Cecil, I think we may lose some perch to natural mortality during spawning time. A few years back, we brought some perch into the lab for spawning studies, and stocked a big female with several males in each aquarium. Several of those big females died after spawning, which has always stuck in my mind. That may be a stressful time when we lose some of the older fish to natural mortality? Perch are a fish that can exhibit high natural mortality rates, even when not harvested by anglers.
