DOWNTOWN — After a decade in the Caribbean Reef exhibit that sits in the center of the Shedd Aquarium, Nickel the green sea turtle, who came to the aquarium after she was struck by a boat's propeller, has a story familiar to many kids and their parents.
But do you know how much she weighs?
To celebrate the 10th anniversary of Nickel's Shedd residency, the aquarium is holding a contest to see who can correctly guess Nickel's weight.
The winner will get to meet Nickel in a private session, said Michelle Sattler, the Shedd's collections manager and the turtle's trainer.
The only hint the Shedd offers is that green sea turtles, which are endangered, can live more than 80 years and reach 700 pounds in the wild, and Nickel is believed to be in her late teens or early 20s.
She has lived at the Shedd since July 22, 2003. She was rescued from Florida's Gulf Coast in 1998, after a run-in with a boat's propeller left her with a damaged shell and back flippers.
After she spent a few years in a rehab facility, it was decided Nickel could not return to the wild. At the time, the Shedd was looking for another turtle after the death of Hawkeye, a beloved hawksbill turtle that had lived at the aquarium for a quarter-century, and Nickel was brought to Chicago.
Visitors became enthralled with Nickel's story, which is repeated throughout the day during feedings at the 90,000-gallon Caribbean Reef. Nickel's peculiar swimming style — she can't paddle her back flippers, which float higher than the rest of her body — makes her stand out in a tank full of amazing specimens.
She has become "iconic," said Sattler, a 16-year Shedd employee who has been close to Nickel since her arrival.
"She just makes so many people so happy," Sattler said. "She brings out a little joy for everyone."
Sattler was inspired to create the weight contest by the aquarium's Beluga-naming contest. She wanted to find a way to recognize Nickel's time at the Shedd, but went with the weight-guessing contest because Nickel — who was dubbed "Pete" until Shedd staff examining her found a 1975 nickel lodged in her throat — already has a fitting name.
Because Nickel swims only with her front flippers, the Shedd trained her to participate in her own health care. Sattler helped develop a special scale and helped train Nickel to swim to it. She also plays catch with her trainers and has been trained to circle a platform at the top of the tank, where Shedd workers can rub her shell and examine her.
A vegetarian, she eats several heads of lettuce a day, and her favorite treat is a veggie sushi roll made of lettuce grown from a sustainable garden at the aquarium. She has also been trained to nudge certain signs for an "award" of lettuce.
She's "very smart, very interactive," Sattler said. "It makes me feel really good that she's had a successful, comfortable home here."
The exact details of the contest have not been set yet, but for updates, check the Shedd's Facebook page or Twitter account.
