An eight-month-old baby bride who captured Thai hearts after being found on a beach in the south of the country last April died of an infection related to plastic waste in his stomach and intestines, local media reported.
The dugong was found in Krabi, about 600 kilometers south of Bangkok, and the vets had hoped to treat the animal and return it to the wild, the Bangkok Post said.
Animal disease has shed light on ocean pollution and plastic waste problems.
The Department of National Parks, Wildlife and Plant Conservation in Thailand confirmed that the animal, Miriam, died as veterinarians were trying to save his life.
The animal had previously been treated in the Andaman Sea but was transferred to custody last week.
Dugongs are marine mammals similar to manatees.
In April, the United Nations said 13 million tons of plastic waste were dumped into the oceans each year.
A recent study has shown that plastics are toxic by nature and, once swallowed, cause serious health complications and, in extreme cases, death.