The Emerging Dun | The Mataura River series by Chris Dore

When it comes to the Mataura River, there's really no one that compares to Chris Dore. Take a moment now to enjoy some more autumn related info on what some people consider the premier fly fishing river in the world. 

 

Part 4 | The Emerging Dun

As mentioned, when trout are feeding upon the emerging mayfly they can become fixated with this phase of the hatch alone. Your pattern must not only resemble the natural in size and shape, but most importantly, its position in, on or below the meniscus. The emerger is the key to matching the hatch upon the Mataura, a time when the trout can be seen rising, but not taking cleanly off the top. This often creates confusion among anglers, who persevere with their traditionally tied Dad's Favorites, and Blue Dun patterns with minimal success.

The emerger is not quite a nymph, not yet a dun (sounds like a pop song), and thus a specialist imitation is required to fill the void left by the more traditional patterns of nymph, and dry fly variety.

 

 Kyle's Nesameletus Emerger

Most dry flies available today imitate the adult dun. Tied to ride high upon the surface, they lack what I believe is the key trigger for selective trout - the sunken abdomen.

Even those tied 'parachute style' fail to correctly imitate this I feel, for whilst they permit the body to hold flush in the surface film, the lower abdomen does not hang invitingly below, on par with the natural.

Now many may think that this is taking things too far, but allow me to assure you, such inane details can, and will make all the difference upon the Mataura and many other waters where trout feed on large, synchronised hatches. 

Bob Quigley, creator of the popular 'Quigley’s Cripple' emerger wrote "On many occasions, traditional types of patterns will suffice, but during blanket hatches—especially on hard-fished waters—I've found fish that want neither nymph nor dun. They want both. A nymph can swim away, and a dun can fly away, but trout have learned that a dun caught trying to emerge from its nymphal shuck can do neither."

This could easily have been written of the Mataura, and not having a good emerger pattern in ones fly box is where many anglers fail.

 

Kyle's Deletidium Emerger 

So what makes an efficient emerger pattern?

Bob Wyatt in his book Trout Hunting claims "The significant visual aspects in these forms - size, silhouette, posture and behaviour - are all primary triggers to the trout’s predatory response. It is worth working out a strategy based on a reliable set of designs that fit the trout’s flexible and inclusive prey image and which incorporates one or more primary triggers."

 Working on this theory, Bob then designed the Deer Hair Emerger (DHE). Tied to be simplistic and more durable than the Klinkheimer series and other parachute ties, the DHE incorporates an erect wing, and hanging abdomen, two of the aforementioned 'triggers'.

Tied on a curved, emerger style hook (kamisan B-100) Bob uses an olive / brown mix of seal and hare fur for the abdomen, fine deer hair for the erect wing, and spiky hares fur for the thorax. Floatant is applied only to the wing and thorax only to ensure the lower abdomen hangs subsurface.

I have been using variations of this pattern a lot over the past decade, favouring the more buoyant properties of the deer hair over my old faithful, the CDC Emerger.

 

CDC Thorax Dun - Dark

Its more durable properties are also a desirable attribute, and as a guide, is something I require in all my flies. Whilst CDC patterns are often referred to as 'once and aways' (one fish and they are gunged up and out of action for the remainder of the day), the DHE can be used on a succession of fish without requiring replacement.

With its hollow fibres and resulting built in 'air pockets', deer hair seems to float longer than CDC and is easier to rejuvenate when waterlogged. A few false casts and your fly is again ready for a new drift.

The emerger should be fished in the same manner as a traditional dry fly - cast upstream and across at your target, and allowed to dead drift. Whilst the natural may be struggling in the meniscus, these movements are minimal, and I have not found this necessary to imitate.

At times however, you may be required to move the fly momentarily to catch the fishes' attention, as it drifts amongst a myriad of naturals. A single twitch is all that is required.

CDC Floating Midge

Not all emerging mayflies make it through the surface. Due to defects or lack of vigour, many will expire while at the surface, and will remain available long after the hatch has tapered off.

These will drift at the mercy of the currents and congregate in backwaters, eddies, and other slack water locations. Using a combination of the knowledge of such places, and a good emerger pattern, it is possible to rise fish long after the initial surface activity has ended. This is where the CDC floating nymph can excel. 

 

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