An eight-month-old dugong nurtured by marine experts after it was found lost near a beach in southern Thailand has died of what biologists believe was a combination of shock and ingesting plastic waste. The female dugong – a large ocean mammal – was named "Marium" and became a hit in Thailand after images of biologists embracing and feeding her with milk and sea grass spread across social media. Veterinarians and volunteers had set out in canoes to feed Marium for up to 15 times a day while also giving her health checks. Soon after Marium was discovered, another orphaned dugong brought the sea cows a celebrity status, the attention of a Thai princess – who named the second one "Jamil" – and round-the-clock webcasts giving viewers a front-row seat to feedings and treatment. Marium was found last week bruised after being chased and possibly attacked by a male dugong during the mating season, said Jatuporn Buruspat, the director-general of the Department of Marine and Coastal Resources. She was brought in for treatment in the artificial sea on Libong Island in Krabi province. "We assume she wandered off too far from her natural habitat and was chased, and eventually attacked by another male dugong, or dugongs, as they feel attracted to her," he said on Saturday. But Mariam died just after midnight after going into shock and efforts to resuscitate her failed, Chaiyapruk Werawong, head of Trang province marine park, said. "She died from a blood infection and pus in her stomach," he said, adding they found small amounts of plastic waste in her intestinal tract. Footage released by the Department of National Parks, Wildlife and Plant Conservation (DNP) showed vets attempting to revive Mariam using CPR. Several pieces of plastic were found in her intestine, with one measuring up to 20 centimetres. "She must've thought these plastics were edible," Mr Buruspat said. The plastic had caused obstructions in the animal's stomach, leading to inflammation and gas build-up, veterinarian Nantarika Chansue posted on Facebook. "We could partially treat the respiratory infection but the obstruction of plastic rubbish... could not be cured," she said in the post, calling for the young animal's death to serve as a lesson. "She taught us how to love and then went away as if saying please tell everyone to look after us and conserve her species." The dugongs are the latest marine creatures to make headlines in Thailand, whose plastic-choked waters are also a threat to habitats. Both the animals were found in southern Thailand, home to about 250 of the sea cows, which are closely related to the manatee and classified as vulnerable. Jamil, whose name translates to "handsome sea prince", is being cared for separately in Phuket. The dugong is a species of marine mammal similar to the American manatee and can grow to about 3.4 metres in length. Its conservation status is listed as vulnerable.