Sandbagged!

Sandbagged!
Photograph by Steve Barnett

Monday 7 May 2012

Trout Heaven?

Or is it Trout Hell?

The chance to "walk" a brook in the company of a young professional scientist with a particular expertise in river habitats was too good to miss.  At the same time it might cast a light onto why a tiny brook in Derbyshire has nothing like the population of wild native brown trout that it really ought to have..  I fished this brook many times as a younger man and enjoyed it even though the catches were never counted in dozens.  It was near to home in those days and the owner of the stretch I fished let me fish for nowt as he knew even then I didn't kill wild trout, believing they were too precious to be only caught once.

This "walk" (more like an assault course for weeding out recruits that were not fit enough for the SAS) was going to start much higher upstream from where I used to fish and then work down to my old haunts.  The mission was for my leader to begin the careful process of assessing what was going wrong for the trout.  Why were they simply not succeeding where, to all intents and purposes, they should be.

Arrived at the headwaters we could see that the brook was a delight here.  Forgive the rough bits to the joined up image here but it shows you what we could see, click it for a bigger view.

The brook looked perfect up here.  Lots of gravel of the right sizes to spawn in, woody debris in the watercourse to provide habitat for all age groups of brown trout, it had to be right for them...


There were branches and trailing roots that caused the current to clean the gravel whilst waiting with their protecting structures to guard millions of tiny spaces for young trout to hide in - had they been there.  It was like looking at lots of perfectly appointed and furnished houses in an abandoned village!

There were classic pool and riffle sequences that trout of all sizes use to their advantage (when they are there)...

Food is here.  We saw midges and olives aplenty and, in despite of the cooler weather that England is famous for every public holiday weekend, there were Hawthorn flies.

Surely this had to be trout heaven.  But it is not, so the question was "Why?"

The first alarm bells were rung as we worked our way downstream.  We kept coming across little weirs.  Some made of stone, some concrete and some of cord wood like this one.  My leader, although still with plenty of work to do yet, started to wonder, "These weirs are not good.  They stop gravel from grading itself and they are barriers to easy fish passage..."

Then we came upon a slower stretch, it was clear there was some form of impoundment downstream of us.  We scrambled our way down, circumnavigating barbed wire, electric fences, holly, brambles, briars and much else. 

There it was!  This tiny brook has a massive weir across it and with the lip on the very top being raised up about four inches it was clearly impassable by any trout.  Even if a trout had forced its way to the top of the weir as it lifted to try and get over the lip, the current would simply scoop under its belly and wash it straight down to the bottom again. 

These structures make me angry as, believe it or not, weirs are, or were illegal, in England.  Paragraph 33 of the Magna Carta states, "Henceforth all the weirs in the Thames and Medway, and throughout all England, except on the sea-coast, shall be done away with entirely."

There is much else wrong lower down the brook but the presence of this weir goes a long way to explaining why the upper reaches of this otherwise ideal little brook has so few native brown trout living in it.  They can't get up there.  What a mess we have made of our water courses...



Regular Rod

10 comments:

  1. A few cracks in a weir could encourage the river to repair herself in time. If you already haven't i'd have the water quality tested for obvious problems? also has a kick sample been taken for invertebrates?
    You might need a Cheiften tank for the big weir.

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    1. Chieftain tank? More like Barnes Wallis and 617 Squadron!

      Regular Rod

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  2. That's my type of stream.

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    1. In good order it certainly would be a wonderful stream.

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  3. An excellent post, compliments on a good piece of detective work, especially the bit about Magna Carta...is it your bedtime reading? I've seen these type of barriers on Lancashire moors and wondered why they were constructed,maybe dialogue with owners and authorities might allow removal or remedial work, but again its going to be finance that will be the stumbling block.

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  4. Surprised that the weir hadn't been discovered before. Can it be torn down? Beautiful stream.

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    1. It has been known for a while as it is marked on the Ordnance Survey maps Howard. I'd never seen it before as it is upstream of where I used to fish. It is only recently that new legislation in Europe called "The Water Framework Directive" (WFD) has triggered proper scientific investigations into waters where things are suspected of being not as they should be. A fish population survey had been carried out at readily accessible places on the brook and this showed the trout population was not at the level expected for such a brook. My young scientist friend had been asked to look into things further to see what might account for the low population. Hence he (and I) were covering all the brook and not just the easily accessible places.

      There is more work still needed before he can finalise his opinion but the barriers are certainly a major factor in preventing natural movement of trout upriver, especially at spawning time.


      Regular Rod

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  5. The Ouseburn here in Newcastle upon Tyne has been killed off by excessive wears. The Ouseburn looks very similar to your brook and would surely support trout if returned to its natural wear free state. Please let me know if you find a way to encourage 'the man' to allow the removal of these unnatural barriers.

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  6. Some of us are moving them. We did this one two years ago - it's been studied. And if successful most if not all on our stretch will be taken out. http://s158.photobucket.com/albums/t92/alexswann/Dovedale%20-%20weir%20removal/ Alex
    By Alex Swann on Trout Heaven? at 13:51

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