A Trip to Arizona's Ocean
You probably wouldn't expect to find an ocean in the arid, hilly landscape that lies in the shadow of the rugged western slopes of the Catalina Mountains, midway between Tucson and Phoenix. But there is one: The University of Arizona's Biosphere 2 harbors a simulated ocean, 100 feet long and 60 feet wide, 21 feet deep at its maximum depth and containing roughly 676,000 gallons of seawater.
The ocean originally was built to simulate a Caribbean tropical reef for the duration of the Biosphere 2 experiments, in which humans endeavored to live isolated within a closed complex, fully self-sustainable, as they would need to be if habitation of another planet were ever to become possible.
Today, the ocean is an important location for research on the vital roles of marine microbes and viruses in driving ocean biogeochemical cycles, and it demonstrates the complexity of these systems as well as their remarkable self-sustaining capabilities.
The ocean is large enough to allow its 10 species of fish and various species of algae and invertebrates to survive on an internal food chain. Algae in the ocean provide nutrients through photosynthesis.
The abundant sunlight, balmy temperatures and lack of substantial current all have contributed to an ideal environment for algae – so much so that the single-celled organisms occasionally overgrow, obscuring the underwater viewing windows, coating the ocean rocks and creating very murky "seawater."
Recently, students from Katrina Mangin's marine ecology and conservation class, ECOL 360, at the UA undertook a weekend field trip to the seaside to help clean up the overabundant algae population. For a half-day, students scrubbed the seashore and skimmed algae out of the water with finely meshed nets, while divers sunk to the ocean depths to clean up the glass and rocky seafloor.
(Photography courtesy of: Tobias Reitmayr, Daniel Stolte, Shelley Littin and Sarah Wolffis)