Sizing Up a Trout Stream for a Better Catch

For a fisherman, reading a stream is easy when the potential prey is in plain sight. When they aren't, however, determining where they're hiding might require us to think like fish. We have to consider where we would seek oxygen, sustenance and sanctuary from predators if we were living in that stream ourselves.

Trout have little difficulty getting adequate oxygen in the colder months. Summer complicates the issue for two reasons. Firstly, warmer water has the capacity to hold less oxygen, which is why it tends to bubble. Secondly, the trout themselves have higher metabolisms and thus their need to get oxygen from the water is increased. The combination of these two factors, within extreme temperatures, can make suffocation a real risk for fish. The churning action of falls and whitewater aerates the water around them, making these areas ideal for gasping trout to congregate - and good places for us to go and seek them out, during the hot months.

Another concern for a trout is keeping itself safe from threats from above. Out in the open, it can make an easy meal for a Kingfisher or a blue heron. In their quest to steer clear of flickering shadows from above water, trout will seek refuge in little rock crevices, log hollows, beneath jutting banks and fallen trees, and towards the bottom of deep water holes. We may not be able to see any trout in a stream, but if we cast our lines into these areas of concealed water we might feel them biting before too long.

Feeding is a constant motivation for our intended prey, too, though they have a different attitude towards it than we do. Instead of seeking it out, they tend to let the current bring it to them. River and stream water sweeps many things along in its flow, including unfortunate insects that landed themselves in the water - and that now find themselves prey for the fish below. If we can detect a bubble or foam line drifting along the current, these helpless fish snacks will probably be there. There are bound to be fish in the vicinity, too, lured by this easy provender.

Successfully sizing up a stream that we intend to fish may require giving equal consideration to these three aspects of a fish's existence: oxygen, shelter and food. The first is not so relevant during the cooler months, but in the middle of summer we might do well to avoid slow and stagnant pools and seek more turbulent (aerated) waters. From there we can scout for areas where trout might seek refuge from predators, and where food can be brought within their reach by the current. A fishing site that satisfies all three of these criteria can bring us good fortune, indeed, on our day out on the water.