Since I may actually see open water in the next few days, I think that
the time has come to broach a somewhat different kind of pond question
than is the norm on this group.

In late 2004, I moved from a high rise condo building on the lakefront
in Chicago to 5.5 acres in rural Minnesota. One of the features on my
property is a pond. It's about 3/4 acre, pear shaped, and 17 feet at
its deepest. This is a "natural" pond; I put "natural" in quotes
because it was actually dug (in the mid 1970s), but it has no lining,
pumps, aerators, or any of the other attributes that often turn up in
discussion here. In other words, I don't think it's your "normal"
rec.ponds pond. [Yes, I know I'm in newsgroup rec.ponds.moderated.]

This pond is the fisherman's dream, if the fisherman happens to be about
five years old. Drop a hook in the water, and you've got a fish in less
than a minute. Bait optional. Take the fish off the hook and throw it
back, repeat, and you would swear that you've caught the same fish.
They're sunfish, I'm told, 6-18 inches in length. It's obvious even to
me that the pond is overpopulated with small fish.

I've not done anything much to the pond. I've had plenty to keep me
busy on the property since I've lived here. My pond maintenance has
been limited to using chemicals to reduce algae growth.

I don't know squat about ponds. Flame me if you must; I'll simply
ignore those. I'm not proud of not knowing about how to handle the
pond, but I'm not ashamed of it either. There are many things to learn
when you move from a downtown condo to a rural house; I've learned a lot
of them, but nothing about the pond. If you would like lessons in
keeping bees, growing vegetables, or brewing beer I'd be happy to help.

So, those of you who know something about the kind of ecosystem I have,
what would you suggest? My inclination is that I need to introduce some
more-aggressive fish that will control the population of the small
sunfish. It would be nice if they could live through the Minnesota
winter like the sunfish do. I'm willing to listen to any advice. So
far the pond has taken care of itself; I'm willing to weigh in only if
there's some likelihood that I'll improve things. Otherwise, Mother
Nature has been doing a rather admirable job.

It's likely that I've left out some crucial information that you need to
understand my situation, so please ask and I'll do the best to provide it.