Jonathan Rueffer | Science Editor
On Aug. 20, 2025, the Georgia Aquarium announced that one of its two whale sharks, Taroko, was euthanized due to his declining appetite and health. Whale sharks, or Rhincodon typus, are the largest fish known to have lived on this planet, growing between 18 and 32 feet. Despite their intimidating size, their temperament and feeding habits give them the reputation as the ocean’s gentle giants. The Georgia Aquarium, located in Atlanta, is the largest U.S. public aquarium and the only home of this aquatic species in the Western Hemisphere.
Although the species’ name invites some confusion, whale sharks are sharks, not whales. They exhibit key shark characteristics: a skeleton made of cartilage instead of bone, gills and a tail that moves side to side. However, unlike most shark species, a whale shark’s mouth is located at the front of its head instead of the underside of the snout. Its mouth contains around 300 rows of small teeth that are not designed for eating but rather aid in filtering small fish and particles, like plankton, into the back of the mouth while water is moved out through the gills. Similar to human fingerprints, the recognizable spotted and striped pattern of their skin is unique to each whale shark and can be used for identification. Whale sharks are natively found in the tropical Atlantic, Pacific and Indian Oceans. They may come close to land in bodies of shallow waters, such as lagoons, bays or coral atolls to feed during seasonal plankton blooms. According to the World Wide Fund for Nature (WWF), less than 10% of whale sharks survive to adulthood, but those that do can live up to 150 years.
The Georgia Aquarium is designed around a 6.3 million-gallon whale shark exhibit, having introduced the species to the American public in 2005. At that time, Taiwan was the only country that permitted the legal fishing and capture of whale sharks under an annual fishing kill quota, which allowed the Georgia Aquarium to purchase four sharks before they could be slaughtered for the seafood market. The importation of whale sharks from Taiwan had never been previously attempted, as it involved transportation by boat, plane and truck, making their appearance in the U.S. even more significant. In 2007, just before Taiwan’s full ban on whale shark fishing took effect, two more whale sharks were rescued from the Taiwanese market: Taroko, named after Taiwan’s Taroko Gorge National Park, and Yushan, named after Taiwan’s Jade Mountain.
After the last of the four initial sharks passed away in 2021, Taroko and Yushan were the sole inhabitants of the aquarium until Taroko’s passing in August. To address public concern regarding Yushan, who is now alone without his 17-year long tankmate, the aquarium stated that Yushan is in good health and that the care team’s primary focus is on his well-being. The aquarium estimated that more than 43 million people saw Taroko during his time in Atlanta.
The Georgia Aquarium’s mission is to “[advance] whale shark conservation and protection through science and education, advocacy, and connecting and inspiring millions of people every year.” A dive team is responsible for the care of these creatures, maintaining a clean enclosure and overseeing programs that allow visitors to swim and dive within the exhibit, which is a unique opportunity that attracts thousands of visitors annually. Other teams monitor the salinity levels of the water and feed each whale shark nearly 40 pounds of shrimp, krill and small fish every day.
Whale sharks are listed as “Vulnerable” on the International Union for Conservation of Nature (IUCN) Red List due to heavy fishing in Asia for their meat and fins, which has caused a dramatic population decrease. Moreover, their ocean home is in danger, with climate change warming the water and plastic pollution leading to entanglement or ingestion for these beloved gentle giants.