MYSTIC, Conn. (WTNH) — Another beluga whale that arrived at Mystic Aquarium from Canada last May has died.

The aquarium said the female beluga passed away despite receiving 24/7 intensive care during the last several months for various health issues and life-saving efforts made Friday morning.

“Our team provided a continuum of world-class care to this whale for many months,” said Mystic Aquarium Chief Zoological Officer Allison Tuttle. “When an animal passes in the wild, it is the circle of life. When it happens at an aquarium, with an animal you have grown to know, care for 24/7 and adore, it is devastating.”

The cause of her death will not be known until a full necropsy is completed.

The female whale was one of five belugas transported to the aquarium from MarineLand in Canada under a research permit last May.

Her passing follows the death of one of the other whales from Canada last August, which the aquarium said at the time had a preexisting gastrointestinal condition.

The Animal Welfare Institute (AWI) issued a statement following Mystic’s announcement Friday, saying it was “appalled” to learn of another beluga whale death at the aquarium.

“These five whales were supposed to be healthy when they were imported, but it is becoming increasingly clear they were not,” said Dr. Naomi Rose, AWI’s marine mammal scientist. “If Mystic knew this and imported them anyway, that is unacceptable. If they did not know, that is incompetence. These whales deserve better — we demand a full government investigation into this situation. What was meant to be an uneventful import for research has become a disaster.”

Connecticut-based Cetacean Society International (CSI) called for a thorough inquiry Friday.

“Serious unanswered questions remain about this import, and Cetacean Society International demands a thorough inquiry, and answers from not only the aquarium, but also government authorities in the U.S. and Canada as to why animals with apparent pre-existing health conditions were allowed to be exposed to the stress of international transport.”

Mystic Aquarium said there are six other whales under care there, one of whom remains in the intensive care unit, while the others are healthy and residing in the Arctic Coast Habitat.

AWI said it will be monitoring the National Fisheries Service’s website for the full necropsy reports for this whale and the whale that died last year.