We run yo yo's all the time in the river lakes this time of year and always put the shiner about 3" below the surface. I think that is a nighttime thing, not a spawning issue. I think WP will come up shallow any time of the year it's just the warmer water I where they lay eggs which is closest to the surface. Maybe it has something to do with incubating the eggs. What do I know anyways, I'm just a gewber!!!! Lol