Authors:

Penguins are an indicator of the health of our watery planet, and if they are unable to survive, we had better take notice or we might find our own survival threatened.

"Penguins". Book by Martin Rees (p. 160), March 1, 2009.
Penguins are an indicator of the health of our watery planet, and if they are unable to survive, we had better take notice or we might find our own survival threatened.