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

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

The animal’s death was confirmed by a boater in Narragansett Bay who took photos of the body somewhere between Prudence and Hog islands.

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 manatee when it was in Narragansett and said it appeared healthy then.

“It did seem, overall, like the animal was in pretty decent shape and was exhibiting normal behaviors,” she said.

According to Callan, the aquarium had been working with its partners and a plan was in place to rescue the animal if it was spotted again.

“We had everything lined up that we needed to for this manatee to come in for rehabilitation, even the food source,” Callan explained. “There were a couple local supermarkets that were willing to donate lettuce.”

Thanks to this manatee, the aquarium will be ready if another decides to take a trip North.

Callan said the animal has likely been dead for several days. The cause of its death may never be known due to the condition of the body.

“I think that anything is really possible,” she said. “It’s hard to say, with the state that it’s in now, what could have happened, but I think pretty much anything is on the table.”

When asked how they could identify whether the manatee was the same one that was previously seen, Callan said she would be shocked if there was another 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. There was a scar on there we’re using to ID that manatee.”

Callan stressed the importance of using the aquarium’s rescue hotline.

“If people do see a manatee, or even any animal that they have concerns about, give our hotline a call as soon as you can so we can really act on these cases immediately,” she advised.

The aquarium doesn’t know where the carcass is now, but they hope to collect samples if it’s seen again.

“I do think we’d still be able to get some information on gender and the age of the animal potentially. Those genetic samples will be really helpful,” Callan added.

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