Interview With A Kokanee: Vision

Part 3: Interview With A Well-Schooled Kokanee

By Gary S. Gordon, Fish With Gary™ Tackle Co.

KOKANEE: Ok, I'll admit it. I'm moody. But that does not mean I'm impossible. But being moody is as much fun for me as it is for the fisherman.

DUDE: You know, that might not be the case for all kokanee fishermen. Some can spend all day chasing you with no results. That is not fun.

KOKANEE: I suppose it is all in your perspective.

DUDE: So tell me why some days you cannot resist one particular color, and then the very next day you shun it.

KOKANEE: Well, it is a little more complicated. I hope you get it. If your readers had really carefully read and understood Kokanee University, Part 1, then the answer would be easy. But alas, you can lead some fish to water, but you can't make them swim.

So here goes.

Humans live in their world and I live in mine. Most everything is different in my world than the human world. If a kokanee fisherman wants to become a whole lot better, he had better stop thinking about the material world, and start thinking about what life is like in my water world.

Humans really enjoy the views from their favorite kokanee lake. Sometimes the vistas are breathtaking. Nothing but miles and miles of awesome scenery. Sit in the middle of some lakes and sometimes you can see for 40 miles. You can see the beautiful white clouds, the blue sky and fiery sunsets. You can see the beautiful forests, green meadows and snowcapped peaks. Sometimes I know that is exactly why humans bother chasing me.

All of that sounds really wonderful. But I wonder how humans would like it if their favorite views were seen in contrasts of shades of gray, and light and dark. Might change their perspective a bit. Or suppose humans could only see color a distance of about 21 inches, and then only right in front of their nose. Or how would humans react if they could not focus their eyes. Limited color vision and no ability to focus. For humans, limited color vision and no ability to focus would likely change a few things in your material world.

DUDE: You sound, maybe a little bitter. Only a guess of course.

KOKANEE: I can do things in my world that humans only dream they could do. That kinda' makes up for any human deficiency in my water world. Balance is achieved. It helps comfort me that my brain is the size of a pea, while the human brain…

DUDE: Please don't go there.

KOKANEE: As I was saying, my color vision is quite limited. And although I can see in shades of gray and black, the clarity of the water becomes a major issue for me. If the water clarity is limited, then that governs how far I can see contrast. Sometimes, the lack of water clarity makes it almost impossible for me to even see even color within that 21 inch window.

DUDE: And the effect of light at depth?

KOKANEE: For sure things get darker at depth. Go deep enough and there is no light. Water literally eats light. Water gobbles light. Depending on the time of year, as much as 40-50% of light that hits the water is reflected back and away from the water. That means there is less light under the water. Always. No exception.

DUDE: You said that water eats light?

KOKANEE: So I did. You are paying attention. When you go down the water column, things get darker. But not darker red or darker orange. As you descend the water column, it gets a reducing combination of darker green, blue, and indigo and purple before it goes completely black.

DUDE: So what happened to red, orange and yellow?

KOKANEE: Dude, the water ate it.

DUDE: When?

KOKANEE: Up front. First the red, then the orange and then the yellow. Gone. And this happens very quickly in fresh water. Except for early season, most of the fishing for us kokanee takes place in water that contains only green, blue, indigo and violet light.

DUDE: Ok. I know that visible light can be put through a prism and it then breaks down into the colors of the rainbow. In fact, as I recall, the colors of the rainbow are always displayed in the same sequence. Freaky?

KOKANEE: This is where you could benefit from having a pea-sized brain. When I am talking about color, I am really talking wavelengths. Most colors that are visible are a blend of other visible colors.

DUDE: Let me stop you right there. You used the term "visible." Are there colors that are invisible?

KOKANEE: No. And I guess I have to make an admission that you humans and us fish actually have something in common. We are both vertebrates and we have vertebrate eyes. Within our eyes are structures that connect our eyes to our brain. We both have corneas, and attached to these corneas are both rods and cones. Although we have them in different proportions, these rods and cones operate the same way. Simply stated, rods help us differentiate between light and dark, while cones take care of visible color detection.

Color is only a visible concept. If you put all of the visible colors together, you get white. White light is what daylight is all about. Run that white light through a prism, and you get a display of the rainbow.

When you look at that rainbow, the colors are always displayed the same way. That is because visible colors have specific wavelengths. Wavelengths are measured by frequency. Frequency can be thought of as a way to measure how long or how short the wavelength is. In the visible spectrum, red has the longest wavelength, whereas violet has the shortest. All of the other visible colors are in between.

DUDE: OK. But how does water eat light?

KOKANEE: It eats light by wavelength frequency. As you descend the water column, the longest wavelengths are eaten first. That would be the visible color red. Go a bit deeper, and you also lose the visible color orange. Go deeper and you also lose the visible color yellow. The very last visible color to get eaten is violet. After that the water is black.

DUDE: I guess that black is the absence of light.

KOKANEE: Technically black is the absence of visible light. There are other wavelengths out there that you might understand and feel the effects of, but their wavelengths are outside of the visible color spectrum.

DUDE: Can you give me some examples?

KOKANEE: Did you use your microwave today?

DUDE: Duh.

KOKANEE: Microwaves are radio waves (a form of electromagnetic radiation). You can't see radio waves, because their wavelengths are not within the visible spectrum. X-Rays are another example of wavelengths you cannot see. Infrared radiation has wavelengths longer than the visible color red. Again, you cannot see infrared radiation. Infrared radiation is responsible for warming the water. Water has a huge capacity for absorbing and retaining this heat energy.

DUDE: I hear so much about UV light. All of the manufacturers want me to buy their stuff because it is "UV."

KOKANEE: Here is where I get to "see" how much you have been paying attention. "UV" is short for ultraviolet. It is called ultraviolet because it is in that part of the spectrum that is beyond violet. It has shorter wavelengths than violet.

DUDE: But if UV light has a shorter wavelength than violet, then that means that it is not part of the visible spectrum.

KOKANEE: Exactly.

DUDE: So what about the claims that fish can see UV light?

KOKANEE: That claim is nonsense. Go back to our discussion of the vertebrate eye. We have rods and cones. There are no rods or cones that can detect UV light. There is a study that attributes UV detection to the Japanese Dace and some goldfish. It has never been shown that salmonids can detect UV light.

DUDE: But the fishing tackle makers would never lie to us, would they?

KOKANEE: Decide that for yourself. I can tell you this, their terminology is incorrect, and the reasons they give for their product effectiveness are incorrect. However, the products are effective.

DUDE: Now you are really confusing me.

KOKANEE: I specialize in confusing fishermen.

DUDE: How can it be incorrectly labeled and still work?

KOKANEE: Think of it as function (how it works) over form (incorrect name). Let me give you an example. A horse is not a dragonfly. No matter how many times you call it a dragonfly, it is still a horse.

DUDE: But when I shine a black light on this UV stuff, I can see bright colors.

KOKANEE: Listen to yourself. Yes you are seeing color. You are not seeing UV. Those colors are excited because of the purple light in your black light, and not because of the UV light component. It is total nonsense that what you are seeing is UV. UV in any form is not visible.

DUDE: Well then, what is the correct terminology for "UV?"

KOKANEE: The correct terminology is the term "fluorescent."

DUDE: Then why don't the tackle makers call it "fluorescent?"

KOKANEE: I suppose because it is a lot harder to spell than "UV." And "UV" is a lot easier to text.

DUDE: Is that black light charging the material, you know, to make it glow?

KOKANEE: No. Glow is phosphorescence. It gives off light energy (glow) regardless of whether there is light present - provided that is has been "charged. Fluorescent materials do not need to be charged. All that is required is for some available light to act on it.

DUDE: Is there a simple way to understand this?

KOKANEE: Indeed there is. Fluorescent materials retain their color all the way down the water column. There is no color fade.

DUDE: Color fade?

KOKANEE: Ordinary colors can fade as you go down the water column. Ordinary red will turn black in just a few feet of water. But a fluorescent red will remain red all the way down the water column, provided there is some light to act on it. Even if there is only one percent light way down deep.

Fluorescent red will remain red in the absence of the red wavelength in the water column. And you will recall that red is the first wavelength to be eaten by the water as you descend the water column. Because I have cones in my eyes, I can see a fluorescent red at 50 feet - if there is some light - even just blue/purple light at that depth.

DUDE: So no fading. Does this work the same for all fluorescent colors?

KOKANEE: Yes. In fact, some fluorescent colors are so effective, they get brighter in the water as you go down the water column. In any event, no fade.

DUDE: You said that the stuff marketed as "UV" is mislabeled.

KOKANEE: All of the stuff marketed as "UV" is really fluorescent. So all of the stuff you bought as UV is still good stuff, but call it UV as much as you like, it is not a dragonfly - it is fluorescent. Remember, since that stuff is in fact fluorescent, there is no color fade as you descend the water column and likely gets brighter as well.

DUDE: Would using UV/fluorescent materials increase the visibility of my presentation?

KOKANEE: That is exactly what it does.

DUDE: But you earlier told me that you can only see color about 21 inches in front of your snoot.

KOKANEE: True. But you forgot that I can see contrast in shades of dark, light and grey at a farther distance. Fluorescent material can still be detected outside that 21 inches because they do provide good contrast.

DUDE: Let me see if I understand this. At about 21 inches you can see color, but outside that you do not see color, but you can detect contrast.

KOKANEE: Exactly. I can approach a target and watch it go from contrast to color the closer I get. There is actually a definable point where that happens. The moment that happens, there is a color flash. If I back off, it returns to contrast. Get closer, it becomes a detectible color.

DUDE: A flash?

KOKANEE: Yes, a flash. Not like a burst of light from a camera. It flashes only in my brain. And I can tell you this, that color flash really acts to turn on my biting response. Of course there are other factors that also turn on that biting response, but color is a significant factor. That is why fluorescent colors are so effective. They retain their color. They make for good flashes in my brain.

DUDE: Fluorescent colors retain their color all the way down the water column independent of your ability to detect them at distance, correct?

KOKANEE: Correct. Color is not the way I get attracted to your lure. What makes me want to investigate is not color, but vibration.

DUDE: Vibration?

KOKANEE: Yep. I'm thinking about good vibrations.

DUDE: Vibrations. Sounds like you are going to have to talk about wavelengths again.

KOKANEE: Sorry, but yes. But this is not difficult to understand. Sound is very important. Humans have a range within which they can hear sound. From low, deep sound to the highest sound. Outside that range, sound exists, but humans cannot hear it. Dogs seem to have greater range of sound detection as do whales. The point is that sound waves are still sound waves even if humans cannot detect them because those sound waves are outside the ability of the human ear.

DUDE: Is there a difference between the way sound acts in water than it does in the air?

KOKANEE: Yes, and very much yes. For one thing, sound travels in air at about 1,000 feet per second. You humans see a flash of lightning then count off one/one-thousand, two/one-thousand, three/one-thousand to determine how far away that lightning struck.

But sound travels way faster in water than air. Sound travels in water at 5,000 feet per second. And I'm not just talking about sounds that you humans can hear. I'm talking about sounds that are beyond human ability to detect. I assure you that I can detect sounds that you cannot. Just because you cannot hear such sound does not mean that such sounds do not exist.

DUDE: My head is starting to reel.

KOKANEE: It is fine with me if you would like to take a break. A few minutes to stretch perhaps?

DUDE: Yes, that would be fine. Catch you then.

KOKANEE: Not likely.

To be continued....

The Saga of the Well-Schooled Kokanee Continues