The number of dugongs in the seas off the southern province of Trang has declined substantially, raising concern among marine scientists and conservationists that the mammals may face extinction as sea grass, their main food, reduces.

The Marine and Coastal Resources Research Centre of the Lower Andaman Sea recently conducted aerial and sea surveys around Libong and Muk islands and nearby seagrass areas, to determine the number of dugongs and other rare marine species.

36 dugongs, including one pairing of mother and baby, six dolphins, including two babies and 38 sea turtles were sighted and were in good health and without wounds caused by fishing gear.

A survey, conducted last year, however, showed there were 194 dugongs, including 12 pairings of mothers and babies.

In the seas off Krabi province, a survey last year showed there were 22 dugongs, including three pairings of mothers and babies, and 74 sea turtles. A recent survey shows there are now 31 dugongs, including only two pairings of mothers and babies, and 25 sea turtles.

The sea off Trang province is Thailand’s largest source of seagrass, scattered along the provincial coast and around several islands, such as Libong, Muk, Kang Kao and Sukorn. It is also rich in marine species, such as crab, fish, sea shells, sea cucumber and shrimp.

Degradation of seagrass beds was first detected about six years ago and has tended to get worse since. In Trang alone, seagrass covers about 5,568 hectares of the seabed and there are 12 seagrass species.

A team of marine scientists, led by Pinsak Suraswadi, director-general of the Marine and Coastal Resources Department, is scheduled to conduct a survey today of the condition of seagrass in the seas off Trang province, in an attempt to identify the actual cause of its degradation and loss.

The remains of a dugong, which were recently washed ashore in Trang, showed signs of malnourishment and its body was covered with ascidians, or sea squirts.