Back Eddies Provide Easy Living For Trout
By: Mark Bachmann
Back Eddies are places in a river where the currents reverse direction and flow upstream. In eddies the currents swirl and revolve, some violently, others are soft and slow. The eddies that are large enough to hold trout are our main interest here. They can be as big as a wash tub or nearly the entire width of the river.
Eddies tend to gather drifting trout food items and condense them toward the slower turning areas. In many slower turning eddies foam- lines form in floating patches. These foamy areas provide cover for feeding trout and trout-food organisms are often gathered in in the foam as a vast smorgasbord. These foamy areas drift with the changing currents or winds. Calm days are usually best for fishing in back eddies as wind often scatters the floating food. Trout can drift around with the food items and foam lines or station up in places where food tends to concentrate. Feeding is usually quiet and deliberate. Normally the only surface disturbance is a small dimple from a nose or dorsal fin. Sight fishing is the best approach. A pair of high resolution binoculars is a real asset for spotting what the fish are feeding on. Back eddy feeders can be very picky. Being able to see what the trout are feeding on is the key to success. Some slow eddies have silty, weedy bottoms and the insects that hatch from them are the varieties that you would expect to find in lakes. But eddies also trap insects from hatches that occur in other parts of the river. This is especially true of crippled or dead insects.
Observation has disclosed that many of the insects that trout feed on in eddies are dead or disabled. Insects that are emerging from their nymphal to adult forms are also targeted. Healthy adult insects are often ignored. Most food items that get trapped in the flow of an eddy are very small. On the Deschutes River most of the back eddy feeding is done on insects that are size 14 through 20. To make the acquisition of these small food items pay off for the trout in the "calories in vs. the calories expended" equation, the expenditure of energy must be very small. Any food item which can escape or takes pursuit is a potential liability. Therefore insects which are incapable of escape are most desirable. Some eddies collect food items in dense translucent rafts that appear as brownish scum. These scum lines revolve in the eddy with the currents. The trout follow them feeding leisurely. These trout are extremely visible to people. Many of these eddies receive a lot of angling pressure. Trout in eddies which receive a lot of fishing pressure can become very suspicious feeders.
Any potential food item that moves un-naturally is refused. Being able to present your fly so that it shows no influence from an attached leader is essential. Long fine tippets made from nearly invisible material are the rule. Being able to present the fly line and leader so that you get a drag free float takes planning. Casting accuracy is essential. Observation is the real key to success in back eddies. Use your polarized sun glasses and a pair if binoculars to study the fish and their prey. Find a comfortable vantage point. Try to position yourself so that you are camouflaged from the fish. Use natural vegetation as a blind. Dress to blend in. Often the feeding fish will forget that you are watching them. Get elevation if you can. Station up in the shade. Use the natural light to give you the best visibility. When trout are spotted, it's hard to turn off the attack instinct. The trout are not going anywhere unless they are spooked into hiding. Remember that once you start your presentation, you will get a limited number of shots. The first shot will be most stealthy. Choose it wisely. Take your time. Survey the whole area.
Know where all the players are holding and what their movement patterns are like. Sooner or later your hunting instinct will point out one fish that is most vulnerable to you. Or possibly it will home in on an individual that is the best trophy. No matter the criteria, you must zero in on one quarry. This is a point where you can blow the whole scene. Remember the first shot. Take an extra measure of time to study the target in fine detail. Watch it feed through your binoculars. See exactly what it eats. If you can match this trout's favorite food item exactly, not only in size, shape and color, but also in buoyancy, your fly is as effective as it can be. Now you can concentrate on the presentation of the fly. How the fly lands on the water in relation to the fish is the first key element. Place the fly on an intercept trajectory with the fish at the closest possible range that won't spook the fish. Use a light touch. The softer the fly lands on the water, the closer you can put it to the fish. The closer it is to the fish the less possibility there is that drag will occur before the fish takes. The cast must take into account the surrounding obstacles such as grass, shrubs and trees. Back eddy fly fishing can rival chess and golf for complexity. That's why we do it.