UV Light

[Oscar O.]

I remember reading in a book that UV light doesn't get very far beyond the water's surface. I've also seen that UV light easily penetrates water. Which is true?

Another thing that I've read is that fish like bass lose their ability to see UV light after some point when they are really young. If this is true, unless we're trying to catch bass fry, wouldn't using baits that utilize the reflection of UV light be pointless?

Can someone please clarify on these two points?

¡Gracias!

[JoePhish]

I've had success with UV type products at deeper depths.

I have used a spray called Fool-a-Fish in the past and have had proven success with it reef fishing (75+ feet of water). I recently purchased a bottle UV Blast hoping for the same results.

In regards to bass fishing, I don't fish deep water most of the time so I don't carry it with me bass fishing.

[BassThumb]

My understanding is that the depth in which UVR penetrates depends on the clarity and level of dissolved organic material(DOM) in the water. I have heard of penetration of 1 centimeter is some waters and 300 meters in the clearest water.

There has been scientific studies done recently on how the different bands of UVR affect the coral reefs of the world and whether or not they contribute to bleaching. A main issue in these studies is how the phytoplankton reacts. It lives in the top 2-3 meters of the water column and feeds the food chain in the ocean, and has reacted differently in various parts of the world because of the differing water clarity.

[Oscar O.]

My understanding is that the depth in which UVR penetrates depends on the clarity and level of dissolved organic material(DOM) in the water. I have heard of penetration of 1 centimeter is some waters and 300 meters in the clearest water.

There has been scientific studies done recently on how the different bands of UVR affect the coral reefs of the world and whether or not they contribute to bleaching. A main issue in these studies is how the phytoplankton reacts. It which lives in the top 2-3 meters of the water column and feeds the food chain in the ocean, and has reacted differently in various parts of the world because of the differing water clarity.

So, I'm guessing that visible light would also work in a similar manner? And compared to visible light, is UV capable of penetrating deeper through the water under the same conditions?

I guess the only question left is whether or not bass can see UV light (or reflections of it, if it makes a difference)!

[BassThumb]

So, I'm guessing that visible light would also work in a similar manner? And compared to visible light, is UV capable of penetrating deeper through the water under the same conditions?

I think that the blue and purple spectrum would penetrate further than ultraviolet radiation would, but I'm not sure.

[Oscar O.]

I think that the blue and purple spectrum would penetrate far further than ultraviolet radiation would, but I'm not sure. I think the UVR could only reach so far, much like the red, orange, yellow spectrum of visible light.

I did some searching around and came across someone saying that the red end of the spectrum and infrared penetrates the deepest. Their evidence was that algae that reside in deeper water have chlorophyll with absorbance peaks with wavelengths in the infrared range. They also said that violet and blue are reflected at the surface more than other colors. Boy, this stuff is confusing

[BassThumb]

Yeah it is.  I was wrong. I thought violet penetrated the deepest.

"The colors at the middle of the visible spectrum (yellow, green and blue) penetrate seawater

to the greatest depth, while colors of longer (violet) and shorter (red and orange)

wavelengths are absorbed and scattered more rapidly."

http://www.montereybayaquarium.org/PDF_files/teaching_activities/Light_in_the_Deep_Sea.pdf

[Oscar O.]

Thank you! Would this apply to freshwater as well? Or does saltwater have different properties than freshwater that could alter the information if it had to be applied to freshwater?

[Getfished]

Yeah it is. I was wrong. I thought violet penetrated the deepest.

"The colors at the middle of the visible spectrum (yellow, green and blue) penetrate seawater

to the greatest depth, while colors of longer (violet) and shorter (red and orange)

wavelengths are absorbed and scattered more rapidly."

http://www.montereybayaquarium.org/PDF_files/teaching_activities/Light_in_the_Deep_Sea.pdf

If this is true then why is it that on dark overcast day one can still get a sunburn ? What wavelength is penetrating to cause this ?

[Nice_Bass]

Yeah it is. I was wrong. I thought violet penetrated the deepest.

"The colors at the middle of the visible spectrum (yellow, green and blue) penetrate seawater

to the greatest depth, while colors of longer (violet) and shorter (red and orange)

wavelengths are absorbed and scattered more rapidly."

http://www.montereybayaquarium.org/PDF_files/teaching_activities/Light_in_the_Deep_Sea.pdf

If this is true then why is it that on dark overcast day one can still get a sunburn ? What wavelength is penetrating to cause this ?

I believe that there is some confusion between uv and visable light here. 

[Getfished]

Methinks so too.

[Oscar O.]

You can still get sunburnt because light from the sun still reaches the Earth's surface (both visible and UV), you can't see UV though because the wavelengths are not within the "visible light" spectrum.

[Getfished]

You can still get sunburnt because light from the sun still reaches the Earth's surface (both visible and UV), you can't see UV though because the wavelengths are not within the "visible light" spectrum.

I agree that you can't see UV wavelengths because they are not within the visible spectrum. But are they within the visible spectrum for bass vision ?

[Oscar O.]

That's one my questions that I was hoping would be answered by starting this thread. Hopefully someone with knowledge of bass, and more specifically their vision, can provide some insight.

[senile1]

Ultraviolet light travels much further than visible light in water. When I say visible, I mean visible to humans. Some lure and lure treatment manufacturers believe that bass in the depths can not only feel lures through their lateral line, but can see the reflection of UV light off of lures as well. You can read what they think at the following links, but remember that these are manufacturers' claims. I was unable to find a scientific study that proves without a doubt that this is true, but it is an intriguing theory.  After all, once you reach a certain depth everything is pitch black. To be able to see UV light would definitely be an advantage at such depths.

http://www.uv-tackle.com/tightlines_history.php

http://www.halibut.net/What-Fish-See.htm

[Oscar O.]

Ultraviolet light travels much further than visible light in water. When I say visible, I mean visible to humans. Some lure and lure treatment manufacturers believe that bass in the depths can not only feel lures through their lateral line, but can see the reflection of UV light off of lures as well. You can read what they think at the following links, but remember that these are manufacturers' claims. I was unable to find a scientific study that proves without a doubt that this is true, but it is an intriguing theory. After all, once you reach a certain depth everything is pitch black. To be able to see UV light would definitely be an advantage at such depths.

http://www.uv-tackle.com/tightlines_history.php

http://www.halibut.net/What-Fish-See.htm

That's what I have been wary of. I've also been looking for a third party study on a bass' ability to see UV light, rather than the ones that come from a manufacturer's website. I hope that at least there are some studies being done that will be published in the near future to clarify. Can Bassresource hire a fish biologist for the forum to answer questions like these? ;D

[Glenn]

Well since he won't tell you guys, I will: Getfished is a dealer/rep for a line of tackle - already mentioned here - that proclaims UV qualities. So he has a vested interest in selling you the concept and baits.  :

That said, I'll give our buddy Mr. Bob Lusk a jingle and see if he'll chime in here. 

[Getfished]

Glenn, you are right. I am new here and was afraid to come out and directly say something to that effect. I have no intent to be deceptive. My understanding of the rule in effect here is that it is a violation to try to market or peddle a product. I have no qualms with folks knowing I am a rep for Tightlines. I would rather not openly proclaim that and jeopardize my membership here than I would sell a few baits here. I don't make the rules. I just try to accept them. Thanks for clearing this up.

Steve

[senile1]

Well since he won't tell you guys, I will: Getfished is a dealer/rep for a line of tackle - already mentioned here - that proclaims UV qualities. So he has a vested interest in selling you the concept and baits. :

That said, I'll give our buddy Mr. Bob Lusk a jingle and see if he'll chime in here.

Hey, Glenn, were you able to speak to Bob?  I am interested in his take on this subject.

[Getfished]

Me too

[Team9nine]

I've studied this one a bit, and to date, I haven't found any published research documenting the ability of adult bass to see UV light. Therefore, it is only speculation at this point that they might, barring some unknown studies to me. There is some literature that has suggested that YOY largemouth bass might have this ability, similar to some other members of the sunfish family, but it is also generally known that UV photoreceptors are only present in many freshwater fishes during early life history stages and coincide with feeding on planktivory.

As for depth penetration, it varies with type of UV wavelength (UV-A or UV-. UV-A typically will penetrate to about twice the depth of UV-B. That said, a lot depends on water clarity which is tied to the amount of organic matter in the water column. In one study I read, where visibility would frequently reach 20' or better, the 1% UV-B light level (only 1% left) reached about 8' in the spring, and was reduced to about 5' in the summer after plankton blooming. In murkier water, these 1% levels would decrease accordingly.

-T9

[Oscar O.]

Yeah I've also read that young fish can see UV light for the reason of feeding on the plankton

So in that study, UV light did not penetrate as far as visible light could? This would back up what was in the link to the PDF by the MB Aquarium. Thanks for the input!