Re: NANFA-L-- Killer rain?

Jerry Baker (nanfa at
Thu, 01 Sep 2005 11:06:13 -0700

Nick Zarlinga wrote:
> I like your dissolved gasses thing. Seems somewhat plausible.

I was thinking it had to be gases to act so quickly (barring any obvious
chemical pollutant). My guess was that something had caused a relatively
large amount of CO2 to be released. Cold rain picking up NO2 from the
atmosphere as NO3, as well as CO2, would be acidic (as rain usually is).
If the ponds in question had a lot of alkalinity, they would have
released CO2 as the buffer "ate" the acidic rain. Perhaps a great deal
of rain in a short period of time was sufficient to produce enough CO2
to suffocate the fish.

That the algae also died tends to discount the CO2 theory though, not to
mention the NO3 theory. The only thing I can figure is that there was a
large concentration of a metal in the air when it rained (such as aluminum).

A conductivity test of the affected water might be revealing.
/ This is the discussion list of the North American Native Fishes
/ Association (NANFA). Comments made on this list do not necessarily
/ reflect the beliefs or goals of NANFA. For more information about NANFA,
/ visit Please make sure all posts to nanfa-l are
/ consistent with the guidelines as per
/ To subscribe, unsubscribe, or get
/ help, visit the NANFA email list home page and archive at