The department surveyed coastal areas of Chachoengsao, Samut Prakan, Samut Sakhon, Phetchaburi, and Bangkok provinces from November 27-30, recording sightings of marine wildlife in the upper Gulf.
On Thursday it announced that nine Bryde’s whales had been found swimming in the upper Gulf during the latest survey.
Six of the whales had previously been recorded in Thai waters and were already logged in the department’s database, but three are newcomers.
The six known whales are logged under the names Sakhon and her calf Salee, Kanya and her calf Mali, Meesub and Singha.
The department’s veterinarians said the whales appear to be in good general health.
However, Sakhon and Meesub appeared to have developed tattoo skin disease (TSD), while Salee and a new whale have flesh wounds on their back fins caused by rope cuts, indicating they may have been caught in fishing gear.
Bryde’s whales are often spotted frolicking in waters 10-15 kilometres off the coast of Samut Sakhon and Phetchaburi.