Chappy the baby seal has died, weeks after being rescued in a Connecticut city

The big-eyed gray seal pup who wandered away from home and into the internet’s hearts has died, just over two weeks after he was rescued from downtown New Haven, Conn.

The Mystic Aquarium, where he was undergoing treatment, announced on Monday that he had succumbed to gastrointestinal issues.

“It’s with the heaviest of hearts that we share the passing of Chappy, the gray seal pup we had been treating in our Animal Rescue Clinic,” it said on social media.

Chappy got his name after a police department naming contest. It’s a nod to the fact that the seal was rescued near Chapel Street, a pizzeria-rich area about a mile from Yale University’s campus and several blocks from the nearest coastline.

Experts have said he likely followed his instincts away from the Long Island Sound— and potential threats like bad weather and other seals — but got lost as he ventured deeper and deeper into the city. He was spotted a few times in the New Haven area in the days before his rescue on Feb. 16.

The aquarium said he was estimated to be only a few weeks old, and found to be “lethargic, dehydrated and in thin condition,” weighing a mere 28 pounds (compared to the average newborn gray seal’s 35 pounds).

Staff told NPR at the time that Chappy was on fluid therapy and an individualized treatment plan, being fed fish formula and getting “fish school (where we teach them that fish are food) daily.”

The aquarium shared photos and videos of the pup on its Facebook page in the ensuing days, celebrating Chappy’s milestones — like his first fish feast and a day that he gave staff “some sass” — but warning that his prognosis was “still guarded.”

Staff said his immune system was showing signs of weakness, and that he was being treated for pneumonia as well as gastrointestinal issues.

The hope was that Chappy would get strong enough to return to the ocean in the coming months.

But, the aquarium said in a statement on Monday, Chappy’s condition took a turn for the worse “as he was transitioned onto whole fish and began having digestive difficulties.”

“Unfortunately, despite all the efforts, his gastrointestinal issues were too severe to treat, and he succumbed to his disease,” it said.

A necropsy performed after Chappy’s death found mesenteric torsion, a life-threatening twisting of the intestines that cuts off blood supply to the gastrointestinal tract. The condition, which can affect humans, dogs, pigs and cattle, can be “challenging to diagnose and has a poor prognosis,” the aquarium said.

“In addition, while unrelated to Chappy’s immediate cause of death, small pieces of plastic were found in his stomach highlighting the threat that marine debris, especially plastics, poses to marine animals,” it said.

The World Wildlife Fund estimates that plastic pollution kills 100,000 marine mammals each year, either through ingestion or entanglement.

The aquarium said this week that they are devastated by Chappy’s death but “proud that they were able to give Chappy the best chance possible.” And they thanked everyone who sent well-wishes and words of support, both on social media and in handmade cards from around the world.

“The reality of working with stranded animals can be tough sometimes, but Chappy was surrounded by love until the very end,” it added.

The New Haven Police Department similarly thanked everyone who had reached out, adding “it was amazing to see how many people this story touched.”

It praised the aquarium “for their efforts to help our little buddy,” and urged people to donate to the aquarium’s Animal Rescue Program in the hopes of helping even more stranded animals.