Trout fishing - Nymphing the Tongariro

Trout fishing - Nymphing the Tongariro

Okay, there’s no denying it – summer is behind us and cooler times are here.

For humans, it is time for a change of clothing, like a deer growing a winter coat. It is also a time for a change of diet, with heartier and more filling food required to ward off the cold. Best of all though, it is time for some of the most exciting trout fishing of the year.

Trout have noticed the change in seasons, too. They have a new drive: to procreate. They are drawn from the big rivers and lakes to small feeder streams, where waters are cold, clear and consistent. There, they will drop their eggs, burying them in pea-sized gravel so they can develop and grow, and hopefully survive to build on present populations.

Almost all these spawning waters are closed to fishing during the winter months when most of the spawning activity takes place. Anglers can watch in wonder as the process unfolds in these small and intimate waters, but cannot fish for the spawning trout.

Some trout choose to spawn in the shallow areas of the bigger rivers where the season remains open; the lower Tongariro River is a classic example. At times many fish can be seen spawning in these waters, offering some great sight-fishing for fly-fishers. While some anglers disapprove and will not fish such areas, others can’t wait for the fish to arrive. It’s a personal thing I guess.

However, keep in mind that while catch-and-release fishing in such places probably won’t affect the spawning outcome much, tramping through the spawning beds will. Consequently, I believe it is better to fish the waters that the trout are travelling through, rather than where they are digging and laying eggs. Besides, fishing those transient areas, which could include large holding pools, will usually put you in touch with a better class of fish.

Talking Taupo, the trout go through quite a change during the spawning season. They leave Lake Taupo bright silver, fat in the flanks, with only a blush of rose on the gill plate and along their lateral line. Their backs are either black or green and their spots are small.

Once in the river, they start to take on a darker hue. Their silver sides turn brown and dull, and the red markings on their gill plates and lateral line become bolder. Once in the process of spawning, they darken even more, some almost turning black. They become thin in the flanks and generally poor in condition.

During spawning, trout all but stop feeding. This, combined with the rigours suffered from the chasing, fighting, digging and egg laying/fertilisation that take place at this time, see some eventually succumbing.

However, those that survive will start ravenously feeding as they make their way down the river towards the lake – anything from small native fish through to tiny hatching mayflies in the evenings. In the process they slowly pick up in condition and will likely return to spawn again next year after a busy feeding period in the lake. (A few will even stay in the river, offering great dry fly fishing opportunities in the summer time.)

Anglers can easily catch these downstream migrants, but care is needed when handling them for release, as these fish will likely be back to produce another generation of trout. So, after unhooking, support them in the water until they are ready to swim off (usually till the time you can’t stand the cold water any longer!). Otherwise, if you want to keep one, dispatch it quickly with a rap on the head using a stone or a stick.

How do we catch spawning river trout?

Through the years, many fishing techniques have worked in the Tongariro River. The main one has been fishing across and down with streamer flies that generally imitate small fish. When the first fly-fishers started fishing the river, they didn’t have the fast-sinking lines we have today. Reading some old accounts on the early streamer fishing, it seems many of the fish caught were hooked near the surface. In Zane Grey’s writings on the Tongariro River, he often says he saw the fish swirl or take the fly near the surface. These anglers often used huge gaudy salmon flies.

These days everyone is obsessed with getting depth. You will hear: “If you’re not losing flies on the bottom, you’re not deep enough.”

I wonder if we should try other approaches sometimes. For example, you will catch fish day and night in the Tongiriro River’s mid and surface waters during the summer.

Upstream dead-drift nymphing is another worthwhile approach, offering great satisfaction when fishing the shallows where the trout can be seen. Nymphing can also be the answer in situations where the across-and-down method is impossible due to fallen trees, or if fast water disappears under bushes. However, drifting nymphs can be taken by trout even in deeper or faster water, offering some exciting fishing.

So, by using these two methods, you have the upstream approach with the nymph and the downstream tactics with the streamer fly, enabling you to cover most of the water. Then add dry fly fishing instead of nymphing and attractor fishing instead of streamer fishing, and even more potential fishing scenarios are covered.

My study of Taupo trout over the years has shown a few ways in which they differ from trout in other fisheries. Taupo trout are gregarious in their formative years. The spawning runs indicate this, as groups of fish arrive to fill pools where the day before there was none. This is important knowledge for the fly fisher. It is said that if you find one fish, you may find many.

The trout will return to spots on an annual basis. For example, I discovered a spot on the lake shore that is regularly visited by trout during August. For the last 20 years or more that spot always produces well-conditioned fish during those few weeks, with nothing changing in all that time. It is an unlikely looking spot, too.

Another thing to keep in mind when fishing Lake Taupo and its rivers is that the trout switch from one food item to another as seasons change. It may be green beetles in November, smelt in December and January, and cicadas in February. While crayfish can be eaten all year round, more seasonal foods include caddis flies, frogs and small native fish such as koaro and cockabullies. Some years these food items are prolific, while others may see them greatly reduced. The following year can see the opposite occurring.

It has never been talked about much, but there are trout in the Taupo fishery that couldn’t care less about the lake, living their lives in the rivers’ headwater areas. One I have fished is the Tauranga-Taupo River up near the falls, which stops further progress to lake fish. The trout here are healthy and strong, and probably live their lives in this part of the river. They have no need for the lake, having plenty of food, cover, spawning water and decent water quality.

There are several dams in the Taupo area where trout live in seclusion and solitude, too. A couple of examples of this are the dam on the Hinemaiaia and another at Kuratau. Their waters run into Lake Taupo, but the fish in the dams have no interaction with the lake itself.

Another river I guided to for many years held big rainbows. An eight-pounder was a singular catch over the years – all the others were over 10 pounds. There were no small ones and no spawners. We called it the Elephants’ Graveyard. There are not a lot of wild rivers where you see more 15-pounders than five-pounders!

I’m trying to make the point that we need to think about our fishing, our fish, and the waters they live in. Everything is not always as it seems. So keep an open mind when fishing and you will get more out of it.

   This article is reproduced with permission of   
New Zealand Fishing News

July 2017 - Gary Kemsley
Re-publishing elsewhere is prohibited

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