On a planet known as Auzurin, an intelligent species of aliens swim and thrive in the ocean amongst the "blood crystals," known as Auzurite to humans. This crystal helps keep the ecosystem on both land and in water alive, as the bottom feeders that feed every creature use this crystal as their energy source. Humans have discovered this crystal and wish to use it to power their space ships and other heavy equipment, but if they mine it, the planet will die.
This is just sort of a small plot I thought of in the shower. It may become a short story, it may (try) to become a book. Just don't be too hopeful for a proper book.