How-Tos Archives - Tom Keer

FISH PATTERNING IS a modern term for a very old methodology. It is a reasonable, deliberate and highly effective way of fishing. It depends on understanding the dynamic relationship between predator and prey in their environment. The phrase describes the essential survival approach to fishing that enabled commercial and professional fisherman to succeed in their day-to-day quest for a good catch that would ensure their livelihood.

Patterning fish behavior is similar to hunting. With all methods of hunting, you must study your quarry to understand their behavior. Many modern sport anglers simply arrive at a familiar spot and hope to catch fish. Their fishing strategy is limited to chance occurrence. Anglers who fish that way are dependent on happenstance alone rather than observed, fact-based knowledge. Fish, like all successful predators, base their feeding routines on the habits of their prey. Fish do not starve to death because of poor luck. They have an intimate knowledge of how to find food. Like these fish, the best fishermen are familiar with their quarry’s routines and use this knowledge to form strategies that enhance their chance of success. Learning how fish find bait in their environment is fundamental to becoming a consistently successful angler.

Develop a Plan

The fast lane to learning how to pattern fish is to study the flats. Flats have finite borders that are filled with classic structures like bars and channels, coves and points, rips, basins, and various bottom types (mud, sand, cobble and grass). And fish are restricted in their ability to move. They are subject to the boundaries of the environment. Flats are first and foremost laboratories for observing fish behavior. The first task is to develop a plan or a strategy that you can use to find fish. Simplicity is the order of the day. Start by heading to a flat at slack low tide so you can study its structure. Fish move along structure lines, and it is critical to note where the bars drop into channels, where one bar ends and another begins, where there are grass beds and where there is higher ground. The bait will follow those edges when the tide floods, and larger fish will follow the bait.

Then start at the shallowest edge that you can get to and move along, and head into the current, parallel to the flow. This will do several things for you in short order. It will eliminate water that is not holding fish in a matter of minutes. Using a depth line as a guide and following it allows you to observe and quantify the life on the flat. This is the most important skill you can master. If you cover an edge thoroughly and find no baitfish, move to a slightly deeper edge. You should spend at least 45 minutes to an hour scouting out the depth line before wetting a line. Resist the urge to cast, even if you see fish. After several passes, you will begin to notice the baitfish moving along an edge, and you will see their relationship to the water’s surface or the bottom. You’ll see how they move along the edges of current seams created by bottom structure and moving water. You’ll notice their depth and whether they are high in the water column (closer to the surface), low in the water column (closer to the bottom) or somewhere in between.

As you move along the depth line, you will come upon shallow bars and edges that focus the current, consolidating the bait into dense schools. These schools will pause and gather together to move over a bar or through a small rip as they move into the current. Observing the patterns of how individual schools of baitfish move is significant; this determines how the predators locate bait in order to feed easily. The patterns of bait change daily, depending on water temperature, light levels, wind velocity and wind direction. Once you locate the bait and register their patterns, it is natural to look up-current and notice where the water flow provides an easy place for predators to ambush them. Use your GPS to mark spots, or do it the old-fashioned way and take ranges (line up two vertical landmarks, one behind the other, like in a rifle sight, such as a house chimney in the back and a flagpole in front of it). Once you have identified the baitfish’s patterns, repeat the same steps, with the focus turned toward predators. Return to the shallowest water you can get into, and this time move quickly along the edges and start looking for your quarry. Move along an edge until you have eliminated it, and then move incrementally into deeper water until you find the depth that the fish are moving in. The difference between your shallow-depth runs and your deeper-water runs will probably be only a matter of inches. Note the depth in which you find fish, for they will stay at that depth as the tide rises. That means if you find them at 21/4 feet, they will constantly move in a depth of 21/4 feet, regardless of their physical location on the flat as the tide rises. If the depths are uneven, then the fish will reposition to move at a depth of 21;4 feet. They will mill at a bar and only pass over it when the water rises to their preferred depth of 21/4 feet for that day. They may go around the bar rather than wait, but that type of movement is not hard to notice. Once they go over the bar, they will continue to move at their preferred depth and search out baitfish as they go along. This depth orientation is one of the most amazingly consistent patterns fish display on flats and an important one for you to know.

Here’s the tough part: To learn how to pattern fish, you’ll need to leave fish in order to find fish. Now is the time to see if the pattern you observed is correct. If you find fish on the southeast corner of a point bar at 2 1/4 feet, go to the next southeast corner of a point bar at 2 l/4 feet and see if they are there. They probably will be. As the tide rises, the bait and the bass will also move up the bar in that 2 1/4-foot zone. They will follow the structure line until it ends. Then they will use a current line to bridge their move to an adjoining structure, always maintaining the same amount of water over their head. Leapfrog your way across the flat, and observe as you go.

Pay Attention to Subtleties

If you have a pattern that is producing consistently and you find a similar structure or current that does not produce fish, do not assume that the pattern has changed. So why is this area barren of fish? Try to discern a difference. You’ll likely notice something, like the current has changed or your pattern was for offshore bars and this one is an onshore bar. Perhaps there is a point bar forming an uptide rip current that pushes the flow into deeper water. Remember that bar, because it may fit into a different pattern that you learn about later on. While that bar did not contain fish on the flood tide, it may be an escape route for the fish once the tide ebbs.

Now you can make your first cast. Because you patterned the fish, you can station your boat or yourself so that you can catch them consistently. You’ll know where they are coming from and where they are moving to. You can deliberately position yourself above them to make a proper presentation. You will not spook them because you are waiting for them, not chasing them.

By patterning fish, you will notice the different mannerisms of fish. You will become aware of whether fish are positive, neutral or negative. Positive fish are easy to catch. Negative fish are spooky fish, jittered by even a sea-gull shadow. Neutral fish are inquisitive and can be caught if you make them interested enough to strike. Hunger governs positive fish, wariness governs negative fish, and indifference governs neutral fish. Positive and neutral fish can be caught through patterning. Negative fish can be caught if you use patterning to intercept them with stealth.

When the tide drops, the direction of the current reverses, and fish will slowly drop back off the flat, always facing into the current. They will move off the flat at the same depth in which they came onto the flat. To learn to pattern fish, you must get rid of your preconceptions. Just go to the water and observe. Avoid routines. If you return to the same spots you always fish, you won’t broaden your skill set. Instead, notice the current, examine the wind, and note how the two interact. Watch how the current and the wind move on structure and form edges and pathways for fish. Look for those edges, and look for bait. If you incorporate observations like these into your fishing, you’ll be able to read water and understand the structure of every flat you encounter.

Fishing is much more than just catching fish. If it were passive, then we might as well go and watch a spectator sport. Sometimes when we go fishing, we spend the entire day and make only a handful of casts. Our day is spent studying the baitfish, the environment and then the fish to see how they interact. When we do make a cast, we hook the fish deliberately. As you spend time patterning fish, test out all hunches, no matter how irrational they seem. If you are wrong about a current or a location today, you may find that it is useful tomorrow. When you are right, log the pattern. You’ll quickly become a savvy angler.

Current Events

When the water begins to move, study the current to see which direction it is going. The fish will move into the current. Note if the current is moving to the left or to the right. Observe how the wind interacts with the current. An onshore wind will push the current and the fish closer to the structure, while an offshore wind will push the current and the fish farther out. A wind that blows into the current slows it down, and a wind that moves with the current increases its speed. If the wind is faster than the current, it will form a surface current that predatory species might move into. Notice what speed of current the fish prefer. See if they favor the hard currents around the end of a point bar or if they prefer the softer current in the middle of a shoal. Look for edges where currents meet and join or where they separate and split. Cardinal points are critical; use these compass directions to note how fish approach bars and which side of the humps they use to move into the current. These behaviors may seem random, but they are patterns that are predictable and consistent.

This article originally appeared in the September/October 2012 issue of Fly Fishing in Salt Waters.

Isonychia – Fly Rod & Reel

Over the years I’ve found brilliance in events that don’t go according to plan.

That was the case last fall when I visited the Farmington River and saw anglers in every spot I wanted to fish. I had to laugh; Indian Summer was in full swing with its warm days and cool nights, the maples were turning scarlet and orange, the white birch were a colorful yellow, and trout were on the feed. Why wouldn’t the river be crowded?

At the bottom of a pool below a feeder stream was a gravel bar that allowed safe passage across the river and my only chance for some solitude. Safely across, I could wade upriver and fish the back side of an overlooked mid-river island.

About halfway up the island was some pocket water. It necked down into a small, shallow riffle that turned into a pool. The pool bent toward shore and cut under a bank. It bounced off some big rocks at the bottom and was a beautiful piece of water, all rolled into a 30-yard stretch.

Shortly, I saw a good brown perform a splashy rise near one of those rocks. Then another, and another. I inspected those rocks, and saw the shucks that explained those rises. Isonychia!

The first time I encountered these rich, eggplant-colored bugs, which are commonly called mahogany duns or slate-wing duns, I spent an entirely frustrating day changing from emergers to a wide variety of dries to a slew of nymphs with no luck. It was only during the final minutes of the day, when I botched a cast that put a lot of drag in my drift and fast motion to the fly, that a big brown whacked that speeding nymph. Since that time I’ve always used a fast swing when fishing this hatch, and it’s served well.

Here’s why that tactic works: Isonychia swim almost as fast as a dace and they climb on structure like a stonefly to shed their nymphal shucks–basically Isonychia duns are unavailable to trout and, therefore, it’s almost futile to fish a dry fly when an emergence occurs. But trout do chase down those fast-swimming nymphs, which I match with a size 12 or 14 Didas’ Swimming Isonychia Nymph.

While those duns aren’t important to trout, the Isonychia spinner is. It occurs most often in riffled water and can be matched by several noted patterns, including the White-Gloved Howdy, an lsonychia Comparadun, or a Beck’s Emerger-lsonychia. In contrast to fishing an Isonychia nymph, when fishing a spinner you’ll want to employ a dead drift.

There are two versions of Isonychia in the fall, the larger bicolor and the smaller sadleri. The hatch occurs on many Eastern, Midwestern and some Southern tailwaters and freestone streams, including emergences on such noted waters as Connecticut’s Housatonic River and Michigan’s Ausable. Wherever it occurs, the hatch typically comes off in early afternoon and lasts into dark-graciously, there’s no need to set the alarm clock earlv for this one.

Because Isonychia nymphs swim quickly you can forgo some of the extreme technical fishing required to match other fall hatches; you know, those painful experiences that require magnifying glasses and 8X tippet. Instead, you can throw a variety of classic patterns, such as the Leadwing Coachman, a Zug Bug or even a Pheasant Tail Nymph. My favorite pattern is Tim Didas’ aforementioned Swimming Isonychia Nymph. Didas spins the bug on a swimming nymph hook, adding a component that lights up the fish.

Looking back, it wasn’t so bad getting displaced by those other anglers on the Farmington. Browns and a few rainbows rose for hours, I had a quiet stretch of river to myself, and I was in the middle of a hatch that didn’t require much precision or stealth. I waited until the sun was long gone before I quit the stream, knowing I’d be back the next day.

Best Bets

Delaware and Beaverkill rivers, NY Connecticut River, NH Deerfield River, MA Penn’s Creek and the Little Juniata, PA Davidson River, NC Manistee and Ausable rivers, MI Hiwassee and Little rivers, TN

Didas’ Swimming Isonychia

Hook: Tiemco TMC400T, size 12 to 14 Thread: Burgundy 8/0 Tail: Three partridge after shafts Body: Burgundy dubbing Rib: Fine gold wire Thorax: Peacock herl Dorsal stripe: White Flexi Floss Wing case: Gray hen hackle Legs: Partridge