Wednesday, 29 May 2013

Respect is Due 2 — Heron on the Sowe

Some time ago now I published a graffitti piece of a zander that suddenly appeared upon one of the M6 motorway support columns where it crosses the Coventry Canal. I don't know about you but graffitti is okay in my book only when it captures the imagination, finding the majority little more than a splash of meaningless colour brightening those drab and neglected corners of the world where the sub-culture that creates them likes to hang out.

I don't appreciate the majority of those pieces because I'm not part of their culture and don't understand the underlying thought processes that lead to someone breaking the law, or even risking life and limb, to create something with such a strictly limited audience and appeal but using such advanced technical skills. I can see they take a great deal of effort to make and require a dab hand to be any good, but who cares how dangerously they were achieved if they don't speak to us?

But then along came Banksy and the stencil revolution. Then we had arresting images cleverly placed carrying ironic/sardonic messages that actually did catch everyone's imagination, not least those of canny art dealers who saw the market early, cut them from their proper context and transported them to their galleries...


I thought that the zander was really something because it suggested that whoever created it actually knew something about the fish population of the canal. Well, it took some time before anything else remotely pertinent to its context and therefore appealing to the eye turned up, but then this piece appeared on the side wall of the weir on the River Sowe in Longford Park one morning last week ~

Clever I think, and if it weren't for the fact that herons actually do visit this river would be ironic...

...but I wonder how difficult it would be to prise those planks off the wall..?

...and if RJL the artist responsible was fully aware that someone might want to take irony a stage further, take them away and stick them back up on theirs...?

Saturday, 25 May 2013

Build It and They Will Come — A Roach by Any Other Name (Pt6)

There's a countrywide movement of enthusiastic amateur involvement in river rehabilitation. Streams all over Britain are in process of an overhaul, their habitat shortcomings rectified and potential maximised not only for the health of river environments, but also for angling too. And that is all to the good.

Much of this work consists of really heavy duty and to my way of thinking, heavy-handed manipulation of the watercourse concerned. A project is considered, cleared by someone high up in the chain of command and then implemented by a gang of hard working volunteers dressed in waders, hard hats and goggles, the director of proceedings with his clipboard and pen ordering this tree to be lopped at the trunk with a chainsaw and turned into the river as a deflector and that channel to be revetted, backfilled by machine and pinched.

Such projects are funded of course and have strict budgets and time deadlines to meet so they're military style operations following a well-planned strategic program of work designed to have the river improved beyond recognition in short order. To this end, presumably a blueprint is drawn up of desirable outcomes and maps are made that show where obstructions are to be introduced and at exactly what scale and these decisions are probably derived from existing flow data modeled into desirable shape by computer.

I wouldn't have thought them in any way haphazard or intuitive...

What's remarkable about such projects is just how many of them are focussed upon chalk streams and the like and with providing suitable habitat for fish such as wild brown trout, migratory sea trout and salmon. I would say that the vast majority of funding moneys currently spent on rehabilitating rivers are spent on those boasting both peerless chemistry and biology and the best chance of having a future as a prime game fishery should things be improved. It's business after all...

When I delivered the menu on offer for the fish of the Sowe I knew full well what a split viewpoint it would create amongst readers. Coarse anglers would see the superb food supply as the staple diet of roach that might grow very big in the future should habitat be created for them, but game anglers would not be concerned with that in the least viewing the river from an entirely different perspective. They'd  not see a roach fishery but a wild brown trout fishery in the making, because that's exactly what its habitat of pool, riffle and glide, pure water and hatches of the right kinds of flying insects suggest it could be.

I don't have a problem with that.

Many game anglers are not principally concerned with catching fish, per se, but are interested very much in the why and wherefore of how they are caught and the natural beauty of the places where they are found and beside getting up to their chests in water in order to fish rivers, adore small streams and their technical challenges like no other and tend to become deeply immersed in their continuing and future health in a way that coarse anglers sitting on the bank at a remove rarely do unless it's about improving access and creating comfortable habitat for themselves. 

That is why the vast majority of the spend on rivers goes where game fish are. Not because they deserve more attention than coarse fisheries — they don't — but because game anglers are so determined to have their rivers healthy they'll quietly organise and then move bureaucratic mountains to ensure they are. 

The list of their achievements is long, and when it comes to the rejuvenation of urban streams such as the Sowe, astonishing, because only they saw the potential early and considered what great fisheries they could be once again, pulled themselves together and created organised bodies to secure money and then worked very hard to achieve that end by getting stuck in where it really matters — at the level of the river bed.

We coarse anglers have a lot to learn...

And a very long way to go before we come close, let alone match their commitment.

Where it all began at the head of the new pool. Next picture just five yards along and I'll be up to my hips in it!


Driving my 'work' on the Sowe is a passion that I admit began as pure self-interest but without which I would never have bothered. I always adored this little river as an angler because it was such a challenge but so rewarding to fish and then somehow and for some reason I began to look deep into its shallows where I saw what was holding it back. 

Then naturally I wanted to see what could be done by trying to improve things but as cost effectively as possible, which in my situation means at the price of nothing but graft, utilising what is already there for free in the way of plants, rubble, sticks and rubbish, in an effort to harness and direct the tremendous power of flowing water to create a more natural course for a despoiled river and a better habitat for its very few but remarkable fish.

I think I've achieved something small but locally speaking, significant, though I can't claim credit for placing a few rocks under a bush and knowing what would happen after — I only remembered I'd done it when the floods came and never seemed to go away! It was nothing but a happy accident.

But it suggested great things could be achieved without funding of any kind — all that was required, actually, was the enthusiasm of a solo amateur who hadn't a clue what he was doing, the river taking care of mistakes by sweeping them away or ignoring them but taking advantage of small things, well-placed.

And finally, closure.
This morning I returned to the pool and peered keenly through the lens of its crystal waters to view the complex world of its aquatic life. They were still there, the minnows and perch, involved in a curious oscillating dance of threat and fear, retreat and peace. I suppose the perch are husbanding their resources, knowing they can ill afford to consume all the supply all at once. The roach were gone though, and that concerned me greatly because they were what started all this and why ultimately I bother with it. 

Perplexed and disappointed I made my way along where in the second, shallower pool I saw nothing at first but adjusting my focus I then saw hundreds of fish too tiny to be the adults of any species no matter how small — it was full of fry! Minnows I'd have thought, but the way the perch were eyeing up the parents they'll be needing all the recruitment they can get...

An hour later after messing downstream observing what hadn't happened and thinking what might happen should I do something else I decided to do nothing at all and made my way back up. There's a thin and fairly deep strip of water fringed with reeds and brambles I'd ignored all the while never intending to change a thing about it because once upon a time in my early reconnaissance trips I'd earmarked it as prime roach territory should it ever deepen enough and gain cover. 

I took a quiet look into the water seeing nothing but dark silt but then the dogs turned up crashing through the undergrowth when a flash of silver followed by a train of fish darting upstream gave them away. Dogs are good for that you know — springing fish from their cover! 

They calmed down, resumed order. Discovered and known to be around they were now quite easy for the eye to appreciate despite their camouflage. The dogs cleared off and I watched them for a while in peace when cruising along came an old friend — the only roach I know by name in all the world — who with an old white scab high upon his otherwise invisible back had given them away once before only to be caught himself a year on...

"White Spot!"

A roach by any other name and what not...

I'd fished for the very shoal he'd always been a member of just after the floods had subsided but they weren't where they usually were. I thought they'd gone elsewhere, to a place close by but one unknown to me, but now it was clear that they'd traveled much, much further from home than I'd ever have thought possible making it all the way up to a new one I'd helped create.  

That was enough. I'd built it, they'd come, and my work there was done.

But elsewhere?

Who can say what the next floods might bring...

And what I may bring to them.


My sincere thanks for sticking at it, staying with me through this long-winded thing, 

... but reading on, 

Jeff





Friday, 24 May 2013

Build It and They Will Come — Nature's Finest (Pt5)

Four years ago when I first took an interest in the Sowe I couldn't understand why it contained such a small head of fish but those few stretches of river I managed to find where the river had never been interfered with contained good mixed shoals with such large individuals in them. It seemed a puzzle because at that time I had no idea that fish living in rivers, and especially very small ones, have exacting standards when it comes to habitat. 

The infant river three miles upstream of the park, diminutive but pristine in every respect...


I thought fish simply required water, and in a large river with plenty of depth that might be the case, but as I walked miles upstream and downstream of the short natural stretch where I'd first found them and in search of more, it became abundantly clear that water alone was not enough here because they were absent if it was too shallow or lacked cover and that was the case pretty much everywhere else.

The mature & ancient natural stretch two miles below with its perfect unspoiled habitat

You may have become accustomed to viewing the river where these experiments of mine 
have been conducted as being far larger than it is in this picture. You'd be right in terms 
of width but not in depth. The river in the picture above has gained the water from one of 
it's main tributaries between here and there and yet it's much narrower, but exactly as it 
should be for the volume it carries — where I'm working is twice as wide but very shallow

I had to walk a full five miles downstream before I discovered another shoal. Between was a river that looked clean and healthy but hadn't any fish in it that I could see apart from one deep pool (the only deep pool!) bursting with minnows but without attendant perch. Upstream things looked far better but the only fish I witnessed there were sticklebacks and an isolated group of small fish I thought to be stoneloach living beneath a piece of roofing tile who vacated when boys took it away and used it in play, never to be seen again.

Sampling the menu
That's about when I started taking a look at what it contained in the way of available food wanting to know if it was a lack of that causing their absence or if it was actually lack of suitable habitat as I thought. So, I ran my first kick samples, getting into the river and throwing gravel up off the toe of my boot collecting what was dislodged in a small net.

I really didn't expect to find much and thought I'd go a long way before getting any result but in the first netful it was clear that not only was there food in the river and plenty of it, but when I got home, identified the species I'd found in an hour or so and checked them against a table divided into three or four classes indicating water purity — the bottom ranking able to live in sewers, the middling classes tolerant to degrees but the top ranking species highly intolerant of pollution — I found the food supply to be high class stuff of the finest quality...

Freshwater pea mussel I believe, and case-less caddis grub
I knew the little green caddis grubs for what they were without diagrams to check against but hadn't a clue about the abundant tiny clams because it was the first time in my life I'd ever seen anything like them living in a river. 

Besides them, all kinds of strange little creatures came up in the samples and when I took a closer look at the stones, limpet-like things I thought to be molluscs were attached to them... 

They were very common indeed.

Water penny — an aquatic beetle larvae



Freshwater shrimps and a mayfly nymph
There were lots of small shrimp-like creatures that looked like the sandhoppers I knew from my sea fishing days but alongside them another lifeform I hoped was a nymph...

Though not as common as the 'hoppers' they were present in good numbers and I was quite excited by them because I thought they might be mayflys, and if so one of the best indicators of water purity there is because they just can't stand any level of pollution...

As it turned out, my instinct was correct because they were indeed swimming mayfly nymphs, and better still, the little 'limpets' turned out to be water penny, an aquatic  beetle larvae and another top ranking species as were the tiny clams, a now quite rare species of freshwater pea mussel due to their need for very clean water.

All together it seemed the river was in sparkling good heath.


Swimming mayfly nymphs.





Then along came the first fish...

A bullhead! 

Only a very small one, but again, one of those species who don't like to live in unclean water. I've only ever caught a very small handful of these curious little fish with heads as big as their bodies but always in very clean rivers that support populations of wild brown trout. 

What I didn't expect to find was an earthworm below the gravel because worms live in soil, right? Well it seems they don't mind living in riverbeds either!



And then to top things off came one of the weirdest looking forms of life I have ever met. A large creature with long legs but who looked as ancient as the hills, as if he was actually a fossil rather than a living thing. Moving very slowly he crawled about clumsily on my hand unable to support his own weight out of water on his spindly limbs... 



I think he's a damselfly nymph who never emerged into the air and never would but missing most of his antennae and all his tail I'm not at all certain about that... 

I only wished I'd taken more photos, because I'm sure I found more that day than I realised.

I'm not much of a scientist when it comes to these things so I didn't count them all and come up with tables and the like, but was satisfied that the river held good food for fish life and plenty of it and even though you'd be forgiven for thinking it was anything but in certain ugly places, the river was actually very clean and its water pure. That was a revelation —I'd expected fair results, not excellent ones!

It was now clear to me that the fish grew just as large as such a small stream could support precisely because of its abundant high quality food supply in combination with good habitat wherever it was found — they couldn't make use of it where habitat was poor — but they could occupy the rest of river, breed and flourish, should what they need be created where for one reason and another it had ceased to exist.

To be concluded...

Thursday, 23 May 2013

Build It and They Will Come — Dammed Hard Work (Pt4)

When I began messing around with rocks and sticks in other places I thought that things would be as easy as they had been — one small intervention, and "viola!" — total transformation of the river for 100 yards downstream. But, it isn't as easy as all that because placement is so critical that should an obstruction be placed badly then it has very little effect, as I was to find out.

There's lots of rocks available down there, none of which are natural to the stream. They are very useful to me though because they're handy portable building blocks that can be arranged on the river bed in various ways, the effect monitored, and if nothing of any consequence seems to be happening then the structure can be easily dismantled and erected elsewhere.

Causing the water to flow into a narrower channel


A groyne was constructed downstream at the same scale as that placed under the willow upstream just to see if rocks alone would achieve anything. Unfortunately the effect of a spate was negligible because the turbulence caused was directionless, just boiling over and dissipating uselessly. When it was at its highest, the groyne vanished below and the water ran straight over it as if it wasn't there at all — when it subsided no effect was measurable apart from a freshening of the gravel directly behind, none of which had moved even an inch.

As the water rose it vanished, the channel broadening and negating any effect it might have had. It needed to be far larger than it was to do anything useful but making large rock structures is not what I want to be doing.


The next willow downstream looked as easy to play with as the one that had had so much effect, so I dismantled the groyne and repositioned it below the branches, but this time installed a number of large dead branches between and plugged the gaps with dead vegetation, emulating what a heavy flood would achieve of its own accord.

When a spate did arrive the whole lot disappeared below the water and seemed to be doing its work, however, when the waters fell away I went back and saw to my dismay that it had achieved very little, in fact it hadn't altered the river bed and had hardly begun scouring the stones of their covering of grey/brown algae let alone move them.

As you can see, nothing whatsoever happened. The riverbed was just as shallow and immovable as before


The problem wasn't that the thing wasn't doing anything, it was. It narrowed the channel and caused all the water arriving from above to pass through a gap half the size of before. The trouble was that the water arrived at it with the heaviest flow along the far bank then passed straight on by without having much of its energy diverted. Consequently, very little turbulence was caused and what little was caused was linear.

The water arrives too gently at Willow Groyne 2,  all useful energy shooting directly along the far bank




Compared with the original successful experiment which in hindsight was entirely fortuitous, this structure was created upon knowledge I thought I'd gained from it. What I had failed to appreciate was that whatever happens downstream of such a structure is entirely conditioned upon what is already happening upstream of it and here the water arrived at the wrong angle which was no angle at all.

The original. Water arrives from upstream at a good angle, backs up, then plunges downward. At the point of the arrow the river is now a foot deep at normal flow but at the trailing edge of the rubbish raft now approaching four 


Taking a second look at the original willow groyne, it was clear the reason it had worked so well was because the heaviest of the water came it hard, backed up in a reservoir of pent up energy compressed by that coming along behind, then plunged downward taking most of its force to the riverbed where I now know it scoured almost three feet of gravel away creating a pool approaching four feet in depth with its deepest parts immediately below the obstruction where the bed now shelves away dramatically.




Of course this meant that if the second willow groyne were to work then something needed to be done to divert the water straight at it. So, I had a play about with rocks and came up with something — a double groyne in the approach way. In the picture above the first groyne is actually far smaller than the second and there to hopefully protect the area behind where rushes are already trying to establish and that I intend to consolidate with a backfill of rocks, gravel and silt otherwise it'll do more harm than good come the next flood, the turbulence caused ripping out the entire bed.

The second is a pretty substantial pile of rocks by comparison and designed to force the water across into the shallow area immediately upstream of the willow. As you can see, it does just that at low water. What it'll achieve at high water though, I haven't a clue! Though I do think it isn't large enough to really work as intended, but...

We'll see.



The last experiment was a loose rock dam that increased the depth of the shallow silted pool behind by a good foot as soon as it was built. In a spate it too disappears but the effect it has at the river bed is quite strong having shifted gravel and scoured it clean in no time. It doesn't seem to impede the progress of fish either because the roach and perch now resident in the pool 100 yards upstream arrived some time after construction.

The trouble is, the pool behind cannot get any deeper than it is right now of its own accord, and might even silt right up if I can't do something to create depth that will self maintain, and that's a headache, especially because I really don't have clue what I'm doing until I've done it, watched it, and learned my lesson!

The 'transverse' riffle is at top, the river between there and the dam remaining a very poor habitat for fish

Perhaps I'll dismantle the dam and use the rocks to create something else above the pool that will help deepen it enough for fish, because even raised by a foot in level it's not nearly deep enough for that without shady bankside cover to live beneath. What that might be though, I don't rightly know but I've heard that V-shaped groynes pointing upstream do scour well below...

Whatever I do attempt next I'm mindful of the need to not get carried away trying to further improve upon what is already improved out of all recognition. There's absolutely no need to interfere with the course between the deep pool and the rather interesting set of features created below — they can now take care of themselves and the river do the work of maintenance.

Everywhere else though? Until the watercourse there starts to approach the structural conditions that both you and I know comprise those of a healthy river fishery just from its outward appearance, then little offense can be caused by my experiments (except not having permission to run them!) but a great deal improved upon because as it stands it's a very long way from being one.

And that's a shame, because it certainly has the fundamental requirement that supports a good head of fish, and that's an abundance of Nature's Finest.

To be continued...