Carlisle Tarn – a natural pond in the Lake District

 

Carlisle Tarn, just below 3000 ft on the flanks of Skiddaw, in the English Lake District

 

It’s natural to assume that the Lake District is mainly notable for its lakes. But it also has a lot of ponds – and the picture above is a typical Lake District sight.

This is Carlisle Tarn, a pond below one of the half dozen highest peaks in the Lake District, Skiddaw.

Carlisle Tarn is a natural waterbody in a classic location for a pond in the mountains – in a small col between two areas of higher ground. Water running off the slopes on either side of the col naturally accumulates in any depressions before overflowing down the side of the mountain.

Even though this little tarn had a centimetre of ice when we were there, below the surface there was no shortage of animal life: a very quick look with the sieve revealed water beetles, midge larvae, young lesser water boatmen and a well-grown hawker dragonfly larva – almost certainly a Common Hawker.

This is one of hundreds of such little water bodies in the Lake District. But even though people have been intensively studying the Lake District lakes for the better part of 100 years, very few have looked in the ponds.

More recently, the Cumbria Tarns Project has started to rekindle interest in what will probably turn out to be some of the most important, fragile and under appreciated freshwater habitats in a notably wet area.

Apologies for the delay

Apologies to contributors for the delay in approving comments. I’ve been away over half-term and the phone reception where I was was so slow it was taking forever to approve things – so I eventually gave up!

Jeremy

Shameless self-promotion…

For those who are not Guardian readers – or rather scanners of the Guardian website because I don’t think it was in the physical paper – this comment piece might be of interest.

http://www.guardian.co.uk/environment/cif-green/2010/oct/13/clean-ponds-uk-water-quality

It’s obviously great that the Guardian is taking this so seriously: their team of writers is an important public voice for nature.

Collecting gas, not creatures

 

Dr Deborah Pearce of Oxford Brookes University collecting samples of methane from a pond yesterday on the Loddington estate of the Game and Wildlife Conservation Trust

 

Often when we visit ponds we’re collecting samples of the creatures living there to find out what the condition of the pond is.

But here we are (this is Dr Deborah Pearce of Oxford Brookes University who is supervising PhD student Ruth Shaw who’s project this is) collecting gas from a pond.

And why are we doing this? To find out how much carbon is trapped in ponds – which ought to be good for the planet – and how much methane and other greenhouse cases – is released from ponds. Which is a bit more problematic.

Are frogs on the verge of dying out?

Thanks to Jon for pointing out the Mail’s article on this new frog disease research.

The opening line of the Mail article is ‘Common frog populations have seen numbers tumble by more than 80 per cent in the face of a virus spreading through the UK, scientists warned today.’

The study doesn’t actually says this: what it’s actually reporting is evidence of  ’long-term localized population declines’. I don’t think the researchers really intended to imply that frogs everywhere fell by 80% – which is more or less the way the news comes across.

You can read more at: http://www.dailymail.co.uk/sciencetech/article-1318548/Frog-numbers-plummet-80-virus-decimates-adult-population.html#ixzz12522A1tC

Oh…now I see it on the Independent site too: http://www.independent.co.uk/environment/nature/new-virus-causing-mass-deaths-of-frogs-2100849.html – much the same headline. Frogs dying everywhere.

And the original article summary is here: http://onlinelibrary.wiley.com/doi/10.1111/j.1469-1795.2010.00373.x/abstract. As usual to read it in full you need access to a university library.

I’ve got a copy of the original paper now – so will report back.

But I think again this shows that we should do all we can to support the National Amphibian and Reptile Recording Scheme, which could do with more funds. Hmmm: somehow I’m not optimistic this will happen at the moment.

It’s not only rivers

A couple of weeks ago the publication of new research on the global threats to rivers was highlighted. The summary of the paper is here, though to read it in full you will need to ask the authors for a copy unless you can get access to the science journal Nature directly.

It’s worth reading because it’s important; and there’s the added benefit that its written in language that any reasonably intelligent English speaker could understand – which is more that one can say for many Nature papers which depend on the dense and, even to the reasonably well-educated outsider, completely impenetrable technical language of the particular science discipline.

But I wanted to highlight something that the paper doesn’t mention: it uses ‘rivers’ as symbolic of freshwater.

But we know that standing waters – lakes and ponds – make up maybe half the global water area.

Remarkably, little ponds (or at least waterbodies no more than 10 ha in area) make up one-third of that water by area. This is because there are millions and millions of them – and only a relative handful of big lakes.

This is not well-known – and unless people have read the study by Prof. John Downing and his colleagues (here) it will be news to them.

In Britain, perhaps elsewhere too (no-one actually knows), little ponds have more endangered species than rivers, and in several places where we have looked around Europe they actually support more species than rivers altogether – not just more rare things.

Overlooking little ponds because they are small is what John Downing has called ‘a long-standing error of scientific reasoning‘ (he says it in this paper).

That part of the story hasn’t yet made it into Nature.

Lesser water boatmen on the wing

 

Chestnut lesser water boatman (Hesperocorixa castanea)

 

It’s tempting to assume that everything in the pond is shutting down for the winter now and traditional advice has always been that autumn in the pond is simply a prelude to winter: autumn is the time ‘to start to prepare [the pond] for the eventual onset of winter‘ or ‘…a time to ready your pond for winter‘.

This may be true of heavily stocked goldfish ponds but in natural ponds there’s a lot of activity going on both in and above the pond - animals dispersing, beginning overwinter growth or simply seeking their winter and spring nursery grounds.

And on warm days in the autumn there are plenty of creatures on the move – including those flying to ponds which have refilled in the autumn.

Late flying dragonflies are easy to spot. But amongst the creatures looking for a new home, some are less conspicuous and today I caught a fleeting glimpse of one of these in the New Pond – a lesser water boatman.

It was too quick to catch, and there was only one, but it looked like either a Hesperocorixa or one of the species of Sigara (from a distance both types look pretty similar, but with a bit of practice the species can be quite easily identified if you have them in the hand).

It must have arrived recently, perhaps in the last few warm days, as I’ve been watching the pond closely and, with the water now clear, it was pretty easy to see. At the very least it must have arrived since the pond refilled earlier in the autumn.

Quite a few kinds of lesser water boatmen move from pond to pond – though not all. The species that prefer bigger permanent water are not so flightly.

It’s been known since the middle of the last century that there are two peaks of flight activity for these animals: in the spring and again in the late summer and autumn.

The autumn move gives the animals a chance to return to those ponds which have dried out in summer – where they should be safer from predators (usually no fish, for example), and face less competition from other water boatmen.

Late tadpoles

Metamorphosing tadpole from the Old Pond today: its getting on for a month later than 'normal'

We naturally assume that Common Frog tadpoles have mostly emerged by this time of the year.

And my standard froggy reference book – Trevor Beebee and Richard Griffiths’ New Naturalist ‘Amphibians and Reptiles‘ – does indeed describe metamorphosis from tadpole to young frog as occurring any time from May to September.

So the tadpoles in my pond today, even with well developed hind legs, are beginning to push the metamorphosis envelope a bit.

My guess (frog experts may care to comment) is that if they’ve got legs now they’ll soon be leaving the pond. If they haven’t they could be heading for overwintering as tadpoles.

Careful of those water plants

People are often advised to pull plants out of their ponds in the autumn.

Luckily for one of our supporters she looked a bit more closely at the plants in her pond before making with the rake.

The plants looked suspiciously interesting, and indeed so they turned out to be for her pond, on the hills not too far from Bolton, shelters one of Britain’s most endangered water plants, Red Pondweed.

There’s a nice picture of the plant here.

Red Pondweed (Potamogeton alpinus) is a plant most people wont see too often unless they go out into more remote parts of the countryside, and then its mostly in the north: in the south, pollution has largely eliminated it.

 

The distribution of Red Pondweed: red dots show the fairly recent records; the yellow dots show where it was found in the past (click the map for a higher quality image)

 

It’s one of the most rapidly declining water plants and now Red listed Oops – no, it’s simply declined a lot – in the UK because of this decline.

Predictably, it’s main requirement is clean, unpolluted, water,

Are ‘frogs on the verge of dying out in parts of Britain due to disease’?

I saw this headline yesterday.

‘Frogs on verge of dying out in parts of Britain due to disease‘ (in the Telegraph).

I’m not sure yet which parts of Britain we’re talking about. Yesterday I saw Common Frogs in our garden and also in woodland about 2 miles away – so that’s OK then!

According to my colleagues in Amphibian and Reptile Conservation about half of all ponds in the countryside have frogs breeding in them. You can see the latest publicly available data, from 2007, here.

I will report back when I can get hold of a copy of the report the article is based on.