ade

whatsoaver, and usually the curve covers about eleven intervals,
in the case of where you have a bit of an
you get a longthoning of the tail,
fou species becoming

oronnic Icad,

In othar words, you get a

entremoly numorous,

This, of course, fits

into our general idea thet in a stecam waich i5 natural, tuat
has no pollution of any sort,as wa usunily think cl pollution,

particularily organic pollution,
Mmorg nuuacrous,

~

Sg

ce

{+

S

{a

O
et
font

by

6

MY

And tne Lirst effe

Q

nuncor of eny one srecis,

ec

you have a great nuiber of species and not any too Liarge a

is to make a few species becone

and then as pollution gots worse and worse, we

is wnat happened to ithe curve.

fae
LS

ct
~

fouremilo cress, @ pollutant wont into that stream, an

por)

You will see here that on one of theso which is in t

So, by Looping these continually

in the water, an@ then by changes and thon, oF course, wo are
not rolying entirely on that,

sumer to check the River,

but wo are going in again this

We do have a continuous method of

diagnosing river conditions.

tenvorature tests wero

©

Now, as to the temperature test that we have done, our
ained at determining what tomperatures

@ stream could stand and yet remain novmal.

At onco, wa

realized fron our exporimonis
that in a natural envirconzent
ae

you must think of ontimun temmcratuves because of connlication
of species and not maninum temvaranturos at which organisms can
live in the laboratory,

This is clearly illustrated by the fact

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