Watching a Trout

What a Fish Holding in Current Can Tell Us

Most anglers spend relatively little time watching trout unless they are preparing to cast to one. Even when a fish is clearly visible, the temptation is to begin fishing immediately. The rod comes out, a fly is selected and attention shifts towards getting a presentation into the right place. There is nothing particularly wrong with that, but I often wonder how much more people would understand about trout if they occasionally left the rod alone and watched one for twenty minutes.

The fish in the accompanying footage had been occupying the same section of the Goulburn for some time. Weeks in fact. From a distance, it often appeared almost motionless, holding in the current with little apparent effort. Look more carefully, however, and there is considerably more happening. The trout makes small adjustments with its fins, changes its body angle and occasionally moves sideways before settling back into almost exactly the same position. Some movements are so slight that they are difficult to distinguish until you have watched for a while.

Holding in current involves a continuous balancing act. Water may be travelling at quite different speeds only a short distance apart, particularly around submerged rocks, changes in the riverbed or the edges of a current seam. A trout occupying a suitable position can remain close to drifting food without constantly fighting the strongest flow. It may need to move only a few centimetres to intercept an insect before returning to the quieter water where it was holding.

That economy of movement is one of the things I find most interesting about watching larger trout. A good fish may allow dozens of drifting items to pass without responding, then move quite deliberately towards something worthwhile. Sometimes it rises gently in the water column, takes the insect and returns to its original position with scarcely a movement of the tail. On other occasions it travels considerably farther, especially when there is a fall of terrestrials happening.

The distinction between a fish that is actively feeding and one that is simply holding can be surprisingly subtle. A trout may remain in the same position for several minutes, making occasional adjustments but showing little interest in food. Then, perhaps as insect activity increases, it begins moving repeatedly into an adjoining seam. Its position may be almost unchanged, yet its behaviour is now entirely different. Recognising that change is vital if we are going to be succesful.

The Goulburn offers excellent opportunities to make these observations, particularly when flows are moderate and the water is clear. There are long glides and slower runs where trout can be watched from a suitable bank or a stationary drift boat. Good light and polarised glasses make an enormous difference. With the sun at the right angle, it is sometimes possible to follow almost every movement of a trout against the riverbed. Move a few metres or let a cloud obscure the sun and the same fish can become remarkably difficult to locate.

I often encourage clients to spend longer watching a trout than they initially think necessary. The first thing I want to establish is not which fly we should use, but where the fish is actually holding and how it is moving to intercept food. The visible rise ring can be misleading. A trout may begin several feet upstream of the disturbance, lift towards an insect and then return to its original lie. Casting repeatedly at the last rise can mean presenting the fly behind the fish rather than allowing it to drift naturally towards it.

On a recent drift we spent close to an hour working on a single trout. Much of that time was spent watching rather than casting. We anchored nearby, adjusted the leader and flies, and followed the fish as it moved between a seam and an adjoining backwater. At one point it disappeared for so long that I stood on the rower’s seat trying to improve my view. Eventually we located it again and continued watching. The clients may have wondered whether the exercise had become a little excessive, but most of the positions the trout occupied would have made a clean presentation extremely difficult.

We waited until it moved into a piece of water where the fly could arrive naturally without immediately being dragged away by another current. When that opportunity finally appeared, the trout ate. I suspect we would have frightened it much earlier had we begun casting as soon as we found it. There was nothing particularly complicated about the fly. The difficult part was understanding the fish’s movements and waiting until we could make a worthwhile presentation.

That relationship between current and holding position becomes especially important on the Goulburn because releases from Lake Eildon change so substantially throughout the year. A trout holding comfortably behind a submerged rock at one flow may find the current considerably stronger after an increase. Alternatively, newly flooded edges, bankside structure and side channels may provide better feeding opportunities. Sometimes the fish move only a short distance, but that can be enough to make an established feeding position appear empty.

I have watched this happen repeatedly. A run that held several good fish one day may be much more difficult after a relatively modest change in releases. When the river settles, the trout may return to their earlier positions or establish themselves somewhere else entirely. This is one of the reasons I am reluctant to assume that a fish will be in the same place simply because we found it there the previous afternoon. The water may look familiar, but the current passing through it can be quite different.

It is also worth remembering that the best holding water is not necessarily the most impressive-looking part of a river. A deep pool with substantial structure may attract our attention, while a relatively shallow run beside a modest rock can provide a more efficient feeding position. I have found very good trout in places that appeared unremarkable until I began examining the current more carefully. Watching fish use those positions gradually changes what you look for when approaching unfamiliar water.

This is particularly useful when teaching beginners. It is easy enough to explain current seams, drag and holding water while standing on the bank, but the lesson becomes much clearer when somebody can watch a trout intercept a drifting insect and return to its lie. Suddenly there is a reason to cast upstream of the fish rather than directly at it, and a reason to position the leader in one current rather than across several. What seemed like a collection of technical instructions begins to make practical sense.

After thousands of days on the Goulburn, I still find it satisfying to discover a good trout in clear water and spend time watching what it does. Sometimes the observation confirms what I already suspected. Occasionally it reveals something about a particular piece of water that I had overlooked. More often, it is simply an opportunity to examine the small adjustments and movements that are easily missed when all our attention is directed towards catching the fish.

The trout in this footage may continued to occupy the same lie for months, provided the current and available food remain suitable. A substantial change in releases could alter the position, or another fish may eventually occupy it.

The current passes around the trout. It adjusts its position slightly, settles again and continues facing upstream and feeding. Nothing particularly dramatic happens, and someone walking past might scarcely give it a moment before excitedly casting.

I think it is worth watching a little longer.

Ant