We have lots of BG, maybe a few smallmouth, a few CC, and few grass carp. I really don't think the leeches are much of a problem, I do think the BG eat their fair share of the leeches. I also think the LMB do as well but with the larger mouth they do not get all of them get down the hatch. We also have quite the variety of weeds which I feel is more of a problem for the fish but that is whole other thread, it does however lead to fairly high denisities of both BG and LMB and possibly a higher abundance of small leeches and snails.