Comments on: Ice and oxygen: the end of the story (for now) http://jeremybiggs.wordpress.com/2009/01/20/ice-and-oxygen-the-end-of-the-story-for-now/ "If only I had found this website last year when I started my pond!” Wed, 09 May 2012 23:22:19 +0000 hourly 1 http://wordpress.com/ By: Jeremy Biggs http://jeremybiggs.wordpress.com/2009/01/20/ice-and-oxygen-the-end-of-the-story-for-now/#comment-2273 Fri, 30 Jul 2010 08:35:15 +0000 http://thegardenpondblog.org.uk/?p=1368#comment-2273 In answer to Brian….

What happened to you happened to a lot of other people last winter – which as I’m sure you know was one of the worst we’d have for a while.

In our ponds we measured oxygen and that was clearly implicated in deaths of fish and frogs. Frogs are happy at low dissolved oxygen levels in the cold but can only stand a few days with no oxygen. Goldfish tolerate zero oxygen for longer but even they succumb eventually.

So far we haven’t measured the other ‘toxic gases’: ammonia, methane, CO2 – so can’t rule them out completely. However, these will often be kept in check when there is oxygen about – so the rise of these gases will probably coincide with lack of oxygen.

It looks like when ponds are reasonably well-oxygenated in winter there should be few deaths of pond animals.

But it’s important to say that we are far from knowing all the details of this problem at the moment.

Jeremy

]]> By: brian http://jeremybiggs.wordpress.com/2009/01/20/ice-and-oxygen-the-end-of-the-story-for-now/#comment-2263 Wed, 28 Jul 2010 22:35:31 +0000 http://thegardenpondblog.org.uk/?p=1368#comment-2263 I read with interest your article on oxygen levels in frozen ponds. Although in your tests this may have been the case what happened with other chemical levels? Did the toxins inncrease also because they could not be vented to the ait or did these drop? The reason I ask this is because I put a pond into my garden last year (april time) and it established a good selection of wildlife inhabitants quite quickly. It had also a waterfall fed from a pump thrrough a uvbiological filter. The pond is about 2.5m x 1.5m maximum and was doing very well up until late autumn when I started having problems with the pump so I turned it off at the beginning of winter thinking it was not necessary. At this time most of the plants started dying back leaving very little to grow through the winter. As you know we had a very severe winter and when the pond froze over I broke the ice as recommended. On one occasion when the weather was particularly bad I could not easily break the ice. This lasted for several days and eventually the ice was just too thick even by pouring boiling water onto it. Once the thaw finished and I started preparing the pond for the coming spring I noticed there was about 30 frogs and even some of the fish dead in the pond. Not frozen in the ice but lower in the bottom and between plant pots etc. The only conclusion I could come to was the toxins built up because of the ice cover over a prolonged period. Do you agree or could there be any other reason? I have not had any more die since and there are frogs, newts and fish in it now.

]]> By: Pond Story: making a new clean water wildlife pond « The Garden Pond Blog http://jeremybiggs.wordpress.com/2009/01/20/ice-and-oxygen-the-end-of-the-story-for-now/#comment-334 Fri, 01 May 2009 09:43:56 +0000 http://thegardenpondblog.org.uk/?p=1368#comment-334 [...] of you who read the blog will know that in my first shallow pond oxygen levels rose during the ice cover this winter to double the normal [...]

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