A new initiative is underway to breathe life back into the 700,000-gallon ocean tank at Biosphere 2. The new ocean at Biosphere 2
will provide a glimpse into the sea that's closest to Southern Arizona – the Gulf of California, which stretches for a thousand miles from the mouth of the Colorado River to Mazatlan on the mainland of Mexico.
The original "ocean" was one of several habitats intended to sustain a crew of scientists living and working inside the Biosphere 2 dome isolated from the outside world. When the "enclosed missions" ended in 1994, the fragile ecology of the ocean habitat collapsed. The corals died and algae and bacterial mats took over, crowding out the reef.