I'm surious how much current there is at the bottom of the pool. If there is a calm zone right beneath the current, that could be an ideal feeding spot. Now only does teh current carry food past, but some of those articles might drop down into the calmer water. If there is a strong, Spring thaw, the current might scour the pool and so keep it from silting. That would be the time when there would be fewer fish, I would think.

Ed