When the National Aquarium in Baltimore was forced to drain the centerpiece Atlantic Coral Reef tank to complete $14 million worth of repairs, its directors had two basic options for refurbishing it:
They could follow the latest industry trend and retrofit the exhibit to include more interpretive gadgets and gizmos that would tell visitors what they're seeing. Or they could focus simply on improving the exhibit itself. As visitors to the newly reopened coral reef tank will discover, the designers made the right choice: By opting to enhance the reef rather than come up with more clever ways of explaining it, they have created an underwater experience that is more powerful than ever.
In the process they have underscored what an ingenious work of design and craftsmanship this exhibit -- and building -- have been all along.
The Atlantic Coral Reef exhibit is one of two two-story, oval-shaped tanks that constitute the centerpiece of the 14-year-old aquarium on Pier 3. Its companion is the Open Ocean shark tank, which reopened in November after a similar overhaul.
Cambridge Seven Associates, the building's architect, designed both of these tanks in an unusual racetrack configuration to give visitors the sense of being surrounded by water and fish. Walking down the crisscrossing concrete ramps in the "infield" of the racetrack, viewers get a sense of descending deeper and deeper into the ocean. Cut off from outside light and views, they become immersed in this shimmering world of water -- and conditioned to respond to the different moods the galleries create.
Both tanks were closed in October 1993 so contractors could repair damage caused by the corrosive effects of salt water on the concrete and underlying steel structures. Workers also altered the life-support system so the exhibit can be controlled -- independently of others in the building.
Aquarium officials decided that as long as they had to drain the coral reef tank, they should take the opportunity to redesign the exhibit as well. To determine what improvements to make, staffers consulted a wide range of experts in marine biology and other sciences.
According to Mark Donovan, senior director of exhibits and design, some suggested supplementing the 335,000-gallon exhibit with video monitors showing footage of real corals, touch-screen terminals containing information about reefs, and other forms of interactive exhibits that are appearing in aquariums and museums around the country.
But aquarium staffers rejected those suggestions. They feared that too many additions would cause visual clutter and detract from the building's main feature -- the naturalistic habitats on display.
"I have a lot of respect for this building and for [Cambridge Seven principal architect] Peter Chermayeff," Mr. Donovan said. "I think it is a landmark building. Our responsibility is to maintain it. It isn't to take my ego or aesthetic and impose it on this place.
"What's strongest here is the entire concept -- the architectural space and the feeling of being surrounded by water. The whole theme is immersion. If you added a lot of interactive technology, you would violate the strongest part of the building."
The first thing a visitor may notice about the refurbished coral reef tank is that it still has the same background music that greeted visitors nearly 14 years ago, a dreamlike electronic score by Newton Wayland.
There's still a 360-degree mural at the top, simulating the views ,, one would get from the deck of a ship at sea. One still walks down the same carpeted ramps in the middle of the ring tank.
But on closer inspection, everything about the coral reef is different. The music is clearer than before. The mural has been repainted. Lighting is softer and more focused. And in innumerable ways, the reef itself is more vibrant, more colorful, .. and above all, more realistic than ever. Walking through this exhibit is like greeting an old friend after a long absence -- and discovering the friend has fared quite well over the years.
Mr. Donovan explained that once the decision was made to stay true to the original concept of the building, designers had to figure out how to take advantage of technological advances of the past 14 years to improve its presentation.
Every aspect of the reef exhibit was rethought and redesigned. The sound system was upgraded. New lights were installed. David Rock of Tucson, Ariz., repainted the mural to make it more vivid and evocative. But the biggest change involved the simulated reef, which carefully duplicates the shape, colors and positions of live coral.
Hard corals are animals that build a base of calcium carbonate, a form of limestone, that becomes the home for some of the most colorful fishes in the sea. A living coral reef couldn't be moved to such a large setting because it would be too heavy and too costly to keep alive, not to mention ecologically unsound to remove from its natural setting. But just as they used technological advances to improve other aspects of the exhibit, aquarium staffers relied on advanced fabricating techniques to build a better reef replica.
As fabricated by Exhibit Technology Inc. of Littleton, Colo., and David Manwarren Corp. of Ontario, Calif., the new reef is denser than the old one. Rising 15 feet, it was made in California from fiberglass-reinforced concrete to simulate reefs in the Caribbean and Florida Keys. Then it was shipped in pieces to the aquarium, where artisans built it closer to the tank's curving windows to encourage fish to swim closer to their human observers.
In all, more than 20 species of stony coral have been replicated, including elkhorn, brain and star. One end represents the shallow part of a reef. Gradually, it deepens, with corals placed lTC as they would grow in nature. There is also a "coral garden" on the outer perimeter of the ring tank, visible to those moving up the "travelators" above the ray tray.
The exhibit is not a replica of any one reef but a sampler of many configurations, with nooks and crannies, ledges and recesses where smaller creatures can hide.
"We've tried to create different reef conditions in a compressed space," said executive director David Pittenger. "It's like having two spurs of a reef heading out toward the deep ocean, as seen at depths ranging from 5 to 25 feet."
The fabricators used flexible urethane to simulate soft corals such as sea fans, sponges and gorgonians. Before, those objects were made of rigid materials, but now they sway with the current and bend when fish swim by.
The tank has been restocked with hundreds of colorful tropical fishes, including bright red squirrelfish, spiny porcupine fish, Spanish hogfish, spotfin butterfly fish, yellow and blue grunts, and silvery lookdowns.
The staff has even arranged to vary water temperature and lighting in the tank to simulate the seasons in a real reef environment. The tank will stay light longer during the summer than in the winter, just as it does in nature, and water temperatures will rise as well. The goal is to make the fish think they are in a natural setting -- so they will act naturally and be more likely to breed.
"We tried to create lots of realistic places that fish would do well in, so there would be lots of realistic behaviors," said staff biologist Valerie Chase.
The emphasis on realism does more than help impart information. It's also an effective way to get visitors emotionally involved.
Located at the midpoint of the aquarium's simulated journey from the rain forest treetops to the ocean depths, the coral reef tank is a key to setting up the illusion that visitors are walking below the water's surface.
While interpretive exhibits can be useful in the right places, introducing new ones at this critical juncture would have disrupted the building's rhythm, breaking the mood that the designers worked so hard to create.
By focusing on making the exhibit more lifelike, however, the designers maintained the flow of the building established by Cambridge Seven. From the colorful swirl of activity in the coral reef tank, viewers descend to the darker and more mysterious shark tank below -- a dramatic juxtaposition that provides one of the aquarium's most memorable moments.
"The tension increases as you get deeper into the tank, building up for the sharks," Mr. Donovan said. "Any intrusion in the coral reef could have made the sharks anti-climatic. That's why we had to be careful about what we added."
Walking through the exhibit now, one tends to forget what a nightmare this could have been for the aquarium, especially given the many other aquariums opening around the country. Yet its directors faced up to adversity and turned it into an opportunity to create an aquatic exhibit unrivaled in realism.
The $84 million Florida Aquarium, which opened last month, has a large and impressive coral reef exhibit, too. But it's nowhere near as powerful as this one. For emotional impact, richness of detail and sheer physical beauty, Baltimore has the best coral reef exhibit in the country.
The transformation of Baltimore's coral reef exhibit is likely to prompt visitors to take another look at the entire aquarium -- to appreciate how well it works after 14 years, and how much it is capable of improving over time. Not every aquarium adapts to change so readily. But that's what the architects for this one set out to make possible as part of their original design.
"The unity of life through water is the main theme of the Baltimore Aquarium," they said in a "statement of purpose" drafted long before construction began. "It will continually reveal new and exciting aspects, like a fugue in a symphony."
For 18 months, the symphony was interrupted by construction activity. With the formal reopening of the coral reef tank this weekend, the aquarium is whole once again. Its story has never been richer.
What: Reef Romp Weekend
Where: National Aquarium in Baltimore, Pier 3, Inner Harbor
When: 9 a.m. to 4:30 p.m. April 9
Highlights: Outside on the pier there will be a free concert with calypso music by Mambo Combo and Trinidad and Tobago Steel Orchestra from 10 a.m. to 4 p.m. Inside the aquarium there will be diver presentations, children's activities such as face painting and crafts and a chance to hang out with the aquarium mascot, Puffin.
Aquarium admission: $11.50 for adults, $9.50 for seniors, $7.50 for ages 3-11, free for ages 3 and under
Call: (410) 576-3800