Earth is a liquid planet.

70 percent of its surface is covered by water
yet much is still unknown about the depths

of the oceans.

They call it inner space - an inhospitable
environment difficult to explore and unfit

for human habitation.

Nevertheless, scientists have figured out
ways to work and live on the ocean floor.

Aquarius is the only operating undersea station
in the world today.

There are very few people that get to do this
kind of work.

This is like getting into a submarine, except
we can swim out any time we want.

The Aquarius Reef Base gives researchers around
the clock access to a coral reef ecosystem.

Over the last several decades, coral reefs
around the world have drastically declined

in health.

Now scientists fear that a change in the chemistry
of the water could add further insult to injury.

Ocean acidification occurs when CO2 dissolves
into seawater and it reacts with the water

to make an acid.

Aquanauts living at Aquarius are the first
to study this process 24/7 - using new high

tech instruments.

What impact might ocean acidification have
on the reef?

What else might the scientists findings
tell us?