A Day in the Life of a Northeast Iowa Trout

By Rod Woten

Trout are absolutely fascinating to me. Whether it’s their ability to live in the smallest streams or the largest lakes, their sheer strength and survivability, their ability to see and intercept even the smallest aquatic insects rushing by in the current or their bold and beautiful yet highly concealing colors, there are just so many cool things about these fish! As an angler that loves to catch these fish, I spend a great deal of time learning about these fish. The fly rod is my preferred method to catch them which only adds to the challenge. The things to learn about how they feed, what they eat, where they like to hide, etc. seem to be never ending and the more I learn the more I realize that I have yet to learn.

Cool, Clear Water
Trout are considered a cold water species. That means they prefer to live in water 60 degrees Fahrenheit or colder which is a considerable departure from the warm water species that most Iowans are familiar with like bass, bluegill and catfish that tolerate water as warm as the 70’s or 80’s. Fortunately, Iowa has a smattering of cold water streams in northeast Iowa that are perfect for trout to live in. These streams exist because of the unique geology of the region referred to as The Driftless Region. It is so named because of its lack of glacial drift that the glaciers that missed this region left behind in other regions of the Great Plains as they receded at the end of the last ice age. The intact limestone host many underground springs that eventually surface and become the cold water streams that the area is so well known for. Because these streams are fed by underground springs, they maintain a fairly constant temperature between 40 and 60 degrees all year around which is ideal habitat for a trout.

Humble Beginnings
While there are a handful of streams in Iowa that host self-sustaining populations of brook and brown trout, and even one or two that are believed to have natural reproduction of rainbow trout, most of the trout in Iowa are stocked. All of these stocked fish are hatched at the state hatchery in Manchester, Iowa. From there they are distributed between the Manchester facility and rearing stations in Decorah and Elkader, Iowa. These fish are fed and raised until they reach stocking size at which point they are distributed by the appropriate facility (Manchester, Decorah or Elkader) into streams within their respective jurisdiction. While many of these fish get caught within a week or two of their stocking, many also remain in the stream to become what we like to call a “holdover” fish. The longer a stocked fish lives in the stream, the more “wild” the fish becomes as it eventually forgets the habits developed to survive the concrete runs of the rearing facility and learns what to eat, where to hide and how to survive in the stream.

A Varied Menu
Trout are very adaptive feeders and can capitalize on any of a number of food sources in the streams they inhabit. Classic trout food includes aquatic insects like mayflies (in both nymph and flying adult forms), Caddis flies (in both pupal and flying adult forms), Midges (in both nymph and flying adult form), sculpins, minnows, worms, ants, beetles, grasshoppers and crickets. Truthfully, just about any insect that ends up in the stream is fair game for a trout. Brown trout are also notorious cannibals and will readily snack on young-of-the-year browns that get too close. In some larger rivers in the western U.S. and Alaska, trout are also know to eat small mammals such as mice, shrews and voles that either fall in the river or attempt to swim across it.

Seasons of Change
The typical day for a trout in the streams in Northeast Iowa varies depending on season, but generally speaking, during any season, their primary concerns are feeding and hiding from predators. In the spring a trout’s metabolism begins to ramp up as it begins to shake off the lethargy of winter. They will begin to feed largely on mayfly nymphs that are drifting in the current of the stream’s flow. This is the time of year to drift a Hare’s Ear or Prince Nymph pattern under a strike indicator or drag a Czech-nymph rig through likely looking water. As the weather warms, the trout’s appetite increases and the hatches of mayflies, midges and caddis flies follow suit, continually increasing until their peak sometime in mid-June. This is prime-time for drifting dry flies that imitate the adult stage of mayflies, caddis flies and midges. To many fly fishermen, this is the only true form of fly fishing, despite the fact that most trout only do 15% of their feeding on the surface at any time of the year. The hatches begin to dwindle as summer ramps up so trout begin to rely on grasshopper, crickets, ants or any of the myriad of other land insects that might find themselves in the water. This is the time of year the many fly anglers will fish with “terrestrials”, of which the grasshopper may be one of the more popular flies to throw. Trout will viciously attack a foam ‘hopper-shaped fly on the surface because grasshoppers are such a dense source of protein and calories, which makes hopper fishing a true adrenaline rush for the angler casting ‘hopper patterns! As fall approaches, the trout become ravenous in an effort to pack on as many calories as possible to hold them through the low metabolism and lethargy that accompanies the impending winter. This means they are looking for high protein, high calorie food sources like sculpins, smaller trout and other baitfish species. The more calories they can get in one bite the more appealing that meal looks to a trout at this time of year. This makes it the perfect time for the fly angler to start aggressively fishing those Wooly Buggers, Muddler Minnows and other flashy streamers that adorn their fly boxes. Winter means it’s time for a trout to slow things down considerably. They will still feed, but will rarely move more than a few inches to pluck a nymph from the current as it drifts by. Often they find some of the deepest, slowest moving pools and set up residence there. This allows them to stay below the fastest moving fingers of current thereby not using up their valuable energy reserves fighting the current all winter long. Fly anglers this time of year need to fish really slowly, and as deep as possible. Small nymph patterns are the best bet at this time of year, and the closer you can get it to being right in front of the trout’s face, the better your chances are that they will eat it.

Prime Lies and Grocery Conveyers
One of the most crucial parts for successfully catching trout is to know exactly where they can be found in the stream. Trout will orient themselves facing into the current and simply wait for the conveyer that is the current of the stream to deliver the groceries to them. These areas are often called “lies”, and not all of them are created equal. The lies that incorporate all of the things that are important to a trout are called “prime lies”, and if the water is clear enough to actually watch the trout, it’s very easy to see which lies are the prime ones. The prime lies are the ones that every trout seems to want to be in…often you will see one trout chase another trout out of a prime lie only to be chased out by a bigger fish. Needless to say, the biggest trout are often the ones that end up with the prime lies. Just watching this back and forth amongst the trout in any given pool can give you a great insight into what constitutes a prime lie, how the trout feed and WHAT they might be feeding on. So what are the things that make a prime lie such a great piece of real estate to a trout? Trout are driven largely by three key needs…the need for food, the need for cover from predators (often in the form of flying predators like eagles and other raptors or wading predators like herons and raccoons), and the need for clean, cold, highly-oxygenated water. The more of these factors a lie has the more “prime” it is. Anywhere that a trout can get near the current makes for a pretty good lie, the lie is even better if they can be just close enough to the finger of current to be able to pick food out as it drifts by but just far enough out of the main finger of current that they don’t have to expend all their energy to maintain that position. This makes small eddies behind or under rocks or under an under-cut bank great lies for feeding. One of my favorite places is on either side of the main current as it dumps into a pool. Trout will wait in the wings on either side, where the current is greatly reduced, and pluck food out of the main current as it curls out to the sides. The undercut banks and rocks can also offer protection from predators making them an even better lie for the trout. Trout will also use deeper water as cover and if they can get below the main current and pick off food as it filters down, it’s even better for them. I love to fish riffles for trout because they can often hide behind the rocks that are creating the riffle, the whitewater gives them great overhead protection from predators AND that water is also highly oxygenated due to the agitation of the water as it tumbles off the riffle area incorporating tremendous amounts of oxygen into the water. The swift water of a riffle is also an advantage of the fly angler because it obscures the fly you’re casting and moves it quickly enough that a trout is reacting more to the general shape and size of your fly rather than focusing on whether or not your fly looks exactly like the particular sub-species of mayfly it’s feeding on at that given moment. On days when the trout are being highly selective and I am having trouble matching the hatch, I can often get the fish in the riffle to strike when I get refusal after refusal from the trout in slower water.

Don’t be Afraid of the Dark
Even as the sun sets a trout’s day is not completely done. Dusk is often the best time of the day for hatch activity and the trout feeding that accompanies it. I’ve lost track of the number of times that I would swear a stream was totally devoid of fish only to see rise after rise as the evening hatches began in earnest and the trout capitalized on it. If you’re not out there casting until you can’t see your fly, you’re missing out on some of the best fishing of the day.

Brown trout, especially BIG brown trout are also fairly well known for being nocturnal. Trout get big for a reason and for some of them it’s because they’re smart enough to remain hidden during the daylight hours only to emerge under the cover of darkness and the relative safety it brings. Similarly to fishing the evening hatches, if you’re not fishing after dark, you’re missing out on a golden opportunity to catch a trophy brown trout!!!

Think Like a Trout
There’s an old adage that in order to catch a fish you have to think like a fish and I find this especially true for trout. It’s a fish that can be so easy to catch in one instant and completely frustrating in another. I truly believe it is a fish you could study for a lifetime and still not have them totally figured out. That being said, I feel it is important to understand their behavior if you intend to become a successful trout angler. The more you can observe them and try to make sense out of why they are behaving the way they do at any given moment, the more success you will have.