough to not have wildlife-capturing folds etc.
Time will tell I guess, hoping the result is an improvement over no net, but I wouldn't be surprised if I get a similar situation as you described.
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foxy
Junior Member
Posts: 61
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Post by foxy on Mar 17, 2017 19:17:27 GMT
Yes, good point, entanglement in the net was something I wasn't sure about, was hoping the rectangular metal loops of the keep-net would keep the micromesh taut enough to not have wildlife-capturing folds etc. Time will tell I guess, hoping the result is an improvement over no net, but I wouldn't be surprised if I get a similar situation as you described. Would some of that rigid plastic netting (sold in garden centres) not be better?  |
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exo
Junior Member
Posts: 60
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Post by exo on Mar 18, 2017 15:27:57 GMT
I've used that rigid plastic 'fencing' net in the past, mostly to keep parts of the pond volume seperate, not too bad, but a little difficult to manage (shape), since it wants to curl up if not kept taut, with bricks or whatever. I'm pretty sure it won't be a barrier to tadpole, and possibly not to frogs as ashgale has seen (certainly when they're still developing for first 'launch'). Thanks for the suggestion though foxy  Only took a couple of hours to get the micromesh keepnet in place, with plastic boxes with the bases cut out inside to give it strength  Will see how it goes... |
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Post by rowanberry on Mar 18, 2017 18:00:01 GMT
Exo, I know very little about pond pumps so am unsure as to the shape... but would it be possible to cut holes in a large pond basket to allow for tubes and put the pump inside that?
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exo
Junior Member
Posts: 60
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Post by exo on Mar 18, 2017 19:46:35 GMT
Great minds think alike rowanberry Yes, that's the way I had it set up for the past few years, i.e. the pump covered in an upturned largest basket available, with a hole cut in the top that just fitted the output pipe, plus filter wool blocking up any other minor gaps. That's what's just under the water surface, under the bricks in the first photos in this thread. But it prove to be fallible this year as it split under the fine material blockage & negative pressure, killing two frogs & very many tadpoles + some efts always did manage to get through somehow. I had bought some more & was going to go to two baskets joined top-to-top somehow (for more surface area) & also doubled-up inside each other (for strength), but possibly the keepnet thing seems more viable since it's got massively greater surface area & much finer mesh, so thinking it'll work better - I hope...time will tell |
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Post by Tringa on Mar 19, 2017 9:07:37 GMT
Good luck with your set up Exo. Having said above that the only way we kept newts out of the pump was by netting it, I've remembered we also had success with blocks of foam. I managed to fit some tightly around the pump intake and it stopped the newts getting in, but our pump was much less powerful than yours.
Dave
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exo
Junior Member
Posts: 60
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Post by exo on Apr 14, 2017 15:54:58 GMT
And now I think there's too many (?), but not seeing any tadpoles in the main pond due to being 'pumped over', which is quite a relief. Also supplementing the natural algae food with fish-food sticks to help them along, When they all hop it I reckon I won't be able to walk in the garden without being careful not to step on them ! Section of the bay, approx. 1/30th of the edge perimeter :  They certainly seem to be getting on well, chomping on the algae:  |
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Post by rowanberry on Apr 14, 2017 20:52:53 GMT
That's great! They certainly look like happy healthy tadpoles. Their water looks nice and clear, too. |
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Post by Tringa on Apr 15, 2017 6:50:06 GMT
Thanks is great, Exo. You've clearly got the conditions just right.
Dave
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) It isn't nice, but it does happen, and I hate to think how many are killed by cars every year.
