So many articles have been written on this, by those that have college degrees, study fish daily, and set at desks typing their results. Like MO said, seems like the next 2 years or so after floods, the amount of catchable fish double. Those fish that were in 5' of water, will still be in that area, now with just 10' over the top if them. Sunlight plays a roll in the spawn as far as penetration, but the greater act in my readings, are locations and what part of the spawn the fish are in when the water rises. If their on the bed when the water rises, then they will remain. If they havent moved up, then they will follow and find wood, hard bottoms, etc. to lay on/in. Fish have been dealing with these issues for many moons, and seem to have it figured out.
Can you amagine turning the tables, and fish doing a study on humans, as to why we fish the way we do, use the baits/lines we do, fish at different hours of the day, etc. They would look as puzzled as we do.