I just got back from a week long canoe trip to the wilderness in northern
Ontario and discovered my own back yard wilderness has suffered. My pond is
400 gallons or so (4 feet wide by 8 feet long and anywhere from 12-30 inches
deep). I've got lots of oxygenating plants that have blossomed, but the
fish, which a neighbor saw thriving on Tuesday, have died over the last
three days.

My first thought was that numerous pears, which have been dropping in from
an overhead tree have changed the chemical composition of the water. The
plan was to snatch them out every day, which I was doing. (They float, at
least for a while) But in my absence a whole bunch came down. Some have
already been chewed on by ravenous squirrels. I noticed also the rocks under
the small waterfall are a bit slimy.

Would a lot of pears adversely affect the chemistry of the pond? My plan for
next year will be to put up a sloped netting during pear-dropping season to
avoid this problem.

(By the way, I don't think our power shortage problem up here in the north
east was the cause, though perhaps it may have contributed. The oxygenators
are plentiful and the pump / waterfall was probably only off for about 10
hours.)

Mark