Chasing trout chasing Duns

Mayflies and trout, a combination intertwined in the legend and mystique of fly fishing. Neil Grose explains his theories on chasing trout feeding on mayfly duns. 

As we move into mayfly time, we can expect the magical times, the memorable times, and often the frustrating times as the mayflies we love so much begin to hatch in regular profusion.


We can cast aside polar fleece's and woollen beanies and reach for the sun screen and the broad brim hat, and settle in for three months of arguably the best fishing available in the season. These dull brown little sail boats are the recipe for some very consistent sport in most fishing seasons, and sensational sport in others. Wherever there are trout, it seems there are also mayflies, whether here in Tasmania, on the mainland, South Africa, New Zealand, Argentina, Chile, and of course the home of our trout, the British Isles. In each of these different places on the globe the mayflies differ in size and colour, but rarely do they vary significantly in behaviour, or in their appeal to trout.

The duns which fly fishers speak of in such reverent terms are the first adult stage of the mayfly, after their emergence from the aquatic nymph. From the dun they go through a final stage into a spinner, which mates, and then dies.

There are a plethora of distinguished authors on the entomological subject of mayflies, and I suggest if you wish to know them in more detail that you consult those author's works. I tend to be quite relaxed in my identification of mayflies, they are either little brown duns, big dark brown duns, or a mixture of both. While there are undoubtably many different species, and the study of them fascinating, you can lose sight of the main objective if you worry too much about exactly identifying them.

Our Tasmanian highland mayflies begin to hatch as duns in dribbles as early as the second week in November on Arthurs Lake, a week later on Little Pine. Good hatches are usually under way on both lakes by the first week in December. All years are slightly different and the earliest I can remember seeing duns on Little Pine is the fifth of November, which was a particularly warm spring. Mayfly hatches will continue to build in strength till near the middle of January, remain relatively consistent till the end of February, and then taper off according to the season. I have fished dun hatches in the Cowpaddock arm of Arthurs Lake as late as the first week in April, but normally they have bid us farewell by March end. There can be a late hatch of duns on Little Pine Lagoon in April, but this is very dependant upon the manipulation of the water levels by the Hydro, and favourable conditions don't occur every year.

There are areas in most lakes on the highlands that support good hatches of Mayflies. Arthurs Lake probably has the best reputation currently as an excellent mayfly water, yet there are some areas on this lake which have very little mayfly activity at all. The Great Lake on the other hand is not well known at all for its mayfly hatch, but if you are in Tods corner in January on a mild cloudy day don't be too surprised to see a really good hatch of duns with the trout showing the appropriate level of interest. Lake Echo in its northern marshes has excellent hatches of duns, the same type as Little Pine, and around two weeks earlier than the Pine. Lake Echo, is perhaps, the most under rated water in the state, the marshes at the northern end are like the ones at Lake Sorell, the main difference being the crystal clear water.

Pine Tier Lagoon has good hatches, as does Bronte Lagoon and to a lesser extent the waters to its south. The Nineteen Lagoons area of the near Western Lakes have excellent hatches, the best of them after Christmas. One water in that area that is often over-looked is Augusta Dam, the first piece of water you come to. There are really good rainbows and browns in here, combined with a reasonable hatch it provides good fishing for all comers. Fundamental to the popularity of Arthurs Lake and Little Pine Lagoon are the lake's structural features that give rise to good hatches of Mayfly. In essence this is the prolific weed growth; where there is little or no weed growth, there is a corresponding lack of mayfly activity. An over simplification perhaps, but basically true.

Little Pine Lagoon has excellent hatches all over the Lagoon, due in great part to the entire lagoon being very weedy. Many anglers curse the weed when it provides refuge for hooked trout, but the reality of the situation is that the weed provides the catalyst for the excellent fish and fishing. As water temperatures climb with the progress of summer, the shallowness of Little Pine Lagoon causes the fishing to flatten out somewhat. The mayflies continue to hatch, but the trout do not often rise well in the heat of the "dog days', a term used by David Scholes to describe the heat of summer. Water temperature of 20 degrees or over at Little Pine and you need to be elsewhere. Better fishing on this water is found at the end of the day, as trout move into the shallows at dusk to feed on the duns that have collected around the tussocks and small bays during the day. The other benefit to this is you will often have the water to your self late in the day, even in the holiday season.

Arthurs Lake, on the other hand has the benefit of deeper gradients of water throughout the prolific mayfly areas, this lessens the effect of high temperatures on both trout and water. This provides for more consistent hatches during the peak of summer. Where Little Pine goes flat during the hottest weather due to the water getting too warm, Arthurs is still firing on all cylinders. The other benefit to Arthurs over Little Pine is the diversity in shoreline structure, mixtures of dead trees and rocky shores, and the ability to always find somewhere out of the wind. This makes Arthurs Lake the best bet if there is any uncertainty over the weather or the hatch.

The timing of the daily hatch is an extremely difficult thing to predict. I have fished hatches as early as nine thirty in the morning, and as late as seven at night. However seventy five percent of hatches occur between twelve midday and four in the afternoon, daylight savings time.

When hatches are occurring late in the day, it is well worth being on the water early the next day in the hope of catching the transition. I just like being on the water at any time, and the off chance of an early hatch is as good a reason as I need to have an early breakfast. First thing in the morning also offers a good chance of some caddis feeders around the quiet shores.

The best weather days for mayfly hatches can often be deceptive. Bright days, with little wind don't often produce good dun fishing on the main mayfly waters of Little Pine and Arthurs, but are excellent days to be in the Western Lakes polaroiding with mayfly imitations to cruising fish  This type of fishing is exhilarating, you can see the fish coming for your fly and sucking it in, all in glorious technicolour. These blue sky days are wasted on Little Pine and Arthurs, so don the polaroids and broad brim hat and head west.

However, when the weather is dull and muggy, even rainy, then Little Pine and Arthurs are the place to be. In this type of weather the duns hatch in great numbers, and sit on the water for a long time, the trout really do feed like pigs and with great method, real suckers for any fly in their path. This type of fishing is nothing short of sensational, lots of fish rising, all working solidly on top to the duns, very visual, and catch rates are usually high. Even when there is a cold change passing through, and it feels like July in January with strong winds and cold rain, the mayfly will hatch, and the trout will take. One of the most memorable days of last season was like this on Arthurs, very cold wind, rain and sleet, yet we caught a lot of fish as the trout crashed through the waves to get the naturals and our imitations.

Most anglers who fish the dun hatches use rods of around nine feet in length, matched with line weights of between five and seven. A six weight is a good compromise, four weights are really too light for most anglers in windy conditions, and eight weights too heavy for dry fly work. Leaders should be well tapered down to a point of around four pounds, and should be at least ten feet long. I often use leaders of up to twenty feet when using multiple fly set ups, but for the normal single fly ten to twelve feet is adequate.

For the majority of mayfly fishing, weight forward lines are better, they are easier to cast into the wind, and if teamed with a longer leader of around twelve feet give a good presentation. An added advantage with modern weight forwards such as the Mastery Series is the ability to shoot a lot of line with minimal false casts. It is really important to keep the false casting to a minimum, it reduces the chance of spooking fish, and increases the time the fly is on the water. I once watched a guy false cast twenty one times before landing the fly on the water, only to pick it up again a short time later. It's very hard for the fish to get the fly in mid air at 60 km/h.

There are as many sure-fire fly patterns for dun fishing as there are anglers, I'm sure. Depending on which stage of the hatch you are fishing, a selection of ten or so patterns will serve you more than adequately. In the early stage of the hatch, when not much is happening save for a few boils, the number one fly for me is the humble brown nymph, a size 10, dressed on a Kamasan B220. I would catch more fish on this fly than any other during the early stages of the hatch. The accepted way of fishing this is to either cast to the boils and retrieve very slowly, or just fish it around the likely areas.

With the advent of the new clear intermediate fly lines from Scientific Anglers and invisible flourocarbon leader materials this type of fishing is set to be even more productive.

Once the duns begin to hatch in larger numbers, the trout will begin to show with more regularity. This is then the time for a fly that is a cross between a dry dun pattern and a wet nymph, called an emerger. There are many and varied patterns to fit the bill, some tied with parachute hackles, or with foam wing cases. I and many others tend to use a brown nymph that is treated with floatant, and presented to trout in the surface film. The shaggier the nymph the better, as it imitates the struggling dun breaking free of the nymphal shuck. On many days you will not get past using an emerging pattern, as the trout will often home-in on the duns at the point of the hatch where they are most vulnerable. When the sound of hearty sucks is heard, this is the time for the dry fly proper. The best overall pattern to imitate the dun at this stage of the hatch I have found is Pecks Dun, a pattern developed by Charles Peck.

(See below.)

Many anglers choose to use hackled versions of brown nymphs, or flies such as the Twilight Beauty, Penstock Brown, March Brown, Hardy's Favourite, Claret Dun, or a multitude of patterns all called "highland duns'. There is also a dedicated band of anglers and guides who will use nothing else but large Red Tags during mayfly time; their success rate is too good to dismiss. Basically, though, get the size, colour and shape of your fly about right, and then concentrate on your presentation, and the manner in which the fly sits in (or on) the water. It's no good having a fly sitting low in the water if the trout are feeding on duns sitting up on the water, and vice versa. For most anglers, the art is in the presentation, not the imitation. Part of the frustration in mayfly fishing comes when trout don't rise with any sort of rhythym, and become what is known as "oncers', fish that only show once. There are other names given to them, none fit to print.

Over the last two seasons I have been working on a technique to try and regularly catch these single risers, utilising the loch style method. After much experimentation, I have simplified it to casting  quickly, directly over the rise form. I use two flies, a weighted Brown Nymph on the point, and a Claret Dabbler as a dropper, one metre up on a 3.5 metre leader.  Let the flies sink for a second or two, and then retrieve the flies quite firmly. Usually there is a reaction as soon as the flies move, if not, lift the rod and work the dabbler in the surface film of the water loch style, this will get the fish that follows the flies to make a lunge. This technique is also deadly during regular hatches as well as in windy conditions. This technique really needs a boat to work properly, which leads to the final element.

Anglers chasing mayfly action are really best served with a boat. That's not to say shore based fishing isn't excellent, it is, but there is more water available to the angler going afloat. For anglers restricted to the shore, one of the most ignored hot spots is the shore onto which the wind is blowing. This means casting into the wind, but the fish are never very far out from the bank. If you see a shore with some crows strutting along it, there is a fair bet they are eating duns blown onto the shore, and the trout won't be far away either. The best shore on Little Pine in a westerly, for example, is often the road shore where duns that hatch in the Untouchables drift across the face of the dam and onto the eastern shore. Wade out past the thick weed, and there are always trout rising quietly to the feast. Anglers on the western shore will have difficulty getting their fly to drift naturally with the following breeze. Casting into or across the wind eliminates this problem.

The other floating method is with a float tube, the potential of these belly boats is unlimited for the thinking angler, they can be like stealth bombers for fly fishers. By going afloat fly anglers can use the wind to their advantage, and can also fish hatches a long way off shore. That said, there are some rules of etiquette that boat anglers need to observe.

With more and more anglers using boats, we all need to make allowances for others. The first thing is; move around quietly in boats, nothing annoys fish or fisherman more than roaring boats during a hatch. Trout don't really mind outboard's at slow speeds in most lakes, but fast boats will put fish down very quickly. The other is; keep away from anglers fishing the shore and other boats. Don't cut across, or in front of another drifting boat - always go behind them. If we keep at least 60 yards between boats, and give shore anglers a wide berth then the day becomes more pleasurable for everybody. The magic of mayfly fishing is there for anglers of all abilities to enjoy.

Whether it be a first time fly fisher, or a veteran of sixty years experience, the sight of a trout engulfing a mayfly dun causes the heart to race and the hands to quiver. As a guide, there is no better way to show off our magnificent wild fishery to visitors than to have them fish during our mayfly hatches, and to sample the quality of fish associated with it.

A wise angler once said

"May time fly till mayfly time.'

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