February 01, 2016
By Matthew Supinski
This story was originally titled “Spring Creek ala Carte: Food for Finicky Spring Creek Trout” and appeared in the Oct-Nov-Dec 2015 issue of Fly Fisherman.
If a trout could choose which gourmet restaurant to dine at, it would LIKELY choose an open table on a limestone spring creek. These "God's special brews," as a Wyoming fly-fishing preacher once labeled them, are the ideal habitats for trout to become very fussy about what they eat.
Given their favorable year-round water temperatures, stable comfortable flows, ideal habitat, and alkaline Akvavit water, these spring creek ecosystems foster an incredible prey biodiversity.
Spring creek trout adapt quickly at a very young age to become epicurean snobs feeding at a leisurely pace and with a high degree of discriminating taste like a Michelin Star food critic. They have a rich smorgasbord of year-round crustaceans, midges, and sculpins, along with seasonal mayfly/stonefly hatches and terrestrials that add a bonus crème de la crème to the dining options.
Understanding the feeding habitats of the browns, rainbows, and brook trout that relish these environments is critical for spring creek success.
Large spring creek trout require highly developed game plans. Each memorable encounter leaves you with specific presentation notes, and opportunities to review and be carefully tweaked in your next approach.
In my book Selectivity (Stackpole Books, 2014), I shared my pursuit of a particular monster brown named Mr. Big on the hallowed Letort Spring Run in Pennsylvania, and also of the Abbots Worthy Mill leviathan brown on the River Itchen in England that chased small ducklings. I wish to now indulge you with another man-versus-fish saga and introduce a persnickety old spring creek trutta nicknamed "The Juggler" who become as elusive and attitudinal as any I've met.
He was a broad-shouldered heavyweight that engaged in his daily feeding forays at Vince's Meadow on Letort Spring Run in Cumberland Valley. This beast followed very specific feeding intervals, usually revolving around the low-light times of early breakfast and late dinner binging. Since brown trout are intolerant of intense light, on cloudy rainy days I'd usually see him foraging with a less restricted range.
In the mornings, The Juggler liked to poke his large snout into the dense spring creek vegetation to dislodge scuds and cress bugs, and then turn downstream into a feeding lane to intercept the crustaceans he had set adrift.
He sometimes approached the surface when a late afternoon midge or Blue-winged Olive hatch appeared, and by dark, he'd turn into a late-night kill artist hunting for sculpins, small trout, and baitfish even a mouse if available. Given this wide array of dining opportunities, this connoisseur was extremely difficult but not too impossible to catch. He finally succumbed to a tiny olive Hyalella #16 scud, which he mistakenly took for a natural at one of his gluttonous breakfast buffets.
When I removed the scud hook from the fish's mouth, The Juggler burped out at least a half a dozen undigested scuds into my net. Despite his obvious feeding preferences, I'm sure I notched up his selectivity-radar index a few degrees, and made him even more wary of scud patterns.
A spring creek habitat is a dark concealed world of underwater vegetation channels with deep undercut banks, open shallow sandy gravel patches, deep pools and concealment structures like small bridges, mill dams, conduits, and cattle crossing stiles. With all that cover, trout often set up prey interception locations that are enhanced by the undulating and shifting currents in the narrow channels that provide easy and convenient feeding stations.
With the stable spring creek stream flows unlike the volatility and turbidity of fast-flowing mountain freestone rivers, where its trout are more hard-pressed to make quick and risky predator decisions here the trout take their time and become extremely reflective in their foraging to make certain their prey is the real deal.
And spring creek trout have seasonally extended feeding windows that make them even more confident in their choosy attitudes. Complicate this year-long feeding with the fact that spring creeks are usually catch-and-release waters, these little jewels over time develop difficult feeding patterns.
An interesting theory on large trout came from river keeper Frank Sawyer on the River Avon. His thoughts were that as a chalk stream/spring creek trout grows larger, it becomes more confident in its food choices and thus less selective. His invention of the simplest patterns such as the Grey Goose were deadly for the larger trout that almost had an arrogant approach to their daily feeding.
But streamers were and still are frowned upon on English chalkstreams where they are considered lures, so sculpin patterns were taboo. Since these waters were private clubs with beat systems and aristocratic and likely less skillful fly fishers, they realistically received much less pressure than today's public waters.
With the clear and shallow environs that spring creek trout find themselves in, their predator radar alert is on high, they have a large window of vision, and they can detect sound vibrations through the soggy spring wetlands with relative ease otherwise, avian predators and small fish-eating mammals like mink and otters make meals out of them. Along with constant angler intrusions into their world, they must assimilate and habituate all this data to a comfortable degree or they would be too paranoid to feed, and eventually starve to death.
"Habituation" is the gradually declining response to a perceived threat, resulting from repeated exposure to the stimulus until it becomes completely nonthreatening and part of a safe, normal environment. All animals and humans habituate to a certain degree like the dog that lies on the couch and eventually realizes that a doorbell sound on a television show or commercial is not a real doorbell and ignores it.
The browns and rainbows on Ole' man Skelly's pasture on the Falling Spring Run in Pennsylvania, would take up foraging positions every day at the same time, and at the same spot, below where the farmer marched his cows through the streambed back to the feed barn. The cows kicked up crustaceans, midges, and nymphs so the trout could also put on the feed bag.
Trout on the San Juan River and elsewhere also realize that wading boots dislodge aquatic worms and larvae, and they react almost the same way.
What this feeding habituation teaches us is that if we slow down, and become part of the scenery, spring creek trout eventually label our intrusion as nonthreatening and begin to feed right off our rod tips. Spring creek angling is more of a matter of hunting/stalking and moving slowly like a heron rather than flailing away all day.
Don't be a bull in a China shop. Observe more, and let the trout reveal its foraging habits to you. Get the best polarizing glasses you can find, move on your hands and knees with a low profile, and dress in tan and green colors to better match the streamside environment.
If a spring creek trout has a Lord's Prayer, it would definitely be, "give us this day our daily scuds and cress bugs." Though Mancasellus cress bugs (isopods) are very standardized in size, olive to grayish tan, freshwater shrimp (amphipods) Gammarus and Hyalella come in varied sizes from size 10 to 22.
Usually the smaller, deeper, weedy channels of a spring creek favor crustacean feeders. These trout often position themselves near the bottom at the edge of the vegetation near the sandy patches of the streambed. This gives them a clear visual background window to intercept the scuds and cress bugs drifting from the weeds.
Like The Juggler mentioned previously, some super-evolved trout learn to munch on or otherwise disturb the vegetation to create their own feeding opportunities.
Some trout cruise the tops of weed beds and in channels of Chara and Elodea scanning for scuds swimming from bed to bed, and any slight movement from cress bugs. A crustacean-feeding trout can become oblivious to any angling/predator intrusions, since their focus is always downward and their gluttony driven like a spring breaker at a crab shack.
Also, the high caloric value makes these specialized feeding trout unusually fat. They can afford to be picky. As a result, your scud and cress bug patterns should imitate the naturals in color, size, translucency, and to the specific phase of sexual maturity, molting, and movement they take on at any time of the year.
When fishing scuds and cress bugs, start with a dead-drift approach. If you experience refusals, try adding little twitches, lifts, and stutters by mending up or downstream, lifting the rod and dropping it to allow the artificial to swim and or crawl in and out the vegetation.
Some spring creeks have a chalky stain due to calcium carbonate emanation, but most are startlingly clear, thus there is no quarter for standard strike indicators they will only alarm fish and distract your attention from the leader, the water, and the fish, and the subtle clues they all provide.
Whether you are nymphing crustacea or midge larvae, sight-nymphing in the old Sawyer/Skues tradition without an indicator is one of the highest echelons of fly fishing, and it can take a lifetime to hone and enjoy. This is the ultimate mind-versus-fish engagement and it requires the same delicacy as dry-fly presentations.
The first challenge is to decide whether to use lead, tin, or tungsten split-shot; or sink putty, attached anywhere from 12 to 18 inches above your offering. If you put the weight any closer, it alarms the trout, especially when you're fishing small fly sizes.
There are all kinds of stealth shot like soft, nontoxic Dinsmores Egg Shot, which range from sandy tan to green and don't spook fish. I often have trout mistake these split-shot for a delectable morsel, and while that shows the trout are not spooked by them, it's not a dependable method to hook and land trout.
Today many anglers use weighted bodies and beads in their nymph patterns but they are often too heavy, and do not naturally flow dead-drift along with the current. Weighted nymphs like these are best for the lift-and-twitch technique previously mentioned, but by attaching split-shot to the tippet or leader, you get longer drag-free floats.
Nymphing spring creeks is often a matter of tiny flies, and seeing the trout take your fly is difficult. One good work-around is to build orange hot spots into your scuds and nymphs Czech and Polish style, with flies like an egg-carrying scud, or a Frenchie Pheasant Tail.
Determining the depth penetration and the drift time of your artificial fly is essential. It's impossible to see your fly or the trout strike if you don't know how deep the fly is, or the length of time and distance it is drifting at that level.
With a large pattern that's easy to see, you merely watch your fly. But with spring creek flies that border on minutiae it's much tougher.
To help my gauging efforts, I carry fluorescent orange Teeny Nymphs with gold bead heads on size 16 to 24 hooks. I use these as "drift testers" to judge where I need to cast the fly and how long it takes for the fly to sink and stay at the depth I want to arrive at a specific 6-inch-wide feeding channel between the weeds.
On rare occasions trout engulf these aberration nymphs, but mostly I make as many test drifts as I need with the high-visibility nymphs, then switch to a more realistic nymph with a similar specific density. I can then focus on a specific spot and depth where I know the fly will be drifting near a trout, and I use binocular vision to watch both the fly and the trout's reaction to the presentation.
If a trout shows interest but does not take, it usually exhibits quivering of pectoral and ventral fins, quick sideways or upward mouth movement, a quick forward movement, or lastly a gradual gliding back and following the fly. You'll see the white mouth open or the trout will shake its head if it eats the fly, but this takes place in micro seconds so your perception needs to be on high alert.
Weapons of Midge Destruction (WMDs)
Spring creek trout can also become habitual or even exclusive midge feeders. The sheer abundance of midges on fisheries such as Big Spring in Pennsylvania, Depuy's and Nelson's in Montana, and Silver Creek in Idaho, makes them a food source trout focus on 365 days per year.
Midge feeders are usually suspended slightly off the bottom if they are feeding on pupae, or right under the surface if there is a heavy emergence going on. In the backwater sloughs and slow water of Western spring creeks like on Hot Creek in California, they often cruise around in established foraging circuits.
Since the natural insects don't move much, the trout position themselves an inch or two below the surface and gulp midges in a lethargic fashion. This gulper behavior is the hallmark of trout feeding on midges and tiny mayflies, and is usually seen starting and noon and later as the insects become more active. Spring creeks are generally cold, and most of the insect activity is in the afternoons and evenings.
While scuds and midges are the foundation of the food pyramid for spring creek trout, there are always some apex predator trout that are more than willing to binge on larger surf-and-turf-type meals when they become available.
Unexpectedly large food items are often exploited by large trout, but not without some trepidation. Large mayflies, mice, sculpins, cicadas, and hoppers might go totally unappreciated upon their first appearance, but that doesn't last for long.
I recall the first emergences of Green Drakes on Penns Creek, Brown Drakes on the Henry's Fork, and Hexagenia hatches on the Au Sable where the trout either remained fixated on scuds and midges, or were outright alarmed by the new large food source but for only a short period. After the initial shock and awe, large trout especially turn into manic predators until the last drake, terrestrial, or cicada of the season is eaten.
Sculpins are different kinds of meaty entrées because they are available all year, and due to their nutritional value, big, carnivorous trout can develop a "prime cut mentality" and hunt for them nearly exclusively. By sheer design, brown trout are lovers of dark places undercut banks, bridges, under surface weeds, and in tangled root wads. They conceal themselves so well that ambushing their prey is circumstantial rather than calculated.
When fishing sculpin and crayfish patterns, use short quick strips with dead drifts, and frequently hesitate the pattern along the bottom, allowing for the more natural swimming/fleeing motions that trout recognize. I can't tell you how many times a trout pulverized my sculpin pattern as it rested on a sandy gravel patch. Monotonous steady stripping only bores the trout.
There's a psychological element to every brown trout hunt, and large browns are often similar in their quirky mentality. They want what they can't have. When you see a trout refuse your streamer at the last second, wait for the fish to go back to its ambush point, and rest it for five minutes.
Give the fish a chance to reflect on how it let that meaty pattern go, and how it could have had a great meal. Regret is a human emotion but sometimes seems like a powerful motivator for trout as well. You may be pleasantly surprised by how your streamer is thrashed the next time the trout sees it.
Matt Supinski is a guide, lodge owner (graydrake.com), and author of the newly released book and DVD Selectivity: The Theory and Method of Fly Fishing for Fussy Trout, Salmon, & Steelhead.