Sábado 22 de Marzo de 2008 00:00
SOONER or later winter brings high water levels, or a severe cold spell, both of which see us delving into boxes of weighted bugs and nymphs to scour the streambed. Nomadic by nature, grayling are considerably free-ranging especially in a given pool when modest flow rates will see them readily move to preferred feeding lies. However, a big spate, or Arctic temperatures often restrict their movements to more comfortable stretches of a stream. In real extremes this might mean only one or two key places. For example, in a raging flood the inside bend of a river offers protection from battering flows (Diagram 1) Equally, a deep depression/hole provides sanctuary in either spate or freezing conditions (Diagram 2) With this and the fact that insect hatches generally ebb during winter months, grayling initially seek food close to the streambed.
Typically, it's the maturing invertebrates that will sustain grayling during harsh winter months. Larvae and nymphs like caseless caddis, cased caddis, shrimps, olive nymphs and stonefly larvae all provide welcome nourishment. Vulnerable, these nymphs spend much of their time ambling about in the relative safety of a streambed. While many small nymphs can be imitated on hooks ranging from size 12-16, some of the stonefly species and cased caddis can attain an inch or more in length, suiting hooks as large as size 8 or even 6. This might sound large, especially when you consider the grayling's fairly small mouth, but even small grayling are capable of engulfing large food morsels.
Key species to imitate include caseless or free-swimming caddis larvae, cased caddis and shrimps. The first two are a grub like creature. The only difference is some prefer to build a shelter (cased caddis) while others (caseless caddis) take their chance simply lodged beneath rocks. But both never venture very far from the streambed during their larval stage. Even when they're dislodged, many river currents act like a downdraft, constantly pinning larvae to the streambed where they helplessly drift until gaining a secure foothold once more. It pays then to constantly bombard this area with our flies.
Shrimps (Gammarus) are often neglected. Yet they feature on most waters and more importantly are a potential food source to grayling all year. I can't stress this last point enough. I think it's a case of what the eye doesn't see' and because of this they are rarely at the fore of our mind. About 40 per cent of my river nymphing fly box contains shrimps, an indication of how much I value them.
In a state of drift both shrimps and caseless caddis often assume a protective curved posture. Equally they frequently straighten their abdomens too. especially shrimps that scuttle about with elongated bodies. So you may question whether to use curved or straight shank hooks? Fish must see a fleeing shrimp, swimming with an extended body — reason enough to tie your fly on a straight-shank hook. On the other hand, shrimps and caddis larvae negotiating the rough and tumble of a relentless river are possibly best copied on a curved/grub hook. Nearly all my shrimp patterns possess this characteristic hump. Remember too, that flies tied on curved hooks tend to fish inverted with the point uppermost. Surely these are less likely to catch any unwanted snags? I suggest you stick with whatever works for you.
No doubt many will be familiar with the phrase Czech nymphing which seems to have become a generic term for any heavy bugs fished in various manners. And while a bunch of patterns fall into the category of Czech nymphs' a much more accurate term for the technique is "short-line nymphing" and was coined by master nymph-fisher Oliver Edwards. It involves having only a couple of feet of fly line outside the rod tip. The huge advantage of this method is that precise control can be achieved over the business end of things.
WHILE a nine-footer is a good all-rounder slightly longer rods facilitate superior line control and one of 9ft 6in. or even 10 foot should be considered when nymphing. Where snags are prevalent, leaders of 51b and more, even 6lb give some hope of claiming your flies from any sunken obstructions. Whatever style of nymphing you chose, a straight-through leader of a given diameter will suffice as the sheer weight of the flies aid leader turnover. A tapered leader possesses a much larger surface area that will impede the flies' descent, especially at the thicker butt section of the leader. Much thinner for its entire length a straight-through leader slices through the water, sinking more readily. Whether you opt for fluorocarbon or copolymer is up to you. Limp and supple my preference is copolymer, mainly because I'm so familiar with it and know its limitations.
With a leader approximately spanning the rod length (9-10 feet) three weighted flies are positioned 20 inches apart (Diagram 3) Initially, the heaviest bug occupies the middle dropper to fish the deepest thus allowing the point fly some freedom with the top dropper acting as a sweeper (Diagram 4a). If you aim to explore more of the water column then consider attaching the heaviest fly to the point (Diagram 4b) While this set-up is widely recognised you're not bound by rules here, so if you're more comfortable with just two flies, or sometimes even one. then use them. Though do remember that there's more ballast in a team of three flies that help access deep or fast-moving water. If fishing a team of two the same weighting arrangements can be employed with either the heaviest fly on the point or dropper (Diagram 5a & 5b).
COLOUR OF FLY
REGARDLESS of river height and state, grayling can respond to flies of varying colours. Brightly-coloured flies like pink and orange are known favourites in stained flood water. Yet. dark flies like black, give a definite outline and can be lethal in murky water.
A trio of bright flies might well spook fish in low, clear conditions. So our team should include one or two drab-looking grubs. Try breaking it up with the sombre fly separating the flashy ones (Diagram 6). maybe then they don't appear too suspicious? Obviously there are many connotations here and. despite water clarity, sometimes grayling want nothing except a bright pink, sparkly job in sunny conditions!
WHERE TO START?
SHORT line nymphing involves pitching the flies, leader and a short section of fly line upstream. Strong flows make casting and negotiating the flies downstream hectic, which is why it's advantageous to fish a shorter, more controlled line.
Fished close together the team of heavy flies will sink quickly. With the rod tip holding fly line clear of the water, track the steeply-angled leader downstream. Remember to guide the rod at a slower speed than that of the surface current. Down on the streambed, friction between water and substrate reduces flow rate. Given any appreciable push, as a guide, good results are often achieved in moving water from knee to waist deep. Though I’ve seen grayling taken from water of only a foot deep and equally from some dark, foreboding pools where one could only guess at their depth.
It's important then to fish into a situation and not just plumb the perceived best areas. So. extending about two foot of the fly line, begin in shallow water by pitching the nymphs broadside on. This subjects them and the entire leader to the flow, influencing them to fish higher in the water.
Progressing to knee-depth water, short lobs are now made more upstream at 45 degrees and once at waist depth, angling casts more directly upstream reduces the current's tell on the leader allowing the flies to plunge deeper. Passing downstream of you. the flies naturally lift in the water on a tightening line. Often a critical moment, this deadly lift can be emphasized by slowly raising the rod. almost like a blind induced take.
If no takes are forthcoming the rod can be lowered again, allowing the bugs to drop back, followed by another lift.
Careful wading is paramount now. as clambering about only serves to warn fish. Try to search water methodically and focus on the fly line off the rod tip. With such a short line, it's easy to assume that fish intercept flies with thumping takes, and sometimes they do. However, many times more delicate takes register as a mere hesitation or halting of the fly line. I'm fully aware that this method is far from new, especially to the seasoned angler. But newcomers will marvel at how close the flies are fished to themselves and that grayling happily tolerate our presence.
Hurtling heavy bugs into the slower main body of a pool, or shallow, skinny riffles, sees the flies hit bottom soon after casting. Now a subtle approach with lighter flies and finer tippets is better. Two nymphs three feet apart, on a 9-12 foot leader is my standard rig though a third can be added, or even a single fly might be used. In shallow water, or away from the turbulent flows, grayling might well spook easily. Likened to fishing Spiders up-and-across this method of upstream nymphing suits such circumstances. Casting slightly longer lines now not only avoids scaring fish; it helps work the flies in medium-paced water.
Deliver a cast of three or four rod lengths up and across the flow. If the current is quite strong then throw an upstream mend (Diagram 7). Though flies pitched directly upstream of you often need little or no mending. The rod tip is projected upwards, sometimes with an out-stretched arm in an effort to keep as much fly line as possible clear of the water (Diagram 8) thus, preventing swirling currents from grasping any line and spoiling a natural drift. With a raised rod tip.
Track downstream, level with the fly line. Watch the bowing fly line off the rod tip for lifting or faltering and respond accordingly. Again, deeper, faster water can be fished with such a rig. by simply casting more directly upstream, perhaps with a marginally longer line. This way. there is less influence from the current, allowing the flies to plunge deep. It will also allow you to explore deeper water, which is not accessible by wading. However, remember that the longer the line the less control you have, so find a balance.
Occasionally, complex currents and eddies wreak havoc with presentation. Equally, there may be a tempting seam or grease of water that looks certain to hold fish - the only problem being, a wide section of fast water separates you from it. Fishing these demanding areas usually results in nasty currents quickly dragging your fly line subsurface, possibly registering as a take. To avoid such phantom takes, beginners might consider some form of indicator. While not using them these days, I have done in the past and despite many having a dim view of them. I feel they have worth in confidence building for those wanting to progress with river nymphing. In awkward riffles, more slack line can easily be introduced into the drift, with knowledge that the subtlest of takes can be detected.
As fish don't betray their whereabouts with rise forms and the fact that takes might frequently be difficult to detect, arguably, river nymphing is one of the more tricky disciplines to master. Fish-holding areas aren't always obvious and sometimes not where you expect them. So. it's important to keep searching water until success is found.