I don't know the terrain or presence of good BG spawning grounds for Lou's pond, but might it be possible that if the pond has "X" amount of individual spawning sites and "3X" or "4X' the amount of breeding sized BG, that the larger BG are dominating the available spawning sites. If the thought held water, than could it explain why Lou sees larger BG up on the beds during spawning, but outside of spawn he catchs bigger ones in the areas of feeding activity?


Excerpt from Robert Crais' "The Monkey's Raincoat:"
"She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."