I appreciate all the input and responses guys. A couple of pre-turnover conditions that I forgot to include:
Pond watershed is about 35 acres and about 25 acres of this is a hay field. My hay man fertilized the fields in early April. The rain last Sunday is the first heavy rain we've had since then.
I mowed the banks for the first time this spring 5 days before the turnover. I mowed with a bat wing which doesn't throw much toward and into the pond, but a fair amount of vegetation did lie in the water on the banks and I assume the decomposition process had started.
I've never sprayed any herbicides around my pond. I'm trying to avoid that if possible and it's been plenty of work, mostly pulling up primrose. May be futile but I'm going to manually combat until not practical.
Thanks again,
Ronnie
PS - I'm hoping the kill is over and I'm estimating I lost ~500 bream and ~100 bass. More heavy rain coming within the hour so I hope that this doesn't trigger any sort of relapse?