Large pond questions

This may be a little off-topic for these lists, but I thought I'd present
the problem to the groups in the hope that someone has some advice, and/or
can point me in the right direction.

Anyway, my friend has a farm out in northeatern Pennsylvania. Last year,
they had a pond constructed on the property from a fairly wild area (no
crops growing here). The pond is about 1/2 to 1 acre on the surface, and
goes as deep as 12-16 feet. It is fed mostly by runoff from the hills above
(in this part of PA, all you have to do is stand still, and you can hear
the water running under your feet).

They had is stocked with some sunfish and Bass this year, and I guess the
fish are ok. There are no plants in the water, it's basically a sandy pool.
THe water is silty, with a light brown tone to it. Visibility from the
surface is no more than 12" or so.

I'd like to be able to recommend to them what they can do to a) clear up
the water and b) improve the conditions for the fish. I was thinking that
on the 'uphill' side of the pond, that they dig out some of the shore, and
replace it with coarse gravel (or scrap rock that can be gotten from a
local quarry), to provide a kind of mechanical filtration for the water
that keeps the pond filled. I hope that this would reduce the silting, and
help clear the water.

Besides the fish, a few frogs have made the pond their home and breeding
ground. Last weekend, we saw 10s of thousands of tadpoles near the
shoreline, just out of reach of the fish. At least there's no mosquitos


Larry West