Fly Fishing the Mighty Columbia River by Don Freschi
One of the finest fisheries in North America is the Columbia River in the West Kootenay region of British Columbia, Canada. One of the last free flowing stretches of the river runs about 40 km, from Castlegar, British Columbia to the Waneta border near Trail, British Columbia. There are plenty of access points along the river but the best way to tackle this large river is by boat (powered or drifted). The river is big and powerful, so I recommend, as a minimum, a 14 ft boat with a 20 hp motor. There are also numerous places to fish the river from shore but most of the best fishing areas can only be accessed by boat.
The river contains a variety of sport fish such as, rainbow trout, walleye, rocky mountain whitefish, northern pike, and small mouth bass but I will focus on the rainbow trout.
The Columbia River fishes good throughout the year, with prime fishing starting in early March and lasting well into November. The river can be fished all winter but I prefer fishing when ice doesn’t form on my guides and the temperature is above freezing.
Let’s start by looking at what you can expect on the Columbia from mid-March through early-May (Spring season). Over the past ten years, the water levels on the Columbia River have become much more consistent and predictable, due to BC fisheries management. BC Fisheries confirmed that having constant lower water levels (25 to 30K CFS) throughout March and April lead to more productive in-river spawning for both whitefish and rainbow trout. The river takes on a whole new look during this low water period as more shallow water runs are created along with slow moving pocket water sections. The larger fish start moving into these runs searching for food items such as baitfish (sculpin, dace, etc.) and various nymphs (stoneflies, caddis, mayflies, etc.). The water temperature, at this time of year, warms to 45-48F (7-9C), which triggers the fish to start feeding more aggressively and causes the baitfish and nymphs to start moving into the runs and other shallow water areas. This is why fly fisherman should key on these shallow and pocket water runs during the spring season.
Over many years, I have found that the biggest fish, up to 15lbs, are caught during this spring period. The larger fish start moving into the shallow water runs and pockets looking for food and the smaller fish seem to stay in the larger, deeper holes, keying on midge hatches and nymphs.
The most effective fly patterns to use during the spring season, in the faster water runs and pocket water are; Bulldogs, Don’s Personal Bulldogs, Columbia River Buggers, ENT Zonkers, and large Stonefly Nymphs. I recommend using the following fly fishing equipment during the spring season in the faster water runs and pocket water:
- Rod/Reel: 8 weight – 9 to 10ft with a large arbour reel (50 yds of backing)
- Line: 8 weight type 6 or 300 grain, sink-tip line (12 to 15ft head)
- Leader: 6 to 8 feet of 10 to 12lb fluorocarbon (no tippet required)
Start fishing at the head of the run and work your fly through the entire run using a down-and-across technique (cast your fly slightly downstream and allow the fly to swing/sweep through the run). Don’t forget to continue retrieving the fly after it’s swung through the run, since many fish follow the fly from the deeper water and only take the fly once its in shallower water. It’s very important that your fly is presented in front of the fish, so make sure your sink-tip line is heavy enough to get you close to the bottom. You could always use a weighted fly or a small weight to get your fly closer to the bottom.
The most effective fly patterns to use during the spring season, in the deeper holes and back eddies, are; Dy’s Buggy Prince, Don’s Purple Prince, Columbia River Nymph, and Pheasant Tail Nymphs. I recommend using the following fly fishing equipment during the spring season in the deeper holes:
- Rod/Reel: 5 weight – 9 foot with a large arbour reel (50 yds of backing)
- Line: 5 to 6 weight WF dry line using a strike indictor and swivel
- Leader: 6 to 8 lb – 12 foot tapered leader
- Tippet: 3 feet of 5 lb tippet material (fluorocarbon preferred)
The only way to effectively work the larger, deeper holes and back eddies is by boat. I drift my boat along the deeper water seams, cast my fly to the edge of the seam, and allow the fly to drift with the current. The fish seem to stay down about 6 to 8 feet when feeding in the seams of the deeper holes, so I adjust my strike indicator to allow my fly to stay in this zone. Using a strike indicator is not critical but I find it easier to detect takes using an indicator. NOTE: This technique works in the big holes ALL year long.
I’ve found that the best section of river to fish during the spring season is from Trail down to the US border, since more runs develop in this section during low water. There are two main boat launches on this stretch of water; one at Gyro Park in Trail and the other at Beaver Creek Provincial Park, near the US border. You can also drift a pontoon boat or drift boat from these two boat launches for a full day of fishing.
For a short period of time, during mid May to mid June, there are two main terrestrial insects the fish will key on; Cicada’s and Flying Black Ants. The first warm days of May softens the ground, in which these insects live and allows them to hatch from their underground homes. As these large winged insects fly around they fall into the water becoming available to trout. The Cicada hatch usually lasts until early June but the Black Ant hatch can last well into June. Using flying black ant patterns is a very productive and exciting way to fish. All the action is in the top 1” of water and you will see the fish take the fly 90% of the time. The nice thing about fishing flying black ant patterns is that you can fish it dry (right on top) or wet (1” below the surface). Either way, you will be able to see and feel the take.
The most effective fly patterns to use during these hatches are; Flying Black Ants and Black Madam X’s, both in size 8 to 10. The following is the equipment I use during this time of year:
- Rod/Reel: 5 weight – 9 ft with a large arbour reel (50 yds of backing)
- Line: 5 to 6 weight WF dry line
- Leader: 9 – 12 ft 3X (6lb test)
- Tippet: 4 ft of 4X (5lb test)
As the summer season (July through September) kicks in and the weather heats up, the water becomes alive at the surface, as all the aquatic insects begin to emerge. The Columbia has one of the largest Caddis hatches I have ever seen and the fish feed on these small insects right through until late October. There are also numerous mayfly hatches throughout the summer season, which can be imitated using a size 14 to 12 Parachute Adams in the following colors, pink, light orange, yellow, hairs ear, and black.
The most effective way to fish the caddis and mayfly hatches is from a boat but anywhere along the shoreline will also work well during these hatches. The fish tend to hold in deeper, cooler water in the day but as the evening nears they move to the large back eddies to feed heavily along the seam lines where the adult caddis and mayflies emerge. The larger fish (6 lbs+) lazily swim with the current and feed on everything that is put in front of them but this is where the fishing becomes technical! You MUST present your ‘drag free’ fly directly in front of the fish, which is tough to do with the currents pulling your line in every direction and the hatch so thick that your fly is one amongst a million. If you hook 2 to 3 fish per evening you are doing well but each fish could be well over 5 lbs. and will take you 10 to 15 minutes to play. The back eddies literally boil with fish from early July until mid August and obviously, some days are better than others. Generally, if you spend 3 to 4 days on the river, you are bound to hit one great day.
The most effective fly patterns I use during the summer season are; Emerging Caddis, Carpet Caddis, CDC Caddis, Elk Hair Caddis (orange or peacock black body), and Parachute Adams in various body colors. I like to use size 12 dry flies during the initial hatches in July and move to size 14’s and 16’s as the summer season progresses. The following is the equipment I use during the summer season:
- Rod/Reel: 4 or 5 weight 9 foot with large arbour reel (50 yds of backing)
- Line: 5 weight WF dry line
- Leader: 12 – 15 foot 4X (5 lb. test)
- Tippet: 2 feet of 5X (4lb test)
The fall season is very similar to the spring, as water levels begin to drop to lower wintertime flows. Use all the techniques explained above, during the fall, and you will have some great days on the water.
- Published in Tips & Techniques
The Rainbow Trout Lake Stocking Program in British Columbia by Brian Chan
British Columbia’s lake stocking program plays an important role in the provision of freshwater fishing opportunities within the province. Annually, about eight million trout, char and kokanee are released into 800 lakes located throughout the province. The angling opportunities created on these stocked lakes make up over half of the total angling effort expended fishing in freshwater each year. The majority of stocked lakes are located in the rural interior regions of the province and the fishing activity on these waters provides significant economic input into local economies. Fishing resorts, hotels, campgrounds, grocery stores, gas stations, tackle shops, angling guides etc all benefit from lake stocking programs.
The Freshwater Fisheries Society of BC (FFSBC) delivers the provincial stocking program in partnership with the Ministry of Environment. Provincial fisheries biologists are responsible for the management of recreational fishing opportunities and do so through the development of regional and lake specific management plans. Stocking rates and species or strains stocked are matched to individual lake physical and chemical characteristics. Other parameters considered include the presence of competitor or predator fish species, type of access, distance from major population centres and the management goal for that lake. For example, lakes can be managed for family fishing, general or regional fishing or quality/trophy fishing opportunities. Specific fishing regulations are then added to complete the management plan for individual or groups of lakes. Fisheries biologists work with FFSBC research staff to regularly assess the performance of stocked fish in lakes located throughout the province.
Rainbow trout are the most common freshwater game fish found in the province. The distribution of most freshwater fish species including rainbow trout in British Columbia is largely a result of the last glaciation event. As glaciers receded, rainbow trout and other fish species were able to move from other glacier-free areas located south of BC and establish populations in newly created lakes and connecting rivers. Populations of fish then evolved and adapted to their new environments. Feeding, rearing, spawning behavior and physical appearances were all developed over literally thousands of years.
The first organized government stocking programs got started back in the early 1920’s. Those first lake stockings concentrated on the many fishless lakes that were located close to populated areas. Today, many of our most popular interior trout fisheries are a result of a long history of stocking initiatives.
Rainbow trout make up approximately 75% of the total number of fish stocked in the province each year. The FFSBC currently utilizes three major strains of rainbows in delivering the provincial stocking program. Two strains, including those from Pennask Lake and the Blackwater River are classified as wild populations. The third strain is the Fraser Valley stock which is a domesticated or captive brood population. Each of these strains of rainbow trout possesses unique attributes which are considered when developing lake management plans. In some cases, only one strain may be appropriate while in other situations any strain would sustain or enhance angling opportunities. Factors that determine the strain deemed most appropriate for a particular lake include a number of physical, biological and fisheries management parameters.
PENNASK LAKE RAINBOW TROUT
Pennask Lake is situated approximately 55 km northeast of Merritt on the Thompson Plateau. It is accessed via highway 97C and the Bear Creek Forest Service Road network. Pennask Lake supports a large population of relatively small, wild rainbow trout that are the only fish species found in the lake. Pennask is a large waterbody with numerous islands and rocky outcroppings mixed with shallow bays with extensive lily pad growth. The major inlet stream is Pennask Creek and it offers many kilometers of prime trout spawning and rearing habitat. The FFSBC operates a seasonal egg collection station on the creek and each year collects up to several million rainbow trout eggs.
Pennask rainbows do well in small, relatively productive or nutrient rich lakes such as those commonly found in the interior regions of the province. This strain of rainbow prefers to eat invertebrates like shrimp and leeches or aquatic insects which means frequenting the shoal or shallow areas of the lake. Pennask rainbows are renowned for their strong fighting ability that is often accompanied by several acrobatic jumps. They do best in monoculture lakes (lakes where they are the only fish species present). Although they do not grow large in their native waters, they can grow to tremendous sizes when stocked into highly productive interior lakes that provide long open water growing seasons. Pennask rainbows are best identified by their relatively light spotting that is typically concentrated above the lateral line. In some lakes the spotting is almost absent which results in those fish resembling bright silver bars. The majority of lakes stocked with the Pennask lake strain are in the Thompson/Nicola, Cariboo, Kootenay and Okanagan regions of the province.
BLACKWATER RIVER RAINBOW TROUT
The Blackwater River originates in the Ilgachuz mountains near Tweedsmuir Provincial Park in the Cariboo region of the province. The river travels in a northeasterly direction for over 200 km including though several lake systems before entering the Fraser River near the city of Quesnel. The river supports a very robust population of wild rainbow trout, Northern pike Minnow and several other non-game fish species. Early investigations into this strain of rainbow trout found that they were very aggressive feeders and showed good growth rates when stocked into small lakes with a multi-species forage fish food base. Blackwater rainbows spend a lot of time feeding in the shallow water or littoral zone of lakes and that coupled with their aggressive feeding behavior have made them quite popular with anglers. Appearance wise, Blackwaters are much more heavily spotted than the Pennask rainbows although the majority of spotting is still above the lateral line. Once hooked they tend to fight deeper in the water column however they will also take long runs as well as provide some spectacular aerial displays.
Dragon lake at Quesnel is the main source of Blackwater eggs that are used in the hatchery system. The FFSBC operates a seasonal egg collection station on a small tributary creek entering the lake. Every few years progeny from wild Blackwater rainbows are released into Dragon lake in order to maintain a managed broodstock. The Blackwater rainbows are differentiated from other strains of rainbows in the lake by the use of fin clips. The majority of lakes stocked with Blackwater rainbows are found in the Thompson/Nicola and Cariboo regions.
FRASER VALLEY DOMESTICATED RAINBOW TROUT
The Fraser Valley strain of rainbow trout was brought into the provincial fish culture program in the early 1960’s when progeny were purchased from a Washington state hatchery. Fraser Valley rainbows form the basis of the catchable trout stocking program in the province. They are fast growing, aggressive feeders that are easily caught on all types of angling gear. Spawning populations of these rainbows are held at provincial hatcheries and their offspring are grown to catchable size which are generally in the ten to twelve inch range. These fish are typically destined for urban lake fisheries located primarily in the lower mainland and southern Vancouver Island areas. More recently, Fraser Valley rainbows have been stocked in productive interior lakes that are susceptible to or have recently winterkilled. These already catchable sized fish grow very quickly in food rich interior lakes and if they do survive another year or two have the potential to reach easily into the double digit weight range. Fraser Valley rainbows are heavily spotted on the body and tail and when caught from productive lakes will have a very deep and short body shape. They are strong fighters but seldom jump.
NON-REPRODUCTIVE RAINBOW TROUT
Triploid or non-reproductive rainbow and brook trout have been used in the provincial stocking program for almost 20 years. The primary reasons for investing in and developing the triploid technology was for improving specific lake fisheries such as those managed for a quality fishing experience and to ensure the preservation of other native genetic stocks. Triploids are sterile and thus will not hybridize with native populations. Pennask and Blackwater rainbow trout are stocked as either diploids (reproductive) or triploids as dictated by the management regime for a particular lake. Fraser Valley rainbow trout are all released as triploid fish. FFSBC fish culturists have taken the triploid process one step further by developing all female triploid rainbow trout. As the name suggests, these are non-reproductive female trout so the stocking would not include any males. Triploid male trout develop secondary sexual maturation traits including bright spawning colouration and incomplete development of gonads. The triploid males cannot successfully spawn and there is mortality associated with the false sexual development. Stocking of all female triploids eliminates the potential loss of male trout from the fishery. The ideal stocking situation for consideration of triploid rainbows and all female triploids would be a highly productive, landlocked interior lake that has extensive shoal or shallow water feeding areas as well as a good mix of deep water habitat. This lake would be managed for quality fishing experiences and would have regulations such as a reduced or 0 limit, gear restrictions and a winter fishing closure. This scenario would allow the non-reproductive trout the best opportunity to grow to trophy size while still offering anglers a chance to catch and release these fish.
INTERPRETING RAINBOW TROUT STOCKING REPORTS
The Freshwater Fisheries Society of BC’s website www.gofishbc.com provides current and historical stocking records for each region of the province. These reports are updated on a regular basis and they can be downloaded for future reference. Each regional stocking report gives information on the waterbody stocked, nearest town, date stocked, species stocked, live stage of fish at stocking, number released and average weight of the fish that were stocked. There are a number of terms and abbreviations used in these reports that need to be understood in order to interpret the data properly. The symbol for rainbow trout is RB. The predominant strains of rainbow trout are seen as Pennask, Blackwater or Fraser Valley and the exact stock released show up as 2N for diploid or reproductive trout, 3N for triploid fish, AF3N for All Female Triploid fish. Rainbows are stocked at four different size ranges. Fry are approximately 6 months old and are generally less than 2 grams in weight. They are typically released in the early fall months with helicopters used to get fish into difficult access lakes. Fraser Valley rainbows are released as either fingerlings or as catchables. Fingerlings are approximately 7 months old and can weigh as much as 20 grams. Catchable Fraser Valley rainbows are the biggest fish raised at provincial hatcheries. They are regularly stocked at weights up to 250 grams or close to one half pound. Pennask and Blackwater rainbows are commonly stocked at the yearling size and as their name implies they are a year old at release. These fish are generally 10 to 20 grams in weight.
Freshwater Fisheries Society of BC research and fish culture staff work with provincial fisheries biologists in continually refining stocking programs as well as working on the development of new strains of trout to fit ongoing small lakes management plans.
- Published in Sustainability
Imitating the Movement of Aquatic Insects by Brian Chan
Aquatic entomology is one of the most important aspects of fly fishing that both lake and stream anglers will be exposed to and learn from. This is a huge subject that one could literally study throughout their entire angling life. However, it is essential that we are at least able to identify those insects that are important trout food and that we also have a basic understanding of the insect’s life cycle and habitat preferences. An integral part of the aquatic entomology subject is recognizing how the various insect life stages move through the water and then applying that information to the way in which we present and/or retrieve our flies.
In streams, much of the aquatic insect life are able to utilize the current to move or drift them as they complete emergence cycles or simply move from one type of habitat to another. In lakes, the larval, nymphal and pupal stages of insects must propel themselves to locate food, avoid predators or reach the surface in order to emerge into the adult form. One of the ways fish recognize prey items is by the unique swimming or movement actions displayed by the food source. Let’s take a closer look at how the various life stages of the important aquatic insect orders move. Keep in mind that these are staple food sources for trout and other fish species found throughout the stillwater world.
Damselflies and dragonflies of the Order Odonata are active swimmers while in the nymphal stage. Damselfly nymphs utilize a 3 lobed set of caudal lamellae or abdominal gills to propel them in a fairly slow, sinusoidal or snake-like motion through the water. They will swim for 3 to 8 inches; pause for up to a couple of seconds then resume moving. Fully developed nymphs swim more continuously as they urgently search out emergent plant stems to crawl up onto and complete the transformation to the adult stage. Dragonfly nymphs swim by venting water through the tip of their abdomen. This action gives the nymph a short, 3 to 5 inch quick burst of speed. Nymphs can sustain several of these fast movements in succession prior to taking a brief rest. In most situations dragonfly nymphs are happy to be crawling along the vegetation or lake bottom in search of food and usually only employ the “jet propulsion” swimming system to avoid predators.
Caddisflies (Order Trichoptera) undergo a complete metamorphosis or life cycle. Most species inhabiting stillwaters belong to the case maker group. These larvae live within a case which is built from bits of vegetation, particles of sand or other debris. Larvae move by using their 3 pairs of legs to crawl and pull their case slowly along the lake bottom and amongst the aquatic vegetation. Their cases leave telltale tracks in the marl or mud flats that cover shoal areas of the lake. Caddis pupa develop within the larval case. The fully developed pupae break out of theirlarval cases and swim quickly to the surface of the lake. Their ascent is aided by an elongated and feathered hind pair of legs which act as oars to quickly move them through the water. Pupae are often swimming up through 20 feet of water and are thus extremely vulnerable to predation by fish. The adult emerges from the pupal stage as soon as the pupa breaks the surface film. The actual pupal swimming action consists of relatively fast 3 to 6 inch long movements followed by brief pauses.
Mayflies (Order Ephemeroptera) are another common inhabitant of productive stillwaters. Most lake dwelling species are good swimmers that are capable of fairly quick but short bursts of speed. Developing nymphs seek food and cover amongst the vegetation growing up from the shallow shoal areas of the lake. When mature, the nymphs will swim to the surface to emerge into the dun or non-reproductive adult stage. The mature nymphs typically swim on a 20 to 30 degree angle to the surface of the lake. They swim in a sinusoidal motion in moderately fast 2 to 4 inch bursts. The nymphs will rest or pause regularly during their ascent. Once at the surface, a split forms along the back of the nymphal shuck to allow the adult form to emerge.
Midges of the Order Diptera are unquestionably the most diverse group of insects inhabiting fresh water. A typical small productive lake in western North America could be host to literally a hundred different species. Midges or chironomids also undergo a complete metamorphosis or life cycle. Larval and pupal stages are poor swimmers but both require an ability to move in order to complete their respective life stages. Most stillwater midge larvae live in the benthic or bottom substrate of the water body. In many instances the larvae construct simple “mud tubes” in which they peer out from to feed on detritus. Larvae do leave their tubes in search of more ideal habitat and in other instances can be swept out of their tubes by strong currents formed during a turnover event or a rapid fluctuation of water levels. In either case the movement of the larvae is restricted to an ineffective wiggling motion. Midge pupa typically develop within the larval tube. Fully developed pupa exit the larval tube and ascend vertically to the surface of the lake. The pupa do not actually swim but wiggle and squirm up through the water. Their ascent is aided by gases trapped beneath the pupal shuck. Often, movement is rather rapid during the last couple of feet before reaching the surface. It is not uncommon for pupa to ascend through 40 feet of water making it a very slow and vulnerable emergence process.
Overall, the movement of these aquatic insects is slow or at best they can move at a moderate speed for a very short distance. Some, like midges only rise or elevate through the water column. It can be hard for many anglers to slow their retrieves down and then maintain the slower pace long enough to effectively retrieve the entire length of a cast.
The strip and hand twist are two basic retrieves that all stillwater fly fishers should be comfortable using with the various food sources being imitated. The strip retrieve is as simple as it sounds and it is the basic retrieve for almost all fly fishing situations. The rod hand lightly pinches the fly line between the thumb and index (first) finger while the retrieve hand uses the same two fingers to pull or strip in a set amount of fly line. It takes a lot of practice to conduct a 4 inch slow strip retrieve cast after cast for several hours but if that is how the damselfly nymphs are swimming then it is best to go with the flow. Without patience and practice, those 4 inch strips soon become 8 then 12 inch pulls!
How slow is slow? For instance, to imitate a slow 2 inch strip retrieve count up to 2 seconds while the 2 inches is being retrieved. A fast 4 inch retrieve would count between 1 and 1.5 seconds per strip. Caddis pupa probably swims the fastest of these aquatic insect food sources. A fast 6 inch strip retrieve should take approx. 2 seconds to complete.
The hand twist is the other basic retrieve that should be mastered by all stillwater fly fishers. This is a busy retrieve, meaning that it requires more hand movement while at the same time helps to slow down the retrieve. The other advantage of this technique is that the angler has more control over the retrieve as the retrieve hand is always in contact with the fly line. The rod and retrieve hand start off in the same positions as the strip retrieve. The fly line is pulled down by the thumb and index finger of the retrieve hand while at the same time rotating the retrieve hand wrist outward thus leaving an open palm. The fly line is then hooked around the bay finger of the retrieve hand and then brought back to the thumb and index finger. This completes a full hand twist. As the maneuver is repeated coils of line will collect in the palm of the retrieve hand. It is best to release the fly line after 2 or 3 coils have accumulated. The hand twist is certainly the preferred retrieve to use when imitating the midge pupa either rising up through the water column or very slowly moving the pupal pattern horizontally through the water. In these instances a complete hand twist could take upwards of 8 seconds to complete.
The strip and hand twist retrieves will allow the angler to match the movement of these essential stillwater food sources. It can also be beneficial to impart a bit of irregular movement to your fly as it is being retrieved. In other words, try adding several very short, quick one inch strips in succession during any normal strip or hand twist retrieve. I routinely mix in 3 or 4 of these quick strip tactics into any stillwater retrieve. Sometimes this off tempo movement is enough to commit an otherwise slightly sceptical trout into taking the fly.
Wind drifting from an anchored boat is also an effective technique to present flies being fished with floating fly lines. It is used most commonly with mayfly nymphs, damselfly nymphs, caddis pupa and midge pupa. Although technically not a retrieve, wind drifting takes advantage of gentle wind conditions to naturally move the sunk fly in a subtle undulating motion horizontally through the water column. A cast is made sideways or perpendicular to the direction of the wind. A large arching bow develops in the fly line as the waves carry it downwind. The length of the leader and weighted versus un-weighted flies determine where in the water column the fly will travel. Make sure the rod is secure when using this tactic!!
It takes practice in order to get comfortable with these retrieves. While on the water watch for the real insects and note their swimming and movement patterns. That will be the best check as to how realistic your retrieves are being conducted.
- Published in Tips & Techniques
A Revealing look at Stillwaters by Brian Chan
For many western stillwaters, early to mid-summer is the time of the year that larger species of chironomids emerge. These pupae which are often in excess of 5/8 th’s of an inch in length regularly emerge from deeper water, sometimes as much as 40 feet in depth. These deep water emergences provide an abundant and safe food source for trout. It is also quite common for trout to feed on both larvae and pupae very close to the lake bottom. Such was the case last year when fishing one of my favourite Kamloops area lakes. A quick look at the waters edge revealed a major windrow of large pupal shucks, a very good sign of things to come. Once the boat was in the water we started slowly covering the lake in search of emerging and adult chironomids while at the same time monitoring my depth sounder. We soon observed pupa suspended in the surface film and adult chironomids sitting on the water that was 29 feet in depth. Almost immediately, fish markings, and some very large ones, began to appear on the sounder screen. There was not a continuous parade of fish crossing the sounder screen but enough to know that they were there and worth spending some time trying to catch them. The sounder also indicated the trout were consistently between 3 and 5 feet of the lake bottom. We chose to fish with strike indicators which would allow pupal patterns to be suspended at the depths the fish were appearing on the sounder. Needless to say, it was not a pretty site trying to cast out a 25 foot long leader plus indicator. However, a very open casting loop and slow casting stroke achieved the necessary results. A slight breeze provided just the right amount of movement to the flies as they slowly moved through the suspended fish. This technique worked well enough that day to fool three rainbows between 5 and 11 pounds.
A good understanding of the chironomid life cycle and appropriate fishing techniques used in conjunction with a properly set up depth sounder were the keys to such a successful day on the water. Depth sounders or fish finders are very sophisticated electronics that can be a valuable aid for the angler in a multitude of fishing situations.
One of the biggest challenges to successfully fishing stillwaters is understanding its underwater structure. To many anglers, a lake appears as a deep featureless bowl. Knowing the “lay of the land” is fundamental in determining where and how to fish a lake. Littoral or shoal areas, drop-offs and deepwater zones of a lake correspond to the riffle, run and pool zones of a typical stream or river. Each of these 3 habitat types offer potential fish and fish food habitat at various times of the stillwater or stream season. Fish finders or depth sounders can accurately point out the key geographic features of a lake basin. This becomes particularly important when fishing murky or algal stained waters as shoals and drop-offs cannot be seen with the naked eye. Key physical features such as the depth and extent of shoals, transition zone of drop-offs, weed beds, sunken islands and even the texture of the lake bottom can all be viewed on the screen of a depth sounder. As their name implies, fish finders can also identify the presence of fish, mark their exact depth and give an indication of relative size or body mass. These units will also mark the extent of algal blooms and the depth where thermoclines become established. Thermoclines are narrow bands of water which are formed when an upper warmer layer of water meets a cooler layer of water. Thermoclines will often act as a barrier to mixing and can therefore affect the distribution of oxygen and the vertical migration patterns of zooplankton.
HOW FISH/DEPTH FINDERS WORK
Fish finders or depth sounders operate using the principals of sonar (SOund, NAvigation and Ranging) which was developed during World War II to track submarines. Sonar uses sound waves to determine the presence and location of underwater objects. A transmitter, transducer, receiver and a display panel make up a sonar unit. Basically, an electrical signal is sent from the transmitter to a transducer which converts the signal to a sound wave and sends it through the water. When the sound wave strikes an object the signal is rebounded or echoed back to the transducer. The transducer then converts the echo to an electronic signal which the receiver sends to a display or viewing screen. The time taken to send a signal and receive a return echo is used to determine the depth of the object. The transmitter sends many signals per second which results in the continuous recording of the bottom image of the lake. Other objects like fish, downed trees or weed beds will also send back signals and show up on the display screen. There are a number of variables that affect the amount and quality of information obtained from a fish finder. High frequency sonar signals (greater than 150kHz) have increased resolution but travel shorter distances in the water. Lower frequency signals have less signal resolution but can travel or receive impulses from a greater distance. The design of the transducer is also important in the effectiveness of a fish finder. The transducer emits a sound wave in a cone shaped beam. Wide cone angles produce a greater view of what is under your boat but at the expense of depth capability. Narrow cone angles such as those less than 15 degrees are more suited for salt water or deeper applications. As an example, a 90 degree transducer cone sending a signal through 25 feet of water will provide a 50 foot wide diameter area of coverage on the lake bottom. Numerous fish finder manufacturers offer models designed with multiple beam transducers in order to achieve the wide cone angles used for more specialized fishing situations.
There are also fish finders designed with side scan or horizontally directed transducers. Some manufacturers offer a side scan transducer as an option thus allowing one to switch back and forth between the two transducers. This feature has good application to stillwater situations because again much of the fishing effort is in shallow water.
There are also compact hand held sounder units available that provide a digital display of the depth. These flashlight sized units are perfect for packing into hike-in lakes or flying into remote fishing camps that may not be set up with more sophisticated fish finders.
SELECTING THE RIGHT FISH FINDER FOR STILLWATERS
Most fish finders are designed for use in a hard hulled crafts such as fibreglass, wooden or aluminum boats. Transducers are designed for both permanent and portable installations. They can be mounted permanently to the inside hull of a boat or to the outside of the transom, fitted to an electric motor or temporarily attached to the transom of a boat with a rubber suction cup support. After market accessories including portable transducer brackets for boats and pontoon boats and float tube fish finder mounts are also available for most of the popular brands of fish finders. The key features to consider are frequency of the signal being sent and received and the transducer cone angle. Cone angles of between 50 and 150 degrees are ideal for stillwaters because the majority of the angling effort is done in water less than 30 feet deep.
INTERPRETING THE FISH FINDER
Present day fish finders are considerably more advanced than those available even 10 years ago. Many manufacturers offer the latest “side imaging” feature that definitely has applicability to trout lakes. As with most modern day electronics, the new depth sounders do a lot more than just tell you the depth. That means one must read and understand the operating manual to fully take advantage of it’s capabilities. A key function found on most fish finders is the sensitivity control. This regulates the ability of the unit to detect objects and create an echo signal. Sensitivity is affected by such things as water clarity, algal blooms and interference from other electronic devices. One of the best ways to learn about your sounder is to play with it on a clear water lake where trout or other fish can be seen swimming under or around your craft. These conditions will illustrate just how fine adjustments can be made in order to filter out the size of sonar markings such as small fish or suspended debris.
Fish finders can be a very useful aid to the stillwater angler. They can be invaluable when learning the underwater structure of a new lake and thus identifying the preferred habitat of trout or other game fish. A properly calibrated unit with the appropriately sized transducer can indicate the location and size of fish plus identify the depth to which algal blooms extend and outline the formation or absence of thermoclines. This “electronic” information can then supplement one’s understanding of prevailing food sources, emergence timing and fishing tactics.
- Published in Tips & Techniques