How Long? (Can this go on)

It's the time of year when salmon fishers rant about the weather.  Seasoned followers of this blog will recall last year's posts,  D - 14 The Countdown and D -7 Divine Madness, as examples of my ranting capacity.  However, a quick scan of the Salmon Fishing Forum, FishPal and Trout & Salmon tells you that the salmon fisher's rant has reached epidemic proportions this year.  Unlike Ebola there's no early prospect of a cure or even a vaccine. But you have to feel genuine sympathy for those fishing in north east Scotland, the ghillies and the owners.  First they sustained a dry spring that ran on into summer; then the awful floods generated by Hurricane Bertha's downpours; and now a sustained dry spell with little rain in early prospect. One of my regular readers is on the bone-dry diminished Deveron this week, having driven the 560 miles from Somerset in the full knowledge of the 7 day forecast.  While that may be a minor jaunt for American and Canadian readers, I would point out that they don't have to contend with the torture of the M5 roadworks (what is this Intelligent Motorway the Department for Transport is building?  How does inanimate concrete gain intellect?) or the lower reaches of the M6.  You have to feel sorry for the poor chap.  I can only hope that the Scottish Police don't make it even worse for him on the way back on Sunday with their beastly 'catch an English angler' speed-trap van on the bridge over the southbound motorway just north of the border at Canonbie.  It's an annual feature on Sundays in September, and a £250 fine is just what you don't need after a blank week, so go carefully on the way home.

While I am pining for our annual trip to Tomatin, which sadly is no more, the fishing conditions are no better in Yorkshire.  The MCX rain gauge is empty, and has been so since early August.  The Ure is on its bones, but thank goodness the autumnal temperatures have spared us the ravages of over-heating and oxygen depletion.  Apart from the Dark Shrimp swimming trial day, I haven't fished seriously for salmon since 30th May.  Thus far in September I've cancelled 3 days and now I'm getting worried about the 3 days I've booked for young HMCX at the beginning of October.

Screenshot of BBC Forecast

Unlike the Vanishing Rain of Inverness, in Wensleydale it's just non-existent.  Like everyone else we need a week-long 3 foot spate to freshen everything up and drag fish away from the delights of Hull, Scunthorpe and Goole.  There's nothing in sight that looks likely to deliver that dream. The shift to a south westerly trend next week may be more about hunch than science.




As a result of all this, there's a pall of gloom over the salmon fishing community.  Hysterical Jeremiahs proclaim the end of the Atlantic Salmon and demand urgent government action for its salvation.  Panic stalks the river banks, fishery boards and opinion. The spectre of 100% catch and release looms large.  Science goes out the window, and what remains is used selectively, narrowly, blindly and partially.  Ulterior motives and agendas crowd the wings of the theatre of debate. These are worrying times, not for the salmon, which survived 2 great and 2 small Ice Ages, 4 corresponding periods of rapid global warming and a host of other things we don't know about in the past million years and more, but rather for the potential unforeseen consequences of the 'something must be done' syndrome.  I fear the effects of good intentions far more than I do the variables of our globe.  Of course I like catching salmon and get upset when I don't or can't.  But if, for a time, I can't catch salmon, it's not the end of the whole world.

One of the few advantages of growing old is the perspective of time.  I'm at that nice, if brief, balance where I can still remember things whilst having accumulated lots to remember.  I'm not 100, but in this year it's fashionable to remember 1914 and the outbreak of the First World War. Of course that year's salmon season was submerged under the mass of big history being made, but the meteorology suggests that it was probably at least as bad as 2014 and possibly worse. Certainly it was far hotter and drier for longer.  More recently 1961, 1976, 1995 (when I watched fish panting to their death in hot pools), 2002, 2003 and 2009 come to mind.

With the perspective of time comes scale.  In pondering longer you tend to think bigger and look more widely, whilst contemplating the complexity of the earth's systems.  In particular, the infinitely variable interactions between its gravity, rotation and temperature (via distance from and aspect to the sun). We know our weather is usually variable, but the causes and effects of that variability have wide ranging consequences elsewhere.  Because the salmon ranges widely across the northern hemisphere in its travels, it encounters both ends of the process - our local variability and the distant consequences.  For example, the far end of the processes that gave us a freezing winters in 2009 and 2010 may conversely have seriously impacted the food chain in the Greenland-Labrador Basin on which maturing Newfoundland salmon rely.

North Atlantic Oscillation
Pressure differential between the Azores and Iceland
& 5 year moving average (black line)
1870 - 2010

And this variability is not new. The weather that comes to us in the autumn and winter is largely determined by the balance between the Azores High and Iceland Low atmospheric pressure systems, known as the North Atlantic Oscillation.  This graphic shows the annual balance over the past 140 years, which is clearly highly variable.  When it's positive (i.e. the 2 systems are in the 'right' place) the cyclones generated by heat at the equator can reach us, and we get 'British' weather.  When it's negative, they can't and don't.

At the moment we're in negative territory. The pressure is higher in Reykjavik than Gibraltar.  In a 'normal' year that lovely low south of Greenland would spend 3 days dumping rain onto Scotland to deliver salvation to the Findhorn.  This year it doesn't look like it's going to happen.  Just like last year, the North Atlantic weather map is a disorderly, but wholly natural mess.  Once a high gets settled, it's hard to shift, sits tight over Scotland and deflects all the nice rain to Spitzbergen.





Now, just when you thought you'd had enough science for one day, we encounter the associated phenomenon, the Arctic Oscillation (or more properly, the Northern Annular Mode).  If I understood the interaction between NAO, NAM and Jet Stream I wouldn't be here.  However, the key point is that our weather and the salmon's life is affected by unpredictable global scale influences, most of which remain unseen and unknown to us.  A couple of seasons of adverse NAO and NAM outcomes may cause a massive change in surface plankton availability in the Labrador-Greenland Basin, leading to copepod losses; consequent capelin, shad and sprat prey species decline; and salmon degradation.  Of course, there's also, and always, a reverse case: think of 2004 or 2011, and hope for 2015.  Please don't panic and don't succumb to 'something must be done' unless it's a genuinely big thing on the Vigfusson scale.  I'd hate to have a blank year, but growing up deep in the countryside I learned that I must accept the inherent variability of the natural world, for without that variability there is no wonder.  My young life was determined by sunrise and sunset; the rise and fall of the tide; the passage of the seasons; and at all times by the weather, over which I had no control.  There are cycles in all natural things, and nothing is constant.  The fact that those cycles trump our desires does not bode the end of the world.

I'm not saying everything is perfect, or denying that the fishing in some rivers is presently in decline.  North Sea oil in the east and salmon farms in the west have undoubtedly had significant consequences.  But I note that others are improving: the Tyne is well documented; the Ure up-count has more than trebled in 3 years; the Wear is coming on nicely; and there are high hopes for the Tees.  The salmon is a uniquely successful and adaptable species (have you seen the latest research on its temperature tolerance range? It's 5 times greater than the cod's), but there are limits.  I suspect it finds the noise pollution of the North Sea oilfields and Aberdeen harbour unbearable.  

On that note, I'll go back to my apple crop, which is cyclically good this year.  Best of all my wife can't see my frantic Yorkshire Rain Dance when I'm in the orchard.

Blinded by the Light

Dark Shrimp's First Swim 22nd August
Swimming and visibility trials

It had been almost 3 months since I had been on the Ure, so I was developing a serious case of salmon blues. The MCX Dark Shrimp was looking at me reproachfully from its box,begging me to take it for a swim.  Each morning, clad in lycra for the 10 miles to work, I could sense the jealousy of my unused waders, jacket and rods, as they were left in the garage and the bike got the outing.  To make matters worse, they were suffering the undignified and dusty consequences of my annual August refurbishment of a couple of sash windows.  One wonders what grumpy conversations take place at night between the unused fishing tackle, the bikes and the joinery tools.  The tackle would be greatly reassured by a quick word from my wife - "don't worry, he thinks of nothing else, insofar as he thinks at all" - but on the other hand, it wouldn't pay to upset the bikes, or least of all the power tools, which have the capacity for very painful vengeance.

To make matters worse, it's been raining frequently and hard in the Vale of York.  Indeed, the remnants of Hurricane Bertha brought our 8 week summer to an abrupt and very chilly end, whilst depositing 65 mm of rain in the process.  There's now a real autumnal feel in the air, which of course triggers every cell in my body to think salmon (it's not just fish that have things embedded in their cellular DNA).  However, Bertha seemed to skirt Wensleydale, probably as a result of the over-stocking of Yorkshire's collective prayers for the Tour de France to have a Grand Depart Sec.  And they were answered!  Anyone who didn't believe in our special relationship with the Almighty should have been convinced by the television coverage.  As a result we've only had one limited spate of about 1.5 m, which didn't persist long enough to bring many fresh salmon up from the Humber.  That put the kybosh on my New Year resolution to catch a salmon on a dry fly, which requires fresh fish and warm water.  On the other hand the sea trout didn't feel so constrained and the river's packed with them (of which more shortly).

I could take this torture no longer: water boarding without water so to speak.  So when a day's rain promised to put the river up by a few inches, I made my break for freedom.  Even though the possibility of catching a fish was very low, a day on the Ure would lift my spirits whilst fulfilling the serious business of conducting the MCX Dark Shrimp's swimming trials.  In addition, the accumulation of large numbers of underwater photos would give me more data to calibrate my theoretical Photoshop models.  So this post records the day whilst also exposing the visual challenges that confront salmon in a combination of bright light and coloured water (and satisfying my interest in the underwater visual aspects of our sport).

Trial Context

MCX Dark Shrimp #9

At #9 the DS was probably a little larger than the ideal for the water conditions.  With the river level at +5"/12cm, bright sunlight and a water temperature of 14C, the MCX score was around 7.  The biggest variable was the sub-surface clarity.  At the edges,or when viewed in shadow, the water appeared very clear.  The situation below the surface was markedly different.

Frodle Dub looking downstream

This shot shows the bright conditions and the clearly visible bottom in the foreground, out to a depth of 12-15"/30-40cm. Taking this view at face value you would be reaching for a #12 Blue Charm or Stoat's Tail.  The photos that follow are all taken with a Panasonic FT20 14mps rugged submersible camera mounted on a tilt-head extending monopod.  Although the FT20's nominal focal length is 7mm, in practical terms it is almost double that of a salmon's eye, with a correspondingly narrower field of view.  There's a fuller discussion of the salmon's visual capabilities in 'Here's Looking at You', but you can take it from me that the conditions illustrated in the succeeding photos would have presented a challenge to the salmon's vision and target detection.  This is for 2 main reasons.  First, unlike the human, the salmon doesn't have a fast-acting iris in its eye to control the amount of light entering.  Instead it relies on a relatively slow-acting chemical pigment on the retina (in effect a bit like putting on dark glasses).  And second, the 160 degree field of view of the salmon's eye will encompass everything from the dark brown bottom to the brilliant sunlit surface circle of Window 1.  Resolving the huge range of contrast between and within those extremes inevitably involves compromises in resolution or sensitivity, or both.

Health Warning.  Once again, please note that I am not claiming that these photos faithfully represent what the salmon sees, because we just don't know.  We do know the optical characteristics of the salmon's eye, but not how its brain processes the inputs, resolves colour, forms an image or employs the product in its situational awareness and decision making (conscious and/or unconscious).  Certainly the salmon's eye has evolved to meet different purposes to ours in a markedly different environment, so it's a reasonable supposition that they don't 'see' like us.  For those reasons the purpose of the succeeding photographs is purely relative within the context of the visible red-yellow-blue spectrum: A is more readily detected than B; under one set of conditions detection is easier than in another; one scene is brighter than the next; and the comparative luminance or transparency of the 3 Windows that comprise the salmon's visual environment.

Depth 3'/1m
Sun Out
Horizontal
Direction - South East

Blinded by the Light.  In contrast to the pretty photo above, this was the reality 3' down, looking across the pool when the sun was fully exposed at 2 pm.  Windows 1 (opaque, bottom), 2 (reflective, middle) and 3 (clear, top) are all in the frame.  The dominant features are the extreme brightness of the direct sunlight in Window 1; its consequential effect on the contrast in the lower regions; and the backscatter caused by fine, highly reflective mineral particles suspended in the water.  The net effect is that a fly 6'/2m away is rendered invisible.

Depth 3'/1m
Sun In (cloud)
Horizontal
Direction - South East

And this was 10 minutes later when the sun went behind a passing cloud.  Brightness, contrast and backscatter are all markedly reduced.  By the way, there's no fly present in this shot.

Depth 2'/60cm
Sun Out
Oblique
Direction - South East

If we raise the angle of sight to the salmon's 45 degree attack angle, things become rather clearer when the fly is viewed in Window 2 at a range of 2'/60cm.  This is what a fish closing in to take would see.  It is interesting to note that the silver banding on the fly's body is invisible under these conditions.

Depth 2'/60cm
Sun In (cloud)
Vertical

However, if we increase the angle towards 90 degrees, the fly appears in Window 1, and is highly visible as a silhouette provided there isn't direct sunlight and rippled water, as shown below, which hides a fly in the dark stripes.  These pictures give a distinct clue to the merits of using floating and hitched flies in high summer.

Dark Shrimp Impressions

The DS swims beautifully - stable, level and entirely without rotation - at all water speeds.  It also flies nicely: well, you don't imagine I spent the whole day without casting!  Owing to its understated dressing it swims somewhat deeper than the equivalent sized Cascade or Ally Shrimp, but not so much as to dispense with the need for sink tips in faster water.

As described above, the trial took place in extremely challenging conditions for detectability - the capacity to catch the salmon's attention - for a fly designed for lower levels of brightness.  I shall need to take more trial shots in the lower light levels prevailing in September and October, which as you can see from the graph are about half those in August, and much better matched to the salmon's visual characteristics and the Dark Shrimp's design brief.

Depth 3'/1m
Sun Out
Direction - South
Low oblique, range 6'/2m

Despite the very challenging conditions of contrast and backscatter, the DS fared well. This shot shows the results at an exceptionally demanding near 2 metre range within Window 1 (the Ally Shrimp was lost at just over 1.3 metres).  There is faint flash from the sparkle in the tail,  but more black in the main and tail dressing could be beneficial.  A salmon would detect this faint target relatively easily, provided that it was moving.

Depth 3'/1m
Sun partial cloud
Direction - South
Oblique, range 4' 6"/1.5m

Up in Window 2 (at midday), at a range of 1.5m the detectability and colour differentiation are good.  I judge that the orange content is about right for the conditions.

2.5 lbs

And here's a second opinion on that! Having set out to design a salmon fly, on this day at least, the Ure's sea trout found the large Dark Shrimp irresistible in bright conditions in broad daylight, and amidst a consistent hatch of sedges that they were taking on the surface.  This was the first and smallest of the three that stayed on to come to hand.  Its successors were 3 and 4 lbs respectively and nicely silver-grey, comprising a most pleasant but wholly unexpected reward in the absence of a salmon.

Conclusions

Overall I judge that the DS provides an excellent basis for further development.  The key test will come in the duller days and lower sub-surface light levels of September and October, which framed the design brief that I gave to Darragh for tying the prototype.  Even at this stage of development I shall fish the Dark Shrimp with some confidence.

Prototype 2 will involve an increase in the black component of the body and tail, and possibly a reduction in the silver banding to a narrower thread.  The orange fore hackle and red head look perfect, so no changes there.

One other thing you may have noticed (or rather not) in the photos, is the near invisibility of the Seaguar fluorocarbon leader in almost every instance.

It's that time of year, I can't wait to get out again, but a very nostalgic trip to France for the commemoration of the 100th anniversary of the outbreak of the First World War and the Battle of Nery on 1st September will take precedence.  Thereafter, with no Tomatin week this year, the Ure will feel the full force of my enthusiasm and energy.  Anticipating your own enthusiasm, I wish you tight lines.

End of the day, job done, DS takes a breather in good company

Comparator Photos

Just for interest I attach a selection of photos of the classic low water flies - Blue Charm and Stoat's Tail - taken during the test, without analysis or comment.

Blue Charm
partial cloud
distant

Stoat's Tail in Window 2
strong sun

Blue charm
full cloud
short range with shallow camera

Stoat's Tail
having crossed the Window 2-3 boundary
short range ca 2'/60cm
excess definition?

MCX Dark Shrimp - The Prototype

MCX Dark Shrimp Prototype 1 #9
(Tied by Darragh Digney)

It's arrived!  You will immediately spot its derivation from the starting point of the Cascade.  What are the differences and the reasons for them?

• There is a greater proportion of black in the body, which also extends into the tail, in order to increase definition and detectability at lower light levels.  
• The tail is made longer to allow shortening when water level and speed so dictate (see Hot & Cold Running Water posted in November 2012 for an explanation of the correlation between fly length and water speed).  You can cut dressing off, but as it doesn't stretch, scope for adjustment is handy.  I regularly reach for the scissors to tailor the overall dressed length of flies to the conditions.
• The dressing is more sparse in order to gain slightly more depth without the need for a sink tip (of which more below).  

It's a nice neat, understated fly, with excellent detailing.  No doubt it will evolve during the development process, but I'm very happy with the starting point: thank you Darragh.

Photoshop Simulation

Here are a couple of photos with the normal water attenuation of the red element of the spectrum applied using Photoshop, at two different sample light intensities.  As usual the significance of the black for definition and detectability is evident.

Of course this sort of photo-simulation is no substitute for the real thing.  It's not intended to be indicative and relative, not precise.  But we do know what water and the stuff floating in it does to light, which we can simulate respectably.


To see what I mean, compare these two views of different rivers, one snow-melt fed, the other mountain spate fed, in almost identical conditions of light intensity, sun elevation and river height (+10").  From above the surface both samples appeared quite clear.

Dee

The green tinting of the Dee in early Spring is a product of the detachment and discharges of rapidly growing vegetable matter in the shallower stretches.  The background water tone is grey, which is what you would expect in the absence of rain run-off transporting peat fragments and soil particles into the river.

Findhorn

The dominant feature in the Findhorn 3 days after a 18"'/45cm lift is the effect of suspended peaty materials, which absorb a very high proportion of the red element of the spectrum (>35% per metre) and thus appear red to the human eye.  Indeed, the dominance of the red light effect diminishes the apparent visibility by over-saturating the image.  What the salmon makes of it is unknown, but the relative shift between the two tints is likely to remain broadly the same.




As I build an increasing library of underwater tones and analyze their spectral make-up, so I shall be able to calibrate the Photoshop simulations more precisely.  But they will only ever be approximations.  Nevertheless, uninformed observation can be far worse!  Not all water is the same.  Rivers differ by nature, tone and colouring tendencies as a result of their geography and geology.  And the angle of impact and intensity of the light is a major factor.  It helps to have an understanding of the medium in which you will present your fly.

The Trial Regime

The next step will be swimming trials and underwater photography at varying depths, distances, water states and light levels, which needless to say will be combined with plenty of random fishing experiments.  Salmon are a statistical and analytical nightmare, the very definition of random.  There's no consistency in behaviour; catching is a very rare event; each event is unique (in all its aspects); and the salmon refuses to undergo debriefing before release, so you haven't a clue why whatever you were doing at that instant worked (or not).  You catch a fish on an Ally Shrimp, but for all you know, it might have fallen for a Cascade or even a roast chicken in that moment of aberrant madness.  My first concern is with what the MCX Dark Shrimp looks like underwater, where it has to be mobile but stable; detectable at distance in a broad span of light and water conditions; and 'impressionist' rather than imitative.  Given some water in the Ure (and yes, it's raining today) the first stage trials should be the subject of my next post.  Even if the water isn't perfect the trials will give me a self-justifying excuse to get out for the first time since the end of May.

The Effect of Dressing Density

You might question the sparsity of the dressing, especially as full-bodied flies seem popular at the moment.  Recently I bought a small tube fly for research purposes that probably denuded a full coop of chickens in its construction.  I'm not convinced by ample dressing.  As a general rule in moving water and at common weight, more dressing generates more lift, which may not be what you want because presentation depth is important.  You might be surprised by the effect of small differences in dressing on the depth at which the the fly swims.

This is the Sparse Stoat's Tail, which I favour in clear, warm, lower water conditions for deeper lying fish, because, despite its diminutive size, it sinks like a small stone, especially in slower moving water.  This is very useful when your target zone is beyond the main flow and sinking time is at a premium. Two examples come to mind, one on the Carron the other on the Alness.  Both involved fish lying very deeply against the side of large rocks, which you could not get at from upstream.  It required a square cast and fast sink with minimum disturbance, which the SST duly delivered.

The small Blue Charm is my favourite for most summer low conditions, but even the small amount of extra dressing causes it to swim higher in the water.  An experiment on the Ure last year indicated that the differential between them could be as much as a foot (30cm) in some cases. As a result takes with the Blue Charm tend to be highly visible, whereas with the SST I have found that is rarely the case.  So please think about the depth at which the fish may be lying as an important factor in your choice of low water fly.


Given some more rain I'll be back to report on the first stage trials of the MCX Dark Shrimp in a couple of weeks.  In the interim, tight lines.

Eye of the Beholder - The Search for the Perfect Fly

I haven't written anything recently because 7 rainless weeks have reduced the Ure to a stream and made fishing fruitless.  Fortunately (from my perspective - my wife disagrees) Yorkshire has been much cooler than southern England - today Wensleydale is 12 degrees cooler than Essex - so to date we've avoided serious depletion of the oxygen that would otherwise threaten the dozing salmon.  There are plenty of fish in the river following an excellent May spring run, but they are now semi-comatose residents unlikely to respond to a fly except during short periods in the early morning and late evening. Under these conditions I prefer to leave them in peace and await the arrival of the early autumn runners.  As the insect life on the Rye has gone on strike, my garden is in unusually good order: it's a very good rose year.

In parallel with this inactivity, the Islamic holy month of Ramadan (28th June - 28th July) has greatly reduced my Gulf clients' work-rate and thus given me ample thinking time.  Amongst other things I decided that I needed to do more on salmon vision and visual stimulation. My March 2013 post - 'Here's Looking at You' - explained how their eyes work and the effects of attenuation on what they might see.  From that I offered some general thoughts on the relevance of those factors to fly design and selection.  Put simply, in the dim and murky world of of an autumnal spate river in mid afternoon, the black component of the fly stands out better and is therefore more likely to catch the salmon's attention than the brighter colours.  In brighter conditions, dull grey or brown tones deny the salmon a clear enough image to see that the fly is something alien.  But neither of those points, valuable as they may be, addressed the inevitable challenge of "so what?"  The discussion was incomplete.

The "too good look"

Over the past month I have been enjoying Topher Browne's Atlantic Salmon Magic, a birthday present from my very generous wife.  That said, she is a Yorkshire lass with a keen eye for value, who would have baulked at the original cover price of £100, but found a 50% price cut irresistible.  There's vast experience and common sense sprinkled throughout its immense volume, in between stunning photographs and backwoods homilies.  Two nights ago one line caught my imagination, in words to the effect that "you need the salmon to notice the fly, but not to get too good a look at it".  In other words, in design, tying and presentation, we must remember that the fly's purpose is stimulation, not imitation.  Indeed, my own experiments involving the observation of salmon reaction (or more often not) to precise representations of food species, suggests that imitation may be an unproductive blind alley.  So the fly needs to trigger embedded responses, but need not be the thing itself.  

Of course we're only guessing and there are some big variables in play:

• We don't know the trigger mechanism and the largest variable is whether the salmon is in the mood to be stimulated and to what degree.
• Then there is presentation and the unanswerable debate between the 'right' fly presented badly and the 'wrong' one fished well.
• There's visibility, which varies from river to river, level to level, day to day and hour to hour, so the 'perfect' fly may only be perfect - or rather good enough - for relatively short periods.
• We don't know how the salmon perceives colours.
• And of course, superimposed throughout, is chance - Falkus' 'outrageous fluke'.  

Fine Distinction

With all these variables, can we know the merit of fine distinctions between patterns?  If nothing else, good salmon flies stimulate fishermen!  My grandfather and father in his turn held that most salmon flies were tied to catch anglers, not fish.  A well tied fly is aesthetically pleasing and often beautiful in the eye of the beholder when viewed in crystal white light.  But the acid test is how it appears when viewed at the taking range of 2m/6' while immersed 30cm/12" deep, tracking through the moving water of a spate river running at +30cm/12" at 3pm on a dull September day.

Selection of shrimp patterns
Images by Fulling Mill on Sportfish website

Here we have a selection of 6 very popular shrimp double patterns.  The differences between them are readily discernible in white light (albeit there's a small white balance problem with No 6).  Of course, there's nothing in the natural environment of these orange/red shades, so there's no imitation here.

Photoshop simulation, not size corrected for distance

Using Photoshop, this picture simulates the brightness and definition of the same flies, in the test conditions described above. You may agree that the differences between them are becoming less readily detectable.  However, as the contrast falls the definition of the black elements is relatively stronger than in white light.  

Photoshop simulation of sinking head presentation
1" Cascade Conehead, depth 1m, range 2m, poor light
Not size corrected for range

Moreover, as depth or range increases, or ambient light declines with the season and conditions, the red component of the light reflected by the fly diminishes rapidly (about 24% per metre).  In those circumstances the orange dressing takes on an an increasingly grey appearance, whilst the definition of the black remains significant. Of course a salmon capable of catching grey sprats in a grey ocean at high latitudes has no problem detecting such objects, provided that they are moving, and for optimum performance, above the horizontal sight-line (i.e. in Window 2 or 3).

Orange, grey or downright dull?

Given that all the patterns in the sample are successful, and all display about the same sort of colour in the specified underwater conditions, then we a heading towards a conclusion that a fly that appears grey with some contrasting black seems to work well in autumn conditions.  This is consistent with the experience-based ghillie aphorism for autumn fishing of turning your fly with the leaves, towards patterns with a predominance of red or orange.  Taking that argument a stage further, let's look at two closely related and very popular patterns.

The Cascade is almost the universal fly for dirty water and anything other than bright conditions.  If I was told that I could only fish with one pattern for a whole season (or life), this would be it (albeit I'd cut back some of the dressing in clear water). But is its success owed to its orange component, the black, or the balance between them?

Its first cousin, the Ally Shrimp, has much less black in the dressing and a red body; and less mass and length in the tail (even after allowing for the smaller size #10 vs #8) .  I find it works better than the Cascade in brighter conditions.  This one certainly did, as you can observe from the damage to the hackle, inflicted by 2 good fish on a bright, warm September day.

Ally Shrimp & Cascade
Photoshop simulation of clear water & bright sky
Depth 1'  Range 3'

Now put them into relatively clear spate river water, at mid-morning light on a bright day, at a depth of about 1'/30cm, and examine the salmon's eye view from a range of 3'/1m as it approaches to take.



This is a very different prospect to the dull September afternoon with the river at +12".  The level of absorption of the red light is greatly reduced, so the orange elements stand out.  The Cascade has very strong definition and contrast.  Does this allow the salmon to get "too good a look"?  In comparison the Ally Shrimp appears more bland and anonymous.  Could it be that its dullness is the key to its superior performance when fished shallow in brighter conditions?

Low clear water flies

Thunder & Lightning, Hairy Mary, Silver Stoat, Stoat's Tail
Clear day, depth 1'

Putting a selection of four popular low water flies together in the same simulated conditions, we observe an almost complete absence of red/orange tones.  However, at this sizing there is strong black definition of the outline.  They are popular because they are successful.  Is there are connection between their success and the absence of red/orange?

If we re-scale my favourite Blue Charm to represent the smaller #12-14 fly size I tend to use in such conditions, and correct for the distance from the approaching salmon, the black definition is slightly suppressed, when viewed horizontally against the background of Window 1.

Viewed obliquely in Window 2 it will look more like this (relative adjustment for background brightness), and in Window 3 it becomes almost entirely black.  It's an approximation of some kind of nymph, but certainly not a close imitation.  As a result the salmon will not be able to discern much and so is less likely to be deterred until the last moment.  In both horizontal and oblique views the black is critical to the detection of a very small moving object at distance (which is why all the RAF's trainer aircraft are now painted black rather than red and white).

Conclusions

So where did all that tell us about fly design?  Everything that follows is wholly conditional, but it appears that:

• In dull conditions and at depth in coloured water, the fine distinctions between broadly similar orange/red shrimp patterns are irrelevant.
• The real value of orange may not be in its high visibility in air, but rather that in water it looks an interesting shade of grey in dull conditions and/or when the fly is fished deeper.
• The orange based grey differs in some way from pure grey, especially at closer ranges.
• Black is the key to detection - alerting the salmon to the fact that there's something there, however small, over extended distances in all water conditions and depths.
• As the water clears and lightens, or when fishing shallow, bright colours and excessive definition may allow the salmon to get "too good a look" at the fly and may therefore be disadvantageous.
• For clear bright water, dull anonymous dressing seems to work well, possibly by preventing the "good look".
• None of the most popular low water flies have any orange/red component.
• There is no obvious way of combining all of those qualities in a single fly.
• The perfect fly is probably two black-bodied flies: orange for dull conditions and deeper fishing; and grey/brown for bright and shallow.
• The open question is the optimum proportion of black in each design, which I can only refine through practical trials on unpredictable fish.

So what?

There's not much point reaching some conclusions and not putting them to the test.  So the next step is to design, refine and test some prototypes.  As I don't tie my own flies the challenge was to find someone open-minded and willing to work with me on the project.  The perfect candidate was the very talented Darragh Digney in Belfast, who despite having little salmon fishing experience, shows an extraordinary and original eye for colour and design in tying flies.  Fortunately he agreed to help me, and after consultation the first prototype of the MCX Dark Shrimp is now complete.

In subsequent posts I shall describe our joint development journey, but I shall certainly need some water for testing and trials!  For the sake of my farming friends (and to avoid being lynched) I'll postpone ordering Dave Bamford's Wensleydale rain dance for a couple of weeks.

For those of you lucky folk with water, tight lines.

Running Lines and Dog Days

Author's Note 11th August 2016

I have now updated this post to reflect my experience with the 35lbs BS Rio Connect Core running line in Norway this year.


One of my regular readers recently reminded me that I hadn't published the review of the Rio Connect Core running line that I took on the spring trip to the Dee.  This post seeks to redress that idleness, and also extends into some more general musings on running lines.  

But as usual I'll issue the usual health warnings: first, I'm not a casting guru; and second, I started using detachable shooting heads with pure running lines only 3 or 4 seasons ago, and as I tend to buy things and stick with them, the range of types I've used is limited.  On that basis I would only recommend buying a new running line if the old one clearly needs replacing.  That said, a running line has a much shorter service life than either the shooting head itself or a classic salmon fly line.  This is because the wear applied by the top ring during casting is concentrated in a very short length adjacent to the end loop - perhaps as little as 1-2 feet - even if you do consciously vary the 'overhang' between successive casts.  Furthermore, the PVC or PU coating is much thinner on a running line and correspondingly less durable.  If it breaks down for whatever reason, the wear then bears directly on the more vulnerable inner core of braided thread or monofilament.  Accordingly I suggest that you check the last 3-6 feet of your running line for damage and wear by sight and feel at the end of each fishing day.

The running line needs the same cleaning and lubrication maintenance as other lines and heads, which I described last year in 'D-14 The Countdown'.  If you look after your running lines and use them for, say, 10-20 days per year at most, then barring accidents and damage, they should last for up to 5 years (as compared to the 10+ you can expect from the heads and classic lines).  But there's no hard and fast rules, and you must keep a close eye on issues like cracking of the coating.

Rio Connect Core

It was wear and tear adjacent to the end loop on my oldest Rio running line that caused me to seek a replacement.  I confess to a long term loyalty to Rio: although I do own some other brands of line, I've always been pretty happy with every Rio salmon line I've bought.  But all the major manufacturers and 'branders' share the same problem.  Their products are generally excellent but last so long that it's hard for them to make a good regular profit (it's what killed most English shotgun manufacturers).  Consequently they have to keep introducing minor improvements, changing the names and advertising furiously to move enough volume to make a living.  By such means did Rio's Windcutter become the Short Spey, and the AFS the Scandi.  There's not great differences between them (apart from new colours) but the angler rapidly becomes boggled by the kaleidoscope of changing names, slogans, categories and ad-verbiage.  In my book the greatest villain is Airflo - the only British manufacturer of salmon fly lines, and uniquely in PU (polyurethane) - because I just can't make head nor tail of their range, which doesn't seem to be fully represented on their own website.  There are lines that are on the Glasgow Angling Mega-Store list, but not on Airflo's, and vice versa.

Rio introduced 2 new running lines for the 2014 season, both with thicker gripping sections, so I duly consulted the dealer and received the following advice:

• The Grip Shooter, which has a monofil core, is best suited to experts for whom absolute distance is paramount.
• The Connect Core, with a braided core, was the better choice for normal mortals and lesser incompetents like me.

Here you can see the extra thickness of the orange gripping section compared to the pale blue body.  It extends to some 15'/5m of additional PVC coating material.

The key question is whether it's useful.  In the first instance I found it quite helpful, especially when wearing gloves in cold spring conditions.  I could get a good firm grip of it against the cork rod handle, and feel it was there (something that isn't always easy with finer and softer products).  On those grounds I suspect that it would be helpful for anyone new to shooting head fishing who was yet to develop the knacks of running line feel, release and control.  For more experienced users it will probably be useful, but it's not transformative.

However, the best thing the fat orange bit did for me was provide much better situational awareness whilst recovering line.   It is a real boon when fishing in low light levels and semi-darkness.  When fishing with a shooting head, after a little bit of 'diddle at the dangle' you tend to strip in the rest of the running line quickly in order to get the fly out and fishing again with minimum delay.  If you're using blandly toned lines with no marked colour differentiation (like the Loop sinking 'green mamba') it's all too easy to overshoot and pull the end loop into the rings, especially if you are using the down-time to think about other things.  The arrival of the thick orange section in your hands sends an immediate signal to slow up: with a 14' rod there's about another 2' 6"/75 cm or one full left-handed strip left to go before the loop arrives at the top ring.  Thus I could position the line consistently in the optimum casting position with minimum thought whilst applying my mind to other things like positioning my feet for the next cast and so forth.  Within an hour I became convinced that this was a thoroughly good thing and well worth having.  My subsequent experience in Norway strongly confirmed this view.

I was, however, less convinced and enamored by the thin blue stuff that comprises the 20lbs BS running line.  My running line management isn't good at the best of times (you can get away with a lot on smaller rivers). This season I've been making a real effort to make orderly loops of about 6-10 feet (i.e. 12-20' of running line) on the fingers of my lower hand, although their sequential release remains somewhat erratic (my excuse is that various bits of my left side don't obey orders reliably).  But despite all my efforts I've had more blue tangles at the bottom rod ring than with other running lines I use regularly.  It's not that frequent, but it is annoying.  Although I suspect my line release may be the villain, that wouldn't explain why it happens more often with this blue line, thereby degrading the advantages of the thick orange bit.

However, in preparation for Norway I bought the heavier straw coloured 30lbs running line.  Its tangle-resistance performance is orders of magnitude better than the blue runner.  Over the course of a week, much of it casting at maximum range with a lot of loops, I had only two tangles.  In that respect it easily trumped my previously favoured Loop red runner, which I was using on my other rod.  As a result of all that, I can come off the fence to state that in my opinion the yellow Connect Core is top dog amongst the running lines I've used in the past 5 years.  But don't buy the 20lbs blue version.

Running Lines - Slick versus Balance

A lot of the promotional language used in relation to running lines focuses on 'slickness' or friction reducing designs such as 'ridging'.  Taking that to its limits, would a zero friction running line be desirable?  I discussed this with Alan Maughan during my last lesson, who staged a small demonstration of the realities.  It involved wrapping the running line around the lower blank between the cork and the stripper ring in order to deliberately add restraining friction to the shooting process.  This produced no discernible impact on distance or loop integrity.  Nor did a second wrap.  The point Alan was making is that for a shooting head to work efficiently there needs to be an appropriate balance between the running line and the head.  I pondered this further during my day on the Tweed at Rutherford where the size of the river required me to work closer to my maximum range than the Ure.  The diagram below helps my understanding of the issues.

Rio Scandi & Connect Core running line in flight
(with acknowledgement to Henrik Mortensen)

What you are aiming to achieve in the later stages of the cast is a slightly higher forward speed in the line in the top half of the loop than in the bottom, which progresses towards a smooth and complete turnover.  That condition requires the restraining drag on the bottom- predominantly made up of the running line - to be slightly greater than the air resistance of the line and fly above.  With a big fluffy fly or tube that resistance can be substantial.  If the resistance is not balanced by tension on the low side, then the unwinding effect of the loop will slow, possibly stall, or worse still go into reverse, leading to turnover failure, with the leader pointing back towards you.  If the lower side tension is excessive, the rotation of the 'wheel' will accelerate, consuming the top side more quickly and thus turning the line over before the full casting distance has been achieved.  The ultimate version of that case is the 'hard stop', when the running line comes to an abrupt halt, leading to a chaotic high-speed turnover or 'bounce-back' with the fly jerked back toward the caster.

Success requires the right balance between the top and bottom of the flying loop, which depends on active control of the running line as it goes out between your fingers and the cork during the final phases of the head's flight.  All too often, when we're starting out, amidst the effort-induced mental blur of the cast, we tend to let everything go at once, which leads to random results at the far end, across the spectrum from stall to hard stop.  A degree of control is essential if we are to achieve optimum presentation and respectable distance (note the order of those two things!).

So what do I draw from that?

• Within limits, for the average caster, slickness is an over-stated feature.
• 'Control-ability' is vital.  Indeed, your ability to do useful things with the running line in the later stages of the cast is as important and gripping it at the beginning.  This is more easily achieved with a thicker running line than a thin one, so consider going up another step on the thickness/breaking strain ladder.  It won't cost you distance and the greater stiffness of the thicker line should reduce the tangling risk.
• Colour differentiation between the running line and the head is very helpful.  Note that pale green is potentially problematic in low light levels, especially if you are using yellow or orange tinted glasses.
• The thicker orange bit on the Rio Connect Core line is generally good news.
• I need more disciplined practice of my running line management.

Dog Days

We're having a strange start to summer in Yorkshire.  It poured with rain through May and into the first week of June, but for the past 3 weeks we've had a cool dry northerly airstream.  Many days have been cloudy and grey, with the temperature only nudging the 20C threshold.  It's had a marked effect on fly hatches on the Rye, which tailed off as it set in.  I can't recall spending 3 hours looking at a beautiful bit of trout water in mid-June without seeing a single olive hatch.  Nature can be strange at times, but its unpredictability is part of its charm and wonder, including the dog days.

I tend to leave the Ure salmon in peace at this time of year and especially under these low water conditions.  The spring fish that ran up into the upper reaches of the river during the May spate are now comfortably ensconced in residential lies, and will only become active in the early morning and late evening, if at all.  The very large hen fish which I've used as the tab for the Ure salmon fishing site was a late evening taker of a very small fly.  More generally, if I've got a beat booked and the water turns out to be low, so be it, and I'll fish.  You'll find some thoughts on low water fishing in an earlier post - Calm Reflections.  But if I know the water's low, as it is now, I won't book a beat and will leave them alone.  After all, I'm still in full time work and the garden's pretty demanding at this time of year, so I must save the rain dances until late July when the harvest's complete (so my farming friends don't lynch me).   Until then, be patient, and tight lines if you do go out.