Thank you for your insight. The pond sits on the back acre of a 4 acre tract and luckily the ground is nothing but clay (great for ponds....no so good for gardening)so I hope there won't be much water saturation outside of the walls, and the pond was dug right outside of the canopy of most of the trees which are well above the water line so I hope that most of them will live. Although it will be more difficult to drop any dead trees later, I agree that now is not the time to start taking out 50 - 100 year old trees.
Thanks again....it is always helpful to talk with someone who's "been there, done that".