The basement of the Commerce building has been swimming with fish for the past 76 years. Now, thanks to a series of renovations, the fish are living a bit more comfortably in their tanks.

Last week, the National Aquarium celebrated the completion of a face-lift that changed its focus to domestic aquatic life and improved the water quality in tanks. The project was made possible in 2003 when the aquarium

formed a partnership with the National Aquarium in Baltimore and received a $573,000 grant and a subsequent agreement of $937,000 from the National Oceanic and Atmospheric Administration.

“Our partnership with Baltimore is a critical component to making the National Aquarium in Washington, D.C., a premier window to the aquatic world with access to world-class programs and exhibits that promote the stewardship of aquatic life,” Bob Ramin, executive director of the National Aquarium, said in a press release. The aquarium is well worth the trip, “particularly if you’re looking for a cool, underwater experience and a respite from D.C.’s oppressive summer heat.”

Before its makeover, the tanks, which are tucked away in the basement of the Commerce building on the corner of 14th Street Northwest and Constitution Avenue, housed a number of creatures that aren’t from the United States. Most of them have been sent to other zoos and aquariums.

“The first thing we did was re-theme the aquarium,” General Manager Andy Dehart said. “The best message for us is to show animals from the U.S. and its territories.”

The new exhibit, titled “America’s Aquatic Treasures,” features animals from the National Marine Sanctuary Program and freshwater ecosystems across the United States, including the American alligator.

The aquarium is confined to one floor and is significantly smaller than its counterpart in Baltimore. “Big showy specimens get too large for our tanks,” Dehart noted. But that’s OK, he said: The aquarium has adapted by finding smaller inhabitants such as swell sharks.

“One thing that is critical to us and who we are is the care of our animals,” Dehart said. “We want to be a perfectly executed small aquarium.”

For instance, the aquarium is committed to cutting back on the practice of populating its tanks with fish captured directly from the ocean.

“At this time it is impossible to get away from wild collection,” he said. “Our goal there is just to lead by example in sustainable practice.”

The National Aquarium was first established in 1873 as a part of the Federal Fish Commission. In 1878, it moved from its original location in Woods Hole, Mass., to the National Mall. It moved to its current home upon the construction of the Commerce building in 1932.