The Smithsonian Institution has long been known for both its original research and its exhibitions.  But, it was not until 1980 that the National Museum of Natural History (NMNH) first exhibited an on-going active research project, the world's first indoor living coral reef.

In the late 1960s, when NMNH paleobiologist Walter H. Adey began experimenting with growing algae, he didn't want to grow it in isolation.  Instead, he wanted to see how algae would react in the presence of other reef organisms.  According to the October 1980 issue of The Torch (the Smithsonian's staff newsletter), Adey believed that "if you knew enough about the natural environment - in this case the light, temperature, water, salinity, currents and other conditions - you could create a live reef microcosm."

In 1975, Adey, newly appointed as Director of the NMNH Marine Systems Laboratory, outfitted a 350-gallon tank with high-intensity halide lamps simulating the sun and a generator to mimic wave action.  He continued developing and refining the reef system and tank and by late 1979, his experiment had been functioning perfectly for almost two years, Adey applied for a grant to begin work on a much larger 3,000-gallon system.  To fill the new tank, Adey went off to collect plants and animals in the Caribbean, an endeavor documented by his wife, Karen Loveland, a film producer in the Smithsonian's Office of Telecommunications (most of the original footage can be found in accession #05-263).

The result of his efforts was an exhibition that opened to the public on October 15, 1980, featuring a 500-gallon lagoon tank connected to a 2,500-gallon reservoir and over 200 species of coral (more than 3 tons of it), algae, fish, sea urchins, crabs, anemones, sponges, sea fans, and mollusks.  A timed lighting sequence simulated the cycle of the sun from sunrise to sunset.  A complex wave generator simulated waves of varying forces and frequencies.  In addition, the exhibit housed a marine laboratory where visitors could watch as scientists performed research and also presented a continuously running film, "Coral Reefs: How to Make Use of 400 Million Years of Evolution," that had been produced by Loveland.

The tank operated for nearly two decades at NMNH, but the exhibition closed in 1999 to make room for an expanded Mammal Hall.  While the Smithsonian Marine Station at Fort Pierce, Florida agreed to take the live exhibition, there wasn’t  yet a place to put it.  In a 2010 oral history interview that is part of the Archives' National Museum of Natural History Centennial Interviews (Record Unit 9622, Sessions 8, 9, 10), Mary E. Rice, Director Emeritus of the Smithsonian Marine Station, described the logistics of finding foster homes for the living inhabitants of the exhibition until their new home was ready.  Three truckloads of specimen were transported to Florida and installed in an incoming seawater system for a nuclear plant before they were moved to the Indian River Community College.  The rest of the tank's inhabitants were distributed among various NMNH departments and facilities throughout Washington, DC, Virginia, and Maryland.

Finally, in August 2001, the tank and all of its inhabitants were reunited in a new building, joined by several smaller tanks displaying six different Florida marine habitats.  The "Marine Ecosystems Exhibit," including the original 1980 tank, is still on display today.