The Garden Pond Blog

In case you haven’t looked at the comments closely the three most recent are particularly interesting and encouraging.

First, from Cliff:

“I put a post on the 25/02/10 reporting the dead frogs and the smelly pink water in my pond.

I decided to empty the pond yesterday (Saturday). I purchased a pump to make the job easier and faster.

On reaching the bottom of the pond I found more dead frogs but surprisingly a greater number of live ones.

I netted these out and cleaned out all the debris at the bottom of the pond.

I then washed out the pond with the hose pipe and then re-emptied before putting in the new water from my rain water butts (that’s good news! – J): this has only filled a quarter of the water needed to fill the pond as I was doing this the rescued frogs were jumping back into the pond even though they had been moved away to be near the fish pond.

This morning I have noticed a large number of frogs are now in this pond even though I have had to put a plank of wood up the side in case they want to get out before the pond is full of rain water.

Second from Nigel:

“Hi Jeremy, Good news! After all the gloom and doom felt in my household with the loss of our over-wintering frogs it was great to find 2 “live & kicking” ones in the pond this morning. Even better was finding a load of spawn – Nothing yesterday at all and full of life today! Nature can be both hard and wonderful at the same time. Regards, Nigel”.

And third, from Jacqui:

“Just counted 7 frogs in our little pond and there is more spawn:-).”

A picture from last night: looking down into the chamber of the German parliament, the Reichstag.

Somehow I can’t imagine the British parliament even considering using a German architect to transform the House of Commons (the Reichstag was re-designed by British architects Foster + Partners).

The building is truly inspirational – in every sense at the front line of modern history.

Oh, and why was I there? We were meeting to discuss the planning of the 4th international meeting of the European Pond Conservation Network, to be held in May in Berlin.

The EPCN exists to promote the conservation of ponds at a European level. Those of a more campaigning bent might like to look at the Pond Manifesto produced by the EPCN.

Steve comments:

‘…you have more information on this site than I have seen anywhere. Great !‘

Thank-you.

Ands asks:

‘Is it all from experience with your own ponds or gained from elsewhere ?’

It’s based on Pond Conservation’s research over the last 20 years, interpreting the work of other freshwater biologists (both those studying ponds and those investigating lakes and rivers), it’s based on our practical experience of making and managing ponds, and most recently it’s from starting to look carefully at garden ponds.

We’ve learnt a huge amount from the two ponds we’ve made in our garden and also from the Big Pond Dip that people started to help us with last year.

There’s masses more that, collectively, we can find out about ponds and their wildlife from garden ponds – I’ll keep you posted about new initiatives (and also the results of the Big Pond Thaw survey, and the 2009 Big Pond Dip results) as they come up.

Final question:

‘Have you any information on what plants would best be suited to this type of shallow wildlife pond.’

Will answer that later!

Is spawn laid on 25 February early? Well – it all depends where you are in the country.

This time last year I posted copies of a couple of maps which show roughly when spawning takes place.

You can see them here.

So if you’re in south-west England, south and west Wales or one the south coast – now’s when spawning begins.

If you’ve recently been living under a rock, you may not have seen the information about the launch of the Defra ‘Be Plant Wise‘ campaign.

The message is: Watch out for those alien pond plants!

If you’re wondering what to do about getting native plants for your garden ponds, see our advice here, which is to get plants from the wild – but remember you need landowner permission to collect common plants – and never collect in protected areas and nature reserves. A number of rarer plants are specially protected.

Oxygen measurements from the Abingdon ponds today are interesting [Click on the graph to see a clearer version].

They vary from almost completely de-oxygenated – and these are mostly ponds with big accumulation’s of leaves in quite deep ponds – to supersaturated with oxygen.

They show just how much ponds differ one from another, and how inappropriate one-size-fits-all management advice is likely to be.

At this time of year you would expect oxygen levels to be generally fairly high: and the supersaturated ponds are mainly those with abundant growths of plants.

Interestingly those abundant growths can be ‘nice’ mosses, as in Jeremy’s Old pond, or caused by thick (and unwanted!) growths of filamentous algae, as in Liz’s Pond.

So should we pull out leaves? Well, not necessarily – in my pond there are plenty of fallen leaves – which are good habitat – but the shallow water prevents a thick layer of oxygen accumulating rotting organic matter building up.

See the latest comment where Paula asks:

‘What’s the best way to enlarge my pond without disturbing it? I thought to make two ponds with a bog area between the two? Any other ideas?‘

Well, actually I don’t have a better suggestion and this is pretty much exactly what I’d do too.

Indeed, unless the pond is dug into a natural substrate, like clay, it’s probably the only practical way of extending the water area in a garden.

The bog area would be good – though not essential, as you don’t need a physical water connection between the ponds for them to work as a unit. Plenty of animals and plants using the ponds will be able to move between them without a wetland connection. One thing to be careful of would be to make sure the bog garden wasn’t a source of nutrients – make it with very low nutrient substrate (and avoid using peat aka destroyed wetland).

My only other thought is why stop at two!

This headline in The Times the other day made me sit up:

Angling Trust calls for cull of otters eating too much fish

Apart from the slightly infelicitous use of English (shouldn’t that be too many fish?), I can’t really believe anglers want to dispatch otters wholesale.

My experience of anglers is that they are mostly harmless folk who simply love fish. If there is a point of criticism its that maybe they sometimes love them just a bit too much.

And it’s understandable, I suppose, if you’ve spent a lot of money getting a good lake full of fish ready for people to catch, to be upset when an otter comes along and grabs your prize (and beloeved) specimens.

But I can’t help thinking that the headline probably wasn’t quite what the Angling Trust really meant to say. The Angling Trust is a respectable organisation that campaigns for anglers and does much good helping to protect rivers from pollution.

The article was meant to publicise their lobbying plans for 2010 – a worthy document but, like all such documents (our own at Pond Conservation included), unlikely to be your first choice for a bedtime read, unless you were trying to overcome a really long-term problem with insomnia. Maybe the headline was just a way of getting attention?

I checked the report – it’s online here – and the nearest it gets to the alarmist (and alarming) headline is to say that the Angling Trust will  ‘Lobby the Environment Agency for more funds to……..support the cost of fencing and other deterrents at still water fisheries to keep out otters.’

Sounds OK to me, and no mention of a cull – which is good news.

Here are the lastest oxygen levels in my pond and, just as important, in our neighbours Sally’s.

Sally’s pond is the green line: I began measurements there part way through the freeze, just before snow covered all the ponds.

Click the graph for a better quality image.

In Sally’s pond oxygen is always much lower. This has been really important to see because at times I’ve found it hard to believe quite how high the oxygen levels have been in my ponds. Sally’s pond has been an important reality check.

Sally’s pond probably has lower oxygen levels because the pond is quite deep, and has more organic matter using up oxygen.

In both my ponds you can see the clear effect of the snow – levels were high under the ice, especially in the old pond, but dropped fast once snow covered the ponds.

Oxygen levels bounced back quickly once the snow melted. The ‘bounce’ is highest in the old pond (the red and purple lines) and a little lower in the new pond – the blue line – which has fewer plants under the water.

Sally’s pond hardly changed during the cold weather – a slight increase as the snow melted, but I think this pond will always be quite low.

With the recent icing over (with no snow) oxygen levels in my ponds have risen again – often my old pond is off the scale as my dissolved oxygen meter only goes up to 20, and its often been higher than that in the latest freeze.

I still don’t know exactly why values are so high but I think the dense moss growth, producing oxygen under the water, and the shallow water are an important part of it.

Great Crested Newts get a lot of bad press.

The stock newspaper story these days about these beautiful animals is ‘newts get in the way of my school/hospital/grandmothers funeral’ (you can add your own deserving cause here which is stopped or disrupted, at great cost, by the animals presence).

Just search the sceptical press for the word ‘newt’ and you will see what I mean (see here and here). And I sometimes feel they do have a bit of a point – for £60,000 we could build 100 new high quality, clean and unpolluted in the Million Ponds Project. And a million pounds – well, that’s a lot of new ponds.

So it was good to see a bit of sympathetic (if sad) coverage of crested newts getting into a local paper following the report here of Sally’s dead Great Crested Newts in her Shropshire garden.

This short paean to newts is from the Shropshire Star.