Its pyramid-shaped rooftops help define the city skyline and are as much a symbol of the new Baltimore as white marble steps, hard-shelled crabs and decrepit docks were of the old.
As the countdown continues to its 20th anniversary Wednesday, the National Aquarium in Baltimore welcomed the 30 millionth visitor yesterday to its submerged world of kaleidoscopic colors and seldom-seen species.
That milestone, marked by considerable fanfare, equates to nearly six times the state's population -- not bad for a building that was derided as a mere "fish tank" when it was proposed but quickly became a cornerstone of the city's Inner Harbor revival.
"I think we're in many ways an icon for what people see about the city," said David M. Pittinger, the aquarium's executive director. "People talk of us as a national attraction. To have that kind of awareness in a relatively short period of time is significant."
And the wave of popularity the aquarium has been riding for the past two decades, during which it has doubled the space of its tanks and tripled the number of specimens in its exhibits, has not crested, officials believe.
When a planned $40 million addition featuring the Australian Outback is completed in four years -- the second major expansion in the aquarium's history -- they expect attendance to spike by 25 percent, to more than 2 million people a year.
The added attendance -- for a building that draws more people each year than any other paid attraction in town except for the Orioles -- in turn will give the aquarium a wider audience for the message of conservation that accompanies many of its exhibits. It will also provide a broader base for the environmental programs that have become a greater part of its mission.
Sydney Butler, executive director of the American Zoo and Aquarium Association, said the National Aquarium is widely regarded as among the top aquariums in North America -- not only because of the popular appeal of its exhibits but also because of its sense of stewardship of the environment.
"When I think of the Baltimore aquarium, I think of it as a community asset as opposed to a community attraction," said Butler, specifically noting its work to restore Chesapeake Bay wetlands.
Indeed, the aquarium receives as much praise from environmentalists as from tourism officials.
Donald Baugh, vice president for education at the Chesapeake Bay Foundation, credits the aquarium for helping raise regional environmental awareness.
"It has a strong conservation message, and it's trying to use motivated members for real-life programs," Baugh said. "It's been far more than just another fish tank."
A "fish tank" was what critics called the aquarium when it was proposed in the mid-1970s.
Conceived of by Robert C. Embry Jr., then the city's housing commissioner, as a way to spur tourism and economic development, the idea took off after Mayor William Donald Schaefer and other city officials visited the New England Aquarium in Boston in 1975.
"I had seen fish before but never in that setting," Schaefer, a former governor and now the state's comptroller, recalled recently. "They couldn't pull me out of there. I said to Bob Embry, `We have to have an aquarium.'"
Construction funds came from a $7.5 million bond issue to be matched with money left from Baltimore's sale in 1972 of Friendship Airport, now Baltimore-Washington International Airport, to the state.
In a debate that would be repeated for decades -- during the construction of two stadiums, the expansion of the Convention Center, and subsidies for private developers for hotels and nightlife complexes -- critics questioned whether public money should be spent to entertain out-of-towners when the needs of so many residents were going unmet.
"We are opposed to continued outpouring of public funds for fripperies when we desperately need so many basics," Bettie Owings Summers, head of a taxpayers' group that formed around the issue, said at the time.
The bond issue passed by a nearly 23,000-vote margin in November 1976.
Even before it opened -- at a cost of $21 million -- the aquarium made a nationwide splash, when Schaefer, clad in a Gay Nineties swimsuit and clutching a rubber duck, jumped into the outdoor seal pool. He was making good on a promise to take a dive if the aquarium failed to make its original July 4 opening date, scheduled to coincide with the first anniversary of Harborplace.
When the building opened, five weeks late, the line stretched from the Pier 3 entrance to Light Street. Projected to draw no more than 700,000 people in its first year, the aquarium surpassed that figure in the first five months.
The aquarium's popularity masked myriad problems. The aquarium's first executive director quit just two months after the opening, and its first few years of operation brought an infestation of tropical ants to the rain forest, the closing of exhibits for repairs and the death of two dolphins.