He soon grew to love the cavern system, which dates back 350 million years, and by the age of seven he had explored it more than 100 times.

For the typically still-water environment, the waves disrupted the shallow shelf that the pupfish use as a spawning area, likely knocking eggs deep into the cavern.

It takes about 10 minutes just for the elevator to reach the detector caverns, Sousa said.

The concerto is full of sonic imagery that travels above and below ground, down to the rivers in deep caverns and up in the skies to the environmentally threatened toh bird.

Crews drilled steel pillars deep into the ground, disturbing a fragile ecosystem of thousands of caverns and freshwater sinkholes known as cenotes.