Luke
On Thu, 14 Sep 2000, Christopher Scharpf wrote:
> Luke said:
>
> >is the Kansas River right here in my home state. 500 years ago it would
> >have generally been a brown, muddy mess containing specific species
> >groups. Now, thanks to Federal resevoirs controlling the flow, it is
> >generally a "reasonably" clear stream, with a totally different group of
> >species inhabiting it.
>
> So you're saying that the Kansas River is better off ecologically because its
> natural turbidity has been reduced by dams (which trap sediments and hold them
> in the reservoir) and because "a totally different group of species" (which I
> presume includes introduced gamefishes) inhabit it?
>
> By that logic, the Colorado River is better off today than when it was a raging,
> turbid "mess" filled with "trash" fish such as humpback chub and razorback
> sucker!
>
> > But, my point is that not every stream in N.A. was at one
> >point "clean and clear" running.
>
> Streams may not have been clear, but they were clean (i.e., free from
> contaminants which harm wildlife and humans).
>
> >Many streams where always dirty in some
> >way and the water not fit for drinking. It's a myth that they were...
>
> Natural turbidity doesn't mean the water isn't potable. Simply let the sediments
> settle for a few hours and then drink up!
>
> The myth, as you describe it here, is simply the common misconception that clear
> water is axiomatically better water. Healthy water is often clouded with life
> (algae, diatoms, etc.). The "more natural looking" water of clear mountain
> streams (so common in beer commericals) is virtually lifeless.
>
> According to FISHES IN KANSAS, the clarity of streams just below impoundments is
> usually offset a few miles downstream due to the erosion of streambanks.
> Flood-protected streams discharge all of their annual flow through the channel,
> which causes even more streambank erosion. Eroding streambanks also stabilize
> the flow bottom, reducing the number of pools and reducing fish habitat. The
> diversity of the fish fauna is thereby reduced.
>
> Of course, dams have produced many lakes in virtually lakeless Kansas, which is
> good for the fish that can live in them, and too bad for the ones that cannot.
>
>
> Chris Scharpf
>
>
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