Georgia Aquarium: Beloved beluga died of heart failure

The Georgia Aquarium said it learned Monday that the beluga whale it lost in October died of heart failure.

University of Georgia pathologists and aquarium veterinarians conducted the necropsy of Maris, whose unexpected death prompted more debate on the aquarium's controversial beluga exhibit.

Microscopic lesions on Maris’ heart supported the conclusion that acute heart failure caused her death despite the fact that an ultrasound earlier in the week had not detected anything abnormal, the aquarium announced through social media.

Maris appeared in excellent physical condition at the time of her death, officials said on the aquarium's blog. The condition she had was hard to detect, they said.

Born in 1994 at the New York Aquarium, Maris arrived at the Georgia Aquarium in November 2005.

A baby beluga whale born to Maris and Beethoven at the Georgia Aquarium in May died in June after not gaining significant weight after the birth.

The pregnancy was the second for Maris. A female whale calf born to Maris and Beethoven at the aquarium in May 2012 died after less than a month.

The aquarium’s 2013 proposal to import belugas from Russia that had been captured wild ignited controversy with some environmentalists who contended the whales were destined for lives of isolation, although aquarium officials contend that Maris was socializing quite well with two other belugas, Grayson and Qinu, before her death.

The proposed importation reversed a 20-year-trend in which there had been no wild-caught whales or dolphins imported to the United States. Marine theme parks often find it difficult to meet the standard of the Marine Mammal Protection Act that captures be humane and not endanger wild populations, according to National Geographic.

The aquarium was suing the National Marine Fisheries Service in federal court to reverse the denial of a permit to import 18 wild belugas, three of which were to be brought to Atlanta. The aquarium wanted the whales for a managed breeding program, while the feds and their allies contended the whales have been taken from a dwindling wild population.

Last month, the aquarium announced it had given up the fight and would not appeal.