Millions of minute mayflies on Lake Meadowbank

Robert Gott explains how the minute caenid mayfly and Lake Meadowbank combine to create a special fishing experience.

Some years ago it was my good fortune to fish with a very colourful Irishman. This fellow was a highly skilled practitioner at the craft and passionate about his fishing in a way that only the Irish can be. I clearly remember two things about him. He was a master fly tier and his creations, minor works of art.

Upon landing a fish, he would always break the fly from his tippet and immediately throw it over his shoulder. Whether or not this was some traditional Irish custom, I am not sure. Nevertheless I always made a point of positioning myself immediately down wind of him when he hooked a fish in order that I may recycle his cast offs!

The second thing was a comment he made late one evening at the shack following a good day on the water. It was at a moment when he had begun to philosophise, something that he was somewhat prone to do. In his lilting Irish accent he stated, "You know Robert, t'ere is no foiner t'ing than fishing to the brown trout with t'droy floy. And there is no foiner fishin ta be had than fishin" to ta caenid feeders on Meadowbank."

He went on to expand on this pronouncement and having "sewn these pearls". I decided to make a point of investigating this bold claim. Meadowbank is the impoundment created by the damming of the Derwent River, downstream of Hamilton. This work was undertaken by the HEC in the mid 1960's resulting in the flooding of a narrow river valley forming a lake some 14 kilometres in length. Water from the lake is also used for irrigation.

The lake is divided by the Dunrobin causeway and bridge. This neatly partitions the upstream section of the water, which is of most interest to the angler, from the downstream, that has an attraction for those misguided souls deriving pleasure from standing on planks of wood and being towed behind an over powered motor boat at high speed. The upstream section of the lake has flooded over flatter ground. This has resulted in the formation of extensive, attractive shallows and channels lined with willows and pin rushes, predominately on the western and north western shores.

The lake is home to a squillion stunted redfin perch as well as some tench. Just last year, the IFC decided to convert the lake into a retirement village for geriatric and overweight brood atlantic salmon. This has created a great deal of interest for punters keen on the chance of catching a fish suitable for hanging on the wall. However, it is the lakes wild brown trout that excite the fly fisher. The fish stocks vary in size from year to year. At present there appears a large class of fish between 0.75 and 1 pound with another smaller group of fish around the two pound mark. The old hands that I have spoken to suggest that the size of fish has declined in recent years and recall fish consistently around 2 pounds plus in the late eighties. Nevertheless, the fish are generally in superb condition by early summer. The lead role in this fishing circus is played by the family Caenidae. These insects are tiny members of the order Ephemeroptera of mayfly. The experts tell us that one genus of caenid is represented in Tasmania; Tasmanocaenis. As a nymph, the caenid lives in the sediment on the lake floor. When it is a year old, it swims to the surface to emerge as a dark squat little dun about 4 mm in length with milky tinged coloured wings, spanning 8 mm.

The dun then quickly flies away to alight on the nearest dry, stable object it can find. This includes the angler. The dun then begins transformation into a spinner with clear blue wings and departs to get on with the major business of procreation. In doing so, it leaves behind its calling card, the shuck of its previous skin. In a heavy hatch the anglers clothing can be covered in these little white husks which are then mistaken by the angler's spouse as serious dandruff!

The male spinners (the ones with the long tail filaments) congregate in squadrons. These columns of males can reach impressive heights, with the insects nervously hovering awaiting to ambush the mate with any passing female. This done, the female lays her eggs in the water and subsequently dies. The male meets the same fate so by the end of the hatch, the water is carpeted with spent caenids, glued in the surface film with wings outstretched.

There must be literally millions of caenids in the northern end of Meadowbank. These insects begin to hatch at this lake around the beginning of December and continue well into January. The positive side of the family Caenidae from a fishing perspective is that they are very reliable.

Given a calm morning over this December - January period, there will be a hatch. The intensity of the hatch and the trout's reaction will vary somewhat according to air temperature, humidity and brightness, but you will get some action.

It is important for the fisherman to closely monitor the weather forecasts and look for calm conditions. Anything more than the slightest zephyr tends to ruin the hatch and the caenid fishing on this water. A light intermittent draught that crinkles the water is OK, in fact it may help your chances in a number of ways (considering the insects and the trout and masking the flaws in your presentation and approach), but anything more and you may as well head home.

I looked out for a settled sea breeze type weather pattern which is dependable in providing calm mornings with the lightest variable breezes usually till late morning - midday. If you are lucky, it will be overcast until the sun "burns away" the clouds mid morning.

The caenid hatch is a morning event although the precise timing varies. In January last year, they were on the job soon after first light with some huge hatches that continued on until 9 am. This season toward the end of December, you could set your watch on the fish beginning to rise in earnest at 7:45 am. Either way, the trout must love them, because at times it would seem that every fish in the neighbourhood is on the surface feeding when the hatch peaks.

Initially the rises are discrete gentle swirls, but as the hatch heightens the trout begin to take from the surface, with nebs clearly visible and leaving bubbles behind. As the hatch wanes and the trout start to concentrate on the spent fly, the rise form is characterised by refined "sips".

The negative side of the caenids (perhaps) is that the catching of the fish that feed on them is incredibly hard. The degree of difficulty is heightened for a host of reasons. First there is a superabundance of food for the trout. That means that they become fixated in the insects and accordingly fussy about what size of artificial fly they will accept. In open water, with lots fly on the surface, the trout feed randomly and have an infuriating habit of wandering in every direction and habitually changing course at the moment of your delivery cast. They also become myopic and appear oblivious to an artificial that misses the "bulls eye".

Finally, in the calm clear conditions that prevail, the trout quickly spot any thing untoward by way of approach and presentation. In short, they are very demanding fish!

To make the most of the hatch, it is necessary to fish from a boat to provide flexibility, mobility and access. One of those float tube arrangements may also work, but it is not something I have tried. The shore angler will quickly become vexed as the fish have a tendency to rise a cast and a half away from the bank.

I have often watched anglers running up and down the causeway in rising frustration, chasing fish. Often there is significant activity at this location as natural drift tends to concentrate the caenids. Nevertheless the trout continue to move randomly, just out of reach. The angler perched above the water on the causeway is clearly visible to his quarry and quickly spooks any fish that does come close.

An electric outboard looks the part for stalking the fish but I stick to sharing turns on the oars with a good mate as an effective means of boat propulsion. The bonus is that you have someone to blame for your lack of success as well as an endless source of advice. My fishing companion is always full of encouragement, making comments such as "Mmmm, yes: I think you have put the one down." Or, "Would you like me to cast the fly for you as well?" The key to success is to predict where the trout is heading and to then delicately present the fly eight to ten inches dead in front so that it sees the artificial land. To add further difficulty, this has to be done in synchronisation with the trouts feeding. The fish tend to rise three or four times in quick succession, to be followed by pause and more often than not a change in direction. (The caenid feeders line dance-rise, two, three, four and pause; rise, two, three and turn-)

For this reason, I try to avoid those random cruisers out in the wide open spaces. There is nothing more frustrating than to quietly creep up on a trout as it confidently feeds away from the boat, only to have it suddenly turn 180 degrees and swim directly toward you. You are left to cower low in the bilge in an effort to hide your seditious activity, knowing this is a desperate final action before being caught red handed. It is much better to look for those fish with "boundaries" around them created by the shore, sunken vegetation and channel edges. In these areas, the fish tend to have more defined patrols which tip the odds in your favour. It is an added bonus if you can catch a glimpse of the fish with the aid of polarised glasses. (I claim that the water in the lake is becoming increasingly turbid making polarising difficult, but I expect my problem is more correctly attributed to my failing eye sight!)

To my mind, the key to success in catching these trout is in the presentation of the fly. This is where the expert caster has a huge advantage. The task is made difficult as you are generally unable to get closer than about thirty feet to these fish and the fly needs to land in a target zone of ideally not much more than six to eight inches in diameter. The fish are few that will, by random chance, swim on to a fly from a misused cast and rise to take it.

For clowns like me on a good ay, this means only twenty percent of casts are hitting the mark and then of course the fish will be more often than not take the natural fly that is sitting next to you fake! If there is one thing you can do to increase success at this caper, it is to work hard at improving your casting. I place less importance as to what fly to use as long as it is small. Flies tied on a size 18 hook don't look too far out of place to the real thing. I cheat and tie three types of fly on a size 16 short shanked, wide gape hook. This gives me a fly that still seems reasonably proportioned which the trout are happy to accept and hopefully improves the chances of hooking and holding a fish.

At the start of the hatch I use a parachute, barred rock hackled, brown bodied fly that sits just on top of the water surface. When I start to see the trout's neb and bubbles in the rise, I change to a peacock herl bodied, barred rock hackle spinner imitation.

Finally, when the fish start to mop up the spent spinners, I tie on a fly with peacock herl body and wings made from white calf hair tied at ninety degrees to the hook shank to form wings. This fly sits in the surface film. By this stage, if it is calm and bright the fish are nearly impossible to catch anyway!

However, this is complicating things by half and demonstrates the lengths one goes to in trying to crack the secret and gain an advantage on these difficult fish. The reality is just as much success is had by fisherman using coch-y-bondhus, red tags and Greenwells glories and the like, provided that the fly is correctly proportioned and presentation is perfect.

It is also important to use fine tippet material, not because the trout is less likely to see it, but more importantly it assists in the presentation of the small fly. Your fake often looks incongruous enough without being tethered to a tow rope!

The material I use has a diameter of 0.12 mm and extreme care needs to be taken with the connecting knots to your leader.

You can also try a range of other ploys. My mate has had good success on caenid feeders in a lake "higher up the hill" using a size 14 black nymph suspended on a six inch dropper, tied on the hook shank of a red tag. The dry acts as a strike indicator. The Meadowbank trout are fairly ambivalent about this approach being cooperative on some days. However for no apparent reason, at other times you have as much success with this as you would throwing a brick at the fish. Some say a wet beetle imitation fished insert on a greased leader will work. Another ploy is to present a mudeye imitation if the fish are on the move at very first light. There is plenty of scope for experimentation.

So there you have it.

Clearly what constitutes "Foine" fishin is a subjective matter. Fishing to the caenid feeders on a good Meadowbank morning, you can be well satisfied if you boat two or three fish. The best I have heard of is eight, taken by a master of the art.

At any rate, fishing to my mind is not about numbers. It's about quality and if this is measured in terms of opportunities to observe and fish to highly discriminating and demanding trout, then perhaps there was a touch more than the blarney to the Irishman's claim.

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