English: Nickel, a Green Sea Turtle at the Shedd Aquarium in Chicago. Named for the 1975 nickel found in her esophagus, Nickel was brought to the Shedd Aquarium in 2003. She can be seen in the Caribbean Reef Exhibit, often napping under the mock coral in the south of the exhibit (as depicted above). Green Sea Turtles are an endangered species, but due to a motor boat gash in the rear of her carapace, Nickel is unable to return to the wild. She was born in the mid to late 1990s.