Jon Cranfield

Archive for the ‘the garden pond blog’ Category

further observations on the pond

In Garden pond, Observations, the garden pond blog, Wildlife on May 14, 2011 at 7:03 am

It is definitely amazing how the pond can attract so much wildlife. The pond is now considered to be on the lower end of the ‘excellent’ score calculated through the Big Pond Dip by Pond Conservation. I found darter dragonfly larvae in the warm shallows of the pond.

Other inhabitants include a large number of scavenger beetles and freshwater hydra – little anemone type creatures.

The pond also has a strong head of water fleas. The water is effectively buzzing with life.

It just goes to should how important ponds are. This pond is not even a year old and it has over a dozen animal groups or species within it.

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pond levels over the last few days

In Garden pond, Observations, the garden pond blog, Wildlife on February 13, 2011 at 2:10 pm
after the thaw the water level dropped

after the thaw the water level dropped

Water beetle Larva

In Garden pond, Observations, the garden pond blog, Wildlife on February 11, 2011 at 10:34 pm

Photo taken - 11th Feb 2011

The invertebrates in the garden pond are doing very well. The pond had low water levels up until two days ago when the rain filled the pond back up again. The new water levels bring the animals closer to the edge where these photos can be taken.

Using an inverted lens – holding it back to front these macro shots were obtained using a sunpak 4000AF flash and a head torch I managed to get this photo after dark

As I get to grips with the method I hope to get some more macro shots of mayfly larvae and the adult water beetles which are also in the pond – this may require capture and setting up the animals in a suitable container with dead leaves and pebbles for natural effect

Hanna Combo finally arrives!

In Garden pond, Observations, the big pond thaw survey 2011, the garden pond blog, Wildlife on February 11, 2011 at 6:16 pm

I have recently purchased a pH/Conductivity Meter as suggested by Pond Conservation. The meter enables a measurement of how much ‘pollution’ or ‘nutrients’ are within ponds which I visit. I have tested my garden pond and I plan to visit several water bodies around the town to see each of them compare. The river in our town is a chalk stream – assumed to be in pristine condition. However I feel that the meter will tell a different story.

Creating ponds according to Jeremy Biggs from pond Conservation is the best way to bring back clean water habitats to our countryside. I have a very clean pond in my garden and I hope to create more as a result of my volunteer and professional work with amphibians. See the photo of the meter

Weather has closed in with plenty of rain!

In Garden pond, great crested newts, Observations, the garden pond blog, Wildlife on February 10, 2011 at 10:44 am

My garden pond is getting a good fill of new rainwater. I have ordered a conductivity meter – from the advice given by Jeremy Biggs at the Herpetofauna Workers’ Meeting this year. Hopefully I will get this delivered today. I can then check up on the water in my garden pond – using the right units over the TDS readings – though the meter will also take TDS readings as well.

I have been going back through my data for a survey where I found the largest number of adult newts in a single survey visit. It was 11 years ago at a flood reservoir. The number I counted was 215 adult newts. Probably one of the largest counts of great crested newts in Essex.

During this survey I collected water measurements – including conductivity and I noticed some interesting readings going back through my notes. The conductivity readings ranged from over 500 and during the survey the conductivity went down to below 200 – I suspect when fresh rainwater flooded into the reservoir.

Anglian water flood reservoir

flooded reservoir revealed plenty of newts!


Flooded LNR

Me standing on bridle path in 2003

The pond in January 2011

In Garden pond, Observations, the big pond thaw survey 2011, the garden pond blog, Wildlife on January 6, 2011 at 10:35 am

We are into the new year now. The garden pond has lost a reasonable amount of its water after the thaw. The Big Pond Thaw Survey 2011 has been filled in for the pond. A few dead invertebrates have been spotted including an adult water beetle, a few water beetle larvae and the mayflies – the pond olives. Over on the Garden Pond Blog Jeremy Biggs has been reporting on the end of year news story from the Environment Agency – Looking at the real situation around the state of the UK’s rivers – Telegraph Article –

Jeremy Biggs Letters in the TimesIndependent

This has led to people tweeting Garden Pond Blog 1 Environment Agency 0 – Habitat Aid for example –

Nick Mann
Habitat_Aid Nick Mann 

Garden Pond Blog 1 Environment Agency 0:
Pond Conservation is another organisation which I hope to support through being a supporter – through my Company Herpetologic ltd after reviewing who we currently support we have managed to make a saving by stopping support for one organisation that we feel we are not getting any value for the money we give them – we can now put money towards excellent charities such as Pond Conservation & ARC Trust instead.

More pond myths…..

In Garden pond, Observations, the big pond thaw survey 2011, the garden pond blog on December 3, 2010 at 4:56 pm

A national charity has this advice for garden pond owners in relation to iced over ponds

‘prolonged freezing stops gases from moving in and out of the pond, leaving the water susceptible to a buildup of toxic gases and chemicals released as animal and plant matter continues to decompose. This can seriously damage the pond ecosystem, affecting a number of animals (not least frogs, which can die of so-called ‘winterkill’). To avoid this, remember to make holes in the ice during frosty weather’

You can do this by leaving a pan of hot water on the ice surface to melt a circular hole. Alternatively leave a ball floating in the water the previous day, and remove this once the pond has iced over.’

Dealing with nutrients the following advice is given for dealing with algae blooms

‘If your pond lacks water fleas then (with permission) consider asking a nearby pond owner for a small amount of silt and water, but be very careful not to transfer any plant fragments with it (see page 12).’

This is interesting advice as previously it has been stated that frog spawn should not be swapped

‘advise that you do not donate your frogspawn to other gardeners, or collect frogspawn to deposit in your own garden pond. The advice is given to help national efforts to stop the spread of invasive pond plants, animals and amphibian disease. In nearly all cases, amphibians will turn up of their own accord, often breeding in the first pond year’

So it is not okay to introduce frog spawn but it is okay to introduce water and silt which would possibly have the same potential to spread amphibian diseases like Rana virus and Chytrid fungus

People have considered the problem of introducing frog spawn to new ponds – the conclusion was that over limited distances it is probably beneficial for frog populations to have new genes introduced into new populations – this would have to be within gardens and not into the countryside

more to follow…..

The big pond thaw survey 2011

In snow news, the big pond thaw survey 2011, the garden pond blog, Wildlife on December 1, 2010 at 11:47 am

Pond Conservation is running its big thaw survey again this winter after a successful survey in 2010 – you can see the results here

I am going to monitor my small garden pond this winter and I will be reporting back to the survey through the online form

From the survey some interesting results were collected and pretty much provided evidence that the usual advice about ponds may not be the best advice

From the results and other research by Pond Conservation

the following advice has been given in relation to amphibian deaths in ponds due to ice

What can we do to reduce amphibian deaths during cold spells?

What are the practical implications of the survey for creating and managing garden ponds so their inhabitants can survive in the cold winter months?

There are several suggestions we can take from all the findings so far:

1. Ponds shouldn’t be too deep for their area. Shallow ponds – less than 30 cm (1 foot) are more likely to have higher oxygen levels in the water which helps amphibians, so a good pond shape is wide and shallow – a saucer rather than a tank.

This is the exact opposite of much of the standard advice, which says that ponds ‘should be deep to protect them from freezing solid’. In fact, we know that most ponds didn’t have more than more than a few centimeters of ice, even during the very coldest days of the 2009-10 winter – so ‘freezing solid’ isn’t the problem.

2. A large build-up of leaves and sediment on the pond bottom is probably not good news – almost certainly because this de-oxygenates water. This is especially a problem in ponds which are small and deep.

3. Having plenty of plants in the pond throughout the winter is a good way of improving oxygenation. Underwater plants, including mosses (which don’t die-back in winter) are ideal, although it’s worth remembering that algae, both filamentous and unicellular (the sort thatcolour the water pea-green) also produce oxygen.

4. There isn’t any evidence that making holes in the ice, or breaking the ice, can prevent amphibian deaths. This is not surprising, as most amphibians hibernate at the bottom of ponds. Oxygen diffuses very slowly into still water, at about 2 millimeters a day! So it takes over 6 months for surface oxygen to reach the bottom of a 50 cm deep pond.

5. BUT – If you have a pump, and you think the pond might have low oxygen levels, it is worth making a surface hole and keeping the pump running so that the water is stirred up – this can move oxygen from the surface to deeper waters. A shallow pond with lots of underwater plants won’t need a pump.

6. If the pond freezes and then snow falls on top of the ice, clearing some snow off the ice to make a ‘sunlight-hole’ can help. But this is only likely to work if your pond has lots of underwater plants (or algae) which can then oxygenate the water.

The first frozen frogs have been reported through this last round of snowy weather

I hope that I can assess the numbers of invertebrates that have died over the frozen period – I will also be seeing whether the pond freezes solid as it is only 20cm deep!



A recent blog post over on the garden pond blog about the EA

In Observations, the garden pond blog on December 1, 2010 at 11:33 am