Caspian, a 27-year-old female beluga brought to Chicago from a shuttered Canadian theme park, has died at Shedd Aquarium. She is the fourth of 10 belugas transferred from Marineland in July and August to die.

Shedd officials said Caspian had been among the whales causing the greatest medical concern since her arrival in August. She was not eating enough to meet her needs for food and water, and staff adjusted her care in hopes of improving her health.

Her condition worsened Wednesday. Aquarium veterinary and animal care teams spent nearly four hours providing life support, but she did not recover, officials said.

A necropsy is scheduled to help determine the cause of death. Shedd said the examination will allow veterinarians and outside pathology experts to look for disease that may not have been detectable through Caspian’s behavior or blood tests.