Steelhead Feeding & Movement

Reflections From The Rivers Edge
By: Les Ober
North Coast Fly Fishers (December 2002 Issue of the Taut Line)

One of the most aggressive feeders among fish species is the Steelhead Trout. While in the lake the Steelhead is known for its savage attacks on schools of bait fish. From the time the Steelhead arrive in the rivers their feeding habits are altered. Aggression gives way to a more passive form of feeding. Their attention has turned to that portion of their life cycle that involves reproduction. Their energy is spent locating their spawning ground rather than seeking a food source. However, they still maintain a strong instinct for feeding.

There seems to be two types of feeding patterns. The first is where the tiny morsels of food are consumed because they are attractive. These food sources fall under the category of eggs from other spawning fish and nymphs that are always present in the river. The second feeding pattern is not really a feeding pattern at all, but where the fish will often violently attack a streamer or Wollybugger. This is a protective reaction against some intruder trying to invade its space. This again reflects on the aggressive nature of the Steelhead.

When Steelhead are left alone, their willingness to take a properly presented fly is remarkable. They are often not very selective as to the pattern that is being presented. The Steelhead is a sight feeder, and if it can see the fly, and it looks natural, it will attack. That is the reason for the use of brilliant flashy material when constructing steelhead flies. Many times if Steelhead are present in a hole or run they will hit on the first two or three drifts. So why is it that on certain days normally productive areas appear to be completely void of fish? This has more to do with the angler’s ability to locate fish and also environmental factors that no one has control over.

Steelhead are constantly on the move. They continuously move from one location to the next. The Manistee strain is capable of moving up to twenty miles a day in Ohio rivers. This movement can occur during the day or night. The level of the river and the current flow will alter how an angler will approach and fish a section of the river, so the angler has to adjust his presentation constantly to water level, flow and clarity. Fishing the river the same way every time, day in and day out, is a certain formula for limited success.

On Elk Creek for example, I have watched the fish move from the riffles to the deep holes in the time span of one afternoon. With experience a Steelheader learns to time a river and predict fish movement. He soon recognizes that rivers clear first in the shallow water of the riffles and in areas of marginal flow. Steelhead like to hold up in areas away from the heavy, silt laden flow of current that dominates the deeper pools during periods of high water .On that particular day, on Elk Creek, the water started high with fish in the riffles and by the end of day the only cover the fish had was in the deeper holes and runs. As a result, I had to adjust my presentation several times during the course of the day by adjusting the amount and position of split shot in relation to the fly, as well as the position of my strike indicator in relation to the split shot. In fact, when I started I was not using a drift-rig at all but rather a Mini-Sink Tip line and a streamer with a down and across presentation.

There are many things that can restrict a Steelhead’s movement, such as water level, clarity and stream temperature. There are two phenomenon that happen annually that have a major effect on Steelhead movement and feeding habits. The first occurs in late fall, when the leaves turn color and fall in to the river. The result of this massive influx of vegetation is the build up of tannic acid in the water. This causes a darkening of the water, similar to putting a tea bag in a cup of clear water. It also puts a large amount of debris in the water. This impairs the fishes sense of vision. The Steelhead is confused and cannot recognize the fly as a food source. The fly becomes just one more piece of debris moving through the current. It is very hard to present a fly under these types of conditions. The bait fisherman has an advantage in that his offering also has a odor which the fish recognize as a food source. Trout have a very keen sense of smell, and they can detect an odor measured in parts per million (ppm). Duplicating the smell of a food source is one thing that is impossible to do with a fly. Unless you add some form of bait such as maggots to the fly.

Another phenomenon that restricts fish movements is a sudden drop in stream temperature. This is not the gradual cooling of water that happens as result of a normal reduction in air temperature. It is a sudden 10 degree plus, drop in temperature that occurs when ice cold run-off enters the river after the first significant snow fall. The fish is temporally stunned, as its body temperature is rapidly cooled. Its metabolism is slowed restricting its movement until its body adjusts to the colder water temperature. This event results in periods where feeding becomes very passive. Presentations have to be made slowly and precisely.

This is where a metabolic restriction in movement is often mistaken for selectivity in feeding. It is not what you offer the fish but where and how it is offered. “Hitting the fish in the nose” is often the term used to describe this type of fishing. Low water temperature for an extended period of time also accounts for the sudden bursts in feeding activity that happens on warm sunny winters day. A slight rise in water temperature will increase the fish’s metabolism and awaken its desire to feed. Winter is also a time when Steelhead adjust to their surroundings. They behave more like stream trout. Their instincts tell them that nymphs and other natural inhabitants of the river are an abundant food source. Wild Steelhead in particular have an instinct for feeding patterns developed during the early stages of their life. This is a time when a properly presented nymph patterns can be very productive.

One of the least documented factors effecting Steelhead movement and activity is angler pressure. No one has studied what the effect that a large group anglers has on Steelhead movement. Common sense would indicate that large numbers of anglers are having a major impact on fish movement, especially in times of low water. How the fish reacts depends on its ability to move in an out of the river. In large rivers the fish may simply move away from crowded areas on the river. Most likely they will drop back into more secluded less accessible areas. On smaller streams they may become trapped in pools. As the water clears and they are exposed to the environment they become traumatized. They will show no willingness to look at, or take a fly. Once hooked most Steelhead will retreat and resist any future offerings. This explains why the first anglers through an area have more success. For those coming through later on, it might be a along day. As crowds increase there will be more negative effects on our fishery. One thing for sure it is getting harder to find solitude on most rivers.

Acknowledgements
Reprinted with permission of North Coast Fly Fishers, Inc. www.ncff.net

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