How do lake trout see in deep water?

Hi All –

First post here! Lately I’ve been fishing in Wisconsin on Big Green Lake and have been doing well on nice sized lakers. Green Lake is very deep (236ft) and my most popular trolling contour has been around 150-160 FOW.

I decided to play around today and attach a gopro to one of the cannonballs and send it down. I figured this might be the case, but once it passed about 80-90 FOW everything went completely black.

I had assumed that light can’t penetrate so far down, but it begs the question: How do lake trout see in deep water and differentiate between colors and UV, etc?

Lakers can focus on the invisible [to us] side of UV light. That light , depending on water clarity, can penetrate to depths well over 900 feet. So what’s black to us is still well lit to a laker.

Thanks Tom

http://www.seagrant.umn.edu/newsletter/2012/07/science_through_the_eyes_of_fish.html

Here is a link from the U of M on Lakers