MAITON ISLAND, Thailand - After a brief countdown by conservationists, a young Indo-Pacific leopard shark glided into the blue waters off Maiton Island in southern Thailand, released in the country's first efforts to "rewild" the endangered species.

Once a familiar sight for snorkellers and divers, the spotted sharks have sharply declined in the wild over the past decade due to overfishing and habitat loss, even as they flourished in private aquariums.

"Why not take the breeding population that is doing well in the aquariums and release them back into the wild so that the wild population can recover?" said Metavee Chuangcharoendee, project manager of the StAR Project Thailand, a partnership launched last year between the government, NGOs and aquariums.

The latest release in December included the sharks Maiton, Hope, Spot and Toty, each nearly two years old. They were among seven pups released so far, after being bred and raised in an aquarium for about a year.

All spent months being taught behaviours they will need in the wild, including in the sea pen off the pier at Maiton Resort, where they adjust to natural conditions.

"This sea pen is built in order to acclimatise the shark to their environment and the shark nannies are taking care of the shark - daily feeding, recording their growth and also recording their general health to be able to keep them healthy and train them for the wild," said Metavee, referring to human caretakers.

Two days before the four pups were released in December, marine veterinarians conducted final health checks to ensure they were fit to be returned to the sea.

The checks included ultrasound examinations to assess the sharks' internal health, along with the fitting of acoustic tracking devices, the collection of DNA samples and measurements, before the animals were cleared for release.

While the species is protected under Thailand's wildlife conservation laws, Metavee said broader efforts such as protecting habitats, reducing pollution and improving marine resource management, are essential for the sharks' long-term survival in the wild.

For Metavee, success is not just about the number of sharks released, but about signs of true recovery — such as regular sightings by divers, evidence of breeding in the wild and the absence of leopard sharks from fish markets.

"That's probably what I would call a long-term success," she said.

-Napat Wesshasartar, writing Chayut Setboonsarng; Editing by Himani Sarkar/Reuters