The hot water additions into the Firehole River also bring more unusual
bacteria into the picture—thermophiles!
These microorganisms thrive in the extreme temperatures of hydrothermal
features. Some are carried away from their natural environments with the
hot runoff into the river. Although they can’t grow or thrive in
their new colder home, they drift downstream and are very useful indicators
of the extent of the thermal additions.
I thought that’s what thermometers are for.
Ah, but now we know that some types of thermophilic bacteria are widespread
outside of Yellowstone in such things as water heaters or steam condensate
lines. These “bio-indicators”
are particularly useful because they allow scientists to observe two different
types of human-caused thermal pollution: that which is caused by large
amounts of warm water and that which is caused by small amounts of very
that thrive in extremely hot conditions
product of condensation. Condensation is when a gas or vapor is
reduced to a liquid or solid form.
living creature whose presence indicates the existence of certain