Going out on a quest to catch a specific fish can be a lot like making a tricky recipe. One incorrect piece of information can drastically reduce your chances of getting what you want.
Kokanee salmon are a temperature sensitive fish, so the best trolling depth will change based on the time of day and season. In the spring, try 10 feet to 20 feet in clear shallow water. Mid to late summer deeper, colder water ranging from 30 feet to 60 feet deep is best.
Let’s take a more “in-depth” look at the different seasons and factors that come into play with Kokanee trolling depth!
Trolling Depth by Season
Each season presents a different set of problems for Kokanee that cause them to vary widely in their normal depth. I will dive into each season specifically as to what the best depth for trolling is.
Spring
As spring comes around, mountain lakes and streams start to fill with the snow melt-off, which keeps the water cool, teaming up with the colder temperature of the air to keep the water fairly cool and cold. This is great news for the Kokanee salmon, who can be killed by water over the temperature of 60 degrees Fahrenheit. Kokanee salmon are an extremely temperature sensitive fish, preferring to stay in water that hovers around 50 degrees. Given that information, we can see why the Kokanee salmon changes the depth it resides in so often.
In the spring (and depending on location, early morning in the summer), the Kokanee salmon will be found in much more shallow water. Try a depth of between 10 feet to 20 feet, in well-lit water, with a grassy or gravel bottom. Food will be plentiful here, and since the temperature is agreeable, a school of Kokanee salmon may also be found here as well. Being in shallow water makes this particular fish easier to find in the spring as well. As they are near the surface or in more shallow water, they are more easily spotted, and the number of places in which Kokanee typically school are fewer in number.
As the season progresses, the runoff from the mountains stop, and the temperature of the water heats up, the Kokanee disperse throughout the lake, making them more difficult to locate and land.
Summer
As spring progresses into summer, the lakes and streams where the Kokanee salmon reside warm up, forcing the fish to colder, deeper water. Using weights on your line is now almost absolutely necessary for getting your bait anywhere near the depth it needs to catch the eye of a Kokanee.Mid to late summer as the temperature starts to change, our Kokanee travel away from the shore, and situate themselves between 30 feet to 60 feet deep throughout the lake, making them harder to locate, and harder to catch. However, unfortunately for the fish, and in favor of the technologically savvy fisherman, they are a schooling fish, making them easy to spot on sonar once you pass over a group.
One Kokanee fisherman, Phillip Johnson, recorded that the strikes on his line more than doubled when he was trolling perpendicular to the sun, as opposed to parallel to its path. He surmised that trolling perpendicular to the sun gave more opportunity for reflections off his flashers and dodgers, which is known to attract Kokanee salmon. He noted that when the sun is highest in the sky, it makes no difference. But in the mornings and afternoons, this technique was almost guaranteed to land him more fish.
Winter
Though less common, you can have limited success fishing for Kokanee salmon in the winter. Most Kokanee salmon will die off after spawning, but some will survive, and among these are “Triploid Salmon”. Triploid salmon are salmon with a chromosomal deformity that not only causes them to grow faster, but renders them sterile, which excludes them from spawning activity, thereby prolonging their lives. You may have some problem with ice, but Kokanee salmon will be closer to the surface in the winter, due to the colder temperatures.
Food Availability
Kokanee salmon survive on a diet that consists almost exclusively of freshwater zooplankton, a microscopic organism that they filter through their gills. They follow the freshwater zooplankton, which eat phytoplankton, or microscopic plants, to survive. This phytoplankton can only grow and thrive where there is light. Light columns, well-lit areas, clearer water, etc. are where the zooplankton and phytoplankton are most likely to be found.
They are light sensitive, so on days that may be too bright, or too dark, the freshwater zooplankton will descend deeper, or rise closer to the surface of the lake, and the Kokanee will follow.
Boat Pressure (Over-fishing)
Sound and electric current sensitivity. In the early spring and on colder days, the Kokanee salmon can generally be found with sonar at around 10 feet to 20 feet, and according to fisherman with experience in catching Kokanee, will typically stay in the same area for most of the day, albeit between 5 feet to 10 feet deeper as the day goes on. That being said, all of that will change if the boating pressure is too high.
Boating pressure consists of the presence of fishermen in their boats on the lake. Kokanee salmon have exceptional noses, can see all the colors we can, are sensitive to electrical currents, are scared off by excessive or loud sound, and will follow their food source, which requires the presence of light. The presence of too any Kokanee fishermen typically will indicate the presence of too many boats, which will over stimulate and scare off the Kokanee salmon, driving it at very least to deeper water, and other areas of the lake or body of water you’re fishing.
If you’re fishing a popular area but determined to catch a Kokanee, and you’re ready to sacrifice some sleep, getting out on the water while it’s dark, and being ready to fish at first light before the water traffic hits give you your best bet at scoring your prize. The presence of loud people, boats, and jet skis are strong Kokanee salmon deterrents, and will most certainly impact the depth of your troll.
Kill Temperature
Higher water temperature for too long will kill them. Spending too much time in the water at or higher than 60 degrees will prove fatal, so fishing for Kokanee in water temperatures in those ranges will most often prove futile.
Kokanee salmon have been observed to occasionally rise closer to the lake surface at temperatures of around 70 degrees Fahrenheit if the food is abundant enough, but will not stay there for long, and will quickly dive back to deeper, colder water.
Soft Mouths: A Warning for Deep Water
When fishing for Kokanee salmon at lower depths, be aware that their mouths are notoriously soft, and any hook will have the potential to get ripped right through its jaw if proper care and techniques are not implemented.
A fish hooked at a lower depth will have more time and opportunity to get away, and by yanking on your line, the hook may get torn loose. To reduce the chances of this happening, you can use a device called a “snubber”, which reduces the impact of strikes on your line, acting as a shock absorber.
All that being said, seasoned fishermen claim that the Kokanee salmon’s mouth is much softer in the spring and earlier seasons, and that the closer the fish gets to spawning time, the harder it is to tear a hook through the jaw of the fish.