Georgia Aquarium holds the title, but only by one measure

The Georgia Aquarium in Atlanta is the largest aquarium in the world by total water volume — it holds 11.5 million gallons. That figure has held since the aquarium opened in 2005. However, "largest" depends on what you measure. If you count by number of animals instead of water volume, other aquariums house more specimens. If you measure by physical floor space, the ranking shifts again. So Georgia Aquarium is the largest by the metric most people think of — the sheer amount of water — but it is not the largest in every way.

When news outlets and record books refer to the "world's largest aquarium," they almost always mean water volume, which is why Georgia Aquarium appears in that position. But if you visited two aquariums and one felt bigger or more impressive, it might have been larger by a different measure.

Key Takeaways

  • Georgia Aquarium in Atlanta holds 11.5 million gallons of water, making it the largest by volume since 2005.
  • Other aquariums around the world are larger by different measures, such as the number of animals or the building's physical footprint.
  • The aquarium's size allows it to house large animals like whale sharks and beluga whales that require enormous tanks.
  • Water volume is the most common way aquariums are ranked and compared in published lists.

How aquariums measure size differently

Aquariums use different yardsticks to claim the "largest" title. Water volume is the most straightforward: you measure how many gallons or liters the tanks hold. Georgia Aquarium's 11.5 million gallons is the highest number recorded for any single aquarium facility.

Floor space is another measure. Some aquariums occupy more building area than Georgia Aquarium but hold less total water because their tanks are shallower or fewer in number. Animal count is a third metric — an aquarium with many small tanks for fish and invertebrates might house more individual creatures than one with a few massive tanks for large animals.

What makes Georgia Aquarium's volume so large

Georgia Aquarium's 11.5 million gallons comes from a relatively small number of very large tanks. The facility's main draw is the Ocean Voyager exhibit, a single tank that holds 6.3 million gallons — more than half the aquarium's total water. This tank is designed to hold whale sharks, the world's largest fish, along with manta rays and other large ocean animals.

The aquarium also has the Beluga whale habitat, which holds 5 million gallons by itself. These two exhibits account for most of the facility's water volume. The remaining galleries — tropical fish, sea otters, jellyfish, and others — make up the rest. This design prioritizes a few spectacular large animals over a high count of smaller exhibits.

Other large aquariums around the world

Several other aquariums are notable for their size, though none exceed Georgia Aquarium's water volume. The Okinawa Churaumi Aquarium in Japan holds 7.5 million gallons and is famous for its large acrylic panel tank. The Shanghai Ocean Aquarium in China holds approximately 5.5 million gallons. The Monterey Bay Aquarium in California is smaller by volume but is often cited as one of the world's most prestigious.

In Europe, the Lisbon Oceanarium in Portugal holds about 2.5 million gallons but is considered one of the largest by floor space. The Point Defiance Zoo and Aquarium in Tacoma, Washington, and the Aquarium of the Pacific in Long Beach, California, are also among the larger facilities in North America, though both hold significantly less water than Georgia Aquarium. New aquariums continue to be built, and some planned facilities claim they will surpass Georgia Aquarium's volume. However, as of now, no operating aquarium has exceeded 11.5 million gallons.

Why water volume matters for animal welfare

Water volume is not just a bragging point — it directly affects how well large animals can be cared for. Whale sharks and beluga whales are migratory animals in the wild and cover vast distances. A larger tank allows them more space to swim and reduces stress. The Ocean Voyager's 6.3 million gallons, while enormous by human standards, is still a fraction of the ocean habitat these animals would occupy naturally.

Aquariums use water volume to calculate filtration rates, temperature control, and chemical balance. A larger volume of water is more stable and easier to maintain at the right conditions. This is one reason why housing certain large animals requires such massive tanks — it is not just about space, but about the physical properties of the water itself.

How Georgia Aquarium uses its size

The Georgia Aquarium's massive volume allows it to house animals that most other facilities cannot. The whale sharks in the Ocean Voyager exhibit are the primary draw — they are the largest fish in the world, and only a handful of aquariums worldwide have the space to keep them. The beluga whales are another signature attraction that requires the 5 million gallon habitat.

The aquarium also uses its size to maintain multiple exhibits simultaneously without compromising water quality. Visitors can see tropical fish, sea otters, jellyfish, manta rays, and other species in separate galleries, each with its own filtration and climate control. This variety would be harder to maintain in a smaller facility.

Frequently Asked Questions

Is Georgia Aquarium still the largest in the world?

Yes, Georgia Aquarium in Atlanta remains the largest by water volume at 11.5 million gallons. No other operating aquarium has exceeded this volume since the facility opened in 2005.

What is the second largest aquarium in the world?

The Okinawa Churaumi Aquarium in Japan is typically listed as the second largest by water volume, holding approximately 7.5 million gallons. However, rankings can vary depending on whether you measure by volume, floor space, or animal count.

How much water does the Ocean Voyager tank hold?

The Ocean Voyager exhibit holds 6.3 million gallons, making it the largest single tank in the Georgia Aquarium and one of the largest in the world. It is home to the facility's whale sharks and manta rays.

Can whale sharks survive in an aquarium tank?

Whale sharks can survive in large aquarium tanks, but their care is complex and expensive. The Georgia Aquarium's 6.3 million gallon Ocean Voyager tank is one of the few facilities worldwide with the space and resources to house them. Whale sharks in captivity require careful monitoring and specialized diets.

Why do some aquariums claim to be the largest if Georgia Aquarium is bigger?

Different aquariums may measure size differently. One might claim to be the largest by floor space, another by number of animals, and another by water volume. Georgia Aquarium is the largest by volume, but other facilities may legitimately claim to be largest by other measures.