(WPRI) — The manatee spotted last month in Rhode Island waters has been found dead offshore, according to Mystic Aquarium officials.

“We are so saddened by it,” Sara Callan, manager of Mystic’s animal rescue program, told 12 News.

The manatee was first seen swimming in Quonochontaug Pond on Sept. 11. It then slowly made its way to Narragansett, and was last spotted alive on Sept. 18 in Warren.

Callan saw the animal when it was in Narragansett and said it appeared healthy then.

The aquarium currently doesn’t know where the carcass is but says it has likely been dead for some time due to the state of the body.

When asked how they could identify if it was the same animal previously seen, Callan said she would be shocked if there was another manatee in the same area.

“I’m 99.9% sure it’s the same one,” Callan said. “Scientifically speaking, we always like to confirm the [identity] but it’s too decomposed, and I haven’t had great photos of the paddle, and there was a scar on there we’re using to ID that manatee.”

Anyone who sees the carcass should contact the Mystic Aquarium Animal Rescue Program by calling 860-572-5955 ext. 107.

No word yet on the cause of death.

This is a developing story. Check back for updates.