Every so often, a new technology comes along that changes our understanding of how things are. Galileo’s telescope, Leeuwenhoek’s microscope, and more recently, the Large Hadron Collider have all helped reshape our concepts of reality. While waterproof digital cameras may not have created as many wows as the Hubble Space Telescope, they have revealed a lot about a world many fly fishers rarely or never visit. Many of the things we believe about how fish behave and how fly-fishing tackle actually works may be due for a bit of a rethink.
Mirrors Everywhere
Anyone who has read books on fly fishing will likely know about “the mirror” and its effect on how fish see things. In short, fish see everything that’s above the water in a circle (“the window”) straight over their heads. The surface of the water beyond the bounds of the window reflects the bottom and is referred to as “the mirror.” Some books provide simple diagrams to explain the mirror, while others go so far as to explain the optics of this counterintuitive effect. For a long time, this accurate, though marginally helpful explanation was all we had.
Things changed in 1980 when John Goddard and Brian Clarke published The Trout and The Fly: A New Approach. Using a specially designed glass tank, they were able to shoot trout-eye-view photographs and videos of real insects and their imitations as they moved across the mirror and into the window. Their images revealed far more detail than the diagrams provided in most books. Of particular note was the way upright wings on real insects appear disconnected from the bug, only to meld back as the insect fully enters the window. Also, the pattern produced by the fly’s legs as they deform the surface film are markedly different from the pattern produced by hackle tips. These insights helped the authors develop new patterns that more accurately reproduce these visual effects. That kind of research is eminently worth doing today, enabled by today’s technologies.
Flash
I had a mirror revelation in the surf that I’ll admit was a complete surprise. I had never thought about the mirror existing in such a chaotic environment. I was working on a baitfish pattern for striped bass and wanted to see how some prototypes looked and behaved. The fly was based on a highly reflective, Flashabou-like material. The idea was that an extraflashy pattern would help draw fish from long range. With a waterproof digital camera, I shot several minutes of underwater video of the fly from various angles and depths.
The fly did produce some strong f lashes of light, but like the highly reflective sides of anchovies and sardines, it became much less visible when not reflecting light directly toward the camera. However, the fly’s blue-colored back and its oversized black eyes were easy to see reflected in the sand-colored mirror.
A more recent mirror epiphany occurred on a local lake in 2019. Largemouth bass were attacking schools of shiners and creating quite a ruckus. Occasionally, there’d be an explosive “rise” to a shiner struggling on the surface. A top-water pattern that seemed like a good match did not impress the bass. I got one hit, but it was clear something wasn’t right. I finned around and finally located a shiner twitching on the surface. I shot some underwater video of the shiner and my fly to see if I was missing something.
I sure was.
Like most fish, shiners have countershading body coloration, dark backs and light bellies, which helps camouflage them when viewed from above or below. Countershading works very well when the fish is right-side up, but quite badly when the fish is upside down. The dying shiner was belly-up, and its silvery stomach created a slash of light that was also reflected in the mirror. My fly, meanwhile, did not produce a bright ref lection. Presumably, the bass were keyed in on the double flash, or perhaps the extra brightness helped them see the dying fish more easily. Either way, an upside-down pattern was needed to match the hatch, and I did not have one.
Top-Water Stripers
Slinging top-water flies is one of the most exhilarating and addictive ways to fish for striped bass. It is also a good way to search for stripers over large tracts of water. Back in 2007, I teamed up with well-known fly tyer and longtime friend Lee Haskin to conduct some underwater video and acoustic tests of popular top-water flies. We figured subsurface noise must be a big part of their success, but couldn’t find any articles on the subject.
Standing next to a swimming pool armed with a homemade hydrophone, a laptop, a waterproof camera, and some top-water flies, we discovered that poppers and divers make the most underwater noise, and it is a lot louder than we had imagined. Depending on the level of ambient noise and how hard a popper is popped, we calculated a fish could detect one from over 60 feet away. That’s a huge advantage when you are working a big lake or the surf, where underwater visibility may be 15 feet or less.
But drawing the fish to a top-water fly is the easy part. In general, they tend to work best around sunrise or sunset. Your chance of actually getting bit during the daytime is usually much lower. As a result, most folks stop using top-water patterns when the sun is above the horizon, even though bass may still be making lots of surface commotions.
In 2017, I started using a hookless popper (based on a plastic transfer pipette) and trailer fly combination. This is a fly-fishing adaptation of a conventional-gear setup that pairs a large pencil popper with a simple bucktail fly trailer. I assume thousands of fly fishers have done something similar with various top-water flies and streamers.
The popper-trailer setup worked quite well, even when the sun was some distance above the horizon. However, there was still the question of why bass don’t hammer top-water patterns when the fish are clearly making loads of splashes. Is there a design issue with top-water flies, or are the fish so focused on prey just below the surface that a top-water pattern is ignored?
In September 2020, a YouTube video titled “Striped Bass Feeding Frenzy” showed East Coast stripers feeding on peanut bunker, as juvenile Atlantic menhaden are called out there. The surface action was identical to what we see over here on the Left Coast when the fish are hitting schools of anchovies or sardines. The underwater footage showed the bass were swimming several feet beneath the bait. Several fish rocketed almost straight up and grabbed their victim just below the surface. Some broke through the surface, but most executed high-speed subsurface U-turns. This video seems to give a bit more support to the idea that the fish are indeed focused on subsurface prey. A top-water fly may be just inches from the strike zone, but those inches might as well be miles.
Wriggling Pupa Pattern?
Fishing a weighted chironomid pupa below an indicator is a popular and successful lake-fishing technique. The angler sets the depth of the rig to ensure the fly is suspended at the feeding depth of the trout, which may be anywhere from just above the bottom to a few feet below the surface. The technique can be very productive when a breeze ripples the water, causing the indicator to bob up and down. Some articles claim that the bobbing indicator causes the fly to jiggle, mimicking the way a chironomid pupa moves as it ascends through the water column. To enhance this action, it is often recommended that you attach the fly with a Loop Knot. I wanted to see if a Loop Knot really does improve the action of the fly and if so, what loop size is best. My underwater video, however, showed that Loop Knots had no noticeable effect on the action of the fly. But that wasn’t the most interesting finding. The fly did move, but instead of jiggling, it rose up a couple of inches and then traveled in a level, decidedly unjiggly way. The indicator was moving slowly across the water in response to the waves, towing the fly behind it. Bigger waves increased the speed of the tow, but did not significantly alter the action of the fly.
Presumably, slight curves in the leader and tippet work like a shock absorber, eliminating a direct connection between the indicator and the fly. One might be able to overcome this by using a heavy fly attached to a supersupple braid leader with nearly zero stretch, but I’m not sure it really matters. The fish are obviously responding positively to the fly as it moves through the water. Besides, braid leaders are more likely to tangle than regular monofilament leaders, and untangling the stuff is a migraine headache most of us can do without.
Snappy Crayfish
Folks who target largemouth bass, smallmouth bass, and big brown trout are likely to have at least one crayfish pattern in their fly box. In many cases, these flies are particularly lifelike, sporting segmented backs, buggy eyes, and two large claws. After all, who doesn’t like to own or tie flies that look like the real McCoy? Besides, we all think that the more realistic a fly looks, the more likely it is to fool bigger, more educated fish. It’s just common sense.
I’ve tied my fair share of realistic crayfish flies over the years, and they’ve certainly caught fish. But as others have no doubt noticed, simpler, less realistic patterns seem to do just as well. Is it because we are less likely to fish a fancy fly in the kind of snaggy spots crayfish inhabit? No one enjoys snapping off a fly that cost five bucks or took over half an hour to make.
A 2018 YouTube video showed a largemouth bass removing a hooked crayfish from its spawning bed. The fish definitely did not like it being near its eggs, but it did not tackle the crayfish blindly. The attacks were always from behind, away from the claws. This may have been because it’s easier to grab the critter from behind, but there is also the possibility it did not want to get bitten. If you’ve ever been nipped by an adult crayfish, you will know those claws can inflict pain.
The aversion to claws seems to be supported by an interesting bit of research at Berkley, a company that makes conventional bass fishing lures. They took 450 bass and for 60 days presented them with a prototype crayfish lure. The first test used the complete lure, and subsequent tests sequentially removed claws and limbs. They got the most strikes when the lure had all of its appendages removed.
Based on the Berkley study and the video, it seems like it might be a good idea to stop using realistic crayfish patterns and instead tie on something like a large Woolly Bugger. This should make the fish more willing to bite and make fly fishers more willing to cast into the snaggy spots where crayfish are usually found. Of course, as my professional fly-tying friends frequently remind me, a fly won’t catch a fish if it doesn’t catch a fly fisher first.
The Final Flutter
Most of us assume fish float to the surface when they are dying, because that’s what we have seen in aquariums and when we have tried to release a fish that has been fought too long or held out of the water for too many grip-and-grin shots. The reality is that a lot of dying fish (probably the majority) sink to the bottom.
This is certainly true for baitfish that have been attacked by predators such as trout, sea lions, and cormorants. When there are hundreds or thousands of baitfish in a school, there are bound to be a number that get injured and spend their final few minutes of life on the bottom. Many predators, including brown trout and largemouth and smallmouth bass, feed on these easy-to-eat morsels.
If you are lucky enough to witness such events and can examine the baitfish closely, you’ll notice they do not swim normally. Most will be on their sides, making short, fluttering hops across the bottom. You can mimic this bottom-hopping action with a Clouser Minnow, a floating line, and a leader that’s between one and a half and two times the depth of the water. This works well in waters less than six feet deep.
However, casting a Clouser can get quite challenging when your leader is over nine feet long. In water that’s deeper than six feet, it’s easier to fish a streamer on the bottom with a sinking line and a short leader. I netted a huge brown trout for a buddy who was twitching a smelt pattern along the bottom of a lake and have lost count how many striped bass and halibut have been caught fishing an anchovy pattern in the surf this way.
So when the initial flurry of feeding activity subsides, don’t assume the bite is over. Drop your fly to the bottom and use a slow, staccato retrieve. You may just land the biggest fish of the day, the season, or your life.
It’s almost inevitable we will gain a better understanding of what happens below the surface as digital and phone-camera technology improves. The really good news is that anyone with a smartphone and a waterproof pouch can participate. Get busy, folks. There is still a lot to discover.
Ketley’s Livebait
The “Catchy Ideas” column in our January/February 2022 issue featured Robert Ketley’s innovative streamer design that he calls “Livebait.” Its construction requires sewing and other forms of fabrication that aren’t usually involved when tying flies. Although the steps for building a Livebait are straightforward (and provided in that issue), their unfamiliarity can lead to confusion, so Robert has posted them on YouTube and added a helpful voiceover. Scan the QR code below to quickly reach the site.
