All my big koi (6) died in Hurricane Isabel (we live in Virginia, along the
stretch where the storm hit the worst) . All the small ones survived.

(Big=15" Small = 3 to 6")

Two of them were dead by the morning after the storm, so I don't think it
was oxygen starvation. (They have survived much longer electrical outages with
no apparent stress. The two were dead after about 12 hours of no electricity.)
One or two large ones died every day after for 3 more days. All fish were top
breathing, however, including my normally bottom dwelling catfish. (The catfish
died later as well.) All smaller koi and my comets survived.

Two big trees fell w/in 30 feet of the pond. Could the 'boom' of the fall
created a shock wave that could kill fish in the same way that breaking ice
(that forms over a pond during the winter) with a hammer can?

Could the steady (but loud) drone of a generator do anything?

Why would only the big ones die?

Thanks for whatever information or "look here" sites that you can provide.
These were beautiful fish and I want to know if there is anything I could have
done to save them?

Roy

All fish were top breathing, however, including my
normally bottom dwelling catfish.

Do you have a bottom drain and good water circulation? Are there "dead
pocket" areas? How heavily was your pond stocked? Gravel? My guess
is this was caused by the pond water being turned or stirred. This,
combined with the power loss caused the oxygen level to diminish.

Sorry for your loss.

Jim
Zone 8a - Dallas, Texas
Pond, Veggie Filter, Pond Maintenance & Pond Tour Pics:
http://community.webshots.com/user/dallas75248

(Roy Lasris) wrote:

Hello Roy

RL All my big koi (6) died in Hurricane Isabel (we live in
RL Virginia, along the stretch where the storm hit the worst) .
RL All the small ones survived.

RL Two big trees fell w/in 30 feet of the pond. Could the
RL 'boom' of the fall created a shock wave that could kill fish
RL in the same way that breaking ice (that forms over a pond
RL during the winter) with a hammer can?

Maybe, it's a bit of a puzzler. I've read that hurricanes can do
pretty strange things to air pressure though, sailors passing through
the eye have reported such low pressure that their eyes and noses
started bleeding. Maybe something like that messed up the oxygen
content a lot?

RL Could the steady (but loud) drone of a generator do
RL anything?

No, unless it was earthing into the water.

RL Why would only the big ones die?

Suggests oxygen to me, but tbh I'm guessing a bit here.

--
Simon Avery, Dartmoor, UK Ý http://www.digdilem.org/