Re: Sterility, Teratogenic Effects, and Other Improbabilities -- or - the Roe not taken

[Bill Wichers <billw at waveform_net>]

> A fish needn't be diseased to carry a potentially harmful
> pathogen.  For example, an animal can carry a virus that
> can cause a disease without actually having the disease, or
> without acutally having the disease yet.

If the fish was carrying a potentially harmful pathogen when captured, it 
would reintroduce the same pathogen to a population where presumably other 
fish were also carrying the same pathogen, so there would be no effective 
change in the population. The only way I could see that this would be an 
issue is that if that normally dormant pathogen was awakened somehow during 
the period of captivity, in which case Tom would most likely no reintroduce 
the fish. I don't think there is a problem with qualified people doing 
research such as this, and I think Tom has demonstrated over the years that 
he does know what he is doing in this particular field.

> If you catch a wild pond fish in a cup and put it back
> right away -- not much chance of changing the pond.  But I
> would guess that the longer you have the specimen in
> another environment (tank or otherwise), the greater the
> chances that changes to the pond can occur with
> reintroduction.  How sterile and isolated are these fish?
> Hmmmm. . . How sterile and fastidiously isolated are these
> fish?   Is there a protocol?  Is there a routine?  The
> chance is probably small for changes but with any
> reintroductions, the chance for changes is probably small
> in almost all cases, anyhow.  It's not a matter of high
> probability but of potentially large impact.  The
> probability for a undesired effect is low but the effect
> can potentially be large.  The two factors combined
> represent the risk.

Seems unlikely that something new would develop in such a short time frame. 
Seems more likely that something pre-existing but dormant being awakened 
would more likely.


> >
> > In fact I would think that the threat of foreign disease
> > introduction is much higher from people (probably most of
> > us) who dump the water from their weekly water changes
> > down the drain.  That water will eventually make it into
> > lakes and streams.
>
> Probably true, but it depends  a lot on which person and
> what they dump.  Anyhow, disturbances in an environ aren't
> a justification for further disturbances  -- in fact, they
> might even be reasons to avoid even further disturbances.

For anyone concerned with sending their tank water down the drain along 
with live critters, just mix the old tank water with some bleach in a 
bucket before dumping it. The bleach treatment is in effect chlorinating 
the water, which is a very effective way to kill just about anything aquatic.

        -Bill


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Waveform Technology
UNIX Systems Administrator