Seub Nakhasathien

Seub was able to save hundreds of animals, but was aware that many more were unable to escape and died. After what he saw as the failure of the Cheow Lan project, he fought against further logging and dam construction projects, such as the Nam Chon Dam. The state's plan to build the dam in the heart of Thungyai Naresuan's forest in the 1990s ignited the country's first environmental protest in which protesters won.

When Seub became superintendent of Huai Kha Khaeng Wildlife Sanctuary in 1990, he was asked to prepare a nomination to UNESCO for Thung Yai-Huai Kha Khaeng to become a Natural world Heritage Site. He, in turn, asked his campaigning colleague, Belinda Stewart-Cox, to help prepare the nomination since it had to be in English and he was too busy to focus on such a major undertaking. In mid–December 1991, approximately a year and a half after Seub's death, UNESCO certified Thungyai Naresuan-Huai Kha Khaeng Wildlife Sanctuary as a World Heritage Site, the first of its kind in mainland Southeast Asia.

On 31 August 1990, Seub worked as usual. Later that day, he started to return things he had borrowed from others and had a meal with some of his companions. One of the people present was the last person to talk to Seub before his death.

Seub's death jolted Thailand into action. Ten days after his cremation, on 10 September 1990, the Seub Nakhasathien Foundation was established. The foundation has received donations from The Queen Dowager Sirikit and Princess Soamsawal and thousands of others. Its goals are to protect natural sanctuaries and the flora and fauna inhabiting them and to protect endangered species.

In 1989, under pressure from many sides while he was working as head of the Huai Kha Khaeng Sanctuary, dealing with multiple problems including the non-payment of worker's wages, disagreements with higher-ups, the death of some employees at the hands of encroachers, Seub became despondent. Seub realised that the best way to fully conserve the sanctuary was to make it a UNESCO World Heritage site. After months of research, he and his colleague completed the nomination just weeks before he died. It was submitted to, and approved by, UNESCO after his death.

In 1988, Seub and his fellow conservationists took action against the Thai Plywood Co., Ltd., a state enterprise under the Ministry of Natural Resources and Environment over a logging concession in Huai Kha Khaeng Wildlife Sanctuary. In his argument, he said "the one who wanted logging business was the Royal Forest Department, and the one who wanted to conserve the forest was also the Royal Forest Department".

The Rajjaprabha Dam Reservoir or Cheow Lan Dam, Thailand's thirteenth, was completed in 1987. The resulting flooding destroyed 185 square kilometres of the country's largest remaining area of lowland evergreen rain forest. For the first time ever in Thailand a rescue operation was carried out to try to save some of the wildlife, which included threatened and endangered species stranded on islands as the waters rose. Over 18 months 1,364 animals of 116 species were captured. Forty-four died soon after. The survivors were released into protected areas nearby.

In 1986, Seub was appointed as wildlife evacuation project leader for the Cheow Lan Dam project, with a budget of only 800,000 baht to evacuate a 100,000-acre (400 km) area.

Seub did not attend his graduation ceremony. He claimed that he did not have enough knowledge to receive the certificate. After graduation (1973-1974), he briefly worked at the National Housing Authority of Thailand [th]. Then, he continued graduate studies in silviculture. In 1979, he was awarded a British Council scholarship for a master's degree at London University to study resource and environmental conservation. In 1989, he was accepted to study for a PhD at Cambridge University the United Kingdom but had to postpone that ambition when he was persuaded to accept the position of superintendent of the Huai Kha Khaeng Wildlife Sanctuary.

In 1959, after he finished Prathom 4 (grade 4 of primary school), he moved to attend St. Louise School (Chachoengsao) [th] in Chachoengsao Province. He was not only a smart student, but he was also the best trumpet player at the school and an accomplished artist, drawing comic books for his friends to read. Because of his passion for the arts, Seub wanted to study architecture. But his university entrance examination result channelled him to the Faculty of Forestry at Kasetsart University, class of 35 from 1967 to 1971. Seub said that, at first, he did not want to study forestry, his fifth choice of study, but as he got accepted he told his mother that he should study there as he was not young anymore. His classmate and fourth year roommate at university said that Seub was a brilliant student, always sitting at the front of the class and taking notes together with drawings. Seub was seen always reading books in the evening when his friends were partying and boisterous. Seub was serious about everything, even playing soccer; it was hard to get the ball through him and score. Seub was also an excellent swimmer and was on the university water polo team.

Seub Nakhasathien (Thai: สืบ นาคะเสถียร, pronounced [sɯ̀ːp̚ nāː.kʰáʔ.sàʔ.tʰǐan],RTGS suep nakhasathian; 31 December 1948 – 1 September 1990) was a Thai conservationist, environmental activist, and scholar who is renowned for his effort to protect Cheow Lan Lake (Rajjaprabha Dam Reservoir), Thungyai Naresuan Wildlife Sanctuary, and Huai Kha Khaeng Wildlife Sanctuary. Seub committed suicide to signify the importance of the environment and to preserve it. According to the Bangkok Post, "The death of Seub Nakhasathien, a forest conservator who committed suicide in 1990,...helped transform the status of Thungyai Naresuan and the adjacent Huay Kha Kaeng Western Forest Complex into a sacrosanct site and inspired many youth to become forest patrol staff."